Chapter 6 Flashcards
1
Q
Cartilage
A
Not Bone
2
Q
Skeletal Cartilage
A
Contains water, lends resiliency
Contains no blood vessels or nerves
Perichondrium surrounds
-Dense connective tissue girdle
–Contains blood vessels for nutrient delivery
All contain chondrocytes in lacunae and extracellular matrix
3
Q
Skeletal Cartilage (3 Types)
A
Hyaline Cartilage
Elastic Cartilage
Fibrocartilage
4
Q
Hyaline Cartilage
A
- Toughest
- Most abundant type
- Provides support/flexibility
- Collagen fibers only
- Articular and costal
5
Q
Elastic Cartilage
A
- External Ear and epiglottis
- Similar to hyaline cartilage, more elastic fibers
6
Q
Fibrocartilage
A
- Thick collagen fibers- has great tensile strength
- Intervertebral discs
7
Q
Growth of Cartilage (3 Types)
A
Appositional Growth
Interstitial Growth
Calcification of Cartilage
8
Q
Appositional Growth
A
External face of existing cartilage
-everything grows out
9
Q
Interstitial Growth
A
Expanding cartilage from within
10
Q
Calcification of Cartilage
A
- Occurs during normal bone growth
- Calcified cartilage is NOT bone
- Growth Plates close
11
Q
Classification of Bones (2 Groups)
A
Location- Axial, Appendicular
Shape- Long, Short, Flat, Irregular
12
Q
Axial
A
Head, neck, trunk
13
Q
Appendicular
A
Arms, Legs
14
Q
Long Bones
A
Longer than they are wide
Shaft and ends
Tibia, Fibula
15
Q
Short Bones
A
Cube shaped bones
Sesamoid bones (within tendons, e.g., patella)
Toes
16
Q
Flat Bones
A
Thin, flat, slightly curved
Ribs, Skull
17
Q
Irregular Bones
A
Complicated shapes
Shoulder Blades, everything else
18
Q
Functions of Bones (7 Functions)
A
Support Protection Movement Mineral and Growth Factor Storage Blood Cell Formation Triglyceride (fat) Storage Hormone Production
19
Q
Support
A
Upright
20
Q
Protection
A
Soft organs
- Skull
- Ribs
21
Q
Movement
A
Muscles pull on bones
22
Q
Mineral and Growth Factor Storage
A
Calcium and phosphorus, and growth factors reservoir
23
Q
Blood Cell Formation
A
Red marrow cavity in certain bones
24
Q
Triglyceride (fat) Storage
A
Bone cavities
-Energy source
25
Hormone Production
Osteocalcin
- Regulates bone formation
- Protection
26
Bones (3 Levels of Structure)
```
Organs
Contains different types of tissues
Three Levels of Structure
-Gross Anatomy
-Microscopic
-Chemical
```
27
Common components of all bones
Dense outer layer of compact bone
-Smooth and solid
Spongy inner core
-Trabeculae
28
Gross Anatomy of Bone
Bone textures
| -Compact vs. Spongy
29
Compact Bone
Dense outer layer
| Smooth and solid
30
Spongy (cancellous or trabecular)
Honeycomb of flat pieces of bone deep to compact called trabeculae
31
Structure of Short, Irregular, and Flat Bones
Grossly
-Thin plates of spongy bone covered by compact bone
-Plates sandwiched between connective tissue membranes
-Periosteum (outer layer) and endosteum
Shaft
-None and no epiphyses
Bone Marrow
-Throughout spongy bone; no marrow cavity
Articular surfaces
-Cartilage covering
32
Structure of Typical Long Bone
Diaphysis
-Long tubular shaft
-Compact bone surrounding medullary cavity
Epiphyses
-Bone ends
-External compact bone
-Internal spongy bone
-Articular cartilage covers articular surfaces
-Between is epiphyseal line
--Remnant of childhood bone growth at epiphyseal plate
33
Articular
Joints where 2 bones come into contact
34
Medullary Cavity
Holds bone marrow
35
2 Membranes
Periosteum- peri- outside
| Endosteum- endo- inside
36
Periosteum
White, double-layered membrane
Covers external surfaces except joint surfaces
-Outer fibrous layer of dense irregular
Osteogenic layer adults bone
-Contains primitive stem cells- osteogenic cells
Vascular and nerves
Anchoring points for tendons and ligaments
37
Endosteum
Covering internal bone surface
Covers trabeculae of spongy bone
Lines canals that pass through compact bone
Contains osteogenic cells that can differentiate into other bone cells
38
Osteogenic
Osteo-genic
| Bone-maker
39
Ligament
Bone to bone
40
Tendon
Muscle to bone
41
Red bone Marrow
Location
-Trabecular cavities of spongy bone
-Scattered throughout flat bones
In medullary cavities and spongy bone of newborns
Location in long bones
-minimal
Yellow marrow can convert to red, if needed
42
Bone Markings
Sites of muscle, ligament, and tendon attachment on external surfaces
Joint surfaces
Conduits for blood vessels and nerves
43
Three types of Bone markings
Projections
Depressions
Openings
44
Projections
Most indicate stresses created by muscle pull or joint modifications
45
Depressions and Openings
Usually allow nerves and blood vessels to pass
46
5 Major Types of Cells in Bones
```
Osteogenic Cells
Osteoblasts
Osetocytes
Bone lining Cells (non-relevant)
Osteoclasts
```
47
Osteogenic Cells (Osteoprogenitor Cells)
```
Mitotically active stem cells
Location
-periosteum and endosteum
Function
-when stimulated differentiate into osteoblasts or bone lining cells
-Some persist as osteogenic cells
```
48
Osteoblasts
```
Function
-Bone-Forming
-Secrete unmineralized bone matrix
-Includes collagen and calcium-binding proteins
Actively mitotic
```
49
Osteocyte
Mature bone cells in lacunae
Monitor and maintain bone matrix
Act as stress or strain sensors
-Respond to and communicate mechanical stimuli to osteoblasts and osteoclasts so bone remodeling can occur
50
Osteoclasts
Derived from hematopoietic stem cells that become macrophages
Giant, multinucleate cells for bone resorption
51
Osteoclasts vs. Osteoblast vs. Osteoctye
- blast- make
- cyte- maintaining
- clast- absorbing
52
Haversian System
Structural unit of compact bone
Elongated cylinder parallel to long axis of bone
Hollow tubes of bone matrix called lamellae
-collagen fibers in adjacent rings run in different direction
--withstands stress-resist twisting
53
Microscopic Anatomy of Compact Bone
Central Canal
Perforating Canal
Lacunae
Canaliculi
54
Central Canal
Runs through core of osteon
| Contains blood vessels and nerve fibers
55
Perforating Canals
Canals lined with endosteum at right angles to central canal
| Connect blood vessels and nerves of periosteum, medullary cavity, and central canal
56
Lacunae
Small cavities that contain osteocytes
57
Canaliculi
Canals that connect lacunae to each other and central canal
58
Canaliculi Formation
Osteoblasts secreting bone matrix
When matrix hardens and cells are trapped the canaliculi form
-Allow communication
-Permit nutrients and wastes to be relayed from one osteocyte to another throughout osteon
59
Central vs. Perforating
Central- middle, whole length, main road
| Perforating- back road
60
Microscopic Anatomy of Bone: Spongy Bone
Appears poorly organized
Trabeculae
-Align along lines of stress to help resist it
-No osteons
-Contain irregularly arranged lamellae and osteocytes interconnected by canaliculi
-Capillaries in endosteum supply nutrients
61
Chemical Composition of Bone: Organic Components
Includes cells and osteoid
- Osteogenic cells, osteoblasts, osteocytes, bone-lining cells, and osteoclasts
- Osteoid- 1/3 of organic bone matrix secreted by osteoblasts
- -Made of ground substance
- -Collagen fibers
- -Contributes to structure; provides tensile strength and flexibility
62
Hydroxyapatites (mineral salts)
65% of bone by mass
Mainly of tiny calcium phosphate crystals in and around collagen fibers
Responsible for hardness and resistance to compression
63
Bone Fun Facts
Half as strong as steel in resisting compression
As strong as steel in resisting tension
Last long after death because of mineral composition
-Reveal information about ancient people
-can display growth arrest lines
--Horizontal lines on bones
--Proof of illness- when bones stop growing so nutrients can help fight disease
64
Ossification (Osteogenesis)
```
Process of bone tissue formation
Formation of bony skeleton
Postnatal bone growth
-until early adulthood
Bone remodeling and repair
-lifelong
```
65
Ossification (2 Types)
Endochondral Ossification
| Intramembranous Ossification
66
Endochondral Ossification
Bone forms by replacing hyaline cartilage
Forms most of skeleton
Forms most all bones inferior to base of skull
-Except clavicles
Uses hyaline cartilage models
Requires breakdown of hyaline cartilage prior to ossification
67
Intramembranous Ossification
Bone develops from fibrous membrane
Forms flat bones, e.g. clavicles and cranial bones
Forms frontal, parietal, occipital, temporal bones, and clavicles
Begins within fibrous connective tissue
68
Postnatal Bone Growth (2 types)
Interstitial (longitudinal) Growth
| Appositional Growth
69
Interstitial Growth
Increase length of long bones
Requires epiphyseal cartilage
Epiphyseal plate maintains constant thickness
Concurrent remodeling of epiphyseal ends to maintain proportion
Result of 5 zones
70
5 Zones of Interstitial Growth
```
Resting (quiescent) zone
Proliferation (growth) zone
Hypertrophic zone
Calcification zone
Ossification (osteogenic) zone
```
71
Resting Zone
Cartilage on epiphyseal side of epiphyseal plate
| Relatively inactive
72
Proliferation Zone
Cartilage on diaphysis side of epiphyseal plate
| Rapidly divide pushing epiphysis away from diaphysis
73
Hypertrophic Zone
Older cartilage cells enlarge
74
Calcification zone
Surrounding cartilage matrix calcifies
75
Ossification zone
Chrondrocyte deterioration
Eroded by osteoclasts
Covered with new bone by osteoblasts
Ultimately replaced with spongy bone
76
Epiphyseal Plate Growth in Interstitial Growth
Near end of adolescence chondroblasts divide less often
Epiphyseal plate thins then is replaced by bone
Epiphyseal plate course
77
Epiphyseal Plate Course
Bone lengthening ceases
Bone of epiphysis and diaphysis fuses
Females about 18 years
Males about 21 years
78
Appositional Growth
Allows bone to widen
Osteoblasts
-Beneath periosteum secrete bone matrix on external bone
Osteoclasts
-Remove bone on endosteal surface
Usually more building up than breaking down
-Thicker stronger bone but not too heavy
Excess of deficits of any cause abnormal skeletal growth
79
Hormones of Regulating Bone Growth (3 Types)
Growth Hormone
Thyroid Hormone
Testosterone (males) estrogen (females)
80
Growth Hormone
HGH
| most important in stimulating epiphyseal plate activity in infancy and childhood
81
Thyroid Hormone
Modulates activity of growth hormone
| Ensures proper proportions
82
Testosterone & Estrogen
Promote adolescent growth spurts
| End growth by inducing epiphyseal plate closure
