Term
Cartilage:
9 Locations and basic structure |
|
Definition
Found throughout adult body
1. Ear
2. nose
3. Articular cartilages (covers the ends of most bones at joints) and 4.costal cartilage (connects ribs to sternum)
5. Larynx (voice box) and epiglottis
6. Intervertebral discs
7. pubic symphysis
8. articular discs (meniscus)
9. cartilage that holds open air ways of respiratory system |
|
|
Term
|
Definition
1. Is abundant in embryo
2. Is surrounded by perichondrium - membrane of fibrous connective tissue that covers the external surface of cartilages
3. Consists primarily of water
4. Resilient tissue – springs back to original shape |
|
|
Term
|
Definition
1. Hyaline cartilage – (glass) – most abundant cartilage
Provides support through flexibility
2. Elastic cartilage – contains many elastic fibers
Able to tolerate repeated bending
3. Fibrocartilage – resists strong compression and strong tension
An intermediate between hyaline and elastic cartilage |
|
|
Term
|
Definition
1. Chondroblasts in surrounding perichondrium produce new cartilage
*Perichondrium is the layer of dense irregular connective tissue which surrounds the cartilage of developing bone |
|
|
Term
|
Definition
| Chondrocytes within cartilage divide and secrete new matrix |
|
|
Term
Bones
Dynamic and ever-changing throughout life
Name 4 tissues contained in bone |
|
Definition
1. Dominated by bone connective tissue
2. Contain nervous tissue and blood tissue
3. Contain cartilage in articular cartilages
4. Contain epithelial tissue lining blood vessels |
|
|
Term
|
Definition
1. Support – provides hard framework
2. Movement – skeletal muscles use bones as levers
3. Protection of underlying organs
4. Mineral storage – reservoir for important minerals
5. Blood-cell formation – bone contains red marrow |
|
|
Term
|
Definition
1. Long bones – longer than wide –
2. Short bones – roughly cube-shaped
3. Flat bones – thin and flattened, usually curved
4. Irregular bones – various shapes, do not fit into other categories |
|
|
Term
| Inner and outer parts of bone |
|
Definition
1. Compact bone – dense outer layer of bone
2. Spongy (cancellous) bone – internal network of bone |
|
|
Term
| Structure of a Typical Long Bone |
|
Definition
1. Diaphysis – “shaft” of a bone
2. Epiphysis – ends of a bone
3. Blood vessels – well vascularized
4. Medullary cavity – hollow cavity – filled with marrow
5. Membranes – periosteum and endosteum |
|
|
Term
|
Definition
1. Anatomy of a bone reflects stresses
2. Compression and tension greatest at external surfaces |
|
|
Term
| Chemical Composition of Bone |
|
Definition
1. 35% organic components
*Composed of cells, fibers, and organic substances
*Collagen – abundant
2. 65% inorganic mineral salts
*Primarily calcium phosphate
*Resists compression |
|
|
Term
| Bone Development: Ossification (osteogenesis) – bone-tissue formation. Two types |
|
Definition
1. Intramembranous ossification. Replacement of sheet-like connective tissue membrane with bony tissue.
*Certain flat bones of the skull and some irregular bones
2. Endochondral ossification. Develops initially from hyaline cartilage
*Most bones |
|
|
Term
| Three types of cells involved in the development, growth and remodeling of bones |
|
Definition
1. Osteoblasts - bone-forming cells
2. Osteocystes - mature bone cells
3. Osteoclasts - break down and reabsorb bone |
|
|
Term
| Endochondral Ossification |
|
Definition
All bones except some bones of the skull and clavicles
*Bones are modeled in hyaline cartilage
*Begins forming late in 2nd month of human development
*Continues forming until early adulthood |
|
|
Term
| Anatomy of Epiphyseal Growth Areas (pt 1) |
|
Definition
* In epiphyseal plates of growing bones
cartilage is organized for quick, efficient growth
* Cartilage cells form tall stacks
* Chondroblasts at the top of stacks divide quickly
* Pushes the epiphysis away from the diaphysis
* Lengthens entire long bone |
|
|
Term
| Anatomy of Epiphyseal Growth Areas (pt 2) |
|
Definition
*Older chondrocytes signal surrounding matrix to calcify
*Older chondrocytes then die and disintegrate
*Leaves long trabeculae (spicules) of calcified cartilage on diaphysis side
Trabeculae are partly eroded by osteoclasts
* Osteoblasts then cover trabeculae with bone tissue
* Trabeculae finally eaten away from their tips by osteoclasts |
|
|
Term
| Postnatal Growth of Endochondral Bones (pt 1) |
|
Definition
* During childhood and adolescence
* Bones lengthen entirely by growth of the epiphyseal plates
* Cartilage is replaced with bone tissue as quickly as it grows
* Epiphyseal plate maintains constant thickness
* Whole bone lengthens |
|
|
Term
| Postnatal Growth of Endochondral Bones (pt 2) |
|
Definition
* As adolescence draws to an end
* Chondroblasts divide less often
* Epiphyseal plates become thinner
* Cartilage stops growing
* Replaced by bone tissue
* Long bones stop lengthening when diaphysis and epiphysis fuse |
|
|
Term
|
Definition
| add bone tissue to the external surface of the diaphysis |
|
|
Term
|
Definition
| remove bone from the internal surface of the diaphysis |
|
|
Term
|
Definition
| growth of a bone by addition of bone tissue to its surface |
|
|
Term
| Growth of 3 Other Types of Endochondral Bones |
|
Definition
1. Short bones – arise from a single ossification center
2. Irregular bones – develop from distinct ossification centers
3. Small long bones
Form from a primary ossification center and a single secondary ossification center |
|
|
Term
Hormonal Regulation of Bone Growth
3 types of hormone and their functions |
|
Definition
1. Growth hormone – produced by the pituitary gland
*Stimulates epiphyseal plates
2. Thyroid hormone – ensures that the skeleton retains proper proportions
3. Sex hormones
*Promote bone growth
*Later induces closure of epiphyseal plates |
|
|
Term
| Bone remodeling: how many years does it take for the bone to be completely replaced? |
|
Definition
1. spongy bone replaced every 3-4 years
2. compact bone replaced every 10 years |
|
|
Term
Bone Remodeling:
Bone deposit and removal.
Where doe it happen? |
|
Definition
| Occurs at periosteal (membrane on outer surface) and endosteal (membrane on inner surface lining spongy bone ) surfaces |
|
|
Term
Bone remodeling: deposit and removal
What cells are involved? |
|
Definition
1. Bone deposition – accomplished by osteoblasts (lays down osteoid - calcification)
2. Bone reabsorption – accomplished by osteoclasts (hydrochloric acid and lysosomal
enzymes are
released to digest bone and release ca2+ and po43- into blood stream) |
|
|
Term
| Simple vs compound fractures |
|
Definition
simple - bone breaks but but does not penetrate the skin
complex- bone protrudes through the skin |
|
|
Term
Treatment by reduction
Closed reduction vs Open reduction |
|
Definition
Open: bone is coaxed into alignment by physicians hands
closed: pins are used to bring broken ends together |
|
|
Term
| periosteum and repair of Bone Fractures |
|
Definition
1. The healing process is mainly determined by the periosteum (the connective tissue membrane covering the bone).
2. The periosteum is the primary source of precursor cells which develop into chondroblasts and osteoblasts that are essential to the repair of bones. |
|
|
Term
| Phases of fracture healing |
|
Definition
1. Reactive Phase: Fracture and inflammatory phase. Granulation tissue formation
2. Reparative Phase: Callus formation
Lamellar bone deposition
3. Remodeling Phase: Remodeling to original bone contour |
|
|
Term
| Skeleton grows until the age of? |
|
Definition
|
|
Term
In children and adolescents
Bone formation _____? |
|
Definition
| exceeds rate of bone reabsorption |
|
|
Term
In young adults
Bone formation and bone reabsorption ___? |
|
Definition
|
|
Term
In old age ___ predominates
Bone mass ____. |
|
Definition
1. reabsorption
2. declines |
|
|
