5b - Skeletal Components

Question 1

What three things comprise the cartilage matrix?

Answer 1

proteoglycans
collagen
elastin

Question 2

What is different in the matrix of hyaline and elastic cartilage?

Answer 2

proportions of the components of the matrix

Question 3

the diaphysis is the bone ___.

Answer 3

bone shaft

Question 4

What is the epiphysis on a bone?

Answer 4

the regions at the two ends of the shaft (diaphysis) “caps”

Question 5

diaphysis contains ___ bone

Answer 5

compact

Question 6

epiphysis contains ___ bone

Answer 6

spongy bone

Question 7

blood cell generations happen in ___ marrow

Answer 7

red marrow

Question 8

yellow marrow contains ___

Answer 8

adipocytes

Question 9

the dense irregular CT layer on the outer bone surface is called ____

Answer 9

periosteum

Question 10

mechanical stress and fractures stimulate bone ___

Answer 10

remodeling

Question 11

remodeling = ____ + _____

Answer 11

remodeling = resorption and ossification

Question 12

resorption is by ___

Answer 12

osteoclasts

Question 13

the deposition is by ___

Answer 13

osteoblasts

Question 14

the bone matrix mineral components is mostly ___

Answer 14

hydroxyapatite

Question 15

what is hydroxyapatite made of

Answer 15

calcium/phosphate polymer

Question 16

what happens to a bone when the organic matrix is removed?

Answer 16

will shatter easily; becomes brittle.

Question 17

What happens when the inorganic matrix is removed from the bone?

Answer 17

bones bend easily without their inorganic matrix (minerals). Cannot resist compression.

Question 18

what are the features of spongy bones?

Answer 18

has spicules and blood vessels move through spaces

Question 19

what are the features of compact bone?

Answer 19

dense bone with canal systems for blood vessels. Run parallel to the shaft.

Question 20

what are osteoblasts and what do they do?

Answer 20

• immature cells. Some can become osteocytes (most don’t).
• They lay down a new matrix
• signal to and control osteoclasts formation and activity

Question 21

what are osteocytes and what do they do

Answer 21

• mature cells found in lacunas
• detects bone deformation
• signals to osteoblasts to begin bone replacement or repair

Question 22

What is unique about mesenchymal stem cells?

Answer 22

can become chrondrocytes or osteoblasts.

Question 23

osteocytes send cell extensions through ___

Answer 23

canaliculi

Question 24

canaliculi provide channels in a matrix for ___ exchange and allow osteocytes to connect in a large web via ___ ___

Answer 24

fluid exchange via gap junctions

Question 25

osteoblasts bury one of their own to become an ___

Answer 25

osteocyte

Question 26

osteoblasts have multiple ___

Answer 26

nuclei

Question 27

what is necessary for the absorption of vitamin C?

Answer 27

Vitamin D

Question 28

What is necessary for collagen synthesis by osteoblasts?

Answer 28

Vitamin C

Question 29

PTH parathyroid hormone ____ blood Ca++

Answer 29

raises

Question 30

Calcitonin ___ blood Ca++

Answer 30

lowers

Question 31

PTH originates from the ____ glands and Calcitonin originates from ____ glands

Answer 31

PTH from parathyroid glands

Calcitonin from thyroid glands