Bones of the Appendicular Skeleton

The bones of the shoulder girdle provide attachment sites for muscles in the arms, chest, and upper back. The shoulder joint has great flexibility and range of motion, and is capable of a variety of movements.

Abduction is the act of moving a limb away from the body; in this case, to extend the arm out to the side of the body. Adduction is the act of moving a limb in toward the body; in this case, to bring the arm back in toward the torso. Rotation is the act of turning a limb about its axis; in this case, to turn the upper arm in and out.

The human hand has twenty-seven bones.

Carpals are the eight small, blocky bones that form the wrist. Metacarpals are the five bones that extend out from the carpals, forming your palm. Phalanges are the fourteen bones that form your fingers: two in the thumb, and three in the other fingers.

The human foot has twenty-six bones, one fewer than the hand.

Tarsals are the seven blocky bones that form the ankle. The largest tarsal bone is the calcaneus, or heel bone. Metatarsals are the five bones that extend out from the tarsals Phalanges are the fourteen bones that form your toes: two in the big toe, and three in the others.

The pelvic girdle is a large structure comprised of three fused bones.

The ischium is a bone on the bottom of the pelvic girdle that supports the weight of the body when seated. The ilium is a large bone roughly shaped like an elephant's ear. You can feel the top of this bone when you put your hands on your hips. The pubis is the smallest of the three pelvic bones, and is located where the right and left halves of the pelvic girdle meet.

The primary function of the lower limbs is locomotion, or forward movement. Humans are able to walk upright because of the structure of the spine, pelvis, and lower limbs. The thick and exceptionally strong bones of the lower limbs can tolerate the forces generated by locomotion. The muscles, tendons, and ligaments in the lower limbs help stabilize the joints during movement.

The knee joint is the largest joint in the body, and allows for three types of movement. Flexion is the act of moving a limb at a joint to reduce the angle formed by the bones that meet at that joint; in this case, to bring the lower leg toward the body. Extension is the act of moving a limb at a joint to increase the angle formed by the bones that meet at that joint; in this case, to kick the lower leg away from the body. Rotation is allowed minimally by the knee joint.

The humerus is the only bone located in the upper arm. It is a long bone that connects to the scapula to form the shoulder joint.

The lower arm is formed by two bones. The ulna is the longer of the two, and is wide at the elbow and thin at the wrist. It forms the elbow joint with the humerus. The radius, the other forearm bone, is wide at the wrist and thin at the elbow.

The many bones in the lower limbs are responsible for supporting bodyweight, walking, and running. The general structure of the lower limb mirrors that of the upper limb. The femur, also called the thigh bone, is one long bone in the upper leg. It extends from the hip joint to the knee, and is the largest bone in the body.

The lower leg is made of two bones. The tibia, also known as the shin bone, is the long, broad bone in the front of the lower leg. The fibula is a thin bone located behind the tibia in the lower leg. The knee joint is formed by the lower portion of the femur and the upper portion of the tibia. Another bone, the patella, or kneecap, is a bone in the front of the knee that protects the knee.

The pelvic girdle supports the weight of the body and protects the organs in the pelvic area. The strong, broad structure of the pelvis enables it to withstand the forces generated by walking, running, and jumping. At the bottom of the torso, the pelvic bones form an oval cup-shaped floor called the pelvic cavity. Several organs located within this cavity are responsible for excretion and reproduction.

The pelvic bones differ in shape and size in men and women. They are shallower, wider, and rounder in women, to enable a baby's head to pass through the pelvis during childbirth. The pelvic girdle also provides the strength to support a growing fetus (unborn baby) during pregnancy.

The pelvic girdle, also called the pelvis, is the region of the body connecting the lower limb to the axial skeleton. The hip joint is formed by the pelvic girdle.

The pelvis is attached to the bones of the spine (backbone) as well as the bones of the legs. The hips can withstand the stress of bearing the weight of the rest of the body. Pelvic bones and organs differ between men and women. In women, the pelvic girdle is wider, with a gap in the middle through which a baby can pass during childbirth.

The bones of the shoulder girdle include the scapula and clavicle.

The scapula, also known as the shoulder blade, is a triangular, flat bone located in the upper back. Each scapula is found on the back side of the rib cage. The clavicle, also called the collarbone, is a curved bone that forms a ridge across the upper portion of the chest. Each collarbone attaches to the scapula at one end and to the sternum, or breastbone, at the other end.

The shoulder girdle includes the anterior (front) shoulder and posterior (back) shoulder. The back of the shoulder is commonly referred to as the shoulder blade.

The shoulder girdle also includes the collarbone, which is a bone that forms a ridge across the upper portion of the chest.

A bone is a type of sturdy tissue that provides shape to the human body and makes up most of the structure of the appendicular skeleton.

The skeleton is an arrangement of bones that forms the structure of the body. The appendicular skeleton is the collection of bones of the appendicular region. Joints are the locations where two bones connect.

In addition to bone, the appendicular skeleton includes:

muscle - a type of tissue that can contract and generate force. tendons - connective tissues that attach muscles to bones. ligaments - connective tissues that attach two bones together. blood vessels - tubes that carry blood throughout the body. nerves - threadlike structures that transmit electrical signals.

shoulder girdle

structure that attaches the upper limb to the torso.

Axial region

the body region that includes the head, neck, and trunk. It's called "axial" because an axis, or invisible line, runs through the center of this region

Appendicular region

the body region that includes the upper limbs, lower limbs, and their girdles. A girdle is a body part that attaches a limb to the axial region

The upper limbs include the:

upper arms. elbows. forearms. wrists. hands. fingers.

The lower limbs are attached to the axial skeleton by the pelvic girdle. The lower limbs consist of the:

upper legs. knees. lower legs. ankles. feet. toes. The bones of the lower limbs also are associated with muscles, tendons, ligaments, and other tissues.