Glossary: The Appendicular System

acetabulum: large, cup-shaped cavity located on the lateral side of the hip bone; formed by the junction of the ilium, pubis, and ischium portions of the hip bone

acromial end of the clavicle: lateral end of the clavicle that articulates with the acromion of the scapula

acromial process: acromion of the scapula

acromioclavicular joint: articulation between the acromion of the scapula and the acromial end of the clavicle

acromion: flattened bony process that extends laterally from the scapular spine to form the bony tip of the shoulder

adductor tubercle: small, bony bump located on the superior aspect of the medial epicondyle of the femur

anatomical neck: line on the humerus located around the outside margin of the humeral head

ankle joint: joint that separates the leg and foot portions of the lower limb; formed by the articulations between the talus bone of the foot inferiorly, and the distal end of the tibia, medial malleolus of the tibia, and lateral malleolus of the fibula superiorly

anterior border of the tibia: narrow, anterior margin of the tibia that extends inferiorly from the tibial tuberosity

anterior inferior iliac spine: small, bony projection located on the anterior margin of the ilium, below the anterior superior iliac spine

anterior sacroiliac ligament: strong ligament between the sacrum and the ilium portions of the hip bone that supports the anterior side of the sacroiliac joint

anterior superior iliac spine: rounded, anterior end of the iliac crest

apical ectodermal ridge: enlarged ridge of ectoderm at the distal end of a limb bud that stimulates growth and elongation of the limb

arcuate line of the ilium: smooth ridge located at the inferior margin of the iliac fossa; forms the lateral portion of the pelvic brim

arm: region of the upper limb located between the shoulder and elbow joints; contains the humerus bone

auricular surface of the ilium: roughened area located on the posterior, medial side of the ilium of the hip bone; articulates with the auricular surface of the sacrum to form the sacroiliac joint

base of the metatarsal bone: expanded, proximal end of each metatarsal bone

bicipital groove: intertubercular groove; narrow groove located between the greater and lesser tubercles of the humerus

calcaneus: heel bone; posterior, inferior tarsal bone that forms the heel of the foot

capitate: from the lateral side, the third of the four distal carpal bones; articulates with the scaphoid and lunate proximally, the trapezoid laterally, the hamate medially, and primarily with the third metacarpal distally

capitulum: knob-like bony structure located anteriorly on the lateral, distal end of the humerus

carpal bone: one of the eight small bones that form the wrist and base of the hand; these are grouped as a proximal row consisting of (from lateral to medial) the scaphoid, lunate, triquetrum, and pisiform bones, and a distal row containing (from lateral to medial) the trapezium, trapezoid, capitate, and hamate bones

carpal tunnel: passageway between the anterior forearm and hand formed by the carpal bones and flexor retinaculum

carpometacarpal joint: articulation between one of the carpal bones in the distal row and a metacarpal bone of the hand

clavicle: collarbone; elongated bone that articulates with the manubrium of the sternum medially and the acromion of the scapula laterally

coracoclavicular ligament: strong band of connective tissue that anchors the coracoid process of the scapula to the lateral clavicle; provides important indirect support for the acromioclavicular joint

coracoid process: short, hook-like process that projects anteriorly and laterally from the superior margin of the scapula

coronoid fossa: depression on the anterior surface of the humerus above the trochlea; this space receives the coronoid process of the ulna when the elbow is maximally flexed

coronoid process of the ulna: projecting bony lip located on the anterior, proximal ulna; forms the inferior margin of the trochlear notch

costoclavicular ligament: band of connective tissue that unites the medial clavicle with the first rib

coxal bone: hip bone

cuboid: tarsal bone that articulates posteriorly with the calcaneus bone, medially with the lateral cuneiform bone, and anteriorly with the fourth and fifth metatarsal bones

deltoid tuberosity: roughened, V-shaped region located laterally on the mid-shaft of the humerus

distal radioulnar joint: articulation between the head of the ulna and the ulnar notch of the radius

distal tibiofibular joint: articulation between the distal fibula and the fibular notch of the tibia

elbow joint: joint located between the upper arm and forearm regions of the upper limb; formed by the articulations between the trochlea of the humerus and the trochlear notch of the ulna, and the capitulum of the humerus and the head of the radius

femur: thigh bone; the single bone of the thigh

fibula: thin, non-weight-bearing bone found on the lateral side of the leg

fibular notch: wide groove on the lateral side of the distal tibia for articulation with the fibula at the distal tibiofibular joint

flexor retinaculum: strong band of connective tissue at the anterior wrist that spans the top of the U-shaped grouping of the carpal bones to form the roof of the carpal tunnel

foot: portion of the lower limb located distal to the ankle joint

forearm: region of the upper limb located between the elbow and wrist joints; contains the radius and ulna bones

fossa: (plural = fossae) shallow depression on the surface of a bone

fovea capitis: minor indentation on the head of the femur that serves as the site of attachment for the ligament to the head of the femur

glenohumeral joint: shoulder joint; formed by the articulation between the glenoid cavity of the scapula and the head of the humerus

glenoid cavity: (also, glenoid fossa) shallow depression located on the lateral scapula, between the superior and lateral borders

gluteal tuberosity: roughened area on the posterior side of the proximal femur, extending inferiorly from the base of the greater trochanter

greater pelvis: (also, greater pelvic cavity or false pelvis) broad space above the pelvic brim defined laterally by the fan-like portion of the upper ilium

greater sciatic foramen: pelvic opening formed by the greater sciatic notch of the hip bone, the sacrum, and the sacrospinous ligament

greater sciatic notch: large, U-shaped indentation located on the posterior margin of the ilium, superior to the ischial spine

greater trochanter: large, bony expansion of the femur that projects superiorly from the base of the femoral neck

greater tubercle: enlarged prominence located on the lateral side of the proximal humerus

hallux: big toe; digit 1 of the foot

hamate: from the lateral side, the fourth of the four distal carpal bones; articulates with the lunate and triquetrum proximally, the fourth and fifth metacarpals distally, and the capitate laterally

hand: region of the upper limb distal to the wrist joint

head of the femur: rounded, proximal end of the femur that articulates with the acetabulum of the hip bone to form the hip joint

head of the fibula: small, knob-like, proximal end of the fibula; articulates with the inferior aspect of the lateral condyle of the tibia

head of the humerus: smooth, rounded region on the medial side of the proximal humerus; articulates with the glenoid fossa of the scapula to form the glenohumeral (shoulder) joint

head of the metatarsal bone: expanded, distal end of each metatarsal bone

head of the radius: disc-shaped structure that forms the proximal end of the radius; articulates with the capitulum of the humerus as part of the elbow joint, and with the radial notch of the ulna as part of the proximal radioulnar joint

head of the ulna: small, rounded distal end of the ulna; articulates with the ulnar notch of the distal radius, forming the distal radioulnar joint

hip bone: coxal bone; single bone that forms the pelvic girdle; consists of three areas, the ilium, ischium, and pubis

hip joint: joint located at the proximal end of the lower limb; formed by the articulation between the acetabulum of the hip bone and the head of the femur

hook of the hamate bone: bony extension located on the anterior side of the hamate carpal bone

humerus: single bone of the upper arm

iliac crest: curved, superior margin of the ilium

iliac fossa: shallow depression found on the anterior and medial surfaces of the upper ilium

ilium: superior portion of the hip bone

inferior angle of the scapula: inferior corner of the scapula located where the medial and lateral borders meet

inferior pubic ramus: narrow segment of bone that passes inferiorly and laterally from the pubic body; joins with the ischial ramus to form the ischiopubic ramus

infraglenoid tubercle: small bump or roughened area located on the lateral border of the scapula, near the inferior margin of the glenoid cavity

infraspinous fossa: broad depression located on the posterior scapula, inferior to the spine

intercondylar eminence: irregular elevation on the superior end of the tibia, between the articulating surfaces of the medial and lateral condyles

intercondylar fossa: deep depression on the posterior side of the distal femur that separates the medial and lateral condyles

intermediate cuneiform: middle of the three cuneiform tarsal bones; articulates posteriorly with the navicular bone, medially with the medial cuneiform bone, laterally with the lateral cuneiform bone, and anteriorly with the second metatarsal bone

interosseous border of the fibula: small ridge running down the medial side of the fibular shaft; for attachment of the interosseous membrane between the fibula and tibia

interosseous border of the radius: narrow ridge located on the medial side of the radial shaft; for attachment of the interosseous membrane between the ulna and radius bones

interosseous border of the tibia: small ridge running down the lateral side of the tibial shaft; for attachment of the interosseous membrane between the tibia and fibula

interosseous border of the ulna: narrow ridge located on the lateral side of the ulnar shaft; for attachment of the interosseous membrane between the ulna and radius

interosseous membrane of the forearm: sheet of dense connective tissue that unites the radius and ulna bones

interosseous membrane of the leg: sheet of dense connective tissue that unites the shafts of the tibia and fibula bones

interphalangeal joint: articulation between adjacent phalanx bones of the hand or foot digits

intertrochanteric crest: short, prominent ridge running between the greater and lesser trochanters on the posterior side of the proximal femur

intertrochanteric line: small ridge running between the greater and lesser trochanters on the anterior side of the proximal femur

intertubercular groove (sulcus): bicipital groove; narrow groove located between the greater and lesser tubercles of the humerus

ischial ramus: bony extension projecting anteriorly and superiorly from the ischial tuberosity; joins with the inferior pubic ramus to form the ischiopubic ramus

ischial spine: pointed, bony projection from the posterior margin of the ischium that separates the greater sciatic notch and lesser sciatic notch

ischial tuberosity: large, roughened protuberance that forms the posteroinferior portion of the hip bone; weight-bearing region of the pelvis when sitting

ischiopubic ramus: narrow extension of bone that connects the ischial tuberosity to the pubic body; formed by the junction of the ischial ramus and inferior pubic ramus

ischium: posteroinferior portion of the hip bone

knee joint: joint that separates the thigh and leg portions of the lower limb; formed by the articulations between the medial and lateral condyles of the femur, and the medial and lateral condyles of the tibia

lateral border of the scapula: diagonally oriented lateral margin of the scapula

lateral condyle of the femur: smooth, articulating surface that forms the distal and posterior sides of the lateral expansion of the distal femur

lateral condyle of the tibia: lateral, expanded region of the proximal tibia that includes the smooth surface that articulates with the lateral condyle of the femur as part of the knee joint

lateral cuneiform: most lateral of the three cuneiform tarsal bones; articulates posteriorly with the navicular bone, medially with the intermediate cuneiform bone, laterally with the cuboid bone, and anteriorly with the third metatarsal bone

lateral epicondyle of the femur: roughened area of the femur located on the lateral side of the lateral condyle

lateral epicondyle of the humerus: small projection located on the lateral side of the distal humerus

lateral malleolus: expanded distal end of the fibula

lateral supracondylar ridge: narrow, bony ridge located along the lateral side of the distal humerus, superior to the lateral epicondyle

leg: portion of the lower limb located between the knee and ankle joints

lesser pelvis: (also, lesser pelvic cavity or true pelvis) narrow space located within the pelvis, defined superiorly by the pelvic brim (pelvic inlet) and inferiorly by the pelvic outlet

lesser sciatic foramen: pelvic opening formed by the lesser sciatic notch of the hip bone, the sacrospinous ligament, and the sacrotuberous ligament

lesser sciatic notch: shallow indentation along the posterior margin of the ischium, inferior to the ischial spine

lesser trochanter: small, bony projection on the medial side of the proximal femur, at the base of the femoral neck

lesser tubercle: small, bony prominence located on anterior side of the proximal humerus

ligament of the head of the femur: ligament that spans the acetabulum of the hip bone and the fovea capitis of the femoral head

limb bud: small elevation that appears on the lateral side of the embryo during the fourth or fifth week of development, which gives rise to an upper or lower limb

linea aspera: longitudinally running bony ridge located in the middle third of the posterior femur

lunate: from the lateral side, the second of the four proximal carpal bones; articulates with the radius proximally, the capitate and hamate distally, the scaphoid laterally, and the triquetrum medially

medial border of the scapula: elongated, medial margin of the scapula

medial condyle of the femur: smooth, articulating surface that forms the distal and posterior sides of the medial expansion of the distal femur

medial condyle of the tibia: medial, expanded region of the proximal tibia that includes the smooth surface that articulates with the medial condyle of the femur as part of the knee joint

medial cuneiform: most medial of the three cuneiform tarsal bones; articulates posteriorly with the navicular bone, laterally with the intermediate cuneiform bone, and anteriorly with the first and second metatarsal bones

medial epicondyle of the femur: roughened area of the distal femur located on the medial side of the medial condyle

medial epicondyle of the humerus: enlarged projection located on the medial side of the distal humerus

medial malleolus: bony expansion located on the medial side of the distal tibia

metacarpal bone: one of the five long bones that form the palm of the hand; numbered 1–5, starting on the lateral (thumb) side of the hand

metacarpophalangeal joint: articulation between the distal end of a metacarpal bone of the hand and a proximal phalanx bone of the thumb or a finger

metatarsal bone: one of the five elongated bones that forms the anterior half of the foot; numbered 1–5, starting on the medial side of the foot

metatarsophalangeal joint: articulation between a metatarsal bone of the foot and the proximal phalanx bone of a toe

midcarpal joint: articulation between the proximal and distal rows of the carpal bones; contributes to movements of the hand at the wrist

navicular: tarsal bone that articulates posteriorly with the talus bone, laterally with the cuboid bone, and anteriorly with the medial, intermediate, and lateral cuneiform bones

neck of the femur: narrowed region located inferior to the head of the femur

neck of the radius: narrowed region immediately distal to the head of the radius

obturator foramen: large opening located in the anterior hip bone, between the pubis and ischium regions

olecranon fossa: large depression located on the posterior side of the distal humerus; this space receives the olecranon process of the ulna when the elbow is fully extended

olecranon process: expanded posterior and superior portions of the proximal ulna; forms the bony tip of the elbow

patella: kneecap; the largest sesamoid bone of the body; articulates with the distal femur

patellar surface: smooth groove located on the anterior side of the distal femur, between the medial and lateral condyles; site of articulation for the patella

pectineal line: narrow ridge located on the superior surface of the superior pubic ramus

pectoral girdle: shoulder girdle; the set of bones, consisting of the scapula and clavicle, which attaches each upper limb to the axial skeleton

pelvic brim: pelvic inlet; the dividing line between the greater and lesser pelvic regions; formed by the superior margin of the pubic symphysis, the pectineal lines of each pubis, the arcuate lines of each ilium, and the sacral promontory

pelvic girdle: hip girdle; consists of a single hip bone, which attaches a lower limb to the sacrum of the axial skeleton

pelvic inlet: pelvic brim

pelvic outlet: inferior opening of the lesser pelvis; formed by the inferior margin of the pubic symphysis, right and left ischiopubic rami and sacrotuberous ligaments, and the tip of the coccyx

pelvis: ring of bone consisting of the right and left hip bones, the sacrum, and the coccyx

phalanx bone of the foot: (plural = phalanges) one of the 14 bones that form the toes; these include the proximal and distal phalanges of the big toe, and the proximal, middle, and distal phalanx bones of toes two through five

phalanx bone of the hand: (plural = phalanges) one of the 14 bones that form the thumb and fingers; these include the proximal and distal phalanges of the thumb, and the proximal, middle, and distal phalanx bones of the fingers two through five

pisiform: from the lateral side, the fourth of the four proximal carpal bones; articulates with the anterior surface of the triquetrum

pollex: (also, thumb) digit 1 of the hand

posterior inferior iliac spine: small, bony projection located at the inferior margin of the auricular surface on the posterior ilium

posterior sacroiliac ligament: strong ligament spanning the sacrum and ilium of the hip bone that supports the posterior side of the sacroiliac joint

posterior superior iliac spine: rounded, posterior end of the iliac crest

proximal radioulnar joint: articulation formed by the radial notch of the ulna and the head of the radius

proximal tibiofibular joint: articulation between the head of the fibula and the inferior aspect of the lateral condyle of the tibia

pubic arch: bony structure formed by the pubic symphysis, and the bodies and inferior pubic rami of the right and left pubic bones

pubic body: enlarged, medial portion of the pubis region of the hip bone

pubic symphysis: joint formed by the articulation between the pubic bodies of the right and left hip bones

pubic tubercle: small bump located on the superior aspect of the pubic body

pubis: anterior portion of the hip bone

radial fossa: small depression located on the anterior humerus above the capitulum; this space receives the head of the radius when the elbow is maximally flexed

radial notch of the ulna: small, smooth area on the lateral side of the proximal ulna; articulates with the head of the radius as part of the proximal radioulnar joint

radial tuberosity: oval-shaped, roughened protuberance located on the medial side of the proximal radius

radiocarpal joint: wrist joint, located between the forearm and hand regions of the upper limb; articulation formed proximally by the distal end of the radius and the fibrocartilaginous pad that unites the distal radius and ulna bone, and distally by the scaphoid, lunate, and triquetrum carpal bones

radius: bone located on the lateral side of the forearm

sacroiliac joint: joint formed by the articulation between the auricular surfaces of the sacrum and ilium

sacrospinous ligament: ligament that spans the sacrum to the ischial spine of the hip bone

sacrotuberous ligament: ligament that spans the sacrum to the ischial tuberosity of the hip bone

scaphoid: from the lateral side, the first of the four proximal carpal bones; articulates with the radius proximally, the trapezoid, trapezium, and captitate distally, and the lunate medially

scapula: shoulder blade bone located on the posterior side of the shoulder

shaft of the femur: cylindrically shaped region that forms the central portion of the femur

shaft of the fibula: elongated, slender portion located between the expanded ends of the fibula

shaft of the humerus: narrow, elongated, central region of the humerus

shaft of the radius: narrow, elongated, central region of the radius

shaft of the tibia: triangular-shaped, central portion of the tibia

shaft of the ulna: narrow, elongated, central region of the ulna

soleal line: small, diagonally running ridge located on the posterior side of the proximal tibia

spine of the scapula: prominent ridge passing mediolaterally across the upper portion of the posterior scapular surface

sternal end of the clavicle: medial end of the clavicle that articulates with the manubrium of the sternum

sternoclavicular joint: articulation between the manubrium of the sternum and the sternal end of the clavicle; forms the only bony attachment between the pectoral girdle of the upper limb and the axial skeleton

styloid process of the radius: pointed projection located on the lateral end of the distal radius

styloid process of the ulna: short, bony projection located on the medial end of the distal ulna

subpubic angle: inverted V-shape formed by the convergence of the right and left ischiopubic rami; this angle is greater than 80 degrees in females and less than 70 degrees in males

subscapular fossa: broad depression located on the anterior (deep) surface of the scapula

superior angle of the scapula: corner of the scapula between the superior and medial borders of the scapula

superior border of the scapula: superior margin of the scapula

superior pubic ramus: narrow segment of bone that passes laterally from the pubic body to join the ilium

supraglenoid tubercle: small bump located at the superior margin of the glenoid cavity

suprascapular notch: small notch located along the superior border of the scapula, medial to the coracoid process

supraspinous fossa: narrow depression located on the posterior scapula, superior to the spine

surgical neck: region of the humerus where the expanded, proximal end joins with the narrower shaft

sustentaculum tali: bony ledge extending from the medial side of the calcaneus bone

talus: tarsal bone that articulates superiorly with the tibia and fibula at the ankle joint; also articulates inferiorly with the calcaneus bone and anteriorly with the navicular bone

tarsal bone: one of the seven bones that make up the posterior foot; includes the calcaneus, talus, navicular, cuboid, medial cuneiform, intermediate cuneiform, and lateral cuneiform bones

thigh: portion of the lower limb located between the hip and knee joints

tibial tuberosity: elevated area on the anterior surface of the proximal tibia

tibia: shin bone; the large, weight-bearing bone located on the medial side of the leg

trapezium: from the lateral side, the first of the four distal carpal bones; articulates with the scaphoid proximally, the first and second metacarpals distally, and the trapezoid medially

trapezoid: from the lateral side, the second of the four distal carpal bones; articulates with the scaphoid proximally, the second metacarpal distally, the trapezium laterally, and the capitate medially

triquetrum: from the lateral side, the third of the four proximal carpal bones; articulates with the lunate laterally, the hamate distally, and has a facet for the pisiform

trochlear notch: large, C-shaped depression located on the anterior side of the proximal ulna; articulates at the elbow with the trochlea of the humerus

trochlea: pulley-shaped region located medially at the distal end of the humerus; articulates at the elbow with the trochlear notch of the ulna

ulnar notch of the radius: shallow, smooth area located on the medial side of the distal radius; articulates with the head of the ulna at the distal radioulnar joint

ulnar tuberosity: roughened area located on the anterior, proximal ulna inferior to the coronoid process

ulna: bone located on the medial side of the forearm