Chapter 6 Bones Flashcards
describe functional properties and common locations of hyaline cartilage
provide support with flexibility and resilience
abundant in articular cartilage, costal cartilage, respiratory cartilage, and nasal cartilage
describe functional properties and locations of elastic cartilage
stretchy to withstand repeated bending
found in external ear and epiglottis
describe functional properties and location of fibrocartilage
compressible with thick collagen fibers
found in knee and vertebrae
explain difference between cartilage formation in apposition growth and interstitial growth
apposition growth: chondrocytes secrete new matrix outside surrounding perichondrium (growth is external)
interstitial growth: chondrocytes within lacunae divide and secrete new matrix (growth is internal)
describe 4 functions of skeleton and bone tissue
- framework/support
- protect (ex. rib cage + skull)
- mineral storage (calcium + phosphorous)
- blood cell production (aka hematopoiesis)
give examples of each of the bone classes (long, short, etc)
long: humerus, femur, metacarpals
short: carpals and tarsals
sesamoid bones: patella + tiny bones on the pollux and hallux
flat bones: sternum, scapula, ribs and cranial bones
irregular bones: vertebrae and hip bones
where is endosteum generally located?
lines the marrow cavities of bones
where is periosteum generally located?
lines outside of bone
what is an organic component of bone and what advantage does it offer bone?
collagen is a protein, thus organic
provides tensile strength (resists tension)
what is an inorganic component of bone and what advantage does it offer bone?
hydroxyapatites such as calcium phosphate
provides compressive strength
describe the process of endochondral ossification
Endochondral: inside cartilage
usually occurs in long bones; begins with the formation of hyaline model, perichondrium turns into periosteum, a formation of bone collar forms around the cartilage, cartilage tissue calcifies, a medullary cavity is produced within the centermost cartilage portion of bone collar
describe the process of intramembranous ossification
Intramembranous: Between/within membranes
usually occurs in flat bones; begins with sheets of unspecialized sheet (mesenchyme cell sheet - think baby skull bones), osteoblasts are formed from some of the mesenchyme cells and spongey bone and periosteum begin to form. Just under either side of the periosteum, a thin layer of compact bone replaces some of the spongey bone.
Describe how epiphyseal plates allow bones to grow
Cartilage within the epiphyseal plate does not change in size, rather, the multiplication of calcified bone cells are what begin to layer and increase bone size
describe and name the first zone of the epiphyseal plate
resting zone: cells are inactive
describe and name the second zone of the epiphyseal plate
proliferation zone: young chondrocytes divide by mitosis
describe and name the third zone of the epiphyseal plate
hypertrophy zone: cells mature and increase in size and begin to calcify
describe and name the fourth zone of the epiphyseal plate
calcification zone: dead chondrocytes left with calcium phosphate and collagen; blood vessels begin to invade due to osteoclasts breaking down matrix. Osteoblasts begin to form bone
explain what parathyroid hormone does and why it would be released
releases when blood levels of calcium decrease
act to stimulate osteoclasts to take action and break down bone matrix in order to release calcium into blood
explain what calcitonin stimulate
stimulates osteoblasts into forming bone matrix
describe why mechanical or physical stress is important for bone development
muscle tension and gravity stimulates osteoblasts. which allows for development of bone to thicken where most stress occurs
(without physical stress, bone can degrade such as with astronauts)
Describe the (simple) steps of fracture repair in bone
- hematoma forms
- fibrocartilaginous callus forms
- bony callus forms
- bone remodeling occurs
what causes osteomalacia and rickets?
calcium and/or vitamin D deficiency
what can happen to children with rickets?
develop bowed legs
what causes scurvy?
vitamin C deficiency
