Skeletal System Unit Review

what are the irregular bones?

os coxa, symphysis pubis, vertabrae

compact bone

forms superficial layer, dense and smooth

spongey bone

deep to compact bone, made up of network of trabeculae that contains red marrow. allows for mobility and bearing of forces. epiphysis of long bones, common in flat bones

red marrow 

produces red blood cells and white blood cells

short bones

cube shaped, mostly spongey bone, locations of TORSION

irregular bones

complicated shapes, mostly spongey bone, areas of shock and force

sesamoid

bone embedded in tendon, where tendon passes over a joint to provide additional protection

projections

outward growths that indicate muscle attachments

depressions

grooves that allow for nerves and blood vessels to pass through bones

diaphysis

long axis, thick compact bone surrounds medullary cavity

medullary cavity

contains yellow marrow (adipose tissue) and nutrient artery

periosteum function and structure

2-layer membrane superficial to diaphysis rich in immune cells, blood vessels and nerves to nourish the bone. outer layer = DCT, inner layer = osteoblasts

perichondrium

nourishes cartilage (except at articular surfaces). 2-layer membrane, outer layer = DCT, inner layer = chondroblasts. NOT highly vascularized

epiphysis

expanded ends of bones mostly made up of spongey bone

epiphyseal plate

“growth plate” of hyaline cartilage in growing bones. ossifies when older to leave the epiphyseal line

articular cartilage

superficial to epiphyses, made of hyaline cartilage, decrease friction between joints

ECM of osteocytes

calcium and collagen

types of osteocytes

osteoblasts build bone, osteoclasts destroy old bone

lacunae

small cavities that contain osteocytes

lamellae

concentric circles that lacunae are arranged in

haversian canal

canal running vertically through bone that contains blood vessels, branches off

canaliculi

channaels that join all lacunae in lamellae, connect osteocytes to nourishment supply

calcium

stimulates osteoblasts

region of spine from superior to inferior

cervical, thoracic, lumbar, sacral, coccyx

steps of ossification process

1) formation of hematoma, clotted blood vessels to fill the fracture site 2) formation of cartilage to replace hematoma (requires brace) 3) osteoblasts produce trabeculae for spongey bone 4) osteoblasts produce compact bone

7 types of fractures

spiral, greenstick, closed(simple), open(compound), comminuted, depression, compression

osteoporosis causes, symptoms, treatments

caused by low calcium, leading to bone break down outpacing bone formation. bones get extremely porous, making them weak/brittle and prone to shattering. treat with biphosphonates to stop osteoclasts + Ca supplements

osteomalacia causes, symptoms, treatments

(rickett’s in peds) lack of vitamin D that leads to poor calcium absorption. leads to fragile bones that may bow laterally. treat with vitamin D supplement and sunlight exposure

osteogenesis imperfecta (OI)

congenital occurring in fetal development, mutation in COL1A1 and COL1A2 gene. ECM lacks collagen and bones become brittle. treat with physical therapy or surgical insertion of telescopic rods to support bones

scoliosis

idiopathic, abnormal lateral curvature of the spine, treat with surgery if inhibiting respiration

paget’s disease

imbalance in rate of remodeling between osteoblasts and osteoclasts, genetic but presents later in life, results in deformed bones prone to fracture, thick and thin parts. treat with biphosphonates

two types of fracture treatment

closed reduction (dr. coaxes bone back together with hands), open reduction (dr. uses pins/wires to hold bones together) ALWAYS needed for comminuted fracture

3 classification of joints

fibrous, cartilaginous, synovial

fibrous joints

bones joined by fibrous connective tissue, mostly collagen, immovable due to it ex) sutures of skull

cartilaginous joints

bones connected by hyaline cartilage, slightly movable ex) vertibrae

synovial joints

encompasses articular cartilage and synovial fluid separating two bones, freely moving ex) knee

osteoarthritis

continual wear and tear of articular cartilage, results in inflammation

how can skeletal remains be used to identify a person

sex (pelvis opening and sacrum), age (growth plates, bone density), height (long bones), old fractures/surgical implants

range of motion for pivot, hinge, ball and socket

pivot = rotation on single axis, hinge = movement in one plane, flexion/tension, ball and socket = all planes of motion