Bone tissues 6b

Question 1

Growth zone

Answer 1

cartilage cells undergo mitosis, pushing the epiphysis away from the diaphysis

Question 2

Transformation zone

Answer 2

older cells enlarge, the matrix becomes calcified, cartilage cells die and the matrix begins to deteriorate

Question 3

Osteogenic zone

Answer 3

new bone formation occurs

Question 4

Growth in length

Answer 4

cartilage continually grows and is replaced by bone

Question 5

Remodeling

Answer 5

bone is resorbed and added by appositional growth

Question 6

Alkaline phosphatase

Answer 6

is essential for mineralization of bone secreted by osteoblasts

Question 7

Osteoid seam

Answer 7

unmineralized band of bone matrix

Question 8

Bone Deposition

Answer 8

Occurs where bone is injured or added strength is needed

Requires a diet rich in protein, vitamins C, D, and A, calcium, phosphorus, magnesium, and manganese

Question 9

Bone Resorption

Answer 9

Accomplished by osteoclasts

Question 10

Resorption involves osteoclast secretion of

Answer 10

Lysosomal enzymes that digest organic matrix

Acids that convert calcium salts into soluble forms

Question 11

Calcium is necessary for

Answer 11

Transmission of nerve impulses
Muscle contraction
Blood coagulation
Secretion by glands and nerve cells
Cell division

Question 12

Rising blood Ca2+ levels trigger the thyroid to

Answer 12

release calcitonin

Question 13

Calcitonin

Answer 13

stimulates calcium salt deposit in bone

Question 14

Falling blood Ca2+ levels signal the parathyroid

glands to

Answer 14

release PTH

Question 15

PTH signals osteoclasts to

Answer 15

degrade bone matrix and release Ca2+ into the blood

Question 16

Bone fractures are classified by

Answer 16

The position of the bone ends after fracture
The completeness of the break
The orientation of the bone to the long axis
Whether or not the bones ends penetrate the skin

Question 17

Nondisplaced

Answer 17

bone ends retain their normal position

Question 18

Displaced

Answer 18

bone ends are out of normal alignment

Question 19

Complete

Answer 19

bone is broken all the way through

Question 20

Incomplete

Answer 20

bone is not broken all the way through

Question 21

Linear

Answer 21

the fracture is parallel to the long axis of the bone

Question 22

Transverse

Answer 22

the fracture is perpendicular to the long axis of the bone

Question 23

Compound (open)

Answer 23

bone ends penetrate the skin

Question 24

Simple (closed)

Answer 24

bone ends do not penetrate the skin

Question 25

Common Types of Fractures - Comminuted

Answer 25

bone fragments into three or more pieces; common in the elderly

Question 26

Common Types of Fractures - Spiral

Answer 26

ragged break when bone is excessively twisted; common sports injury

Question 27

Common Types of Fractures - Depressed

Answer 27

broken bone portion pressed inward; typical skull fracture

Question 28

Common Types of Fractures - Compression

Answer 28

bone is crushed; common in porous bones

Question 29

Common Types of Fractures - Epiphyseal

Answer 29

epiphysis separates from diaphysis along epiphyseal line; occurs where cartilage cells are dying

Question 30

Common Types of Fractures - Greenstick

Answer 30

incomplete fracture where one side of the bone breaks and the other side bends; common in children

Question 31

Osteomalacia

Answer 31

Bones are inadequately mineralized causing softened, weakened bones Main symptom is pain when weight is put on the affected bone Caused by insufficient calcium in the diet, or by vitamin D deficiency

Question 32

Rickets

Answer 32

Bones of children are inadequately mineralized causing softened, weakened bones Bowed legs and deformities of the pelvis, skull, and rib cage are common Caused by insufficient calcium in the diet, or by vitamin D deficiency

Question 33

Osteoporosis

Answer 33

bone reabsorption outpaces bone deposit Occurs most often in postmenopausal women Bones become so fragile that sneezing or stepping off a curb can cause fractures

Question 34

Osteoporosis: Treatment

Answer 34

Calcium and vitamin D supplements Increased weight-bearing exercise Hormone (estrogen) replacement therapy (HRT) slows bone loss Natural progesterone cream prompts new bone growth Statins increase bone mineral density

Question 35

Paget’s Disease

Answer 35

Characterized by excessive bone formation and breakdown Pagetic bone with an excessively high ratio of woven to compact bone is formed Pagetic bone, along with reduced mineralization, causes spotty weakening of bone Osteoclast activity wanes, but osteoblast activity continues to work Usually localized in the spine, pelvis, femur, and skull Unknown cause (possibly viral)

Question 36

Paget’s Disease treatment

Answer 36

Treatment includes the drugs Didronate and | Fosamax

Question 37

OSTEOGENESIS IMPERFECTA

Answer 37

A defect in collagen synthesis | Genetic (from parents), or could be a spontaneous genetic mutation