The Skeletal System

Question 1

Periosteum

Answer 1

Connective tissue that covers bone and contains two important cells that continuously repair and upgrade bones

Question 2

Osteoblasts

Answer 2

Cells that lay down new bone material where damage or weakness occurs

Question 3

Osteoclasts

Answer 3

Cells that break down bone material for the purposes of proper shaping or mineral needs. These cells work together when a fracture occurs, whenever bone is weakened, or when minerals are needed.

Question 4

What are the five main functions of the skeletal system?

Answer 4

Structural Support – structural support for soft tissue, including muscles and internal organs.
Protection – protective cage for more delicate parts of the body (ie. Brain is protected by the skull; the rib cage protects the heart and lungs).
Growth Centre for Cells – red blood cells and platelets are made in bones (in the bone marrow).
Reservoir of Minerals – A reservoir that the body can call upon in order to regulate the level of calcium and phosphorus in the body.
Movement – Muscles attach to bones by tendons. Muscles contract and move bones to facilitate movement.

Question 5

Long bones

Answer 5

Found in the arms and legs (e.g., the femur, the humerus).

Contain both spongy and compact bone.

Question 6

Short Bones

Answer 6

Most common in the wrists (e.g., the carpal bone).

They consist mainly of spongy bone. These are often “load-bearing” bones.

Question 7

Flat Bones

Answer 7

Flat and thin and are found in the roof of the skull.

They also produce more blood cells than other bone types.

Question 8

Irregular Bones

Answer 8

Include odd-looking bones such as the sphenoid bone or vertebrae.

Question 9

Sesamoid Bones

Answer 9

Unusual, small, flat bones wrapped within tendons that move over bony surfaces (e.g., the patella or knee bone).

Question 10

Axial Skeleton

Answer 10

Comprised mainly of the vertebral column (the spine), much of the skull, and the rib cage. (80 bones)
Most of the body’s core muscles originate from the axial skeleton.
These core muscles help stabilize and support the axial skeleton, thus providing proper posture and alignment.

Question 11

Appendicular Skeleton

Answer 11

Includes the movable limbs and their supporting structures (girdles), which play a key role in allowing us to move.
Can be divided into six major regions: pectoral girdle (4 bones); arms and forearms (6 bones); hands (54 bones); pelvis (2 bones); thighs and legs (8 bones); and feet and ankles (52 bones).