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grcc bi121 exam3
GRCC BI 121 Exam 3 Skeletal System
Question | Answer |
---|---|
Bone function: e.g. support | Pelvis |
Bone function: e.g. Protection | ribs, cranium |
Bone function: Leverage/Body movement | work with muscle musculoskeletal |
Bone Function: Blood cell formation (hemopoiesis) in flat bones and vertebrae | Formed in red marrow; postpartum in spongy tissue in what type of bones? |
Bone Function: Mineral storage | Calcium & phosphorus as calcium phosphate (70% by wt) |
what is required for clot formation, nerve impulse conduction, and muscle contraction | Calcium and phosphorus which is stored in bones |
bone function: shock absorption (recall chicken bones from lab) | collagen and joints |
bone function: fat storage | yellow marrow |
Long bone anatomy | Epiphysis;diaphysis;periosteum;compact bone; spongy; medulla; endosteum, marrow |
Long bone anatomy: epiphysis | flared edn with hyaline cartilage that forms joint |
Long bone anatomy: diaphysis | shaft of the bone |
Long bone anatomy: Periosteum | Fibrous and vascular membane covering all non-cartilage surfaces |
Long bone anatomy: compact bone | Composed of osteons (no gaps) |
Long bone anatomy: spongy (cancellous) bone | Composed of trabeculae (with gaps) |
Long bone anatomy: Medulla | Linear cavity formed by the hollow of the compact bone |
Long Bone anatomy: Endosteum | Membrane containing bone forming cell that lines the medulla |
Thin membrane containing bone forming cells | endosteum |
Long bone anatomy: Marrow | soft connective tissue that fills medulla. |
Red marrow | RBC/WBC/Platelet formation |
Red marrow location | Medulla before birth |
epiphysis after birth | red marrow location |
Yellow marrow | fat storage |
Microscopic bone anatomy: bone cells | Bone cells; osteoblasts; osteocyte; osteoclasts; osteon; central canal; perforating canals |
Microscopic bone anatomy: Osteoblasts function | bone deposition; immature bone cells; bone building |
Known as the constructin crew | Osteoblasts |
Microscopic bone anatomy: Osteocyte | In lacunae |
Function of osteocytes | removes wastes; transports nutrients; mature osteoblasts |
Known as the maintenance crew | Osteocytes |
Microscopic bone anatomy: osteoclasts | bone and fiber reabsorption: from fused monocytes |
Osteoclast | The destruction crew |
Bone destruction causes release of calcium and phosphoate in blood | osteoclasts |
Microscopic bone anatomy: osteon | Concentric deposit of inorganic salts, collagen, elastin and osteocytes. |
Microscopic bone anatomy: central canal | parallel to bone axis; contains vessels and nerves |
Microscopic bone anatomy: perforating canals | Perpendicular to bone axis; contains vessels, nerves |
Osteoblasts mature into what? | Into an osteocytes |
Bone development | Intramembranous bones; Ossification |
How do intramembranous bones originate | Originate in sheet like layers of connective tissue. |
e.g. flat bones such as skull and clavicles | Intramembranous bones |
Step 1 intramembranous ossification | sheet like layers of relatively undifferentiated connective tissue appear at sites of future bones |
Step 2 intramembranous ossification | Prtially differentiated connective tissue cells collect around blood vessels in these layers |
Step 3 intramembranous ossification | Connective tissue cells further differentiate into osteoblasts, which deposit spongy bone |
Step 4 intramembranous ossification | Osteoblasts become osteocytes when bony matrix completly surrounds them. |
Step 5 intramembranous ossification | Connective tissue on the surface of each developing structure forms a periosteum. |
Step 6 Intramembranous ossification | Osteoblasts on the inside of the periosteum deposit compact bone over the spongy bone. |
Intramembranous bones start with | sheet like layers of undifferentiated conn tissue at sites of future bones |
Sheet like layers originate in future bone | step 1 |
Blood vessels collect around sheet like layers | step 2 |
Tissues turning into osteoblasts & deposit in spongy bone | step 3 |
Osteoblasts turn into Osteocytes when surrounded by bony matrix | step 4 |
Periosteum forms from connective tissue on surface | step 5 |
Compact bone developed via Osteoblasts inside the periosteum deposit compact bone over spongy bone | step 6 |
Periosteum gives rise to osteoblasts- what happens first and then second? | Spongy bone formed first and then compact bone |
Endochondrial bones | from ossification of hyaline cartilage bone models |
Which process are most bones produced? | endochondrial bones |
endo | in |
chond | cartilage |
Long bones are formed | endochondral bones |
there are no gaps in this part of the long bone | compact bone is composed of osteons. |
There are gaps in this part of the bone | spongy bone is composed of trabeculae |
Where does ossification start in endochondral bones | This begins in diaphysis and moves to epiphysis |
Where does secondary ossification move towards? | Secondary ossification moves does toward diaphysis |
step 1: massess of hyaline cartilage form what? | Models of furture bones |
Step 2: Cartilage breaks down and what develops? | periosteum |
Step 3: Blood vessels & differentiating osteoblasts from what? | the periosteum, and they invade the disintegrating tissue. |
Step 4: Osteoblasts form what and what space does this new formed tissue occupy | spongy bone is formed in the space occupied by cartilage. |
Step 5: Osteoblasts beneath the periosteum do what? | deposit thin layers of compact bone |
Step 6: Osteoblasts become what? | Become osteocytes when completely surrounded by bony matrix |
What happens to epiphyseal plate? | will eventually ossify and called epiphyseal line. |
What is epiphyseal plate made of? | cartilage |
growth plate = | epiphyseal plate |
what happens if fracture of epiphyseal plate? | If fractured, growth plat forms assymetrically. |
assymetrical | no balance, |
Bone cancers affect Osteoclasts therefore | bone loss; osteoclasts release ca & phosphates; overproduction of osteoclasts can lead to too much. |
Prostate cance can stimulate osteoblasts therefore | bone production; overproduction leads to too much growth. |
Factors affect bone growth | Vit D, A, & C |
Vit D | Required for calcium absorption in small intestine & helps with bone building |
Vit A | required for osteoblast and osteoclast activity during fetal development |
Vit C | req for collagen formation in bones. |
Low Vit D = | bone softening or rickets or ostomalacia |
rickets | bone softening in children |
Osteomalacia | bone softening in adults. |
Factor affecting bone growth | UV exposure |
How does UV exposure affect Vit D absorption | Vit D synthesized from substrate in presense of UV ; via skin and digestive tract |
Digestive tract | Is better for absorbing Vit D.... |
Factors that affect bone growth: mechanical stress | Stimulates osteoblasts |
Osteoblasts decreases and osteoclasts increases | Result of mechanical stress |
Factors that affect bone growth: hormones | Secreted by the pituatary, thyroid, parathyroid, ovaries and testes. |
Pituatary stimulates | Growth hormone |
Thyroid stimulates | replacement of cartilage in the epiphyseal plates of long bones |
Stimulates osteoblast activities | Thyroid stimulates |
Parathyroid stimulates | Increase number & activity of osteoclasts which break down bone. |
Ovaries and testes stimulates | testosterone and estrogen promotes bone formation; stimulates ossification of epiphyseal plate |
Hormonal Osteopathology | pituatary dwarfism; pituatary gigantism;acromegaly |
pituatary dwarfism | decreased levels of human growth hormone |
HGH stimulates | cartilage cells- which eventually turn into bone. |
normal body proportions but dwarfed | Pituatary dwarfism |
Pituatary gigantism | Increase levels of human growth hormone (therefore increase mitosis in cartilage) results in stature up to 8 feet. |
Increase mitosis and pituatary gigantism that leads to death | rapids growth leads to losing telomeres resulting slow down mitosis leading to early death. |
Acromegaly | increase levels of human growth hormone results in enlarged hands, feet, jaw, ears. |
Cause of acromegaly | pituatary tumor |
treatment for pituatary dwarfism | administer HGH could lead to up to inces of growth..has to be adminstered at right time. |
Timing of administrating HGH to stimulate growth is based on what | the stage of epiphyseal plate... |
Osteopathology/osteotrauma | Chondrodysplasia; osteogenesis imperfecta; factures |
chondrodysplasia | irregular collagen fibers leads to stunted growth and deformed joints |
Osteogenesis imperfecta | Too few collagen fibers; easily broken bones |
To give rise to imperfect bones | Osteogenesis imperfecta |
Insufficient collagen fibers = | Brittle bones; osteogenesis imperfecta |
fractures | Any cracklying or breaking of bones |
Traumatic fracture | via injury |
pathological fractures | via disease |
fracture origins | traumatic and pathological |
Fracture extent | closed; compound; complete, incomplete |
Closed fracture | skin not broken via bone movement |
compound fracture | skin broken via bone movement exposing fracture |
Open fracture = | compound fracture |
Complete fracture | bone broken in 2 or more pieces |
incomplete fracture | bone not broken into 2 pieces |
communited fracture | complete fracture; broken into 3 or more pieces; common in old and brittle bones |
Compression fracture | Crushed bone; common in porous bones (i.e. osteoporosis); at risk for extreme caution as in a fall. |
Spiral | Twisting of bone; common sports fracture |
Epiphyseal break | Epiphysis seperates from diaphysis along epi plate |
greenstick fracture | Incomplete fracture; break occurs on convex surface of the bend in the bone. |
Fissured fractures | incomplete fracture; longitudinal break |
Transverse fracture | complete; break occurs at right angle to axis of bone |
Oblique fracture | complete;occurs at an angle other than right angle of the axis of bone |
Depressed fracture | broken bone portion is pressed inward; typical skill fracture |
green stick fractures are common in children because | there bones are more organix matrix and more flexible that those of adults |
four major steps in bone repair | 1. hematoma formation, 2. fibrocartilage callus formation; 3. bony callus formation; 4. bone remodeling |
Stage 1: hematomoa formation | bone repair; blood escapes severed blood vessels forming a hematoma |
stage 2: fibrocartilaginous callus formation | spongy bones form close to developing blood vessels, fibrocartilage forms |
Stage 3; bony callus formation | This replaces fibrocartilage |
Stage: Bone remodeling | Stage 4: osteoclasts remove excess bony tissue- new bone is restored. |
Low calcium level stimulates | parathyroid which stimulates parathyroid hormone which stimulates osteoclasts that break down bone to release calcium into blood |
High Calcium level stimulates | thyroid gland to release calcitonin, then stimulates osteoblasts which deposit calcium into bones |
Osteoporosis | trabeculae are lost and compact bone develops open spaces |
In osteoporosis, trabeculae are lost & compact bone develops open spaces causes | inactivty of osteoblasts (which builds bones) and continued activity of osteoclasts (which break down bone) |
List risk factors for osteoporosis | female, postmenopausal, light complexion, alcohol, smoking, genes, anorexia and lack of exercise in adolesence. |
Approx 25% of gender diagnosed with osteoporosis | American Men |
Extra calcium in blood means what? | There is less calcium in the bone- extra calcium in blood serum activates ostoblasts |
deficient calcium in blood serum activates? | Osteoclasts, which break down bone and release Ca into the blood. |