Info

Location

Name and Number

Location

Special Features

Name and Number

Special Features

Clavicle (2)

Base of neck between sternum and scapula

Sternal end, acromial end

Scapula (2)

Upper back, forming part of shoulder

Body, spine, head, acromion process, coracoid process, glenoid cavity

Humerus (2)

Arm, between scapula and elbow

Head, greater tubercle, lesser tubercle, intertubercular groove, surgical neck, deltoid tuberosity, capitulum, trochlea, medial epicondyle, lateral epicondyle, coronoid fossa, olecranon fossa

Radius (2)

Lateral side of forearm, between elbow and wrist

Head, radial tuberosity, styloid process, ulnar notch

Ulna (2)

Medial side of forearm, between elbow and wrist

Trochlear notch, olecranon process, head, styloid process, radial notch

Carpal (16)

Wrist

Arranged in two rows of four bones each

Metacarpal (10)

Palm

One in line with each finger

Phalanx (28)

Finger

Three in each finger; two in each thumb

pelvic girdle together form the bowl-shaped pelvis. The pelvic girdle supports the trunk of the body, provides attachments for the lower limbs, and protects the urinary bladder, the distal end of the large intestine, and the internal reproductive organs. The body's weight is transmitted through the pelvic girdle to the lower limbs and then onto the ground.

Coxae

Each coxa develops from three parts—an ilium, an is-chium, and a pubis. These parts fuse in the region of a cup-shaped cavity called the acetabulum (as"e-tab'u-lum). This depression, on the lateral surface of the hipbone, receives the rounded head of the femur or thighbone (fig. 7.50).

The ilium (il'e-um), which is the largest and most superior portion of the coxa, flares outward, forming the prominence of the hip. The margin of this prominence is called the iliac crest. The smooth, concave surface on the anterior aspect of the ilium is the iliac fossa.

Posteriorly, the ilium joins the sacrum at the sacroiliac (sa"kro-il'e-ak) joint. Anteriorly, a projection of the ilium, the anterior superior iliac spine, can be felt lateral to the groin. This spine provides attachments for ligaments and muscles and is an important surgical landmark.

A common injury in contact sports such as football is bruising the soft tissues and bone associated with the anterior superior iliac spine. Wearing protective padding can prevent this painful injury, called a hip pointer.

On the posterior border of the ilium is a posterior superior iliac spine. Below this spine is a deep indenta tion, the greater sciatic notch, through which a number of nerves and blood vessels pass.

The ischium (is'ke-um), which forms the lowest portion of the coxa, is L-shaped, with its angle, the ischial tuberosity, pointing posteriorly and downward. This tuberosity has a rough surface that provides attachments for ligaments and lower limb muscles. It also supports the weight of the body during sitting. Above the ischial tuberosity, near the junction of the ilium and ischium, is a sharp projection called the is-chial spine. Like the sacral promontory, this spine, which can be felt during a vaginal examination, is used as a guide for determining pelvis size. The distance between the ischial spines is the shortest diameter of the pelvic outlet.

The pubis (pu'bis) constitutes the anterior portion of the coxa. The two pubic bones come together at the midline to form a joint called the symphysis pubis (sim'fi-sis pu'bis). The angle these bones form below the symphysis is the pubic arch.

A portion of each pubis passes posteriorly and downward to join an ischium. Between the bodies of these bones on either side is a large opening, the obturator foramen, which is the largest foramen in the skeleton. An obturator membrane covers and nearly closes this foramen (see figs. 7.49 and 7.50).

Greater and Lesser Pelves

If a line were drawn along each side of the pelvis from the sacral promontory downward and anteriorly to the upper margin of the symphysis pubis, it would mark the pelvic brim (linea terminalis). This margin separates the lower, or lesser (true), pelvis from the upper, or greater (false), pelvis (fig. 7.51).

The greater pelvis is bounded posteriorly by the lumbar vertebrae, laterally by the flared parts of the iliac

Acetabulum

Symphysis pubis

Figure

Acetabulum

Symphysis pubis

Illium

-Sacral promontory

Sacrum

Pubic tubercle Ischium Pubic arch

Pubis

Sacroliliac joint

Illium

-Sacral promontory

Pubis

Sacrum

Pubic tubercle Ischium Pubic arch

Sacral canal Ilium

Sacrum

Sacral hiatus

Coccyx

Ischium

Obturator foramen

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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