Unit 3 Test

functions of the skeletal system

support, protection, mineral storage, blood cell formation, triglyceride storage (fats in yellow marrow)

long bone shape

length, have a diaphysis and epiphysis, most all appendicular bone

long bone anatomy

articular hyaline cartilage on the ends, epiphyseal plate for interstitual growth, periosteum covers external surfaces

diaphysis

compact bone has yellow marrow cavity inside

epiphysis

external compact bone, internal spongy bone, has red marrow

shape of short bones

cube shaped, carpel, tarsal, sesamoid bones are sesame seed shaped short bones (knee)

shape of flat and irregular bones

thin and flat, like the skull and sternum

irregulars have no other category like the vertebra

osteocytes

mature cells that maintain the matrix around them and live in lacunae inside bone

compact bone anatomy

osteons

lamellae (// bundles of collagen fibers)

lacunae (between adjacent lamellae w osteocytes inside)

Volkman perforating canals (connects vessels in periosteum and central canals)

canaliculi (canals that connect lacunae)

spongy bone anatomy

no osteons, incomplete lamellae form trabeculae (contain lacunae and canaliculi w osteocytes)

intramembranous ossification

formation of flat bones

osteoblasts secrete bone matrix and turn into osteocytes that develop canaliculi

endochondral ossification

develops long bones

hyalin cartilage template of bone formed, bone collar forms, chondrocytes in center die starting calcification, vessels invade diaphysis and cartilage is replaced by bone, vessels invade epiphysis to form spongy bone inside

bone remodeling

osteoclasts remove and absorb old bone and osteoblast deposit new bone, requires minerals and vitamins, PTH, TH, calcitonin, and growth hormone

comminuted fracture

fragments into three of more pieces, common in elderly

compression fracture

bone is crushed, common in porous bones, extreme trauma like a fall

spiral fracture

excessive twisting forced, common in sports

epiphyseal fracture

epiphysis separates from the diaphysis along the epiphyseal plate, occurs where cartilage is dying and calcification is occurring

depression fracture

broken bone portion is pressed inward, typically in skull

greenstick fracture

incomplete like a twig, common in children

healing a bone fracture

hematoma forms, fibrocartilaginous callus forms, bony callus forms, bone remodeling occurs

osteoporosis

any disease that causes bone reabsorption to occur faster than depositing, bones become light and fragile

risk factors include genetics, lack of exercise, small body frame, smoking, poor nutrition

joint

site where two to more bones articulate, soft but flexible for mobility, must be rigid and strong enough to hold the skeleton together

synarthroses

immovable joint ex) epiphyseal plate

amphiarthroses

slightly moveable joint ex) intervertebral discs, pubic symphysis

diarthroses

freely moving joint ex) shoulder, hip, elbow, wrist, pivot

fibrous joints

connected by fibrous connective tissue, no cavity, usually synarthroses

suture fibrous joints

short fibers, usually ossifies

syndesmoses fibrous joints

short ligaments

gomphoses fibrous joints

peg in socket

cartilaginous joints

connected by cartilage, no cavity, usually synarthroses to amphiarthroses

synchondroses cartilaginous joints

bones connected by hyaline cartilage

symphyses cartilaginous joints

articular cartilage and a fibrocartilage pad

synovial joint

synovial fluid filled cavity, most commo joint, usually diarthroses, articular cartilage, articular capsule, reinforcing ligaments

factors that affect synovial joints stability

shape of articulating surfacesm, ligaments, tone in mucled crossing the joint

origin of synovial joint

attachment to the bone that does not move when the muscle contracts

insertion of synovial joint

attachment to the bone that moves during contraction

sprain

ligaments reinforcing a joint is stretch or or, lumbar ankle and knee are common, slow healing