Chapter 6: Bone and Skeletal Tissues Flashcards
Cartilage
- Location and basic structure
- Found throughout the body
1. External Ear
2. Nose
3. Articular Cartilages: end of bones at movable joints
4. Costal Cartilages: connect ribs to sternum
5. Larynx and Epiglottis
6. Rings of Trachea and Bronchi
7. Intervertebral Discs
8. Pubic Symphysis
9. Articular Discs-Meniscus of Knee - Abundant in embryo than adults
- Forms most of skeleton to be replaced by bone during fetal and childhood
Properties of Cartilage
- No nerves or blood vessels
- Surrounded by dense irregular connective tissue-perichondrium. Acts as a girdle to prevent outward expansion; growth & repair
- Consists primarily of water
- Resilient Tissue- it springs back to original shape
Types of Cartilage
- Hyaline “Glass” Cartilage
- Elastic Cartilage
- Fibrocartilage
Hyaline “Glass” Cartilage
- looks like frosted glass by unaided eye
- most abundant
- matrix contains collagen fibers
- provides support through flexibilty
Elastic Cartilage
- matrix contains elastic fibers
- able to tolerate repeated bending
- occurs in epiglottis and outer ear
Fibrocartilage
-resists strong compression and strong tension
-occurs in ligaments, intervertebral disc and knee meniscus
-intermediate between hyaline and dense regular connective tissue
(collagen fibers alternating between rows of chondrocytes)
Growth of Cartilage
- Cartilage grows 2 ways
1. APPOSITIONAL GROWTH: “growth from outside” Chrondorblasts in surrounding perichondrium produces new cartilage by actively secreting matrix
- INTERSTITIAL GROWTH: “growth from within” Chrondrocytes within cartilage divide and secrete new matrix
- Cartilage stops growing in late teens when the skeleton stop growing
- Chrondrocytes stop dividing; regenerates poorly in adults
Tissues in Bone
-Bones contain several types of tissues
- Dominated by bone connective tissue
- Contain nervous tissue and blood and blood vessels
- Contain cartilage in articular cartilages
- Contain epithelial tissue lining blood vessels
Function of Bones
SUPPORT: provides hard framework
MOVEMENT: skeletal muscle use bones as levers to move body parts
PROTECTION: underlying organs
MINERAL STORAGE: reservoir for important minerals (calcium and phosphate)
BLOOD: cell formation-bone contains red marrow to make blood cells
ENERGY STORAGE: osteoblasts secret osteocalcin which increases insulin sensitivity to increase glucose uptake-fat storage in yellow marrow
Classification of Bones
there are two main divisions of bones of the skeleton (location):
- Axial Skeleton: skull, vertebral column and rib cage
- Appendicular Skeleton: upper and lower limbs and the girdles that attach them to the axial skeleton
There are 4 Main Classifications of Bone (Shape):
- Long Bones
- Short Bones
- Flat Bones
- Irregular Bones
Long Bones
are longer than they are wide, have a shaft and two ends, and consists of all limbs bones except patellas, carpals, and tarsals
Short Bones
are cubed-shaped and include the carpals and tarsals
Seasmoid Bones: shaped like a sesame seed-patella
Flat Bones
are thin, flattened, often curved bones that include most skull bones, the sternum, scapula, and ribs
Irregular Bones
have complicated shapes that do not fit in any other class, such as the vertebrae and cotae
Gross Anatomy of Bones
LAYERS OF BONE
- COMPACT BONE: dense outer layer of bone
- SPONGY BONE: trabecular bone; honeycomb of small needle like- flat pieces
- form internal network of bone
- filled with red or fellow marrow
- align along stress points
