Ch. 7: Bone Functions, Structure,Development

Question 1

What are the main functions of the skeletal system?

Answer 1

Support, protection of internal organs, movement, calcium storage, and hemopoiesis (blood cell formation).

Question 2

How does the skeletal system help the body move?

Answer 2

By working with muscles that pull on bones at moveable joints.

Question 3

What mineral does the skeletal system store?

Answer 3

Calcium.

Question 4

Which hormone increases calcium storage in bones?

Answer 4

Calcitonin (CT).

Question 5

Which hormone reduces calcium storage in bones?

Answer 5

Parathyroid hormone (PTH).

Question 6

Where does hemopoiesis (blood cell formation) occur?

Answer 6

In red bone marrow.

Question 7

What are the four major types of bones by shape?

Answer 7

Long bones, short bones, flat bones, and irregular bones.

Question 8

Give an example of a long bone.

Answer 8

Humerus (arm).

Question 9

Give an example of a short bone.

Answer 9

Carpals (wrist).

Question 10

Give an example of a flat bone.

Answer 10

Frontal bone (skull).

Question 11

Give an example of an irregular bone.

Answer 11

Vertebrae (spinal column).

Question 12

What is a sesamoid (round) bone, and give an example.

Answer 12

A bone embedded in a tendon; example: patella (kneecap).

Question 13

What is the diaphysis of a long bone?

Answer 13

The shaft or hollow tube of compact bone.

Question 14

What is the medullary cavity?

Answer 14

Hollow area inside the diaphysis containing yellow bone marrow.

Question 15

What are the epiphyses of a long bone?

Answer 15

The ends of the bone made of spongy bone with red bone marrow.

Question 16

What is the function of articular cartilage?

Answer 16

Cushions joints by covering the epiphyses.

Question 17

What is the periosteum?

Answer 17

A strong membrane covering the bone except at joint surfaces.

Question 18

What is the endosteum?

Answer 18

A membrane lining the medullary cavity.

Question 19

How are flat bones structured?

Answer 19

Spongy bone layer (diploë) sandwiched between two compact bone layers.

Question 20

What is diploë?

Answer 20

The spongy bone layer inside flat bones.

Question 21

What is cancellous (spongy) bone made of?

Answer 21

Needlelike threads of bone called trabeculae.

Question 22

Where is spongy bone found in long bones?

Answer 22

In the epiphyses (ends).

Question 23

What fills the spaces in spongy bone?

Answer 23

Red bone marrow.

Question 24

What are osteons?

Answer 24

Structural units of compact bone with concentric lamellae.

Question 25

What are lamellae?

Answer 25

Concentric rings of calcified matrix in compact bone.

Question 26

Where are osteocytes found?

Answer 26

In small spaces called lacunae.

Question 27

What connects osteocytes in compact bone?

Answer 27

Tiny canals called canaliculi.

Question 28

What are chondrocytes?

Answer 28

Cartilage cells embedded in a gel-like matrix.

Question 29

Why does cartilage heal poorly?

Answer 29

It lacks blood vessels.

Question 30

What are osteoblasts?

Answer 30

Cells that form new bone by producing bone matrix.

Question 31

What are osteoclasts?

Answer 31

Cells that break down bone for remodeling and calcium regulation.

Question 32

What are osteocytes?

Answer 32

Mature bone cells that maintain bone tissue.

Question 33

What is endochondral ossification?

Answer 33

Process of replacing cartilage with bone during development.

Question 34

What minerals are deposited during ossification?

Answer 34

Calcium and phosphate.