Bone

Question 1

3 functions of bone

Answer 1

mechanical
synthetic
metabolic

Question 2

what are the 3 parts/characteristics that all contentive tissue has

Answer 2

1. specialized cells
2. extracellular protein fibers
3. fluid ground substance

Question 3

what is the bone forming cell

Answer 3

osteoblast

Question 4

what do osteoblasts do

Answer 4

secrete osteoid matrix (collagen for bone)

Question 5

what is the bone-reabsorbing cell

Answer 5

osteoclasts

Question 6

what is the function of osteoclasts

Answer 6

bone remodeling

Question 7

what does the interaction between osteoclasts and blasts determine

Answer 7

bone health

Question 8

what is an osteocyte

Answer 8

an osteoblast trapped by secretion of osteoid

Question 9

what is the purpose of an osteocyte

Answer 9

maintenance of bone integrity and Ca+ homeostasis
- mechanoreceptors (signal transduction)

Question 10

what type of collage fibers is found prodomenetly in osteoids

Answer 10

type I (90%)

Question 11

what are bone salts

Answer 11

solid ground substance made from calcium, magnesium, sodium and chlorine

Question 12

what percent of bone volume is made up by bone salts

Answer 12

50%

Question 13

what do bone salts do

Answer 13

give bone its rigidity and stiffness as it is 75% of bone weight

Question 14

bone health requires…

Answer 14

integrity of collagen and mineralization

Question 15

what is rickets disease

Answer 15

impaired VItD, phosphorous or calcium metabolism (very frequent)

Question 16

what are the clinical signs of rickets

Answer 16

• large forehead
  -stunted growth
• wide bones
• large abdomen
  -wide joints

Question 17

what is osteomalacia

Answer 17

childhood rickets
hypercalcemia

Question 18

what is renal disease

Answer 18

def Vit D or lack of dietary calcium

Question 19

what is a disease of connective tissue in the bone

Answer 19

osteogenesis imperfecta (brittle bone disease) its a genetic disease

Question 20

what occurs in brittle bone disease

Answer 20

insufficient connective tissue (type 1 collagen)

Question 21

signs of brittle bone disease

Answer 21

white part of eyes look blue, poor teeth, prone to fracture, barrel chest and round back, deafness

Question 22

what are the two types of bone

Answer 22

cortical and cancellous (trabecular)

Question 23

at the ___________ there is ___ difference between the two types of bone

Answer 23

cellular level, no

Question 24

what is the difference between the two types of bone and why

Answer 24

density and it is due to the porosity
compact = 5-30%
trabecular = 30-90%

Question 25

where is the osteon observed

Answer 25

in the compact bone

Question 26

where is the osteon found in the bone

Answer 26

along the long axis shaft or diaphyses of long bones

Question 27

what does the osteon consist of

Answer 27

bone matrix laid down in concentric layers called lamellae

Question 28

what does the lamellae surround

Answer 28

a central haversian canal (Hc)

Question 29

purpose of Hc

Answer 29

contains the blood vessels, nerves and lymphatics

Question 30

where are the osteocytes in relation to the Hc

Answer 30

arranged in a concentric ring around the central Hc

Question 31

how are the osteocytes connected to the Hc

Answer 31

via canaliculi and acts as a mechanotransducer

Question 32

what is the shaft of a bone called

Answer 32

the diaphysis

Question 33

what is the rounded end of a long bone

Answer 33

the epiphysis

Question 34

what is the episphysis filled with

Answer 34

red bone marrow which produces red blood cells

Question 35

what is the region between the diaphysis and epiphysis

Answer 35

metaphysis

Question 36

what is the role of the metaphysis

Answer 36

part of the bone that is growing during childhood

Question 37

what is the growth plate

Answer 37

the epiphyseal line located in the metaphysis

Question 38

what would happen if there was a fracture through the growth plate

Answer 38

normal growth resumes

Question 39

what would happen if there was a fracture through the growth plate and the metaphysis

Answer 39

normal growth would resume

Question 40

what would happen if there was a fracture through the growth plate and epiphysis

Answer 40

possible growth disturbances

Question 41

what would happen if there was a fracture through the growth plate and epiphysis and metaphysis

Answer 41

possible growth arrest

Question 42

compression fracture of the growth plate

Answer 42

bad, high chance of growth arrest

Question 43

growth homoneq

Answer 43

stimulates the liver to produce IGF-1 = promotes chondroycte proliferation in GP High impact of bone growth

Question 44

IGF-1

Answer 44

directly promotes chondrocyte proliferation in GP, crucial for bone elongation

Question 45

estrogen and testosterone

Answer 45

estrogen is crucial for growth spurt and eventual closure of growth plate, while testosterone promotes gbone growth and maturation

Question 46

PTh

Answer 46

influeces bone remodeling and mineralization (indirect affect)

Question 47

T3/4

Answer 47

regulates maturation, essential for normal development and bone growth

Question 48

two types of ossification

Answer 48

intramembranous ossification and endochondral ossification

Question 49

what is intramembranous ossification

Answer 49

direct ossification of embryonic connective tissue (bones of skull)

Question 50

what is endochondral ossification

Answer 50

ossification of hyaline cartilage - cartilage mineralization around hypertrophic chondrytes - blood vessels then penetrate, causing the mineralized carilage to be resorbed causing growth

Question 51

what is the secondary ossification centre

Answer 51

epiphysis - we see the formation of articular cartilage and epiphysal plate

Question 52

do males or females have greater bone development/maturation after age 12

Answer 52

males

Question 53

90% of bone mass is accounted for at age __

Answer 53

19

Question 54

as we are hitting the growth spurt ages there is a ___ in stiffness due to ___ in length while area remains

Answer 54

decrease, increase

Question 55

bone mineralization _____ peak height velocity growth

Answer 55

lags behind - this increases injury risk

Question 56

this rapid change causes

Answer 56

motor control and coordination decreases as there is a change in COM of the limbs increasing the risk of injury temporarily increases in nutrition overuse injuries as there is an increase in stress of growing bones and joints

Question 57

what do viscoelastic tissues exhibit

Answer 57

stress relaxation creep strain rate dependecy hysterisis anisotropy

Question 58

what contributes to the porosity of a bone

Answer 58

Hc lacunae and canaliculi pathologies (tumor, infection, etc)

Question 59

in cancellous bone trabeculae form along

Answer 59

the aces of loads (remodelling)