Chapter 8: The Skeletal System - The Appendicular Skeleton

Vocabulary flashcards covering the components, structures, and development of the appendicular skeleton based on the Tortora and Derrickson textbook.

Appendicular Skeleton

The portion of the skeletal system consisting of the $126$ bones of the upper and lower limbs and the girdles that attach them to the axial skeleton.

Pectoral Girdle

The shoulder girdle which includes a clavicle and a scapula to attach the upper limb to the axial skeleton.

Clavicle

An S-shaped bone, also known as the collarbone, that articulates medially with the sternum and laterally with the scapula.

Sternal end

The medial end of the clavicle that articulates with the manubrium of the sternum.

Acromial end

The lateral end of the clavicle that articulates with the acromion of the scapula.

Scapula

A flat bone located in the superior part of the posterior thorax between the second and seventh ribs.

Glenoid cavity

The depression in the scapula that serves as the attachment point for the head of the humerus.

Humerus

The longest and largest bone of the upper limb, commonly called the arm bone.

Anatomical neck

A groove on the humerus just distal to the head, representing the former site of the epiphyseal plate.

Surgical neck

A constricted portion of the humerus distal to the tubercles, so named because it is a common site of fracture.

Trochlea

A pulley-shaped surface on the distal end of the humerus that articulates with the ulna.

Capitulum

A rounded knob on the lateral aspect of the distal humerus that articulates with the head of the radius.

Ulna

The bone of the forearm located on the medial side, which includes the olecranon.

Radius

The bone of the forearm located on the lateral (thumb) side.

Olecranon

The large, proximal end of the ulna that forms the prominence of the elbow.

Coronoid process

An anterior projection at the proximal end of the ulna that, along with the olecranon, forms the trochlear notch.

Trochlear notch

The large curved area between the olecranon and coronoid process that wraps around the trochlea of the humerus.

Interosseous membrane

A fibrous connective tissue that joins the shafts of the radius and ulna (and the tibia and fibula).

Carpal bones

A group of $8$ small bones of the wrist held together by ligaments and arranged in two rows.

Scaphoid

The lateral-most bone in the proximal row of carpals.

Lunate

A proximal row carpal bone shaped like a crescent moon.

Triquetrum

A proximal row carpal bone articulating with the lunate and pisiform.

Pisiform

A small, pea-shaped bone in the proximal row of carpals.

Trapezium

The lateral-most bone in the distal row of carpals.

Trapezoid

A distal row carpal bone located between the trapezium and the capitate.

Capitate

The largest carpal bone, located in the center of the distal row.

Hamate

The medial-most bone in the distal row of carpals, characterized by a hook-like process.

Metacarpals

The $5$ bones that form the palm and back of the hand, numbered $I$ through $V$ starting from the thumb.

Phalanges (Upper Limb)

The bones of the digits, comprising $14$ total bones per hand.

Pollex

The thumb, which contains only $2$ phalanges: proximal and distal.

Pelvic (Hip) Girdle

Consists of two hip bones that articulate anteriorly at the pubic symphysis and posteriorly with the sacrum.

Os coxa

Also known as a hip bone or coxal bone, which is composed of three fused bones.

Pubic symphysis

The joint between the two pubic bones, containing a disc of fibrocartilage.

Ilium

The largest and most superior of the three bones that form the hip bone.

Ischium

The inferior, posterior portion of the hip bone.

Pubis

The anterior and inferior portion of the hip bone.

Acetabulum

The deep socket that receives the head of the femur, formed by the ilium, ischium, and pubis.

Pelvic brim

The boundary that divides the pelvis into superior (false) and inferior (true) portions.

False (greater) pelvis

The expanded portion of the bony pelvis located superior to the pelvic brim.

True (lesser) pelvis

The portion of the bony pelvis located inferior to the pelvic brim.

Pubic arch (Female)

The angle formed by the pubic bones that is typically greater than $90^{\circ}$ in females.

Pubic arch (Male)

The angle formed by the pubic bones that is typically less than $90^{\circ}$ in males.

Femur

The longest, heaviest, and strongest bone in the body, which forms the thigh.

Greater trochanter

A large, blunt projection on the proximal and lateral part of the femur.

Linea aspera

A vertical ridge on the posterior surface of the body (shaft) of the femur.

Patella

A triangular sesamoid bone that develops in the quadriceps tendon.

Tibia

The larger, medial, weight-bearing bone of the lower leg, also called the shin bone.

Fibula

The smaller, lateral bone of the lower leg that does not bear weight.

Tibial tuberosity

The projection on the anterior surface of the tibia that serves as the attachment point for the patellar ligament.

Medial malleolus

The distal projection of the tibia that forms the inner prominence of the ankle.

Lateral malleolus

The distal projection of the fibula that forms the outer prominence of the ankle.

Tarsus

The collection of $7$ tarsal bones in the ankle region.

Talus

The tarsal bone that articulates with the tibia and fibula to form the ankle joint.

Calcaneus

The largest and strongest tarsal bone, which forms the heel.

Navicular

A tarsal bone located on the medial side of the foot between the talus and cuneiforms.

Metatarsals

The $5$ bones that form the sole and dorsal surface of the foot, numbered $I$ to $V$ from the big toe.

Hallux

The big toe, which contains two phalanges: proximal and distal.

Longitudinal arch

The foot arch consisting of a medial and a lateral portion that runs from the front to the back of the foot.

Transverse arch

The foot arch that runs across the foot, formed by the navicular, cuneiforms, and the bases of the metatarsals.

Mesoderm

The middle primary germ layer from which most skeletal tissue and the skeleton of the limbs are derived.