Chapter 5-Skeletal System Flashcards

1
Q

2 types of bone tissue

A
  • compact(dense smooth bone)

- spongy(bone with open spaces within)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Components of Skeletal system

A
  • cartilage
  • bone
  • tendons
  • ligaments
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

functions of skeletal system

A
  • protection
  • support (rigid structure)
  • movement (bones as levers)
  • storage (ca, P, fat)
  • blood cell protection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

cartilage consists of

A

-cells

extracellular matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

cells in cartilage

A

chondrocytes found in compartments called lacunae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

extracellular matrix

A
  • collagen/elastic fibers

- ground substance of chondrotin sulfates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

types of cartilage

A

hyaline
elastic
fibrocartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

why does cartilage heal slowly?

A

no arteries, veins or lymphocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

hyaline cartilage

A
  • most common

- made up of chondrocytes, chondrotin sulfate, some collagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

location of hyaline cartilage

A

embryonic skeleton, articular surfaces, respiratory passages, nasal septum, between ribs and sternum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

elastic cartilage

A
  • flexible
  • structure: chondrocytes, chondrotin sulfate, densely packed elastic fibers
  • location: auricle, tip and lateral walls of nose, epiglottis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

fibrocartilage

A
  • very strong
  • structure: chondrocytes, chondrotin sulfate, densely packed collagen fibers
  • location: intervertebral disc, public symphysis, articular cartilage in knee
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

perichondrium

A
  • fibrous connective tissue
  • surrounds cartilage
  • provides support and protection; new chondrocytes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

perichondrium location

A

hyaline cartilage and elastic cartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

absent form perichondrium

A

articular surfaces and fibrocartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

layers of perichondrium

A
  • outer: binds cartilage to adjacent tissues; provides support and protection
  • inner: for growth and maintenance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

apposition growth

A
  • starts in perichondrium
  • mesenchymal cells at periphery form in inner layer of perichondrium
  • mesenchyme move towards matrix to become chondrogenic cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how are chondrocytes formed from apposition growth

A
  • chondrogenic cells aggregate and become chondroblasts
  • chondroblasts secrete matrix-force cells apart
  • chondroblasts become enclosed in matrix and become chondrocytes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

interstitial growth

A
  • chondrocytes enclosed in matrix and divide
  • as the move apart, matrix forms between them
  • growth of cartilage from within
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

osseous tissue

A
  • supportive CT
  • contains specialized cells
  • solid extracellular matrix
  • –osteoid (organic portion, protein fibers)
  • –ground substance (Ca salts)
  • –water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

osteoprogenitor

A
  • bone cell
  • mesenchymal cells
  • predecessor to osteroblasts
  • play role in initial growth and fracture repair
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

osteoblasts

A
  • derived from osteogenic cells
  • secrete osteoid
  • common in growing bone
  • predecessor to osteocytes
  • more osteoblasts=stronger bone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

osteocytes

A
  • mature cells
  • exist within bone matrix
  • maintain Ca and PO4 homeostasis
  • found in spaces called lacunae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

osteoclasts

A
  • involved in osteolysis (bone break down)
  • increase osteoclast activity=weaker bone
  • very large
  • formed from fusion of many white blood stem cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
bone matrix is composed of...
``` Inorganic material -65% -brittle salts --mostly hydroxyapatite Osteoid -orgaic -35% -flexible fibers (collagen, glycoproteins, proteoglycans ```
26
2 types of bone
compact bone -arranged in osteons spongy bone -arranged in trabeculae
27
compact bone osteocytes communicate how?
osteocytes | -osteocytes communicate through canaliculi that radiate outward and connect one cell to the next cell
28
osteons
a unit of compact bone - concentric lamellae of matrix surrounding acentral canal - contains blood vessels and nerves
29
how are osteons connected to each other
perforating canals
30
3 types of lamellae
-concentric interstitial circumferential
31
concentric lamellae
- layers of bone surrounding the central canal | - make up osteons
32
interstitial lamellae
- found between osteons | - represents older osteons partially removed during tissue remodeling
33
circumferential lamellae
surround the compact bone | -directly produced from periosteum
34
spongy bone contains
trabeculae - osteocytes in lacunae - canaliculi - matrix
35
spongy bone does not contain
- osteons | - central canal
36
trabeculae
- latticework of thin plates of bone oriented along lines of stress - spaces are filled with red marrow where blood cells develop - found in ends of long bones and inside flat bones - lightens the bones, allows for movement
37
periosteum
- encloses bone | - absent at site of attachment of muscles, tendons and ligaments; surfaces covered by articular cartilage
38
layers of periosteum
outer fibrous: gives rise to collage | Inner: for growth or new cells and maintenance
39
endosteum
- 1 cell layer | - covers surfaces of spongy bone and medullary cavity
40
cell types of endosteum
osteogenic osteoblasts osteoclasts
41
anatomy of a long bone
diaphysis: shaft epiphysis: one end of long bone metaphysis: growth plate region articular cartilage: over joint surface; acts as friction and shock absorber medullary cavity: marrow cavity
42
2 types of bone marrow
- yellow marrow | - red marrow
43
yellow marrow
- areolar and adipose CT - in medullary cavity of long bones - energy storage - absent in infants
44
red marrow
- areolar and myeloid (precursor to red blood cells) tissue | - produces all types of blood cells
45
location of red marrow
- medullary cavities of infants | - spongy bones in adults
46
blood and nerve supply of bone
- periosteal arteries: supply periosteum - nutrient arteries - -enter through nutrient foramen, supplies compact bone of diaphysis and yellow marrow - metaphyseal and epipheyseal arteris - -supply red marrow ad bone tissue of epiphysis and metaphyses
47
how does bone growth occur
ossification (replacing CT with bone)
48
2 types of ossification
intramembranous -mesenchymal cells->spongy bone endochondral -hyaline cartilage->spongy bone
49
intramembranous ossification begins when and forms what
``` about 8 week in embryo -mainly finished by week 15 Forms: -cranial flat bones -facial bones -dentary bones -clavicle -sesmoid bones ```
50
primary ossification center
- intramembranous oss. | - location where bone growth begins
51
where does bone growth begin plus beginning steps
primary ossification center - mesenchymal cells arrange around BVs - bone morphogenic proteins release - mesenchymal cells divide and become osteoblasts
52
what do osteoblasts do after formation
- secrete osteoid - become isolated->osteocytes - produce spicules of bone that interconnect
53
how does spongy bone form during intramembranous ossification
- mesenchymal cells at surface form inner layer of periosteum - calcified matrix is degraded by osteoclasts to form spongy bone - end up with spongy bone covered in thin layer of compact bone
54
when does endochondral ossification begin and what forms
-bone relaces cartilage model -begins at week 7 of embryo -continues to adulthood Forms: -long bones -most short bones -non-cranial irregular and flat bones -middle ear ossicles
55
step 1 of endochondral ossification
- hyaline cartilage forms model of future bone - cartilage enlarges; chondrocytes near center hypertrophy - -matrix reduced to struts - -chondrocytes deprived of nutrients and die
56
step 2 of E.O.
BV's grow around and penetrate cartilage - cells differentiate into osteoblasts - compact bone forms around diaphysis
57
step 3 of E.O.
- spongy bone forms in center of model - -primary ossification center (creates diaphysis) - nutrient artery in spongy bone forms and penetrates
58
step 4 of E.O.
remodeling of the shaft - formation of the medullary cavity - length increases
59
step 5 of E.O
- BV's penetrate ends of model | - secondary ossification centers form at both epiphyses (created here)
60
step 6 of E.O.
- ends with incomplete ossification of epiphysis - some cartilage remains - -articular cartilage - -epiphyseal plate (growth plate)
61
bone growth: elongation
-occurs at epiphyseal plate growth in length continues until 2 ossification centers meet -relative thickness of epiphyseal plat does not change until growth almost complete; then: --cartilage depleted and epiphyseal plate narrows to epiphyseal line
62
bone growth: appositional
- compact bone deposited beneath periosteum - bone thickens - bone remodeling occurs throughout life - -due to osteoclasts and osteoblasts
63
bone remodeling
- ongoing since osteoclasts carve out small tunnels and osteoblasts rebuild osteons - continual redistribution of bone matrix along lines of mechanical stress - 4% of compact bone, 20% of spongy bone remodeled per year - distal femur fully remodeled every 4 months
64
fractures: break in a bone (types)
closed (simple): break that does not penetrate skin | open (compound): broken bone penetrates through skin
65
bone repair
-fractures treated by reduction and immobilization
66
stages of bone repair
- fracture hematoma - fibrocartilage callus - bony callus - remodel tissue
67
fracture hematoma formation
- facture hematoma forms within hours of injury - mass of blood - swelling and inflammation occur in response to dead bone cells - phagocytes and osteoclasts eliminate dead cells/broken matrix
68
fibrocartilaginous callus formation
- consists of mass bridging broken ends of bone - fibroblasts in periosteum produce collagen - periosteum cells differentiate into chondrocytes - results in fibrocartilage - about 3 weeks
69
bony callus formation
- endochondral ossification - formation of bony callus occurs as fibrocartilaginous callus is converted to spongy bone trabeculae - bony callus lasts 3-4 months
70
bone remodeling
- remaining dead bone fragments are resorbed, compact bone replaces spongy bone - well-healed fracture is virtually undetectable - process can take weeks to months depending on severity
71
factors affecting growth, repair, development
- nutrition=vitamin D - sunlight (vit D) - hormones: PTH, calcitonin, GH, thyroid hormone, sex hormones - physical stress
72
osteoporosis
- abnormal reduction of bone mass - reasons: - loss of estrogen at menopause - deficiency of minerals in youth - imbalance in activity between osteoblasts and osteoclasts
73
fibrodysplasia ossificans progressiva
- CTP gets ossified when injured - genetic - injury results in inappropriate bone formation - early adulthood: freezing of joints - early 20s: confined to wheelchair - starvation and pneumonia result - no treatment