Chapter 3: The Skeletal System

Question 1

What is the skeletal system?

Answer 1

Includes: bones, connective tissues, cartilage, ligaments and tendons.

Question 2

What are the functions of the skeletal system?

Answer 2

Support, leverage, protection, storage (calcium, phosphorus and other minerals) and blood cell production (bone marrow).

Question 3

What are the two major divisions of the skeleton?

Answer 3

Appendicular (126 bones – limbs, shoulder, pelvis) and the axial (80 bones – skull, vertebrae and thorax).

Question 4

What are the two main types of bone?

Answer 4

Compact bone and spongy bone (the spaces in spongy bone are filled with bone marrow).

Question 5

Where are compact bones normally found?

Answer 5

Regions of high stress such as long bones of arms and legs.

Question 6

Where are spongy bones usually found?

Answer 6

Most commonly found in regions of low stress such as the skull.

Question 7

What is yellow bone marrow?

Answer 7

A high concentration of fat cells and an energy reserve.

Question 8

What is red bone marrow?

Answer 8

A mixture of red and white blood cells.

Question 9

What are the three main cells that make up bone tissue?

Answer 9

1. Osteocytes: mature bone cells that make up active bone tissue
2. Osteoblasts: cells that continuously secrete a matrix that helps build and repair bones
3. Osteoclasts: bones that actively help to reshape the bone in response to stress.

Question 10

What is intramembraneous ossification?

Answer 10

The first stage of fetal bone development.

Question 11

What is endochondral ossification?

Answer 11

The second part of fetal bone development in which cartilage is present. Cartilage gets turned into bone.

Question 12

What are the 5 bone categories?

Answer 12

1. Long bone – humerus
2. Short bones – carpals
3. Flat bones – bones in skull
4. Irregular – vertebrae
5. Sesamoid – patella (knee cap)

Question 13

How does bone adapt to exercise?

Answer 13

Bone responds to exercise stress by getting stronger through increase production of the matrix in collagen fibers.

Question 14

What is bursitis?

Answer 14

The inflammation of the bursa (a small fluid filled sac lined by a membrane -acts as a cushion) that is caused by physical trauma or friction.

Question 15

What is tendinitis?

Answer 15

The inflammation of the tendon sheath in result of overuse and repetitive activities.

Question 16

What is a sprain?

Answer 16

Stretched to torn ligament or tendon.

Question 17

What is arthritis?

Answer 17

Inflammatory or degenerative disease that affects joints. Osteoarthritis affects the elderly or athletes that have used or abused their joints. Rheumatoid-arthritis is a chronic inflammatory condition that progresses over time.

Question 18

How are bones affected with age?

Answer 18

They get thinner and weaker due to the matrix becoming less dense and collagen becoming harder and less flexible. Starts between ages 30-40.

Question 19

What are the four spinal curves?

Answer 19

1. Cervical
2. Thoracic
3. Lumbar
4. Sacral

Question 20

What are three abnormal curves of the spine?

Answer 20

1. Scoliosis: lateral curvature most common in the thoracic region – genetic
2. Kyphosis: abnormal thoracic curvature, like a hunchback (upper back) – more evident in males, often result of osteoporosis
3. Lordosis: Excessive lumbar curve – result of excessive weight gain, bad posture or weak abdominal muscles