chapter 6 Flashcards
bone
organ made up of several tissues working together: bone tissue, cartilage, dense connective tissue, epithelium, adipose tissue and nervous tissue
basic functions of skeletal muscle
- support
2.protection - assistance in movement
- blood cell production
- triglyceride storage
- mineral homeostasis
function: support
skeleton supports soft tissue and providing attachment points to the tendons of most skeletal muscle
function: protection
protects internal organs
function: assistance in movement
muscle attach to bone when they contract, they pull on bone to produce movement
function: blood cell production
red blood marrow produces RBC, WBC, and platelets in process called hemepoeisis. It consists of developing blood cells: adipocyte, fibroblast and macrophage within network of reticular fiber
-in fetus and some adult bone: hips, ribs, sternum, vertebrae, skull, femur, humerus
-older you get RBM turn yellow
function: triglycerides storage
yellow bone marrow consists mainly of adipose which stores triglycerides= potential chemical energy reserve
function: mineral homeostasis
-bone tissue males up 18% of weight, stores minerals (calcium and phosphorus) which help bone strength
-bone tissue stores 99% of body calcium
-on demand, bone releases minerals into the blood to maintain homeostasis and bring minerals to rest of the body
long bone
and what does it consist of
one that has greater length than width and consists of
-diaphysis
-epiphysis
-metaphyses
-articular cartilage
-periosteum
-medullary cavity
-endosteum
diaphysis
bone shaft, main portion
epiphysis
proximal and distal end of bone
metaphyses
-region between epiphysis and disphysis
-contain epiphyseal plate/ epiphyseal line
epiphyseal plate
layer of hyaline that allows disphysis to grow in length
epiphyseal line
when the bone length growth stops cartilage in epiphyseal plate is replaced by bone
articular cartilage
thin layer of hyaline cartilage covered the part of epiphysis where bone forms a joint with another bone
-reduces friction and absorbs shock
-repair of damage is limited due to lack of perichondrium and blood vessels
periosteum
what is it made of?
function
how does it attach?
what is it?
-tough connective tissue sheath and is associated with blood supply that surrounds bone surface where there is no articular cartilage
-composed of outer fibrous layer (irregular connective tissue) and inner osteogenic layer (cell)
-helps grow in thickness, not length
-protects bone, assists in fracture repair, nourish bone tissue, attachment point for tendons and ligament
-attaches to bone by perforating fibers (thick bundles of collagen extend from periosteum ito extracellular matrix)
medullary cavity
what is it?
function
-hollow, cylindrical space with diaphysis that contains yellow fatty bone marrow and blood vessels (in adults)
-minimizes weight of bone by reducing dense bone material where it is least needed
-long, tubular design provides max strength with min weight
endosteum
-thin membrane that line medullary cavity
-contains single layer of bone forming cells and small amount of connective tissue
what does the extracellular matrix consist of
15% water, 30% collagen, 55% crystallized mineral salts (calcium phosphate) and hydroxyapatite (calcium phosphate + calcium hydroxide)
calcification
minerals are deposited into framework formed by collagen fibers of extracellular matrix, they crystallize and tissue hardens
-initiated by bone building cells (osteoblasts)
bone hardness
depend on crystallized inorganic mineral salts
bone flexibility
depend on collagen fibers
4 types of cells present in bone tissue
1.Osteoprogenitor Cells
2.osteoblasts
3. osteocytes
4.osteoclasts
Osteoprogenitor cells
what is it
found where?
-unspecialized bone stem cells derived from mesenchyme
-only bone cells to undergo cell division= develop into osteoblasts
-found along inner portion of periosteum, in the endosteum and the canals with bone containing blood vessels