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
"Soft spots" in the cranium at birth; these spaces are made of membrane and cartilage, and they allow for the enlargement of the skull as the brain grows.
medullary canal
A cavity in the diaphysis of a long bone.
periosteum
The tough membrane that covers the outside of a bone; it contains blood vessels, lymph vessels, and osteoblasts (special cells that form new bone tissue).
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, keeps the yellow marrow intact, and produces some bone growth.
foramina
Openings in bones that allow nerves and blood vessels to enter or leave the bone.
metacarpals
The 5 bones that form the palm of the hand.
phalanges
The bones of the fingers and toes; there are 3 on each finger and 2 on the thumb, and 2 on the great toe and 3 on each of the other 4 toes.
carpals
The 8 bones of the wrist.
epiphysis
The two extremities, or ends, of a long bone.
humerus
The upper arm bone.
metatarsals
The 5 bones of 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 collarbones.
femur
The thigh bone.
joints
Areas where two or more bones join together.
os coxae
The two coxal, or hip, bones.
red marrow
Found in certain bones (like vertebrae, ribs, sternum, cranium, and proximal ends of the humerus and femur). It is where hematopoiesis (the formation of blood cells) occurs, producing red blood cells, platelets, and some white blood cells.
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
The 12 pairs of bones that attach to the thoracic vertebrae on the dorsal surface of the body.