Skeletal System Test Review

Support

Provides structural support for the body and its organs.

Protection

Surrounds and protects vital organs, such as the brain and spinal cord.

Movement

Serves as attachment points for muscles, allowing for body movement.

Storage

Stores minerals, especially calcium and phosphorus, for metabolic use.

Blood Cell Formation

Hematopoiesis occurs in the bone marrow, producing blood cells.

Axial Skeleton

The central skeleton (including the skull, vertebral column, and rib cage).

Appendicular Skeleton

The extremities (arms and legs).

Compact Bone

Dense and hard outer layer of bone.

Spongy Bone

Porous and less dense inner layer of bone.

Long Bones

Long bones, mostly compact bone (femur, humerus).

Flat Bones

Thin, flattened, and usually curved (skull bones, ribs).

Short Bones

Roughly cube-shaped, mostly spongy bone (carpals, tarsals).

Irregular Bones

Have complex shapes that don't fit into other categories (vertebrae, hip bones).

Diaphysis

The shaft or long main portion of a bone.

Periosteum

A tough membrane covering the outer surface of bones.

Epiphysis

The end part of a long bone, initially growing separately from the shaft.

Articular Cartilage

Tissue covering the ends of bones at joints.

Epiphyseal Line

The line left when growth stops in adulthood.

Epiphyseal Plate

Growth plate in bones that allows them to grow longer, especially during childhood and adolescence.

Medullary Cavity

The central hollow part of a bone where marrow is stored. Red marrow makes blood cells, and yellow marrow stores fat.

Osteocyte

Mature bone cell.

Lacunae

Small cavities in bone that contain osteocytes.

Lamellae

Layers of bone matrix.

Central Canal

Canal in the center of osteons, containing blood vessels and nerves.

Osteon

Structural unit of compact bone.

Perforating Canals

Channels that extend from the periosteum to the central canal.

Osteoblasts

Builders of bone, they help in bone formation.

Osteoclasts

Break down bone, playing a role in bone remodeling/breakdown.

Parathyroid Hormone

Regulates blood calcium levels.

Hypercalcemia

Too much calcium in the blood.

Hypocalcemia

Too little calcium in the blood.

Comminuted Fracture

Bone is broken into multiple fragments.

Impacted Fracture

One fragment is driven into another.

Transverse Fracture

Break occurs at a right angle to the bone.

Oblique Fracture

Break occurs at an angle to the bone.

Spiral Fracture

Break occurs when excessive twisting forces are applied.

Greenstick Fracture

Incomplete break, common in children, where the bone is bent and only partially broken.

Plane Joint

Allows for sliding or gliding movements. Ex:Carpals.

Hinge Joint

Allows for movement in one plane, like a hinge. Ex:Elbow, knee.

Pivot Joint

Allows for rotation around an axis, between radius and ulna.

Saddle Joint

Allows for movement in two planes. Ex:Thumb.

Ball and Socket Joint

Allows for the most movement, with a spherical head fitting into a cup-like socket. Ex:Hip, shoulder.

osteoporosis

bone thinning disease affecting older people that results in bone weakness and fracture, women are particularly vulnerable to osteoporosis following menopause when estrogen levels drop

osteoarthritis

“wear and tear” condition where articular cartilage breaks down over time, common in older people“wear and tear” condition where articular cartilage breaks down over time, common in older people

rheumatoid arthritis

inflammatory disorder where the immune system attacks joint tissue, more common in women than men, impacts people of all age groups

gout

occurs when uric acid accumulates in blood and gets deposited as crystals in joints, more common in men than women