Exam 2 Skeletal system part 3 Flashcards
Development of the bones @ the top of the skull + clavicle are classified as what type of growth?
Intramembranous (dermal) bone growth
Development of the bones of the skull bas + all postcranial bones
Endochondral bone growth (cartilaginous)
Endochondral bone growth: ________ model forms (composed of hyaline cartilage)
Cartilaginous
Endochondral bone growth: Cartilage disintergrates excavates _____ of the bone; blood vessels invade, bringing undifferentiated _________ cells
Interior; Mesenchymal cells
Endochondral bone growth: Mesenchymal cells differentiate into _______, which start forming spongy bone
Ostroblasts
Endochondral bone growth: ________ forms; osteoblasts w/in the cellular layer of the _______ form compact bone.
Periosteum; periosteum
Endochondral bone growth: Further bone growth takes place in 2 directions:
B/t diaphysis & epiphysis (interstitial growth), Increase in over-all size (appositional growth)
Interstitial growth: Blood vessels invade ends of bone, which become _______ centers of ossification
secondary
Zone of cartilage remaining b/t primary & secondary ossification centers, site of active growth
Epiphyseal plate
Growth ceases when plate ______
ossifies
appositional growth: new compact bone deposited by osteoblasts just below the _______
periosteum
_____ @ inner bone surface destroy bony connective tissue & enlarge the ______ cavity (if present); remodel compact bone/spongy bone interface
Osteoclasts; medullary cavity
Intamembranous bone: Membranes form around _____ _____
Blood vessels
Intamembranous bone: Undifferentiated connective tissue cells around blood vessels differentiate into ______, which start forming ______ bone
Osteoblasts; spongy
Intamembranous bone: periosteum forms cells w/in the _____ layer differentiate into _______ which start forming compact bone below periosteum
cellular layer, osteoblasts
Intamembranous bone: Remaining growth takes place via mechanism similar to appositional growth of ________ bone
Endrochondral bone
- Necessary for proper collagen formation
- Deficiency leads to scurvy
Vitamin C
Synthesized w/in the skin or ingested in the diet
Vitamin D
Vit. D facilitates proper bone mineralization by increasing absorption of calcium w/in the ________ & reabsorption of calcium in the _______
Small intestines; Kidneys
Vit. D deficiency in children leads to?
Rickets
Vit. D deficiency in adults leads to?
Osteomalacia
_______ hormone increases amount of calcium in blood by indirectly stimulating osteoclast activity
Parathyroid hormone (PTH)
Parathyroid hormone binds to receptors on the ______. which then release __________ ligand
Osteoblast; osteoprotegerin
Osteoprotegerin ligand activates receptors on _______ cells, which causes them to mature into _______
preosteoclast cells; osteoclast
Excess of parathyroid hormone leads to ____ ______
Bone thinning
Stimulates body, bone growth
Pituitary growth hormone
Excess pituitary growth hormone in children leads to ______
Gigantism
Excess pituitary growth hormone in adults leads to ______
Acromegaly
Deficit of pituitary growth hormone in children leads to:
dwarfism
Green stick fracture:
bone is bent & incomplete break, usually seen in children
Comminuted fracture:
bone fragments = no blood supply, death to cells can happen quickly
Compression fracture:
found in limbs, vertebral column, could be from disease weakening the bone & then gravity the bone would become compressed
What goes into healing a fracture?
- Fracture hematoma formed from ruptured blood vessels
- Soft callus forms (mixture of spongy bone & fibrocartilage)
- Hard callus forms by mineralization of soft callus
- Remodeling of hard callus to mature (compact/ spongy) bone
Inflammation of bone tissue caused by injury or infection
Osteitis
Inflammation of periosteum caused by trauma or infection
Periostitis
Inflammation of bone interior caused by bacteria, usually initially entering the bone via wound or via blood stream
Osteomyelitis
Can spread to the spongy bone (particularly of the vertebral bodies), resulting in bone & joint destruction
Tuberculosis
Benign Neoplasms:
Osteochondroma
osteoma
Malignant neoplasms:
Osteogenic sarcoma (osteosarcoma) multiple myeloma
Reduction in bone mass, most prevalent in middle aged & elderly women
Osteoporosis
Can lead to osteoporosis:
- Vit. C defincy
- osteoblast can’t keep up w/ osteoclast = loss of bone density
