Chapter 5: Skeletal System

Question 1

Name three reasons we study human bones.

Answer 1

To learn the age at death, ancestry, sex, height, health conditions, habits, DNA

Question 2

Where is a good place to extract DNA from bones?

Answer 2

Teeth

Question 3

Which bone(s) is best for estimating height?

Answer 3

Femur, tibia, humerus (long bone length correlates with height).

Question 4

Which bones are best for determining sex?

Answer 4

Pelvis (best) and skull.

Question 5

What information do the eye orbits give?

Answer 5

Information about ancestry.

Question 6

Which bone is best for determining both ancestry and sex?

Answer 6

Skull

Question 7

What are the five functions of the skeletal system?

Answer 7

Support, protection, movement, blood cell production, mineral storage.

Question 8

Where are blood cells and platelets produced in bone?

Answer 8

Red bone marrow.

Question 9

What is a stem cell?

Answer 9

An immature undifferentiated cell that can divide and become specialized cells.

Question 10

Why are stem cells important?

Answer 10

They allow for growth, repair, and replacement of tissues especially or degenerative diseases

Question 11

Where is compact bone found?

Answer 11

The outer layer of bones, especially the shaft.

Question 12

Where is spongy bone found?

Answer 12

Inside bones, especially in the heads

Question 13

What is the growth plate?

Answer 13

where bones grow in length during childhood.

Question 14

What happens to the growth plate as we age?

Answer 14

It ossifies and closes (by ~18–21 years old).

Question 15

What is ossification

Answer 15

When at about 2-3 months old cartilage turns into bone and starts in the shaft o the bone and then in the heads

Question 16

What is (articular) cartilage?

Answer 16

Cartilage covering bone ends/heads to reduce friction at joints.

Question 17

What is yellow marrow used for and where is it found?

Answer 17

Fat storage, and its found in the shaft

Question 18

What does red marrow produce and where is it found?

Answer 18

Red blood cells, white blood cells, platelets. Its found in the heads of the bone between the pores in the spongey bone

Question 19

What do osteoblasts do?

Answer 19

Bone building cells.

Question 20

What do osteoclasts do?

Answer 20

Cells that break down bone

Question 21

What do osteocytes do?

Answer 21

Mature cells at get entombed in the caves as bone is laid down (Maintain bone tissue)

Question 22

What do chondrocytes do?

Answer 22

Cartilage cells that help make new cartilage in the embryonic skeleton and growth plates, in parts of the skeleton, this will be turned into bone

Question 23

When does ossification begin?

Answer 23

begins before birth

Question 24

What is bone remodeling?

Answer 24

Lifelong process where old bone is reshaped based on STRESSORS on the Skelton by osteoclasts (bone removed) and osteoblasts (bone added). It responds to changes during one’s lifetime

Question 25

How often does the skeleton replace itself?

Answer 25

About every 10 years.

Question 26

Name the four stages of bone repair.

Answer 26

Hematoma (blood clot forms) → cartilaginous callus forms → bony callus forms→ remodeling occurs.

Question 27

What is a sprain?

Answer 27

Injury to a ligament.

Question 28

What is arthritis?

Answer 28

Inflammation and degeneration of joints.

Question 29

What is osteoporosis and how can risk be reduced?

Answer 29

Bone density loss; reduce risk with calcium, vitamin D, exercise, not smoking. Where osteoclasts are more than osteoblasts (more common in women and/or those aging)

Question 30

What does tiny and large pores in bones mean

Answer 30

Tiny means healthy, big pores mean osteoporosis and less bone density