Chapter 6- Bones

Exam 2

major functions of skeletal system

protection, mineral storage, blood cell formation, fat storage

compact bone structure

osteon

structure of long bone

compact perimeter and spongy center with endosteum in between

regions of long bone

epiphysis on end and diaphysis in middle

what is the medullary cavity

location of red or yellow bone marrow in long bone

what is periosteum

outer connective layer of long bone

main types of connective tissue in bones

compact and spongy

where is yellow bone marrow found

limbs of adults storing fat, infants have none

what holds the periosteum in place

perforating fibers made up of collagen

what is tte nutrient foramen

openning for 1 nutrient artery to enter bone

types of bone classifications

long, short, irregular, flat, sesamoid

structure of spongy bone

trabeculae like maze lines

function of spongy bone

bone marrow production and shock absorption

main organic material of bone

osteoid made of mostly collagen that provide flexibility

main inorganic material of bone

hydroxyapatite mainly calcium and phosphorus that harden the matrix

role of osteoblast

deposit bone until they become osteocytes

what are osteocytes

mature bone cells

role of osteoclast

degrade and resorp bone

role of lucuna

store bone cells

role of central canal

house nerves and blood vessels

role of canaliculi

connect lucunae and central canal for transfer of nutrients

what type of ossification do most bones experience

endochondral

when does intramembranous ossification take place

many flat bones built on embryonic connective tissue model

how does endochondral ossification occur

osteoblats calcify cartilage and replace it with bone

how does intramembranous ossification occur

osteoblasts secrete organic material that calcifies to spongy and compact bone

what is osteoporosis

inadequate inorganic material in bones causing bone loss

where does growth occur in a bone

epiphyseal plate from division of chondrocytes

at which zone do chondrocytes divide in the epiphyseal plate

zone of proliferation

why is fracture at epiphyseal plate bad

could cause premature closure of plate

what is appositional growth

bone growing in diameter not length as circumferential lamella are added

what is bone depostition

osteoblasts putting down bone

what is bone resorption

osteoclast breaking down bone

what gland is activated when blood calcium level decreases

parathyroid gland releasing PTH

steps of bone repair after fracture

break, bleeding, hematoma, soft callus, bony callus, secondary bone

what is a hematoma

localized collection of blood outside of blood vessels