Chapter 8: The Skeletal System - The Appendicular Skeleton

Vocabulary flashcards covering the components, markings, and classification of bones in the human appendicular skeleton based on Chapter 8 notes.

Axial skeleton

A principal division of the human skeleton consisting of $80$ bones, including the skull bones, auditory ossicles, hyoid bone, ribs, sternum, vertebrae, and sacrum.

Appendicular skeleton

A principal division of the human skeleton consisting of $126$ bones, including the bones of the upper and lower extremities and the girdles that attach limbs to the axial skeleton.

Long bones

Bones that have a greater length than width, such as the femur, humerus, ulna, radius, metacarpals, metatarsals, and phalanges.

Short bones

Bones that are generally cube-shaped, such as the carpals, tarsals, patella, and talus.

Flat bones

Thin, flattened, and usually curved bones consisting of thin layers of parallel plates, such as most bones of the skull, ribs, sternum, and scapula.

Irregular bones

Bones with complex shapes that do not fit into other shape categories, including the vertebrae, hip bones, and calcaneus bone.

Sesamoid bones

A specialized type of short bone that forms within tendons (such as the patella) to reduce tendon friction and excessive wear and tear.

Pectoral girdle

The shoulder girdle composed of a clavicle and a scapula, attaching the upper limb to the axial skeleton.

Clavicle

An S-shaped anterior collarbone whose medial half is convex anteriorly and lateral half is concave anteriorly, helping to form the shoulder joint and prevent shoulder dislocation.

Conoid tubercle

A bony landmark on the inferior surface of the lateral end of the clavicle that serves as an attachment point for the conoid ligament.

Impression for the costoclavicular ligament

A feature on the inferior surface of the sternal end of the clavicle that serves as a point of attachment for the costoclavicular ligament, connecting the clavicle to the first rib.

Scapula

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

Glenoid cavity

A shallow depression on the lateral surface of the scapula that serves as the attachment point for the head of the humerus.

Supraspinous fossa

A depression on the posterior surface of the scapula superior to the spine that serves as a surface of attachment for the supraspinatus muscle of the shoulder.

Infraspinous fossa

A surface on the posterior scapula inferior to the spine that serves as an attachment site for the infraspinatus muscle of the shoulder.

Subscapular fossa

A slightly hollowed-out area on the anterior surface of the scapula that serves as a surface of attachment for the subscapularis muscle.

Coracoid process

A projection on the anterior surface at the lateral end of the superior border of the scapula, providing attachment for tendons of the pectoralis minor, coracobrachialis, and biceps brachii muscles.

Sternoclavicular joint

The joint formed by the articulation of the medial (sternal) end of the clavicle with the manubrium of the sternum.

Acromioclavicular joint

The joint formed by the articulation between the lateral (acromial) end of the clavicle and the acromion process of the scapula.

Humerus

The arm bone that articulates proximally with the glenoid cavity of the scapula and distally with the radius and ulna.

Surgical neck of humerus

A constricted region distal to the tubercles of the humerus that is a common site of bone fractures.

Deltoid tuberosity

A rough, V-shaped area on the lateral shaft of the humerus that serves as the insertion site for the deltoid muscle.

Radial groove

A depression running along the posterior surface of the humerus near the deltoid tuberosity that contains the radial nerve.

Capitulum

A lateral rounded structure on the distal end of the humerus that articulates with the head of the radius.

Trochlea

A surface located medial to the capitulum on the distal humerus that articulates with the trochlear notch of the ulna.

Coronoid fossa

An anterior depression on the distal humerus that receives the coronoid process of the ulna during flexion.

Olecranon fossa

A depression on the posterior distal humerus that receives the olecranon of the ulna during extension.

Ulna

The medial bone of the forearm whose proximal olecranon and coronoid process form the trochlear notch that wraps around the trochlea of the humerus.

Radius

The lateral bone of the forearm located on the thumb side, featuring a head that articulates with the capitulum of the humerus and with the ulna.

Radial tuberosity

A point of attachment on the proximal shaft of the radius for the tendons of the biceps brachii muscle.

Carpals

Eight small wrist bones arranged in two rows of four: proximal row (scaphoid, lunate, triquetrum, pisiform) and distal row (trapezium, trapezoid, capitate, hamate).

Metacarpals

Five bones forming the palm and back of the hand, numbered I through V starting with the thumb.

Phalanges (hand)

Fourteen bones of the digits of the hand; the thumb contains two (proximal and distal), while fingers two through five contain three each (proximal, middle, and distal).

Bony pelvis

A deep, basinlike structure formed by the complete ring of the two hip bones, pubic symphysis, sacrum, and coccyx.

Ilium

The largest and most superior of the three individual bones that fuse to form each hip bone.

Iliac crest

The superior border of the ilium.

Greater sciatic notch

A large indentation on the posterior ilium that allows blood vessels and the large sciatic nerve to pass from the pelvis into the thigh.

Ischium

The inferior, posterior portion of the hip bone, commonly referred to as the sit bones.

Ischial tuberosity

A roughened area on the inferior ischium that receives body weight when sitting.

Ischial spine

An anatomical landmark on the ischium that narrows the pelvic outlet through which a baby must pass during the birth process.

Pubis

The most anterior and inferior part of the coxal bone, consisting of a superior ramus, an inferior ramus, and a body.

Pubic symphysis

A cartilaginous joint featuring a disc of fibrocartilage located between the anterior surfaces of the two pubic bones.

Acetabulum

A deep fossa formed where the ilium, ischium, and pubis fuse together, articulating with the head of the femur as a ball-and-socket joint.

Obturator foramen

A large opening enclosed by the rami of the pubis and ischium through which blood vessels and nerves pass into the anterior thigh.

False (greater) pelvis

The region of the bony pelvis superior to the pelvic brim containing the superior portion of the urinary bladder (when full), lower intestines, and female reproductive organs.

True (lesser) pelvis

The region of the bony pelvis inferior to the pelvic brim surrounding the pelvic cavity, containing the rectum, urinary bladder, vagina, cervix, prostate, and seminal glands.

Female pelvis

Pelvis characterized by light/thin general structure, a shallow greater pelvis, a wide/oval pelvic inlet, a pubic arch angle $\text{greater than } 90^{\circ}$, and a wide greater sciatic notch (almost $90^{\circ}$).

Male pelvis

Pelvis characterized by heavy/thick general structure, a deep greater pelvis, a narrow/heart-shaped pelvic inlet, a pubic arch angle $\text{less than } 90^{\circ}$, and a narrow greater sciatic notch (about $70^{\circ}$).

Femur

The thigh bone, recognized as the longest, heaviest, and strongest bone in the human body.

Fovea capitis

A small central depression on the head of the femur that connects the femur head to the acetabulum via the ligament of the head of the femur.

Greater and lesser trochanters

Projections from the junction of the femoral neck and body that serve as points of attachment for tendons of thigh and buttock muscles.

Linea aspera

A vertical ridge on the posterior surface of the femoral body that serves as an attachment point for tendons of several thigh muscles.

Patella

A triangular sesamoid bone developed within the quadriceps tendon that protects the knee joint.

Tibia

The shinbone; the larger, medial, weight-bearing bone of the lower leg and second largest bone in the human body.

Tibial tuberosity

A point of attachment on the anterior surface of the proximal tibia for the patellar ligament.

Medial malleolus

A medial projection on the distal end of the tibia that forms the inner part of the ankle.

Fibula

The smaller bone of the lower leg located laterally relative to the tibia.

Lateral malleolus

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

Tarsals

Seven bones of the tarsus (ankle), including the talus, calcaneus, navicular, cuboid, and three cuneiform bones.

Metatarsals

Five bones forming the sole and dorsal surface of the foot, numbered I through V starting with the big toe.