Bone/Cartilage

Question 1

is cartilage avascular or vascular

Answer 1

avascular

Question 2

what percent is cartilage composed of water?

Answer 2

80%

Question 3

are there nerves in cartilage

Answer 3

no nerves

Question 4

three types of cartilage and roles/locations

Answer 4

hyaline:
—role: support, flexibility, resilience (weakest, most widespread)
—loc: articular surfaces, costals, respiratory (trachea/larynx), nasal

Fibro:
—role: compressible, high pressure, stretch (strongest)
—loc: intervertebral disks
—no perichondrium
—both type 1 and 2 collagen

elastic:
—role: elasticity and maintain shape
—loc: external ear, nasal tip, eustachian tube, epiglottis
—type 2 collagen and elastin

Question 5

cartilage cells

Answer 5

chondroblasts: immature/undiff cells
chondrocytes: mature cells (lacunae enclosure)

Question 6

ground substance of cartilage

Answer 6

proteoglycans (chondroitin sulfates/hyaluronic acid/electrostatic repulsion)

Question 7

what are the components of cartilage

Answer 7

cells, ground substance, collagen

Question 8

perichondrium

Answer 8

dense irregular ct that envelopes elastic and hyaline cartilage (not fibrocart)

Question 9

general bone functions

Answer 9

support/shape
protection
assist homeostasis
blood cell production

Question 10

is bone vascular or avascular

Answer 10

vascular

Question 11

compact vs spongey bone

Answer 11

cortical/compact:
— outer layer of bone
—dense
—osteons
—80% of bone
cancellous/spongey:
—inner layer
—trabeculae

Question 12

bone remodeling cells

Answer 12

osteoclast: resorb bone
osteoblast:build bone

Question 13

hydroxyapatite comp

Answer 13

39% calcium
18% phosphorous

Question 14

where is 99% of calcium sored in the body?

Answer 14

bone

Question 15

calcium homeostasis hormones

Answer 15

parathyroid hormone (PTH)
calcitonin
“activated” Vit D

Question 16

PTH does what when calcium blood levels are too low

Answer 16

stimulates Ca release from bone
increase Ca absorption from gut
promotes Vit D act

Question 17

calcitonin does what when calcium blood levels get too high

Answer 17

reabsorption of calcium from bone

Question 18

osteomalacia/rickets

Answer 18

defective bone matric calcification due to Vit D deficiency (and/or Ca deficiency)

Question 19

osteopetrosis

Answer 19

impaired osteoclasts (fragile bone)

Question 20

osteoporosis

Answer 20

excess osteoclast function

Tx: biphosphonates, teriparatide (bone-building drug)

Question 21

Biphosphonate-associated osteonecrosis of the jaw

Answer 21

biphosphonate therapy for osteoporosis: disfiguring jaw conditions involving serious infection and abnormal build-up of bone