Bones of the Back - Listed in Superior to Inferior Order
|
| Bone |
Structure |
Description |
Notes |
|
occipital
|
|
the bone forming the posterior surface of the skull |
it articulates superolaterally with the parietal bones through the lambdoid
suture, anteroinferiorly with the temporal bone and anteriorly with the body
of the sphenoid bone |
|
external occipital protuberance |
a low process on the external surface of the occipital bone in the midline |
it is an attachment site for the ligamentum nuchae; the superior nuchal lines of the two sides meet in the midline at the external occipital protuberance; also known as: inion (Latin, occiput = against head; Greek, inion = back of head) |
|
inferior nuchal line |
a low ridge that runs transversely on the external surface of the squamous
part of the occipital bone inferior to the superior nuchal line |
it is an attachment site for deep neck muscles (Latin, nucha = nape) |
|
superior nuchal line |
a low ridge that runs transversely on the external surface of the squamous
part of the occipital bone |
it is an attachment site the for the trapezius and splenius mm. (Latin, nucha = nape) |
|
occipital condyle |
a low, wide projection from the inferior surface of the lateral part of
the occipital bone |
paired; it articulates with the atlas (Latin, occiput = against head; Greek, condyle = knuckle) |
| vertebra |
|
one of a series of irregular bones that form the spine |
a vertebra has two parts: the vertebral body and the vertebral arch; there are 33 vertebrae total: 7 cervical, 12 thoracic, 5 lumbar, 5 fused to form the sacrum, 4 coccygeal; features of a typical vertebra include: body, pedicles, transverse processes, laminae, articular processes, spinous process (Latin, vert = to turn) |
|
vertebral body |
the largest part of the vertebra |
it is shaped like a short cylinder; adjacent vertebral bodies articulate through a symphysis (Greek, symphysis = a growing together) |
|
vertebral arch |
the ring of bone formed by the paired pedicles and paired laminae of the
vertebra |
the transverse processes and spinous process are attached to the neural
arch; the neural arch protects the spinal cord |
|
pedicle |
short strong process that extends posteriorly from the posterolateral surface
of the vertebral body |
paired; it connects the body with the transverse process; it is marked by
superior & inferior vertebral notches |
|
transverse process |
a lateral process the extends from the junction of the pedicle and the lamina
of the vertebra |
a site for muscle attachment and rib articulation |
|
lamina |
a broad flat plats of bone located between the transverse process and the
spinous process of the vertebra |
paired; it is flattened markedly in the anteroposterior direction; ligamenta
flava span the interval between the laminae of adjacent vertebrae |
|
articular processes |
processed that project inferiorly and superiorly from the junction of the
lamina and pedicle of the vertebra |
two pair on each vertebra (superior and inferior); the superior articular
processes of one vertebra articulate with the inferior processes of the adjacent
vertebra through synovial joints |
|
intervertebral notch |
a notch on the superior and inferior surface of the vertebral pedicle |
the superior intervertebral notch of one vertebra combined with the inferior
intervertebral notch of the adjacent vertebra forms the intervertebral foramen
|
|
intervertebral foramen |
an opening between the pedicles of adjacent vertebrae |
adjacent intervertebral notches form the intervertebral foramen; an opening for passage of the spinal nerve (Latin, foramen = an aperture) |
|
vertebral canal |
the opening formed by the combination of the body and the vertebral arch |
it contains the spinal cord, meninges, epidural fat and the internal vertebral
plexus of veins |
|
spinous process |
a posterior midline process arising from the junction of the two laminae
of the vertebra |
it projects downward and inferiorly; it is an important site of muscle attachment;
spinous processes of cervical vertebra 2-6 are bifid |
| cervical vertebrae |
|
the seven vertebrae of the neck |
cervical vertebrae have the features of the typical vertebra plus all have
transverse foramina (for passage of the vertebral artery); C2-C6 have bifid
spinous processes; cervical vertebrae have relatively small bodies; several
cervical vertebra are named: atlas, axis, vertebra prominens |
|
atlas (C1) |
the first cervical vertebra |
atlas has no vertebral body, only anterior & posterior arches; it articulates with the odontoid process of the axis (Greek, atlas = a titan who supported the earth on his shoulders)
|
|
axis (C2) |
the second cervical vertebra |
the odontoid process (dens) projects superiorly from its body; it articulates with the anterior arch of the atlas |
|
vertebra prominens |
the seventh cervical vertebra |
it has a long, non-bifid spinous process which is prominent at the nape
of the neck, hence its name |
| thoracic vertebrae |
|
the 12 vertebrae associated with the thoracic region |
thoracic vertebrae have the features of a typical vertebra plus they are
characterized by long slender spines that project inferiorly; they have facets
for articulation with ribs; thoracic vertebrae have bodies of intermediate
size |
|
costal articular facet on the body |
small smooth areas at the junction of the body and the vertebral arch |
most thoracic vertebrae have 2 costal facets on each side (one superior
and one inferior); the superior costal facet of one vertebra and the inferior
costal facet of the adjacent vertebra both articulate with the head of the
same rib; also known as demifacets |
|
costal articular facet on the transverse process |
a small smooth area on the transverse process of the thoracic vertebra |
it articulates with the articular facet on the tubercle of the rib |
| lumbar vertebrae |
|
the 5 vertebrae located in the lumbar region |
lumbar vertebrae have the features of a typical vertebra plus they are characterized
by short, blunt spines that project posteriorly; lumbar spines do not overlap
making the lumbar level a good one for spinal tap; lumbar vertebrae are built
strong and have the largest bodies of all vertebrae |
| sacrum |
|
a triangular bone that is the posterior skeletal element forming the pelvis |
it is formed by 5 fused vertebrae; the sacrum and two os coxae bones form the pelvis (Latin, sacrum = sacred because it was believed to escape disintegration and to serve as the basis for the resurrected body) |
|
anterior sacral foramina |
an opening in the anterior surface of the sacrum |
there are four pairs; each transmits the ventral primary ramus of the respective sacral spinal nerve; branches of the lateral sacral aa. enter the sacral canal through these openings (Latin, foramen = an aperture) |
|
posterior sacral foramina |
an opening in the posterior surface of the sacrum |
there are four pairs; each transmits the dorsal primary ramus of the respective sacral spinal nerve (Latin, foramen = an aperture) |
|
promontory |
a projection of the superior part of the sacrum in an anterior direction |
the body of the fifth lumbar vertebra sits on the sacral promontory and articulates with it through a symphysis |
|
sacral canal |
the opening in the center of the sacrum |
it is the continuation of the vertebral canal at sacral vertebral levels |
|
auricular surface |
the roughened area located on the lateral surface of the sacrum |
this surface articulates with the ilium in the sacroiliac articulation |
|
body |
the central portion of the sacrum |
the body is equivalent to the bodies of the other vertebra |
|
base |
the superior part of the sacrum |
the base of the sacrum includes the articular surface for the fifth lumbar
vertebra (through an intervertebral disk) and the superior portion of the two ala |
|
sacral hiatus |
an opening in the posterior surface of the sacrum in the midline |
it is a normal feature that results from the failure of fusion of the laminae of the fifth sacral segment (and sometimes the fourth) during development (Latin, hiatus = to yawn) |
|
ala |
the lateral portion of the sacrum |
paired; it projects laterally from the body of the sacrum; it represents the fused costal and transverse processes of the first sacral vertebra (Latin, ala = wing) |
| coccyx |
|
the most inferior portion of the vertebral column |
the coccyx results from the fusion of the four coccygeal vertebrae; it may be a single bone or the first coccygeal vertebra may be separated from the other three; it articulates with the fifth sacral segment; coccygeal vertebrae are reduced in complexity, having no pedicles, laminae or spines (Latin/Greek, coccyx = cuckoo's beak) |
Bones of the Upper Limb - Listed in Proximal to Distal Order
|
| Bone |
Structure |
Description |
Notes |
| clavicle |
|
an "S" shaped bone located between the sternum and the scapula |
it articulates medially with the manubrium of the sternum and laterally with the acromion process of the scapula; it forms a strut that supports the upper limb; it is frequently fractured; it is the first bone to begin ossification during development (Latin, clavicula = little key, this term was used to refer to the catch that fastens a window as well as to keys. Curved window fasteners resemble the shape of this bone) |
| |
sternal extremity |
the thickened proximal end of the clavicle |
it is triangular in cross-section; it articulates with the clavicular notch
of the sternum through a synovial joint with two joint cavities separated by
an articular disk; the sternoclavicular joint has the action of a ball and
socket joint, but not the physical shape of one |
| |
acromial extremity |
the flattened lateral end of the clavicle |
it is marked on its inferior surface at the junction of the medial 2/3 and the lateral 1/3 by a roughened area for attachment of the coracoclavicular ligament; it articulates with the coracoid process of the scapula through a syndesmosis; it articulates with the acromion process of the scapula through a synovial joint; due to the shape of the distal clavicle, the acromion process passes inferior to the clavicle in acromioclavicular dislocations (Greek, ackron = tip) |
| scapula |
|
the bone of the shoulder |
the scapula floats in a sea of muscles, so it is difficult to fracture;
it articulates with the axial skeleton through only one bone - the clavicle at the coracoclavicular and
acromioclavicular joints |
|
superior border |
the superior edge of the scapula |
the superior border of the scapula is marked by the scapular notch laterally |
|
medial border |
the border of the scapula that runs from the superior angle to the inferior
angle |
it is an important site of muscle attachments for the intermediate layer
of back muscles |
|
superior angle |
the angle of the scapula formed at the union of the superior and medial
borders |
it is the attachment site for the levator scapulae m. |
|
lateral border |
the portion of the scapula that runs inferomedially from the infraglenoid
tubercle to the inferior angle |
it is an important site of muscle attachments for the teres major m., teres
minor m. and the long head of the triceps brachii m.; it has a groove for passage
of the circumflex scapular a. |
|
inferior angle |
the angle of the scapula formed by the union of the medial and lateral borders |
the inferior angle of the scapula often has a slip of origin of the latissimus
dorsi attached to it |
|
glenoid cavity |
the articular surface located at the junction of the superior and lateral
borders of the scapula |
it articulates with the head of the humerus; it is deepened by a fibrocartilaginous
rim called the glenoid labrum |
|
supraglenoid tubercle |
a projection of bone located superior to the glenoid cavity |
it is the attachment site for the tendon of the long head of the biceps
brachii m. |
|
infraglenoid tubercle |
a projection of bone located inferior to the glenoid cavity |
it is the attachment site of the tendon of the long head of the triceps
brachii m. |
|
spine |
a heavy ridge that runs from the medial border of the scapula to the acromion
process |
it supports the acromion process; it divides the posterior surface of the
scapula into a supraspinatous fossa and an infraspinatous fossa |
|
scapular notch |
a notch on the superior border of the scapula located medial to the attachment
of the coracoid process |
it is bridged by the superior transverse scapular ligament; the suprascapular
a. passes superior to the superior transverse scapular ligament and the suprascapular
n. passes inferior to it (Army goes over the bridge, Navy goes
under the bridge) |
|
coracoid process |
a beak-like process that projects anteriorly from the lateral end of the
superior border of the scapula |
it is the attachment site for the short head of the biceps brachii m., the
coracobrachialis m., the pectoralis minor m. and the coracoacromial and coracoclavicular
ligaments |
|
acromion |
a broad, flat process located at the lateral end of the scapular spine |
it articulates with the clavicle through a synovial joint (acromioclavicular joint) (Greek, akron = tip + omos = shoulder, therefore the tip of the shoulder) |
|
supraspinatous fossa |
a broad depression located superior to the spine of the scapula |
it is the site of origin of the supraspinatus m. |
|
infraspinatous fossa |
a broad depression located inferior to the spine of the scapula |
it is the site of origin of the infraspinatus m. |
| humerus |
|
the bone of the arm (brachium) |
the humerus articulates proximally with the scapula at the glenoid fossa;
it articulates distally with the radius and ulna at the elbow joint |
|
head |
the smooth, rounded proximal end of the ulna |
it articulates with the glenoid cavity of the scapula to form the shoulder
joint |
|
anatomical neck |
the constricted region located inferolateral to the head |
it is located at the circumference of the smooth articular surface of the
head |
|
surgical neck |
the proximal part of the shaft of the humerus |
it is located inferior to the greater and lesser tubercles; it is a site
of frequent fracture; fractures of the surgical neck of the humerus endanger
the axillary n. and the posterior circumflex humeral a. |
|
greater tubercle |
the large projection located lateral to the head of the humerus |
it is the attachment site of the supraspinatus, infraspinatus & teres minor
mm. |
|
lesser tubercle |
the projection located lateral to the head of the humerus on the anterior
surface |
it is the insertion site of the subscapularis m. |
|
intertubercular groove |
the groove on the anterior surface of the humerus that is located between
the crest of the greater tubercle and the crest of the lesser tubercle |
it is occupied by the tendon of the long head of the biceps brachii m.;
the transverse humeral ligament spans the intertubercular groove and holds
the biceps tendon in place; it is the attachment site for the tendon of the
pectoralis major (lateral lip), teres major (medial lip), and latissimus dorsi
(floor) |
|
crest of the greater tubercle |
the ridge of bone on the anterior surface of the humerus extending inferiorly
from the greater tubercle |
it forms the lateral lip of the intertubercular groove; it is the attachment
site for the transverse humeral ligament and the pectoralis major m. |
|
crest of the lesser tubercle |
the ridge of bone on the anterior surface of the humerus extending inferiorly
from the lesser tubercle |
it forms the medial lip of the intertubercular groove; it is the attachment
site for the transverse humeral ligament and the teres major m. |
|
deltoid tuberosity |
the roughened process on the lateral surface of the mid-shaft of the humerus |
it is the insertion site of the deltoid m. |
|
radial groove |
the groove that spirals around the posterior surface of the shaft of the
humerus |
it is a depression for the radial n. and the deep brachial vessels; fracture
of the humerus at mid-shaft can injure the radial nerve and deep brachial vessels
because they are in contact with bone at this location |
|
medial supracondylar ridge |
a narrow ridge running proximally from the medial epicondyle of the humerus |
the pronator teres m. takes origin from the common flexor tendon near the
most inferior part of the medial supracondylar ridge |
|
lateral supracondylar ridge |
a narrow ridge running proximally from the lateral epicondyle of the humerus |
it is the site of origin of the brachioradialis m. and the extensor carpi
radialis longus m. |
|
lateral epicondyle |
a knob-like projection on the lateral side of the humerus proximal to the
capitulum |
it is the site of attachment of the common extensor tendon which is the origin of several forearm extensor muscles (extensor carpi radialis brevis m., extensor digitorum m., extensor digiti minimi m., extensor carpi ulnaris m. and supinator m.); inflammation of the attachment of the common extensor tendon is called lateral epicondylitis which is also known as "tennis elbow" (Greek, condyle = knuckle) |
|
medial epicondyle |
a knob-like projection on the medial side of the humerus proximal to the
trochlea |
it is the attachment site of the common flexor tendon which is the origin for the superficial group of forearm flexor muscles (pronator teres m., flexor carpi radialis m., palmaris longus m., flexor carpi ulnaris m. and flexor digitorum superficialis m.); inflammation of the attachment of the common flexor tendon is called medial epicondylitis which is also known as "tennis elbow"; the ulnar nerve is in contact with bone as it courses posterior to the medial epicondyle where it is susceptible to injury from blunt trauma or fracture (Greek, condyle = knuckle) |
|
coronoid fossa |
the depression on the anterior surface of the humerus located proximal to
the trochlea near the elbow |
it accommodates the coronoid process of ulna when the elbow is flexed |
|
radial fossa |
the depression on the anterior surface of the humerus located proximal to
the capitulum near the elbow |
it accommodates the head of the radius when the elbow is flexed |
|
olecranon fossa |
the depression on the posterior surface of the humerus located just proximal
to the elbow |
it accommodates the olecranon process of the ulna when the elbow is extended (Greek, olecranon = the head or point of the elbow) |
|
capitulum |
the rounded process that caps the distal end of the lateral condyle of the
humerus |
it articulates with the head of the radius; capitulum means "little
head" |
|
trochlea |
the grooved process that caps the distal end of the medial condyle of the
humerus |
it articulates with the trochlear notch of the ulna; the shape of the trochlea and the trochlear notch limits side-to-side movement and guarantees a hinge action; (Latin, trochlea = pulley) |
| ulna |
|
the bone on the medial side of the forearm (antebrachium) |
the ulna articulates proximally with the trochlea of the humerus and the head of the radius; it articulates distally with the ulnar notch of the radius (Latin, ulna = elbow) |
|
olecranon |
the proximal end of the ulna |
it is the insertion site of the tendon of the triceps brachii m.; when the elbow is extended, the olecranon of the ulna engages the olecranon fossa of the humerus (Greek, olecranon = the head or point of the elbow) |
|
trochlear notch |
the crescent shaped notch on the anterior surface of the proximal end of
the ulna |
it is located between the olecranon and the coronoid process; it articulates with the trochlea of the humerus; a ridge within the trochlear notch fits into the groove in the trochlea of the ulna which limits side-to-side movement and guarantees a hinge action (Latin, trochlea = pulley) |
|
coronoid process |
the anterior projection of bone located distal to the trochlear notch |
it is the insertion site of the brachialis m. |
|
radial notch |
the notch on the lateral surface of the humerus located just distal to the
trochlear notch |
it accommodates the head of the radius; the annular ligament of the radius
attaches to the anterior and posterior edges of the radial notch of the ulna
to encircle the head of the radius |
|
body |
the long slender midportion of the ulna |
it is also called the shaft or diaphysis; the interosseous membrane attaches
to the entire length of the interosseous border of the body of the ulna |
|
head |
the distal end of the ulna |
it is small and rounded for articulation with the radius |
|
styloid process |
a small projection from the distal surface of the head of the ulna |
it is the site of attachment of the articular disk of the distal radioulnar
joint |
| radius |
|
the bone on the lateral side of the forearm (antebrachium) |
the radius pivots on its long axis and crosses the ulna during pronation
|
|
head |
the rounded proximal end of the radius |
it has a smooth, rounded surface for articulation with the ulna; the head
of the radius is encircled by the annular ligament (4/5 of a circle) and the
radial notch of the ulna (1/5 of a circle) |
|
neck |
the constricted area of the radius located distal to the head |
the annular ligament of the radius surrounds the head of the radius, not
the neck of the radius |
|
radial tuberosity |
a roughened area on the anteromedial surface of the radius located just
distal to the neck |
it is the insertion site of the tendon of the biceps brachii m. |
|
body |
the long, slender midportion of the radius |
it is also known as the shaft or diaphysis; the interosseous membrane attaches
to the entire length of the body of the radius along its interosseous border;
a fracture of the distal end of the body of the radius with a dorsal displacement
of the distal fragment is quite common and is called a Colles' fracture |
|
ulnar notch |
a shallow notch located on the medial surface of the distal end of the radius |
it articulates with the head of the ulna |
|
styloid process |
the distal-most projection from the lateral side of the radius |
the radial styloid process projects lateral to the proximal row of carpal
bones |
| carpal bones |
|
the bones of the wrist |
eight bones arranged in two rows; a pneumonic for memorizing the carpal
bones is " some lovers try positions that they can't handle" - the
first letters of these eight words are the first letters of the names of the
eight carpal bones arranged from lateral to medial, proximal row first: scaphoid,
lunate, triquitrum, pisiform/trapezium, trapezoid, capitate, hamate |
|
proximal row |
lateral to medial: scaphoid, lunate, triquetrum, pisiform |
the scaphoid and lunate bones of the proximal row articulate with the distal
end of the radius |
|
distal row |
lateral to medial: trapezium, trapezoid, capitate, hamate |
the distal row of carpal bones articulates with the metacarpal bones of
the hand |
| scaphoid |
|
the most lateral carpal bone of the proximal row |
the scaphoid bone is located in the floor of the anatomical snuff box; it is frequently fractured by hyperextension and abduction of the wrist; (Latin, scaphoid = boat-shaped) |
| lunate |
|
the carpal bone located between the scaphoid and triquetrum in the proximal
row |
the lunate is so named because it is "moon-shaped" (crescent shaped) in longitudinal section; the head of the capitate sits within the crescent of the lunate (Latin, lunate = moon or crescent-shaped) |
| triquetrum |
|
the most medial bone in the proximal row of carpal bones |
it articulates with the pisiform which sits anterior to it |
| pisiform |
|
a sesamoid bone in the tendon of the flexor carpi ulnaris m. |
it articulates with the triquetrum; the pisiform bone provides a protective
function for the flexor carpi ulnaris tendon by bearing the forces generated
by the tendon riding across the triquitrum, especially during wrist extension;
pisiform means "pea-shaped" |
| trapezium |
|
the most lateral carpal bone of the distal row |
it forms a saddle joint with the metacarpal bone of the thumb; "the
thumb swings on the trapezium" |
| trapezoid |
|
the carpal bone located between the trapezium and the capitate in the distal
row |
the trapezoid is named for its trapezoid shape |
| capitate |
|
the carpal bone located between the trapezoid and the hamate in the distal
carpal row |
the capitate is the largest carpal bone; it is named for its rounded head;
forces generated in the hand (as during a punching blow with the fist) are
transmitted through the third metacarpal bone to the capitate and proximally
through the lunate to the radius |
| hamate |
|
the most medial carpal bone in the distal row |
the hamulus (Latin, hamus = hook) of the hamate is its distinguishing characteristic; it is an attachment point of the flexor retinaculum |
| metacarpal bones |
|
the bones located between the carpal bones and the phalanges of the hand
|
there are a total of five metacarpal bones in the hand; the metacarpals
of the four fingers are bound together by ligaments to form a firm foundation
for finger movements; the metacarpal of the thumb is more independent in its
range of motion |
|
base |
the proximal end of the metacarpal |
it articulates with the distal row of carpal bones |
|
body |
the slender shaft of the metacarpal |
it is also known as the diaphysis |
|
head |
the rounded distal end of the metacarpal |
it articulates with the proximal phalanx of the corresponding digit |
| phalanx (phalanges) |
|
the distal two or three bones in the digits of the hand |
there are a total of 14 phalanges in the hand; the thumb has two phalanges (proximal and distal) and each finger has three phalanges (proximal, middle and distal); (Latin, phalanx = line of soldiers) |
|
base |
the proximal end of the phalanx |
the base of the proximal phalanx articulates with the head of the corresponding
metacarpal bone; the base of the middle or distal phalanx articulates with
the head of the next most proximal phalanx |
|
body |
the slender shaft of the phalanx |
also known as the diaphysis; the body of the distal phalanx is very short |
|
head |
the distal end of the phalanx |
the proximal, middle and distal phalanges each have a head; the head of
a proximal or middle phalanx articulates with the base of the next most distal
phalanx |
Bones and Cartilages of the Head and Neck - Listed Alphabetically
|
| Bone/Cartilage |
Structure |
Description |
Notes |
| arytenoid cartilage |
|
a pyramid shaped cartilage located on the superior margin of the cricoid lamina |
paired; each is connected to the epiglottis above via the aryepiglottic m. and to the thyroid cartilage anteriorly via the vocal ligament; paired arytenoid cartilages are pulled together (adducted) by the arytenoid m. (Greek, arytenoid = ladle-shaped) |
| corniculate cartilage |
|
a small cartilage located on the apex of the arytenoid cartilage |
corniculate cartilage is found in the base of the aryepiglottic fold; it is yellow elastic cartilage (Latin, corniculum = a little horn) |
| cricoid cartilage |
|
the inferior and posterior cartilage of the larynx; it forms a complete cartilaginous
ring; its arch projects anteriorly and its lamina is broad and flat posteriorly |
connected: above to the thyroid cartilage via the inferior horn of the thyroid
cartilage, to the conus elasticus, to the arytenoid cartilages which sit atop
the lamina; connected below to the first tracheal ring via the cricotracheal
ligament |
| cuneiform cartilage |
|
small cartilaginous nodule located in the aryepiglottic fold |
cuneiform cartilage is yellow elastic cartilage (Latin, cuneus = wedge + forma = shape) |
| epiglottis |
|
the superior part of the larynx |
epiglottic cartilage is covered by a mucous membrane (Greek, epi = upon + glottis = the larynx) |
| ethmoid |
|
delicate bone located between the two orbits |
highly pneumatized bone that contains the ethmoid air cells; forms the fragile medial wall of the orbit (Greek, ethmoid = sieve-like) |
|
cribriform plate |
perforated portion of ethmoid bone on either side of the crista galli |
perforated for passage of the olfactory nerves (Latin, cribriform = sieve-like) |
|
crista galli |
superior midline projection of the ethmoid bone into the anterior cranial
fossa; it arises between the cribriform plates |
anterior anchor point of the falx cerebri (Latin, crista gali = cock's comb) |
|
perpendicular plate |
midline process projecting inferiorly into the nasal cavity |
forms the superior part of the bony nasal septum |
|
superior nasal concha |
medial projection of the ethmoid bone from the superolateral wall of the
nasal cavity |
forms the superior nasal meatus below it and the sphenoethmoidal recess
above it |
|
middle nasal concha |
portion of the ethmoid bone that projects inferomedially from the lateral
wall of the nasal cavity |
forms the superior nasal meatus above it and the middle nasal meatus (which
overlies the bulla ethmoidalis and hiatus semilunaris) below it |
|
bulla ethmoidalis |
rounded elevation on the lateral wall of the nasal cavity |
located under cover of the middle nasal concha; middle ethmoidal air cells drain at its apex (Latin, bulla = bubble + ethmoidal = sieve-like) |
|
ethmoidal air cells |
pneumatized spaces (3-18 in number) within the ethmoid bone; located between
the orbits |
three groups may be identified: anterior (drain into the hiatus semilunaris in the middle nasal meatus), middle (drain onto the apex of the bulla ethmoidalis in the middle nasal meatus), posterior (drain into the superior nasal meatus) (Latin, ethmoidal = sieve-like) |
|
ethmoidal foramen, anterior |
opening in the medial wall of the orbit |
transmits anterior ethmoidal vessels and nerve (Latin, ethmoidal = sieve-like) |
|
ethmoidal foramen, posterior |
opening in the medial wall of the orbit |
transmits posterior ethmoidal vessels and nerve (Latin, ethmoidal = sieve-like) |
|
hiatus semilunaris |
groove in the ethmoid portion of the lateral nasal wall between the uncinate
process below and bulla ethmoidalis above |
receives the frontonasal duct anterosuperiorly, opening of the maxillary sinus posteroinferiorly, and the openings of the anterior ethmoidal air cells in between (Latin, hiatus = to yawn) |
| frontal |
|
the anterior bone of the skull which underlies the forehead |
articulates with the parietal bone posteriorly; zygomatic, ethmoid and sphenoid
bones inferiorly; maxilla, nasal and lacrimal bones anteriorly; it is formed
from two ossifications centers which normally fuse in the midline - if they
do not fuse, a midline "metopic suture" is the result |
|
orbital plate |
flat portion of frontal that forms the roof of the orbit |
a very thin portion of the frontal bone which is like an egg shell in thickness |
|
foramen cecum |
opening near the anterior end of the crista galli |
transmits an emissary vein which may result in transfer of infectious materials from the nasal cavity to the cranial cavity with resulting meningitis (Latin, cecum = blind) |
|
frontal sinus |
pneumatized space in the frontal bone |
usually paired; each drains through the frontonasal duct into the uppermost
part of the hiatus semilunaris in the middle nasal meatus |
|
superior orbital margin |
arch of bone above the orbital opening |
skin over this region is supplied by branches of the frontal nerve (supraorbital
and supratrochlear nn.) |
|
superciliary arch |
the ridge of bone above the orbital margin |
located deep to the eyebrow, blunt trauma to this region often results in
cuts within the eyebrow |
|
glabella |
midline point between the paired superciliary arches |
(Latin, glabellus = hairless or smooth) |
|
supraorbital notch |
notch in the superior orbital margin |
occasionally present as a foramen; opening for the passage of the for supraorbital
neurovascular bundle |
| hyoid |
|
a "U"-shaped bone consisting of several parts: body, 2 greater horns, 2
lesser horns |
the hyoid bone ossifies completely in middle life; the body articulates with the greater horns via cartilage and with the lesser horns via fibrous joints prior to ossification; an important site for muscle attachments (suprahyoid and infrahyoid muscle groups) (Greek, hyoid = U-shaped) |
|
body |
the middle portion of the "U"-shaped bone |
the body of the hyoid bone articulates with the greater horns posteriorly |
|
greater horn (cornu) |
posteriorly directed limbs of the "U"-shaped bone |
each greater horn articulates with the body and lesser horns anteriorly; origin of middle pharyngeal constrictor m. and hyoglossus m. (Latin, cornu = horn) |
|
lesser horn (cornu) |
articulates with the greater horn at its junction with the body |
the inferior end of the stylohyoid ligament attaches to the lesser horn (Latin, cornu = horn) |
| inferior nasal concha |
|
a separate bone on the lateral wall of the nasal cavity |
it articulates with the maxilla; forms the inferior nasal meatus below it
and the middle nasal meatus above it |
| lacrimal |
|
small bone forming part of the medial wall of the orbit |
articulates: anteriorly with frontal process of maxilla, superiorly with frontal bone, posteriorly with ethmoid, inferiorly with orbital process of maxilla; forms part of the canal for the nasolacrimal duct (Latin, lacrima = tear) |
| mandible |
|
the U-shaped bone forming the lower jaw |
contains the inferior teeth; formed from the mesenchyme of the 1st pharyngeal
arch, and its muscles are innervated by the nerve of the 1st arch (mandibular
division of trigeminal n.) |
|
body |
the anterior part of the mandible |
paired halves are fused in the midline at the symphysis menti |
|
symphysis menti |
the midline symphysis between the two halves of the mandible |
the two halves of the mandible fuse during the first postnatal year (Greek, symphysis = a growing together) |
|
mental protuberance |
the projection on the anterior midline of the mandible |
the bone of the chin; mental means relating to the mind, a reference to
the act of resting the chin on the hand while thinking (see the sculpture by
Rodin: "The Thinker") |
|
mental spines (genial tubercles) |
the spines on the inner surface of the mandible posterior to the mental
protuberance |
attachment site for the genioglossus and geniohyoid mm. |
|
mylohyoid line |
the ridge running obliquely from posterosuperior to anteroinferior on the
medial surface of the body of the mandible |
attachment site for the mylohyoid muscle; the submandibular gland is located
inferior to this line and the sublingual gland is located superior to this
line |
|
mental foramen |
the opening on the anterior surface of the body of the mandible inferior
to the premolar teeth |
transmits the mental neurovascular bundle; covered superficially by the
depressor anguli oris and depressor labii inferioris mm. |
|
ramus |
the angled portion of the mandible that joins the posterior portion of the
body |
it rises nearly vertically from the body; the chondyloid process and the coronoid process extend from the superior end of the ramus; the mandibular foramen is located on the medial surface of the ramus; the medial pterygoid m. attaches to the medial surface and the masseter m. attaches to the lateral surface of the ramus (Latin, ramus = a branch) |
|
angle |
the posteroinferior bend formed by the union of the body and the ramus |
|
|
mandibular foramen |
the opening on the medial surface of the ramus |
it is the opening into the mandibular canal; it transmits the inferior alveolar
neurovascular bundle |
|
mandibular canal |
the canal that runs through the body of the mandible |
it transmits the inferior alveolar neurovascular bundle from the infratemporal
fossa to the mandibular teeth and gingivae |
|
lingula |
the projection of bone medial to the mandibular foramen |
it is the attachment site of the inferior end of the sphenomandibular ligament (Latin, lingula = tongue) |
|
coronoid process |
the process that projects anterosuperiorly from the ramus of the mandible |
it is the attachment site of the temporalis m. |
|
condylar process |
the rounded process that projects posterosuperiorly from the ramus of the
mandible |
it articulates with the mandibular fossa of the temporal bone |
|
mandibular notch |
the notch between the coronoid and condylar processes |
it transmits the masseteric neurovascular bundle from the infratemporal
fossa to the deep surface of the masseter m. |
|
mandibular neck |
the constriction below the articular chondyle on the chondylar process of
the mandible |
part of the lateral pterygoid m. inserts into the pterygoid fossa of the
mandibular neck |
|
pterygoid fossa of the neck |
a shallow depression on the anterior surface of the neck of the mandible |
part of the lateral pterygoid m. inserts into the pterygoid fossa of the
mandibular neck |
| maxilla |
|
bone forming the midface |
it forms the inferior orbital margin and contains the teeth and maxillary
sinus |
|
frontal process |
the part of the maxilla that projects superiorly medial to the orbit |
it articulates with the nasal bone, the frontal bone and the lacrimal bone;
it forms part of medial orbital wall & margin; it forms the anterior part of
the canal for the nasolacrimal duct |
|
orbital process |
the part of the maxilla that forms the floor of the orbit |
also known as the orbital surface of the maxilla; it contains the infraorbital
groove and canal; it forms the roof of the maxillary sinus |
|
zygomatic process |
the lateral projection of the maxilla |
it articulates with the zygomatic bone |
|
infraorbital groove |
groove in orbital process of the maxilla located in the posterior part of
the orbit |
transmits the infraorbital neurovascular bundle from the infraorbital fissure
to the infraorbital canal |
|
infraorbital canal |
canal in orbital process of the maxilla located in the anterior part of
the orbit |
the direct continuation of the infraorbital groove; transmits the infraorbital
neurovascular bundle from the infraorbital groove to the infraorbital foramen |
|
infraorbital foramen |
opening at the anterior end of the infraorbital canal located inferior to
the orbit |
it transmits the infraorbital neurovascular bundle |
|
alveolar process |
"U"-shaped process of bone that holds the maxillary teeth |
contains sockets (alveoli) for the roots of the maxillary teeth |
|
maxillary tuberosity |
the roughened posterior aspect of the body of the maxilla |
the posterior superior alveolar nn. Enter the maxilla directly superior
to this structure |
|
anterior nasal spine |
anterior projection of bone in the midline, inferior to the anterior nasal
aperture |
the cartilaginous part of the nasal septum sits atop this structure |
|
maxillary sinus |
pneumatized hollow center of the body of the maxilla |
paired; each maxillary sinus drains through the hiatus semilunaris into
the middle nasal meatus |
|
palatine process |
shelf of bone that projects horizontally to meet at the midline in the intermaxillary
suture |
paired; together, they form the roof of the oral cavity (hard palate) and
the floor of the nasal cavity |
|
incisive foramen |
opening in the midline, posterior to the maxillary incisor teeth |
it transmits the terminal branches of the nasopalatine nn. & sphenopalatine
aa.; it marks the point of union during development of the primary and secondary
palate |
| nasal |
|
thin bone that forms part of the bridge of the nose |
articulates with the frontal bone superiorly, the frontal process of the
maxilla laterally and the contralateral nasal bone medially |
| occipital |
|
the bone forming the posterior surface of the skull |
it articulates superolaterally with the parietal bones through the lambdoid suture, anteroinferiorly with the temporal bone and anteriorly with the body of the sphenoid bone (occiput = the back of the head) |
|
pharyngeal tubercle |
projection located anterior to the foramen magnum |
attachment site for the superior pharyngeal constrictor m. |
|
squamous part |
the flat, thin portion of the occipital bone located posterior to the foramen
magnum |
it articulates with the petrous part of the temporal bone anteroinferiorly
and the parietal bones superolaterally at the lambdoid suture |
|
external occipital protuberance |
a projection on the external surface of the squamous part of the occipital
bone in the midline |
it is the attachment site of the ligamentum nuchae and the trapezius m.;
its highest point is called the inion |
|
inferior nuchal line |
a low ridge that runs transversely on the external surface of the squamous
part of the occipital bone inferior to the superior nuchal line |
it is an attachment site for deep neck muscles |
|
superior nuchal line |
a low ridge that runs transversely on the external surface of the squamous
part of the occipital bone |
it is the attachment is the for the trapezius and splenius mm. |
|
foramen magnum |
the opening in the occipital bone posterior to the basal part |
it transmits the spinal cord, two vertebral aa., and two spinal accessory
nerves |
|
basal part |
the portion of the occipital bone located anterior to the foramen magnum |
it articulates with the body of the sphenoid bone |
|
lateral part |
the portion of the occipital bone located lateral to the foramen magnum |
paired; it is pierced by the hypoglossal canal and the condylar canal |
|
hypoglossal canal |
an opening in the lateral part of the occipital bone |
paired; it transmits the hypoglossal nerve |
|
condylar canal |
an opening in the lateral part of the occipital bone |
paired; it transmits the condylar emissary vein |
|
occipital condyle |
a low, wide projection from the inferior surface of the lateral part of
the occipital bone |
paired; it articulates with the atlas |
|
jugular notch |
a notch located on the anterolateral edge of the lateral part of the occipital
bone |
it forms the posterior margin of the jugular foramen; the temporal bone forms the anterior margin of the jugular foramen (Latin, jugulum = throat) |
| ossicles |
|
a chain of three bones in the tympanic cavity (middle ear) connecting the
tympanic membrane to the oval window; arranged from lateral to medial: malleus,
incus, stapes |
the ossicles are joined by synovial articulations that may become arthritic
in old age, resulting in conductive deafness |
|
incus |
the middle ossicle of the middle ear |
articulates with the head of the malleus and the head of the stapes; (Latin, incus = anvil) |
|
malleus |
the lateral ossicle of the middle ear |
the manubrium is attached by its handle to the inner surface of the tympanic membrane at the umbo; its head articulates with the incus; (Latin, malleus = hammer) |
|
stapes |
the medial ossicle of the middle ear |
it articulates with the long process of the incus and its base fills the fenestra vestibuli (oval window); (Latin, stapes = stirrup) |
| palatine |
|
the bone that forms the posterior part of the hard palate |
paired; failure of the perpendicular plates to fuse during development leads
to a midline defect (cleft palate) |
|
perpendicular plate |
the vertical portion of the palatine bone located posteriorly on either
side of the nasal cavity |
it articulates anteriorly with the maxilla; posteriorly it forms the medial
wall of the pterygopalatine fossa and the lateral wall of the nasal cavity;
its posterior edge contributes to 1/2 of the sphenopalatine foramen |
|
sphenopalatine notch |
a notch at the posterosuperior margin of the perpendicular plate of the
palatine bone |
along with the sphenoid bone it forms the sphenopalatine foramen |
|
sphenopalatine foramen |
an opening in the lateral wall of the nasal cavity formed by the perpendicular
plate of the palatine bone and the body of the sphenoid bone |
it transmits the nasopalatine nerve and the sphenopalatine vessels |
|
orbital process |
a small, superior projection from the perpendicular plate of the palatine
bone |
it forms a small part of the floor of the orbit located posteroinferiorly
near the apex |
|
horizontal plate |
the portion of the palatine bone that forms the posterior 1/3 of the hard
palate |
paired; the two horizontal plates meet at the midline |
|
greater palatine foramen |
an opening in the hard palate located medial to the 3rd maxillary molar
tooth |
it transmits the greater palatine neurovascular bundle; it is an important
site for oral anesthesia |
|
lesser palatine foramen |
an opening in the hard palate located posterior to the greater palatine
foramen |
there may be more than one; it transmits the lesser palatine n. and vessels |
| parietal |
|
a broad, flat bone forming the lateral surface of the skull |
paired; this bone articulates with the contralateral parietal bone in the
midline at the sagittal suture; it articulates anteriorly with frontal bone
at coronal suture; it articulates posteriorly with the occipital bone at the
lambdoid suture; it articulates inferiorly with the greater wing of the sphenoid
bone at the pterion, the squamous part of the temporal bone at the squamous
suture and the mastoid part of the temporal bone at the parietomastoid suture |
|
inferior temporal line |
an arching ridge on the external surface of the parietal bone |
it is an attachment site for the temporalis muscle |
|
superior temporal line |
an arching ridge on the external surface of the parietal bone |
it is an attachment site for the temporalis muscle and the temporal fascia |
|
parietal foramen |
an opening in the parietal bone located near the sagittal suture |
it transmits the parietal emissary vein, a valveless vein which connects
the scalp to the cranial cavity |
|
granular foveolae |
small pits located on the inner table of the parietal bone |
for the arachnoid granulations |
| thyroid cartilage |
|
the large anterior cartilage of the larynx; it has several parts: laminae
(2), superior horns (2), inferior horns (2), oblique line, superior thyroid
notch, |
connected above to the hyoid bone via the thyrohyoid membrane; connected
below to the cricoid cartilage via the inferior horn of the thyroid cartilage;
connected posteriorly: to the arytenoid cartilage via the vocal ligament and
thyroarytenoid m., to the epiglottic cartilage via the thyroepiglottic ligament;
it tilts anteriorly to increase the length of the vocal ligament and raise
the pitch of the voice |
|
lamina |
a broad flat plate of cartilage forming one side of the thyroid cartilage;
two laminae fuse anteriorly in the midline to form the thyroid cartilage |
the laryngeal prominence is the line of fusion of the two laminae; each lamina is connected superiorly to the hyoid bone by the thyrohyoid membrane (Latin, lamina = a thin plate) |
|
superior horn |
the rounded, superior projection of the posterior border of the thyroid
lamina |
it is connected superiorly to the greater horn of the hyoid bone by the
lateral thyrohyoid ligament |
|
inferior horn |
the rounded, inferior projection of the posterior border of the thyroid
lamina |
it is connected inferiorly to the cricoid cartilage by the cricothyroid
articulation (a synovial joint) |
|
oblique line |
ridge which descends diagonally from superior to inferior on the lateral
surface of the thyroid lamina |
a line of muscle attachment |
|
laryngeal prominence |
the line of fusion of the thyroid laminae |
known to the lay person as the "Adam's apple"; the laryngeal prominence
is a secondary sexual characteristic - in postpuberal males the angle of the
laryngeal prominence is approximately 90Á and in females the angle is approximately
120Á |
|
superior thyroid notch |
the notch at the superior end of the laryngeal prominence |
it is connected to the hyoid bone by the median thyrohyoid ligament |
| sphenoid |
|
an irregularly shaped bone forming the central portion of the skull |
it has many parts, including a body, greater wing, lesser wing and pterygoid plates (Greek, sphenoid = wedge-shaped) |
|
body |
central part of the sphenoid bone |
contains the sphenoid sinuses; attachment point for the wings and pterygoid
plates |
|
sphenoid sinuses |
pneumatized spaces within the body of the sphenoid bone |
usually paired; it drains into the sphenoethmoidal recess of the nasal cavity (Greek, sphenoid = wedge-shaped) |
|
jugum |
the anterior-most portion of the sphenoid bone |
articulates with the cribriform plate of the ethmoid bone (Latin, jugum = a yoke) |
|
chiasmatic sulcus |
the groove for the optic chiasm |
located between the jugum & the tuberculum sellae |
|
optic canal |
canal located at the lateral end of the chiasmatic sulcus and medial to
the anterior clinoid process |
paired; it transmits the optic nerve and the ophthalmic artery from the
cranial cavity to the apex of the orbit |
|
tuberculum sellae |
the anterior limit of the sella turcica |
the middle clinoid processes project from its lateral ends |
|
sella turcica |
depression on the superior surface of the body of the sphenoid bone |
roughly equivalent to the hypophyseal fossa; area between the tuberculum sellae and the posterior clinoid processes (Latin, sella turcica = Turkish saddle) |
|
anterior clinoid process |
projection at the medial end of the lesser wing of the sphenoid bone |
the internal carotid artery passes medial to this structure |
|
lesser wing of the sphenoid |
thin rim of bone projecting laterally from the anterior clinoid process |
bilateral; it forms the posterior margin of anterior cranial fossa; it articulates anteriorly with the orbital plate of the frontal bone (Greek, sphenoid = wedge-shaped) |
|
greater wing of the sphenoid |
broad plate of bone swinging laterally from the body of the sphenoid bone |
bilateral; it forms the medial part of the floor of the middle cranial fossa, part of temporal fossae laterally, and the posterior part of the lateral wall of orbit; it articulates anteriorly with the zygomatic bone, superiorly with the frontal & parietal bones (at the pterion), posteriorly with the squamous & petrous portions of the temporal bone (Greek, sphenoid = wedge-shaped) |
|
superior orbital fissure |
slit-like opening between the lesser & greater wings of the sphenoid bone |
it transmits the oculomotor nerve, the trochlear nerve, the abducens nerve,
branches of ophthalmic division of the trigeminal nerve, the superior ophthalmic
vein and lymphatics from the cranial cavity into the orbit |
|
foramen rotundum |
opening in the floor of the middle cranial fossa through the greater wing
of the sphenoid bone |
it transmits the maxillary division of the trigeminal nerve |
|
foramen ovale |
opening in the floor of the middle cranial fossa through the greater wing
of the sphenoid bone |
it transmits the mandibular division of the trigeminal nerve; it is located
between the foramen rotundum and the foramen spinosum |
|
foramen spinosum |
opening in the floor of the middle cranial fossa through the greater wing
of the sphenoid bone |
it transmits the middle meningeal artery and the meningeal br. of the mandibular
division of the trigeminal nerve (cranial nerve V) |
|
spine of the sphenoid |
process of bone that projects inferiorly from undersurface of greater wing
of the sphenoid |
it is the superior attachment for the sphenomandibular ligament (Greek, sphenoid = wedge-shaped) |
|
pterygoid process |
process that projects inferiorly from the junction of the body & greater
wing of the sphenoid bone |
it has several parts: lateral & medial pterygoid plates, hamulus, pterygoid
fossa, scaphoid fossa; the pterygoid plates are separated by the large pterygoid
fossa throughout most of their length, and by the small scaphoid fossa superiorly |
|
lateral pterygoid plate |
thin plate of bone that projects posterolaterally from the pterygoid process |
it is the attachment site of the lateral & medial pterygoid muscles (lateral
pterygoid m. on its lateral surface, medial pterygoid m. on its medial surface) |
|
medial pterygoid plate |
thin plate of bone that projects posteriorly from the pterygoid process |
it is the attachment of the superior pharyngeal constrictor m. & the pharygobasilar
fascia |
|
scaphoid fossa |
an oval depression at the superior end of the lateral pterygoid plate |
it is the site of origin of the tensor veli palatini m. |
|
pterygoid hamulus |
hook-like projection from the inferior end of the medial pterygoid plate |
it acts as a pulley for the tendon of the tensor veli palatini m. (Latin, hamulus = hook) |
|
pterygoid canal |
canal that occurs at the junction of the greater wing, the pterygoid process
and the body of the sphenoid bone |
it transmits the nerve of the pterygoid canal from the pterygoid region
to the pterygopalatine fossa |
| temporal |
|
bone forming the lateral side of the skull |
(Latin, temporis = of time, referring to the passage of time, which is marked by the appearance of gray hair on the side of the head |
|
petrous part |
the hard part of the temporal bone located in the floor of the cranial cavity |
it contains the tympanic cavity (middle ear) and the bony labyrinth of the
inner ear |
|
internal acoustic meatus |
the opening on the posteromedial surface of the petrous part of the temporal
bone |
it transmits the facial n., the vestibulocochlear n., and the labyrinthine
a. |
|
facial canal |
a canal which courses through the petrous part of the temporal bone |
it transmits the facial n. from the internal acoustic meatus to the stylomastoid
foramen |
|
carotid canal |
a canal which courses through the petrous part of the temporal bone |
it transmits the internal carotid a. and the internal carotid plexus of
nerves into the cranial cavity |
|
mastoid process |
the process located posteroinferior to the external acoustic meatus |
it projects inferiorly from the junction of the petrous and squamous parts
of the temporal bone; it contains the mastoid air cells that open into tympanic
cavity through the mastoid antrum |
|
tegmen tympani |
thin plate of bone forming the roof of the tympanic cavity |
located on the floor of the middle cranial fossa |
|
jugular fossa |
a depression on the posterior surface of the petrous part of the temporal
bone |
it forms the anterior margin of the jugular foramen; the occipital bone
forms the posterior margin of the jugular foramen |
|
styloid process |
the spike of bone that projects inferiorly from the petrous part of the
temporal bone |
it is the attachment site for the stylohyoid, styloglossus and stylopharyngeus
mm. and the stylomandibular and stylohyoid ligaments |
|
tympanic part |
the part of the temporal bone consisting of the external acoustic meatus
and the tympanic ring |
the medial 1/3 of the external acoustic meatus is bony and the lateral 2/3
is formed by cartilage |
|
external acoustic meatus |
the opening in the lateral surface of the temporal bone |
it extends medially from the surface to the tympanic membrane; it allows
sound to reach the tympanic membrane; the medial 1/3 of the external acoustic
meatus is bony and the lateral 2/3 is formed by cartilage |
|
tympanic ring |
the rim of bone surrounding the medial end of the external acoustic meatus |
it is the attachment site of the tympanic membrane |
|
squamous part |
the thin flat portion of the temporal bone that constitutes the side of
the skull above the ear |
it articulates with the parietal bone and the greater wing of the sphenoid
bone at the squamous suture |
|
zygomatic process |
the projection of bone that arises anterior to the external acoustic meatus |
it articulates with the temporal process of the zygomatic bone to form the
zygomatic arch |
|
mandibular fossa |
the depression located medial to the origin of the zygomatic process |
it articulates with the condylar process of the mandible |
|
articular tubercle |
an inferior projection located anterior to the mandibular fossa |
dislocations of the temporomandibular joint result when the mandibular condyle
slides anterior to this structure |
| vomer |
|
thin plate of bone forming the posteroinferior part of the nasal septum |
articulates superiorly with the perpendicular plate of the ethmoid bone and the body of the sphenoid bone; articulates inferiorly with the palatine processes of the maxilla and the horizontal plate of the palatine bone (Latin, vomer = a ploughshare, derived from vomere which means to vomit, because the plough "throws up" the earth) |
| wormian bone |
|
small irregular bone that occurs between sutures of the skull |
wormian bones are variable in occurrence and are especially common at the
junction of the squamous suture and the lambdoid suture |
| zygomatic |
|
the bone that forms the cheek |
the zygomatic bone is frequently fractured in blows to the side of the orbit; the temporal fascia attaches to the zygomatic arch (Greek, zygoma = a yoke, as this bone yokes or joins several bones together) |
|
temporal process |
the portion of the zygomatic bone that projects posteriorly |
it articulates with the zygomatic process of the temporal bone to form the
zygomatic arch |
|
frontal process |
the portion of the zygomatic bone that projects superiorly and medially |
it forms the inferior part of the lateral orbital margin and the anteroinferior
part of the lateral orbital wall; it articulates with the frontal bone anteriorly
and the greater wing of the sphenoid bone posteriorly |
|
maxillary process |
the part of the zygomatic bone that projects medially |
it forms the lateral part of the inferior orbital margin and the anterolateral
part of the orbital floor; it articulates with the maxilla |
|
zygomaticofacial foramen |
a small opening on the lateral surface of the zygomatic bone |
it transmits the zygomaticofacial n. |
Bones of the Abdomen, Pelvis and Perineum
|
| Bone |
Structure |
Description |
Notes |
| os coxae |
|
one of three bones that form the pelvis |
paired; the os coxae forms the lateral part of the pelvis; it is formed
by three fused bones: ischium, ilium & pubis; also known as the innominate
bone |
|
acetabulum |
a cup-shaped depression in the lateral surface of the os coxae bone |
acetabulum means vinegar cup; it is the socket for the head of the femur; it is formed by the: ilium (1/5), ischium (2/5) and pubis (2/5); the acetabular fossa lies in the floor of the acetabulum (Latin, acetabulum = a shallow vessel or cup) |
|
acetabular notch |
a notch in the inferior margin of the acetabulum |
it is spanned by the transverse acetabular ligament; the acetabular br.
of the obturator a. enters the hip joint by passing through the acetabular
notch |
|
acetabular fossa |
a roughened depression in the center of the acetabulum |
the ligament of the head of the femur occupies the acetabular fossa |
|
lunate surface of the acetabulum |
the smooth articular surface of the acetabulum |
the lunate surface surrounds the acetabular fossa and the acetabular notch
|
|
obturator foramen |
a large foramen formed by the pubic and ischial rami |
obturator means to occlude or stop up, a reference to the fact that the
obturator membrane closes the obturator foramen almost completely; a site of
attachment for the obturator externus m. and the obturator internus m. |
| pubis |
|
an angulated bone the forms the anterior part of the pelvis |
one of three bones that form the os coxae: ilium, ischium, pubis; its body
forms 1/5 of the acetabulum; its symphyseal surface unites with the pubis of
the opposite side to form the pubic symphysis; the superior and inferior pubic
rami participate in the formation of the obturator foramen |
|
body |
superolateral portion of the pubis |
the body of the pubis forms about 1/5 of the acetabulum |
|
pubic crest |
ridge on the superior border of the superior ramus |
attachment of rectus abdominis & pyramidalis mm. |
|
pubic tubercle |
process at the lateral end of pubic crest |
attachment point of the medial end of the inguinal ligament |
|
superior ramus |
superior "limb" that passes medially from the body of the pubis |
articulates with the superior ramus of the opposite side at the pubic symphysis (Latin, ramus = a branch) |
|
pecten |
ridge on superior surface of the superior pubic ramus |
attachment point of the pectineal ligament |
|
inferior ramus |
inferior "limb" that passes inferolaterally from the pubic symphysis |
articulates with the ischial ramus to form the ischiopubic ramus; attachment site for the root of the penis (clitoris) (Latin, ramus = a branch) |
|
obturator groove |
groove on the inferior surface of the superior pubic ramus |
marks the area of passage of the obturator vessels and n. in the obturator
canal |
| ischium |
|
the "V"- shaped bone that forms the posteroinferior part of the
pelvis |
one of the three bones that form the os coxae: ilium, ischium, pubis |
| |
ischial ramus |
the limb of the ischium that passes anteriorly and superomedially toward
the pubis |
it articulates with the inferior ramus of the pubis (Latin, ramus = a branch) |
|
body |
the part of the ischium that participates in the formation of the acetabulum |
it articulates with the ilium and the pubis at the acetabulum; the body
of the ischium forms 2/5 of the acetabulum |
|
ischial tuberosity |
the roughened projection that protrudes posteroinferiorly from the body
of the ischium |
it is the site of attachment of the sacrotuberous ligament; it is the site of origin of the inferior gemellus m., quadratus femoris m. and the hamstring mm. (semitendinosus, semimembranosus, long head of biceps femoris, ischiocondylar portion of the adductor magnus) (Latin, ischion = hip joint) |
|
lesser sciatic notch |
the notch located between the ischial tuberosity and the ischial spine |
the lesser sciatic notch is converted to the lesser sciatic foramen by the
sacrospinous ligament and the sacrotuberous ligament |
|
ischial spine |
the spine that arises just superior to the lesser sciatic notch |
it is the site of attachment of the sacrospinous ligament and the site of origin of the superior gemellus m. (Latin, ischion = hip joint) |
| ilium |
|
fan-shaped bone that forms the lateral prominence of the pelvis |
one of three bones that form the os coxae: ilium, ischium, pubis |
|
body |
the portion of the ilium that participates in the formation of the acetabulum |
the body of the ilium forms 2/5 of the acetabulum |
|
iliac crest |
arching superior edge the ilium that forms the rim of the "fan" |
attachment for abdominal wall muscles |
|
iliac fossa |
broad depression on the medial surface of the ilium |
iliac fossa is part of the false (greater) pelvis |
|
iliac tubercle |
roughened area along the outer edge of the iliac crest |
|
|
greater sciatic notch |
the notch on the inferior portion of ilium located posteromedial to the ischial spine |
the greater sciatic notch is converted to the greater sciatic foramen by the sacrospinous ligament and the sacrotuberous ligament |
|
anterior superior iliac spine |
spine at the anterior end of the iliac crest |
lateral attachment of the inguinal ligament |
|
posterior superior iliac spine |
spine at the posterior end of the iliac crest |
position marked by a dimpling of the skin |
|
arcuate line |
ridge running from anteroinferior to posterosuperior on the inner surface
of the ilium |
inferior boundary of the iliac fossa; marks the plane of transition from abdominal cavity to pelvic cavity (Latin, arcuate = bowed) |
| sacrum |
|
a triangular bone that is the posterior skeletal element forming the pelvis |
it is formed by 5 fused vertebrae; the sacrum and two os coxae bones form
the pelvis |
|
base |
the superior part of the sacrum |
the base of the sacrum includes the articular surface for the fifth lumbar
vertebra and the superior portion of the two ala |
|
promontory |
a projection of the superior part of the sacrum in an anterior direction |
the body of the fifth lumbar vertebra sits on the sacral promontory and
articulates with it through a symphysis |
|
ala |
the lateral portion of the sacrum |
paired; it projects laterally from the body of the sacrum; it represents the fused costal and transverse processes of the first sacral vertebra (Latin, ala = wing) |
|
anterior sacral foramina |
an opening in the anterior surface of the sacrum |
there are four pairs; each transmits the ventral primary ramus of the respective
sacral spinal nerve; branches of the lateral sacral aa. Enter the sacral canal
through these openings |
|
posterior sacral foramina |
an opening in the posterior surface of the sacrum |
there are four pairs; each transmits the dorsal primary ramus of the respective
sacral spinal nerve |
|
sacral canal |
the opening in the center of the sacrum |
it is the continuation of the vertebral canal at sacral vertebral levels |
|
sacral hiatus |
an opening in the posterior surface of the sacrum in the midline |
it is a normal feature that results from the failure of fusion of the laminae of the fifth sacral segment (and sometimes the fourth) during development (Latin, hiatus = to yawn) |
|
articular surface |
the roughened area located on the lateral surface of the sacrum |
this surface articulates with the ilium in the sacroiliac articulation |
|
body |
the central portion of the sacrum |
the body is equivalent to the bodies of the other vertebra |
|
base |
the superior surface of the sacrum |
the base of the sacrum articulates with the fifth lumbar vertebra through
an intervertebral disk |
| coccyx |
|
the most inferior portion of the vertebral column |
the coccyx results from the fusion of the four coccygeal vertebrae; it may be a single bone or the first coccygeal vertebra may be separated from the other three; it articulates with the fifth sacral segment; coccygeal vertebrae are reduced in complexity, having no pedicles, laminae or spines (Greek, coccyx = a cuckoo's beak) |
Bones of the Lower Limb - Listed in Proximal to Distal Order
|
| Bone |
Structure |
Description |
Notes |
| femur |
|
the bone of the thigh |
the femur is the longest and strongest bone in the body |
| |
head |
smooth, rounded proximal end |
the head of the femur articulates with the acetabulum of the pelvis |
|
fovea capitis femoris |
a shallow pit in the head of the femur |
it is the attachment site of the ligamentum capitis femoris; a small artery for supply of the head is found within this ligament (Latin, capitis = head) |
|
neck |
the constricted area distal to the head of the femur |
most of the blood supply to the head of the femur courses along the surface
of the neck; fractures of the neck of the femur may result in avascular necrosis
of the head |
|
greater trochanter |
a large process that projects superiorly from the junction of the neck and
shaft of the femur |
the greater trochanter is the insertion site of the gluteus medius m., gluteus minimus m., piriformis m. and obturator internus m. (Greek, trochanter = a runner or roller, from trochos, a wheel. Originally used for the head of the femur, which turns like a wheel in its socket. Eventually it came to mean the bony processes of the femur) |
|
gluteal tuberosity |
a roughened area located on the posterior surface of the femur at the superior
end of the lateral lip of the linea aspera |
it is one of the insertion sites of the gluteus maximus m. |
|
lesser trochanter |
a large process that projects from the posteromedial surface of the femur
just distal to neck |
it is the insertion site of the common tendon of the psoas major and iliacus mm. (iliopsoas m.) (Greek, trochanter = a runner or roller, from trochos, a wheel. Originally used for the head of the femur, which turns like a wheel in its socket. Eventually it came to mean the bony processes of the femur) |
|
trochanteric fossa |
a depression on the medial side of the greater trochanter on its posterior
surface where the greater trochanter joins the neck |
it is the insertion site of the obturator externus m. |
|
intertrochanteric line |
a ridge on the anterior surface of the femur that connects the greater and
lesser trochanters |
it is the line of attachment of the fibrous joint capsule |
|
intertrochanteric crest |
a heavy ridge on the posterior surface of the femur that connects the greater
and lesser trochanters |
the quadratus femoris m. inserts on the intertrochanteric crest |
|
body |
the long slender shaft of the femur |
the linea aspera runs the entire length of the posterior surface of the
body |
|
linea aspera |
a vertical ridge on posterior surface of the femur |
it is the insertion site of the medial (adductor) group of thigh muscles and the origin of the vastus intermedius m. and the short head of the biceps femoris m. (Latin, linea aspera = rough line) |
|
adductor tubercle |
a process that projects superior to the medial epicondyle of the femur |
it is the insertion site of the ischiocondylar part of the adductor magnus
m. |
|
medial epicondyle |
the enlargement of bone on the medial side of the femur just superior to
the medial condyle |
it is the attachment site of the tibial collateral ligament of the knee
joint |
|
lateral epicondyle |
the enlargement of bone on the lateral side of the femur just superior to
the lateral condyle |
it is the attachment site of the fibular collateral ligament and the site
of origin of the popliteus m. |
|
medial condyle |
the rounded inferior end of the femur on the medial side |
it articulates with the medial condyle of the tibia |
|
lateral condyle |
the rounded inferior end of the femur on the lateral side |
it articulates with the lateral condyle of the tibia |
|
intercondylar fossa |
the deep depression on the posterior surface of the femur between the condyles |
the anterior and posterior cruciate ligaments are located here |
| |
patellar surface |
the smooth anterior surface at the inferior end of the femur |
it articulates with the posterior surface the patella |
| patella |
|
the bone that forms the knee cap |
the patella is a sesamoid bone in the tendon of the quadriceps femoris muscle;
it provides a protective function by withstanding the grinding forces of the
quadriceps femoris tendon against the patellar surface of the femur, especially
in full knee flexion |
| tibia |
|
the bone on the medial side of the leg |
the tibia is the weight-bearing bone of the leg |
| |
medial condyle |
the heavy prominence on the medial side of the proximal end of the tibia |
the medial condyle articulates with the medial condyle of the femur; it
is larger than the lateral condyle of the tibia |
|
lateral condyle |
the heavy prominence on the lateral side of the proximal end of the tibia |
the lateral condyle articulates with the lateral condyle of the femur and
with the head of the fibula |
|
intercondylar eminence |
the ridge of bone on the proximal end of the tibia that projects between
the condyles |
the intercondylar eminence has a medial and a lateral tubercle; it is the
attachment site for the cruciate ligaments, medial meniscus and lateral meniscus |
|
tibial tuberosity |
the roughened protuberance on the anterior surface of the tibia located
just distal to the condyles |
it is the attachment site of the patellar ligament, which represents the
insertion of the quadriceps femoris tendon |
|
body |
the long, robust shaft of the tibia |
the medial surface of the body of the tibia is subcutaneous throughout its
length; when the shin is painfully bumped, the nerve endings are stimulated
in the periosteum covering the body of the tibia |
|
interosseous border |
the sharp ridge that runs longitudinally along the junction of the lateral
surface and the posterior surface of the tibia |
the interosseous membrane attaches to the interosseous border of the tibia (Latin, inter = between + os = bone) |
|
soleal line |
a ridge of bone that descends obliquely from lateral to medial on the posterior
surface of the tibia |
it is the site of origin of the soleus m. |
|
medial malleolus |
the large bony prominence on the medial side of the ankle |
the medial malleolus of the tibia forms the medial side of the ankle joint;
it articulates with the medial surface of the talus |
| fibula |
|
the slender bone on the lateral side of the leg |
the fibula is not a weight-bearing bone, it is a muscle attachment bone
|
| |
head |
the enlarged proximal end of the fibula |
it articulates with the lateral condyle of tibia; the fibular collateral
ligament of the knee attaches to the head of the fibula |
|
neck |
the constricted portion of the fibula located just inferior to the head |
fractures of the neck of the fibula can injure the common fibular n. |
|
body |
the long slender shaft of the fibula |
the interosseous membrane attaches to the entire length of the interosseous
border of the fibula |
|
interosseous border |
the sharp ridge that runs longitudinally along the medial surface of the
fibula |
the interosseous membrane attaches to the interosseous border of the fibula (Latin, inter = between + os = bone) |
|
lateral malleolus |
the enlarged distal end of the fibula |
the lateral malleolus of the fibula forms the lateral side of the ankle
joint; it articulates with the lateral surface of the talus; forcible lateral
displacement of the foot can cause the fibula to fracture superior to the lateral
malleolus, a condition called a Pott's fracture |
| tarsal bones |
|
the bones of the ankle |
there are seven tarsal bones: talus, calcaneus, navicular, medial cuneiform,
intermediate cuneiform, lateral cuneiform, cuboid |
| talus |
|
the most proximal of the tarsal bones |
the talus articulates with the medial malleolus of the tibia and the lateral
malleolus of the fibula to form the ankle mortise joint |
| |
body |
the proximal part of the talus |
its superior (trochlear) part participates in the ankle joint and its inferior
part articulates with the calcaneus |
| |
trochlea |
the superior portion of the body of the talus that lies between the two
malleoli |
it has a smooth articular surface; it participates in the formation of the ankle joint (Latin, trochlea = a pulley) |
|
head |
the portion of the talus that projects anteriorly |
it articulates with the navicular bone |
|
neck |
the constricted part of the talus located proximal to the head |
|
| calcaneus |
|
the tarsal bone which forms the heel |
it is the largest and strongest bone in the foot; a fracture of the calcaneus which separates the tuberosity from the body can be a debilitating injury (Latin, calcaneus = the heel) |
| |
calcaneal tuberosity |
the posterior roughened area of the calcaneus which contacts the ground
during weight-bearing |
it is the insertion site of the calcaneal (Achilles') tendon (Latin, calcaneus = the heel) |
|
sustentaculum tali |
the shelf-like medial projection of bone located inferior to the medial
malleolus |
it is a shelf of bone that articulates with and supports the talus; it is grooved inferiorly by the tendon of the flexor hallucis longus m. (Latin, sustentaculum = to hold upright) |
| navicular |
|
the tarsal bone located distal to the talus and proximal to the three cuneiform
bones |
it articulates with the head of the talus and all three cuneiform bones; it is the attachment site for an important ligament (plantar calcaneonavicular or "spring" ligament) that supports the medial longitudinal arch of the foot (Latin, navicular = a small boat shaped structure) |
| cuneiform, medial |
|
the most medial bone in the distal row of tarsal bones |
the cuneiform bones articulate with the navicular bone proximally and the bases of the metatarsal bones distally (Latin, cuneus = wedge + forma = shape) |
| cuneiform, middle |
|
the intermediate bone of the three cuneiform bones |
the cuneiform bones articulate with the navicular bone proximally and the bases of the metatarsal bones distally (Latin, cuneus = wedge + forma = shape) |
| cuneiform, lateral |
|
the bone that is located between the middle cuneiform and the cuboid bone |
the cuneiform bones articulate with the navicular bone proximally and the bases of the metatarsal bones distally (Latin, cuneus = wedge + forma = shape) |
| cuboid |
|
the most lateral bone in the distal row of tarsal bones |
the cuboid bone articulates with the calcaneus proximally and the fourth
and fifth metatarsal bones distally |
| metatarsals |
|
the bones located between the tarsal bones and the phalanges |
there are five metatarsal bones in the foot |
|
base |
the proximal end of the metatarsal |
it articulates with the distal row of tarsal bones |
|
body |
the slender shaft of the metatarsal |
it is also known as the diaphysis |
|
head |
the rounded distal end of the metatarsal |
it articulates with the proximal phalanx of the corresponding digit |
| phalanx (phalanges) |
|
the distal two or three bones in the digits of the foot |
there are a total of 14 phalanges in the foot; the great toe has two phalanges (proximal and distal) and each of the other four toes has three phalanges (proximal, middle and distal); (Latin, phalanx = line of soldiers) |
|
base |
the proximal end of the phalanx |
the base of the proximal phalanx articulates with the head of the corresponding
metatarsal bone; the base of the middle or distal phalanx articulates with
the head of the next most proximal phalanx |
|
body |
the slender shaft of the phalanx |
also known as the diaphysis; the body of the distal phalanx is very short |
|
head |
the distal end of the phalanx |
the proximal, middle and distal phalanges each have a head; the head of
a proximal or middle phalanx articulates with the base of the next most distal
phalanx |
