APPENDICULAR Skeleton

Female pelvis characteristics

Light Wide Dorsally located Wide and oval shaped Better suited for a petite body and for child birth

Pectoral Girdle: scapula

The scapula is the thin, triangular bone that covers the dorsal surface of ribs 2-7. Although there are a number of surface landmarks on this bone, for now recognize that the spine marks the posterior surface.

The medial bone of the forearm

contributes to the major articulation of the elbow joint. [Great Job! Along with the humerus, the ulna forms the major articulation of the elbow. (not to minimize the role of the radius...)]

Pelvic Girdle: ilium

creates the crest of the pelvis

pubis

forms the anterior region of the pelvis

Upper limb: "forearm" There are two bones in the forearm: ulna

is the medial bone of the forearm. Its head is the more distal portion of the bone that articulates with the bones of the wrist (carpals). Proximally it forms the primary articulation with the humerus. When you palpate (feel) your elbow you are actually feeling the olecranon process of the ulna. The u-shaped proximal portion of the ulna may remind you of a wrench or an ice-cream scoop?

Lower limb: ankle bones calcaneus

the larger, inferior bone that forms the "heel"

Lower limb: "leg" The two bones of the leg. fibula

the more lateral of the two leg bones. Much smaller and thinner. Plays a role in stabilizing the ankle joint.

ischium

the posterior bone that we "sit on"

Upper limb: "arm"

The bone of arm is the humerus. Proximally it articulates with the scapula (shoulder blade) and distally it articulates with the bones of the forearm (radius and ulna)at the elbow.

Upper limb: "hand"

Distal to the carpals are the 5 metacarpals that form the palm of the hands. These bones distally articulate with the proximal phalanges.

Pectoral Girdle:

The bones that attach the upper limb to the torso: clavicle (collar bone) scapula (shoulder blade) This girdle is light-weight to allow a wide range of motion for the upper limb. It provides the attachment site for the many muscles that connect the limb to the torso.

Lower limb: foot

The structure of the foot mirrors that of the hand. Distal to the tarsal bones there are 5 metatarsals that form the arch of the foot. Then distal to the metatarsals are 14 phalanges in each foot. Like the hand, the "big" toe has only two phalanges.

Pectoral Girdle: clavicle

This thin, s-shaped bone articulates medially with the manubrium ("sternoclavicular joint") and laterally with the acromion of the scapula ("acromioclavicular joint").

What two bones does the scapula primarily articulate with?

humerus and clavicle [Great Job! Now when you get to lab you can focus on the relationship of these two bones and learn the important bony landmarks that participate in these articulations.]

Pelvic Girdle: true vs. false true pelvis

located inferior to the pubic brim; this is the region that forms the actual pelvic cavity and contains the organs found there.

Although there are a number of bony markings, can you make an educated guess as to why this bone is given both an anatomic and a surgical neck?

Answer: the surgical neck is the portion of the humerus that is more commonly fractured.

Upper limb:

Attached to the torso via the pectoral girdle. The subdivisions of the upper limb would include the: arm or brachium - region intermediate to the shoulder and elbow forearm or antebrachium - region between the elbow and wrist wrist hand with digits

Pelvic Girdle:

Attaches the lower limbs to the torso. Unlike the pectoral girdle, this structure is much less mobile, but is heavier and can withstand greater weight and stress. In addition to this, the pelvic girdle also supports the abdominal viscera.

Clinical Relevance: a very common injury occurs to one of the carpal bones, the scaphoid, when a person falls on their out-stretched hand. This bone forms an important articulation point with the distal radius but it also happens to have a poor blood supply. This can make fractures in this area difficult to heal.

If you want to recognize the location of the scaphoid using surface anatomy, it is found in the region of what is called the "anatomic snuff box". Perhaps you can guess where the name came from?

Lower limb: ankle bones

There are seven short bones that form the ankle. Collectively these bones are called the tarsal bones.

Pelvic Girdle:

This girdle is formed by the two coxal bones (a.k.a hip bones or os coxae) which articulate with the sacrum posteriorly to create the deep basin of the pelvis. Each coxal bone in an adult was formed by the fusion of three separate bones: ilium ischium pubis

Male pelvis characteristics

Very thick and heavy Narrow Ventrally located Narrow and heart shaped Better suited for support of a larger body and muscles

Upper limb: "wrist" There are 8 short bones

called the carpal bones that form the wrist. Although each of these bones has an individual name, you will not be required to learn them.

A feature of the female pelvis would be a

dorsally directed sacrum. [Great job! If the sacrum and coccyx were directly ventrally, they would project into the pelvic canal which could impend the proper descent of an infant at the time of delivery.]

The lateral bone of the leg is called the

fibula

Upper limb: "forearm" There are two bones in the forearm: radius

is the lateral bone of the forearm; its proximal "head" articulates with the humerus. This head may remind you of a golf tee? Distally the radius articulates with the bones of the wrist (carpals).

Pelvic Girdle: true vs. false false pelvis

located superior to the pubic brim; this cavity is actually considered part of the abdomen and contains some of the organs found there.

Lower limb: ankle bones talus

the bone that articulates with the distal tibia to primarily form the ankle joint.

phalange

the bones of the digits; there are 14 phalanges in each hand. Each finger contains a proximal, middle and distal phalange. The thumb only has a proximal and distal phalange. If you ever forget this, you have a portable study specimen in your own hand!

Lower limb: "leg" The two bones of the leg. tibia

the larger and more medial of the leg bones. It forms the major articulation with the femur and primarily creates the knee joint. Distally it articulates with the ankle bones (primarily the talus) to form the ankle joint.

Lower limb: "thigh" Femur

the largest bone in the body and the only bone of the thigh. In lab notice the thickness and heaviness of this bone compared to bones of the upper limb? Why do you think this bone would be so much thicker and heavier? Proximally the femoral head articulates with the pelvic bones to form the hip joint.

Lower limb: patella

the small triangular bones that cover the anterior knee. Recall that these are a special kind of a short bone because they develop in within a tendon. Do you recall the name for this kind of short bones?

Lower limb: Attached to the torso via the pelvic girdle. The subdivisions of the lower limb would include the:

thigh- region intermediate to the hip and knee leg - region between the knee and ankle ankle foot with digits