Chapter 6: Bone Tissue Flashcards Preview

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Flashcards in Chapter 6: Bone Tissue Deck (51)
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1
Q

Bone

A

an organ made up of several different tissues

2
Q

Functions of Bone

A
  • provide support
  • protect the internal organs
  • assist body movement
  • mineral homeostasis (stores & releases calcium + phosphorus)
  • participates in blood cell production (hemopoiesis)
  • stores triglycerides in adipose cells of yellow marrow
3
Q

Long Bone

A

consists of diaphysis, 2 epiphyses, 2 metaphyses, articular cartilage, periosteum, medullary cavity, endosteum

4
Q

diaphysis

A

bone shaft

5
Q

epiphyses

A

both ends of the bone at the joints

6
Q

periosteum

A

connective tissue surrounding the diaphysis

7
Q

medullary cavity

A

hollow space within diaphysis

8
Q

endosteum

A

thin membrane lining medullary cavity

9
Q

what are the 4 types of cells found in bones?

A

osteoprogenitor cells, osteoblasts, osteocytes, osteoclasts

10
Q

osteoprogenitor

A

bone stem cells able to differentiate into other types of cells

11
Q

osteoblasts

A

bone building cells that secrete matrix

12
Q

osteocytes

A

mature bone cells

13
Q

osteoclasts

A

remodel bones and cause bones to release calcium

14
Q

histology of bone

A

osetoprogenitor cells develop into an osteoblast –> osteoblast form bone extracellular matrix –> osteocytes maintain bone tissue –>osteoclasts functions in resorption, the breakdown of bone extracellular matrix

15
Q

compact bone

A

good at providing protection and support

16
Q

spongy bone

A

lightweight, and provides tissue support

17
Q

periosteal arteries

A

accompanied by nerves; enter the diaphysis through the Volkmann’s canals. They are accompanied by periosteal veins

18
Q

nutrient artery

A

enters the center of the diaphysis through a nutrient foramen

19
Q

nutrient veins

A

exit through nutrient foramen

20
Q

what do the metaphases and epiphyses have in common?

A

they have their own arteries and veins

21
Q

ossification (osteogenesis)

A

process of bone formation

22
Q

what 4 situations do bones form in?

A

during embryological and fetal development, when bones grow before adulthood, when bones remodel, and when fractures heal

23
Q

intramembranous ossification

A

occurs in flat bones when a connective tissue membrane is replaced by the bone

24
Q

endochondral ossification

A

replaces cartilage with bones in the developing embryo and fetus; occurs in the epiphyseal plates of long bones as they grow in length

25
Q

how do bones thicken?

A

cooperative action of osteoblasts and osteoclasts

as osteoblasts deposit bone on the outer surface, osteoclasts widen the medullary cavity from within

26
Q

fracture

A

break in the bone; healing process involves 3 different phases

27
Q

reactive phase

A

early inflammation phase

28
Q

reparative phase

A

formation of a fibrocartilaginous callus first, and then a bony callus

29
Q

bone remodeling phase

A

last step as bony callus is remodeled

30
Q

open (compound) fracture

A

broken ends of the bone protrude through the skin.

31
Q

closed (simple) fracture

A

bone does not break the skin

32
Q

comminuted fracture

A

bone is splintered, crushed, or broken into pieces at site of the impact, and smaller bone fragments lie between the two main fragments

33
Q

greenstick fracture

A

partial fracture in which one side of the bone is broken and the other side bends, similar to the way a green twig breaks on one side while the other stays whole but bends; typically occur in children whose bones are not fully ossified

34
Q

impacted fracture

A

one end of the fractured bone is forcefully driven into the interior of the other

35
Q

pott fracture

A

fracture of the distal end of the lateral leg bone (fibula), with serious injury of the distal tibial articulation

36
Q

colles fracture

A

fracture of the distal end of the lateral forearm bone (radius), in which the distal fragment is displaced posterioly

37
Q

bone’s role in calcium homeostasis

A
  • bone stores 99% of the body’s calcium
  • the parathyroid gland secrets the parathyroid hormone (PTH) when calcium levels drop too much & PTH stimulates the production of calcitriol in the kidneys to increase calcium absorption in the intestines
38
Q

aging

A
  • more bone is produced than lost during remodeling

- post menopausal women experience a decrease in bone mass when resorption outpaces deposition

39
Q

calcium + phosphorus

A

make bone extracellular matrix hard

40
Q

magnesium

A

helps bone form extracellular matrix

41
Q

fluroide

A

helps strengthen extracellular matrix

42
Q

manganese

A

activates enzymes involved in synthesis of bone extracellular matrix

43
Q

vitamin a

A
  • needed for activity of osteoblasts during remodeling of bone
  • deficiency stunts bone growth
  • toxic in high doses
44
Q

vitamin c

A
  • needed for synthesis of collagen

- deficiency causes low collagen production which slows bone growth and delays repair of broken bones

45
Q

vitamin d

A
  • active from calcitriol / produced by kidneys; helps build bone by increasing absorption of calcium from GI tract to blood
  • deficiency causes faulty calcification and slows down bone growth
  • may reduce risk of osteoporosis but is toxic in high doses
46
Q

vitamin k and b12

A
  • needed for synthesis of bone proteins

- deficiency leads to abnormal protein production in bone extracellular matrix and decreased bone density

47
Q

growth hormone

A

secreted by anterior lobe of piutary gland; promotes general growth of all body tissues including bone, mainly by stimulating process of insulin like growth factors

48
Q

insulin like growth factors

A

secreted by the liver, bones and other tissues on stimulation by growth hormones; promotes normal bone growth by stimulating osteoblasts and by increasing the synthesis of proteins needed to build new bone

49
Q

thyroid hormone (T3 and T4)

A

secreted by thyroid gland; promotes normal bone growth by stimulating osetoblasts

50
Q

sex hormones - estrogens and testosterone

A

secreted by ovaries in women and by testes in men; stimulate osteoblasts and sudden growth spurt that occurs in teenage years; shuts down the growth at epiphyseal plate around age 18-21 causing lengthwise growth of bones to stop

51
Q

disorders include

A

osteoporosis, rickets, osteomalacia