L4 Part 2

Question 1

Long bones develop according to ______ ossification. this means these bones started off as a ______ model
what type of cartilage was this model?

Answer 1

endochondral
cartilage
hyaline

Question 2

What 2 areas remain untouched at the end of endochondral ossification (in long bones)

Answer 2

articular cartilage(hyaline) at the joint (ball)
epiphysial plate

Question 3

In interstitial bone growth, Name the 4 functionally different zones that arrange into a pattern that allows fast and efficient growth

Answer 3

1. resting cartilage
2. proliferating cartilage
3. hypertrophic cartilage
4. calcified/ossified cartilage

Question 4

In interstitial bone growth, how are the 4 fictionally different zones arranged on either side of the long bone?

Answer 4

the calcified cartilage is always closest to the diaphysis/medullary cavity (they reverse order depending what side of the long bone they are on)

Question 5

In interstitial bone growth, in one of the 4 fictionally different zones; Resting cartilage zone: what does this zone do?

Answer 5

chondrocytes anchor epiphyseal plate to epiphysis of bone

Question 6

In interstitial bone growth, in one of the 4 fictionally different zones; Proliferating zone: what does this zone do?

Answer 6

chondrocytes divide, secreting ECM PUSHING epiphysis from diaphysis

Question 7

In interstitial bone growth, in one of the 4 fictionally different zones; Hypertrophic Zone: What does this zone do?

Answer 7

cartilage is pushed further away from the epiphysis and they hypertrophy and die

Question 8

In interstitial bone growth, in one of the 4 fictionally different zones; which zone has bone cells?

Answer 8

the calcified/ossification zone

Question 9

In interstitial bone growth, in one of the 4 zones is the calcification and ossification zone. in this zone,
bone forms in place of _____
_______ dissolve calcified cartilage and ________ secrete bone matrix. this becomes the _______

Answer 9

cartilage
osteoclasts, osteoblasts
diaphysis

Question 10

The epiphyseal plate remains the same width during interstitial growth, how?

Answer 10

because of the hypertrophic zones eating away the unnecessary tissue above and below the plate as it moves farther away from the medullary cavity elongating the bone.

Question 11

Appositional Growth is responsible for the growth of length or width? What types of cells are involved?

Answer 11

Width

only bone cells

Question 12

interstitial is growth from _____ occurring from the ______ ______ and is cartilage with the exception of the _____ ______.

Answer 12

within, growth plates

calcified ossification zone

Question 13

once the bone has been formed after interstitial growth and (this phase is complete by _____) However once the bone is developed where does cartilage remain? it remains at the ____ ____ and the ______

Answer 13

(birth)
articular cartilage
epiphyseal plate

Question 14

Appositional Growth has 4 steps what are they?

Answer 14

Osteoblasts secrete bone matrix
ridges fold around the blood vessel
concentric lamellae (fills in the tunnel) formed by matrix secreting osteoblasts
circumferential lamella is formed by osteoblasts deep into the periosteum

Question 15

the central canals in bone are formed around _____ _____ ____.

Answer 15

preexisting blood vessels

Question 16

what is a series of concentric lamellae called?

Answer 16

an osteon

Question 17

Bone remodeling: Resorption….. is accomplished by _____. Osteoclasts ‘ruffled- hair like’ borders function is _____ a seal on ____ and _____ surfaces. Then lysosomal enzymes _____ fibers acids and calc salts into soluble forms.

dissolved matrix transported via _______ across osteoclast.

substances _____ from the interstitual fluid into _____ _____

osteoclasts ______ while ________ enter

Answer 17

osteoclasts
creating a seal on endosteal and periosteal surfaces
digest

transcytosis

diffuse, blood capillaries

leave while osteoblasts enter

Question 18

where does bone reabsorption take place on the bone?

Answer 18

endosteal and periosteal surfaces

Question 19

what is transcytosis?

Answer 19

both endo and exocytosis across a cell

Question 20

bone deposit is accomplished by _______.

The bone deposit has 2 steps what are they?

where and why does this process occur

Answer 20

osteoblasts

osteoblasts move into repair the resorbed area
the new matrix is secreted by osteoblasts and matures for 1 week before it calcifies.

Occurs where injured bone is or where more strength is needed

Question 21

bone remodeling requires both ____ _____ and bone _____.

Answer 21

bone resorption and bone deposit

Question 22

Factors Affecting bone tissue _____ -and _______

Answer 22

mineral and vitamins

Question 23

important Hormones in infancy and childhood that affect bone tissue are ___ and ____ which control epiphyseal plate activity.

Thyroid hormones modulate the activity of ____ to ensure ____ _____ as it grows by stimulating osteoblasts.
insulin increases synthesis of _______ ______ (______)

Answer 23

GH and IGFs

GH, proper proportions

bone protiens (collagen)

Question 24

During puberty the hormones that take over are
they increase _____- activity and promote adolescent growth spurts.
cause masculinization and feminization of ___ ____ ___ ___ ___.

Answer 24

testosterones and estrogens
osteoblast
specific parts of the skeleton

Question 25

women get testosterone by the adrenal gland producing __________. this creates their testosterone. men get estrogen by conversion of testosterone into estrogen in _______ tissue

Answer 25

gonadocorticoids

adipose

Question 26

primarily _____ promotes osteoblast activity in puberty

Answer 26

estrogen

Question 27

Adulthood hormones like tesosterone and estrogen slow _____ and premote ______. While estrogens program the death of ______.

Parathyroid hormone, calcitonin and cacitriol regulate blood _____ levels via _____ of reabsobption and deposit

Answer 27

resorption, deposit
osteoclasts
calcium levels via stimulation

Question 28

what hormone breaks down bone in bone tissue (pushes calc in to blood) in adulthood? what takes in calcium into bone?

Answer 28

parathyroid hormone

calcitonin

Question 29

Factors affecting bone tissue: Calcium homeostasis

Parathyroid hormone increases PTH//
increases _____ ____ in kidneys.
Stimulates ______ witch increses _____ absorption in ______.

Calcitonin:
inhibits _______ and prmotes _______
it allso speeds up calcium ______ and ______

Answer 29

Calcium absorption
calcitriol, with incenses calcium absorption in intestines

osteoclasts and promotes osteoblasts

uptake and deposition

Question 30

Where are PTH and calcitonin Released respectively?

Answer 30

PTH is released by parathyroid glands, (cheif cells)

calcitonin is released from the thyroid glands from parafollicular cells

Question 31

Calcitonin comes in to play when blood calcium levels are about ____% above normal.

Answer 31

20 %

Question 32

osteoblasts generate n____ _____ and osteoclasts remove ____ ____.

Answer 32

osteoblasts generate new bone and osteoclasts remove old bone

Question 33

Fracture and Repair *
(1)Early inflamation: 
Fracture \_\_\_\_\_\_\_\_ (blood\_\_\_\_)
Bone cells cutt off from \_\_\_ \_\_\_\_\_ die
phagocytes and osteoclasts \_\_\_\_ \_\_\_\_ damage

Answer 33

Fracture hematoma blood clot
blood cells cut off from blood supply die
phagocytes and osteoclasts clean up damage

Question 34

Fracture and Repair *
(2)Reparative phase:
_____bridge gap between fractured ends
A. Fibrocartilfenious callous formation
Periosteal osteoblasts produce ______
Periosteal chondroblasts produce_____
B Boney Callus formation
Osteoblasts in areas ____ from fracture ends
produce ____ bone.
Spongy bone _____ living tissue and dead portions of ____ fragments

Answer 34

calluses 
fibers
fibrocartilage 
further, spongy
connects, bone

Question 35

Fracture and Repair *
(3)Remodeling Phase: 
Callus remodeling 
   Dead portions are \_\_\_\_\_.
   compact bone \_\_\_\_\_\_ \_\_\_\_\_\_ bone. 
   thickened portion on \_\_\_\_\_ \_\_\_\_\_\_.

Answer 35

reabsorbed
replaces spongy
bone surface