Bones and Joints Flashcards
function of skeletal system
- reservoir of minerals
- protection of organs
- production of blood cells
- movement
- shape
cortex
outer later of compact bone
trabeculae
inner spongy bone
bone marrow
spaces between the trabecula
red bone marrow
hematopoiesis
yellow bone marrow
fat storage
osteoblasts
- builder
- lay down the matrix to get mineralized
osteoclast
- break down bone for resorption
- specialized type of macrophage that secretes contents of lysosomes to break down the bone
osteocytes
- bone cell
- start as osteoblast but get stuck in matrix
- have extensions that help them communicate
endochondral ossification
- lay down cartilage and bone
- ossification of epiphyseal plate (growth plate)
intramembranous ossification
- no cartilage phase
- flat bones
bone mineral density
amount of mineral per cm of bone
-indicator of fracture risk
factors affecring bone mineral density
- physical activity
- diet
- hormones
- ethnicity
- age
- sex
achondroplasia
- no laying down of chondrocytes causing no bone growth
- leading cause of dwarfism
- genetic disease cause mutation in fibroblast growth factor 3
- main risk: paternal age
osteogenesis imperfecta
- “brittle bone” disease
- thin and delicate bones easily break
- mutation in genes resulting in abnormal collagen formation (not enough collagen)
- autosomal dominant
- increase risk of bone fracture
congenital clubfoot (talipes)
- most common congenital disorder of the leg
- not genetic
- not painful
- multifactorial
- treatment: slightly turn foot and cast it and repeat
fracture
any disruption in continuity of bone
-pain from tearing of periosteum
simple fracture
bone broken into 2 pieces
comminuted fracture
bone shattered into many pieces
compound fracture
overlying skin is broken with potential for infection
pathologic fracture
fracture through diseased area in bone
greenstick fracture
bone where growth plates haven’t fused together yet
healing a fracture
-must bring fragments together and stabilize it
osteomyletis
- bacterial infection on bone and bone marrow
- can spread from somewhere else in body or follow trauma or surgery
- symptoms: fever, local pain, tenderness
- X-ray and antibiotics or surergy
- complications: spread of infection or amputation
osteoporosis
- bones become porous
- multifactorial disease by absolute reduction of total bone mass
- age related
- women more likely than men
primary osteoporosis
cause is intrinsic to bone itself or a decline in estrogen
secondary osteoporosis
cause is second to disease excess cortisol or increased PTH
when does peak bone mass occur
- ages 25-30 years
- want to maximize bone density early
