Ch. 7.4 Skeletal System Key Terms
Appendicular skeleton
Forms the extremities and is composed of the shoulder girdle, arm bones, pelvic girdle, and leg bones.
Diaphysis
The long shaft of a long bone.
Fontanels
Spaces in the cranium at birth, also called "soft spots," that allow for the enlargement of the skull as brain growth occurs.
Medullary canal
A cavity in the diaphysis of a long bone. It is filled with yellow marrow.
Periosteum
A tough membrane that covers the outside of bone, containing blood vessels, lymph vessels, and osteoblasts. It is necessary for bone growth, repair, and nutrition.
Axial skeleton
Forms the main trunk of the body and is composed of the skull, spinal column, ribs, and breastbone.
Endosteum
A membrane that lines the medullary canal and keeps the yellow marrow intact. It also produces some bone growth.
Foramina
Openings in bones that allow nerves and blood vessels to enter or leave the bone.
Metacarpals
The five bones in the palm of the hand.
Phalanges
The bones of the fingers and toes.
Carpals
The eight bones of the wrist.
Epiphysis
The two extremities, or ends, of a long bone.
Humerus
The upper arm bone.
Metatarsals
The five bones in the instep of the foot.
Radius
The lower arm bone on the thumb side that rotates around the ulna to allow the hand to turn freely.
Clavicles
The two collarbones.
Femur
The upper leg bone (thigh bone).
Joints
Areas where two or more bones join together.
Os coxae
The two coxal, or hip, bones that make up the pelvic girdle.
Red marrow
Found in certain bones (vertebrae, ribs, sternum, cranium, and proximal ends of the humerus and femur) where hematopoiesis (production of red blood cells, platelets, and some white blood cells) takes place.
Cranium
The spherical structure that surrounds and protects the brain.
Fibula
The slender smaller bone of the lower leg that attaches to the proximal end of the tibia.
Ligaments
Connective tissue bands that help hold long bones together at joints.
Patella
The kneecap.
Ribs
There are 12 pairs of these bones that attach to the thoracic vertebrae.