4.3: Physiology of the Skeletal System

Question 1

yellow bone marrow

Answer 1

a fat storage tissue found mainly in long bones

Question 2

red bone marrow

Answer 2

• found primarily in short and flat bones
• primarily to produce red blood cells
• newborns have all red bone marrow; over time it is converted to yellow bone marrow in long bones

Question 3

diaphysis

Answer 3

• shaft
• center part of the bone

Question 4

compact bone

Answer 4

• solid outer layer of the bone
• usually found on the surface of the bone
• surrounds an interior of spongy bone

Question 5

proximal and distal epiphysis

Answer 5

On the ends of each long bone

Question 6

articular cartilage

Answer 6

• cushions joints
• enable them to move freely

Question 7

cartilage

Answer 7

• another type of connective tissue w/ a flexible matrix

Question 8

Spongy bone

Answer 8

• contains numerous bony bars and plates separated by irregular spaces
• lighter than compact bone
• designed for strength

Question 9

osteoclasts

Answer 9

Bone absorbing cells
- remove worn cells
- deposit calcium in the blood
- large cells that secrete enzymes that breakdown bone matrix
- break down bone

Question 10

osteoblasts

Answer 10

• repair the destruction caused by the work of osteoclasts
• take calcium from the blood as they form new bone
• synthesize bone matrix

Question 11

osteocytes

Answer 11

• bone cells
• maintain bone tissue structure

Question 12

ossification

Answer 12

• cartilaginous models are converted to bones
• calcium salts are deposited in the matrix
• first by precursor cartilaginous cells
• later by bone-forming cells: osteoblasts

Question 13

endochondral ossification

Answer 13

• ossification of long bones from hyaline cartilage

Question 14

growth plate

Answer 14

• cartilaginous portion of long bone where the longitudinal growth of the bone takes place
• rate of growth is controlled by hormones
• During puberty, the disks become completely ossified and the bone stops growing
• individual attains full adult height when this occurs

Question 15

intramembranous ossification

Answer 15

• the formation of flat bones from connective tissue

Question 16

closed (or simple) fractures

Answer 16

• occur when the bone breaks but remains within the skin

Question 17

open (or compound) fracture

Answer 17

occurs when the bone breaks, but part of the bone shaft breaks out of the skin

Question 18

greenstick fracture

Answer 18

• occurs when the bone bends and breaks, but not all the way across
• occurs commonly in children because the bone tissue is still developing and soft

Question 19

comminuted fracture

Answer 19

• happens when a bone is broken into more than two segments
• typically are repaired surgically

Question 20

impacted fracture

Answer 20

• occurs when one end of the broken bone shaft is pushed inside the other part of the bone

Question 21

rheumatoid arthritis

Answer 21

• autoimmune disease
• immune system attacks the cells that line synovial joints
• may cause inflammation, stiffness and pain

Question 22

osteoarthritis

Answer 22

• old-age arthritis
• articular cartilage at the ends of the bones disintegrates
• two bones of the joint become rough and irregular so that it becomes painful to move the joint
• affect the joints that have received the greatest use over the years

Question 23

Osteoporosis

Answer 23

• a bone tissue disease
• when bone tissue degenerates faster than is replaced, the bones become weak
• brittle bones cause increased pain and are more likely to fracture