7.4 Skeletal System Vocabulary

Skeletal System

Organs made up of bones

Diaphysis

Long shaft (of the extremities- arms & legs)

Epiphysis

2 extremities/ends

Medullary Canal

Cavity in the diaphysis (filled with yellow marrow)

Yellow Marrow

Mainly a storage area for fat cells, also contains cells from leukocytes/white blood cells

Endosteum

Membrane that lines the medullary canal and keeps the yellow marrow intact

Red Marrow (in certain bones)

vertebrae, ribs, sternum, and cranium, and in the proximal ends of the humerus and femur

Periosteum

Outside of bone is covered w/ a tough membrane and contains blood vessels, lymph vessels, and osteoblasts, special cells that form new bone tissue

Axial Skeleton

Main trunk of the body and composed of the skull, spinal column, ribs, and breastbone

Appendicular Skeleton

Forms the extremities and composed of the shoulder girdle, arm bones, pelvic girdle, and leg bones

Cranium

Spherical structure that surrounds and protects the brain

Fontanels

“soft spots,” all for the enlargement of the skull as brain growth occurs

Sutures

Areas where cranial bones have joined together

Clavicles

Collarbones

Scapulas

Shoulder Bones

Humerus

Upper arm

Radius

Lower arm

Ulna

Larger bone of lower arm, upper end forming the elbow

Carpals

Wrist

Metacarpals

Palm of the hand

Phalanges

3 each finger, 2 on the thumb

Sinuses

Air spaces in the bones of the skull that act as resonating chambers for the voice

Foramina

Openings in bones that allow nerves and blood vessels to enter or leave the bone

Vertebrae

the 26 bones that compose the spinal column

Sternum

Breastbone, last bone of the axial skeleton

Os Coxae

Makes up pelvic girdle, coral/hip bones, joins the sacrum on the dorsal part of the body

Ribs

12 pairs, “costae” attach thoracic vertebrae on the dorsal surface of the body

Femur

thigh

Patella

Knee cap

Tibia

Large weight-bearing bone of the lower leg commonly called the shinbone

Fibula

Slender/smaller bone of the lower leg that attaches to the proximal end of the tibia

Tarsals

Ankle

Metatarsals

In step of foot

Joints

Areas where 2 or more bones join together

Ligaments

Connective tissue bands, help hold long bones together at joints