Exam 2 - Bone and Cartilage Flashcards Preview

Histology - Exam 2 > Exam 2 - Bone and Cartilage > Flashcards

Flashcards in Exam 2 - Bone and Cartilage Deck (70)
Loading flashcards...
1
Q

how does cartilage get nutrients

A

nutrients/waste pass to/from cell through matrix - avascular

2
Q

what does cartilage contain

A

chondrocytes embedded in ECM

3
Q

functions of cartilage

A

supports soft tissues, guides development/growth of long bones

4
Q

where is hyaline cartilage located

A

at articular ends of long bones in adults, walls of respiratory system (nose, larynx, trachea, bronchi), ventral ends of ribs; also temporary skeleton for fetus until replaced by bone

5
Q

type of collagen in hyaline cartilage

A

type 2

6
Q

hyaline cartilage matrix

A

homogenous, amorphous ground substance w/ proteoglycan aggregates (w/ chondroitin, keratan sulfate, hyaluronic acid) and chondronectin embedded type 2 collagen + territorial/capsular matrix

7
Q

where is territorial matrix found

A

adjacent to chondrocytes

8
Q

composition of territorial matrix

A

low collagen, high GAGs

9
Q

staining of territorial matrix

A

very basophilic and metachromatic; more intense with PAS stain than intercapsular matrix - due to sulfate groups on proteoglycans

10
Q

perichondrium composition

A

dense irregular CT

11
Q

perichondrium location

A

surrounds hyaline cartilage except at articular surfaces

12
Q

perichondrium layers

A

outer fibrous layer and inner cellular layer

13
Q

perichondrium function

A

provides blood supply for avascular cartilage

14
Q

outer fibrous layer of perichondrium

A

type 1 collagen, fibroblasts, blood vessels

15
Q

inner cellular layer of perichondrium

A

chondrogenic cells

16
Q

what are chondrocytes

A

mature cartilage cells (chondroblasts that have been completely surrounded by matrix)

17
Q

chondrocyte location

A

embedded in lacunae in matrix

18
Q

chondrocyte function

A

maintain cartilage matrix

19
Q

chondroblast function

A

produce cartilage matrix

20
Q

isogenous groups

A

groups of 2-8 chondrocytes in the same lacunae

21
Q

elastic cartilage composition

A

matrix w/ network of elastic fibers (yellowish color)

22
Q

elastic cartilage location

A

where flexible support needed - external ear, Eustachian tube, epiglottis, larynx

23
Q

elastic vs. hyaline cartilage degeneration

A

elastic less prone to degeneration

24
Q

type of collagen in elastic cartilage

A

type 2

25
Q

elastic cartilage perichondrium

A

similar to that of hyaline cartilage

26
Q

fibrocartilage perichondrium

A

doesn’t exist

27
Q

composition of fibrocartilage

A

alternating rows of fibroblast-derived chondrocytes and thick bundles of type 1 collagen fibers - properties b/w dense CT and hyaline cartilage

28
Q

location of fibrocartilage

A

may align along lines of stress - found where support and tensile strength needed in conjunction w/ hyaline cartilage: IV discs, articular discs, pubic symphysis, tendon and ligament insertions, knee joint menisci

29
Q

what is fibrocartilage easily confused with

A

dense regular CT

30
Q

in general, what is bone

A

calcified ECM with osteocytes embedded in matrix

31
Q

three main functions of bone

A

protects vital organs, supports fleshy structures, provides calcium reserve

32
Q

how is bone dynamic

A

constant shape change, absorption, resorption in response to biomechanical forces

33
Q

inorganic calcified portion of bone matrix

A
  • contains calcium, phosphate, bicarbonate, citrate, magnesium, potassium, sodium
  • primarily hydroxyapatite crystals
  • minerals are 50% of dry weight
34
Q

organic portion of bone matrix

A

mainly type 1 collagen with ground substance containing chondroitin sulfate, keratan sulfate

35
Q

primary bone

A

immature, woven bone that is the first bone formed in fetal development and in bone repair

36
Q

primary bone mineral content

A

lower than secondary bone

37
Q

secondary bone

A

mature, lamellar bone - two types: compact, spongy

38
Q

compact bone

A

dense, outer portion of bone with outer and inner circumferential lamellae and osteons around haversian canals

39
Q

volkmann’s canals

A

connect osteons to each other

40
Q

what is outer circumferential lamellae adjacent to

A

below periosteum

41
Q

what is inner circumferential lamellae adjacent to

A

marrow cavity

42
Q

spongy bone

A

meshwork of trabeculae in bone interior that helps distribute weight

43
Q

spongy bone changes in osteoporosis?

A

becomes narrower

44
Q

bone periosteum

A

layer of non-calcified CT covering bone on external surfaces, except synovial articulations, w/ outer fibrous, dense collagenous layer and inner cellular (osteogenic) layer

45
Q

bone periosteum function

A

distribute blood vessels to bone

46
Q

sharpey’s fibers

A

type 1 collagen - attach periosteum to bone

47
Q

haversian canals

A

hold blood vessels in the bone

48
Q

canaliculi

A

microchannels b/w cells so cells can make contact w/ each other - have gap junctions

49
Q

endosteum - what and where

A

thin specialized CT that lines marrow cavities

50
Q

endosteum function

A

source of osteoprogenitor cells and osteoblasts for bone growth and repair

51
Q

cement line

A

region where remodeling has occurred - highly mineralized line

52
Q

osteoid

A

non-mineralized bone matrix laid down first by osteoblasts

53
Q

osteoprogenitor cells

A

flattened/spindle shaped cells that can differentiate into osteoblasts

54
Q

osteoprogenitor cell location

A

inner layer of periosteum and endosteal cells that line marrow cavity

55
Q

osteoblast shape and function

A

cuboidal/polygonal shaped cells that secrete collagen, ground substance, osteoid - regulate mineralization of bone

56
Q

osteoblast location

A

single layer of cells in regions where bone is being formed

57
Q

osteocyte function

A

maintain bone matrix - to limited extent can both synthesize and resorb bone

58
Q

osteocyte location

A

in lacuna

59
Q

how do osteocytes communicate w/ each other/osteoblasts

A

via processes that extend through canaliculi

60
Q

osteoclasts description and function

A

multinucleated, acidophilic, phagocytic cells that actively resorb bone by releasing lysosomes into extracellular space - seal off area, acidifies and secretes acid hydrolases that resorb bone

61
Q

Howship’s lacunae

A

depression in bone created by osteoclast

62
Q

osteoporosis

A

decrease in bone mass associated with normal ratio of mineral to matrix - due to decreased bone formation, increased bone resorption, or both

63
Q

osteoporosis with old age

A

due to lower secretion of GH

64
Q

osteoporosis in immobile patients

A

due to lack of physical stress on bone

65
Q

osteoporosis in PMS women

A

due to lower estrogen secretion

66
Q

osteomalacia

A

bone disorder due to calcium deficiency in adults - deficient calcification of newly formed bone and decalcification of calcified bone

67
Q

osteomalacia and pregnancy

A

may be severe in pregnancy - calcium requirements of fetus may cause calcium losses from mom

68
Q

Rickets

A

osteomalacia in children - mostly vitamin D deficiency, but calcium deficiency can contribute - deficient calcification in newly formed bone usually accompanied by deformation of bone spicules in epiphyseal plates - slow growth, deformation

69
Q

Paget’s disease

A

osteitis deformans - dysfunctional bone remodeling leading to bone that is abnormal, enlarged, not as dense, brittle and prone to breakage

70
Q

acromegaly

A

excessive pituitary growth hormone in adults - very thick bones in extremities and in parts of facial skeleton