U2- Bone Histology Flashcards
bone function
support against gravity
protection for organs
mvmnt (ligaments)
electrolyte balance (release Ca + Phos. ions)
acid-base balance (bone tissue buffers blood)
blood formation (hematopoiesis)
osseous tissue
CT
hardened by mineral deposits
shapes of bones
sesamoid flat short irre. long
sesamoid bones
dev. btw tendons
osteoclast
bone dissolving cell
multinucleated
dev. from WBC
releases Ca to regulate blood conc.
osteogenic
stem cells from mesenchyme
evolve to diff. types of cells
hydroxyapatite
ground substance of bone
forms crystalline structure
gives bone rigidity
spongy bone
lattice structure w/ trabeculae
adds support w/out weight
interstitial lamellae
prts of old osteons found
feedback loop- dec blood Ca
stimulus- Ca levels high in blood
receptor- Calcintonin cells of thyroid gland control Calcitonin
message- calcitonin
effector- osteoblast inhibit osteoclast break dwn
Ca reabsorb. not encouraged
feedback loop- inc blood Ca- Calcitriol
absorbed by intestines to inc concen.
inc. osteolysis (Ca break down)
halts Ca excretion in kidneys
Feedback loop- inc blood Ca- PTH
receptor+ control c- parathyroid gland cells sense Ca lvl
mesage- PTH (enters blood)
effector- osteoclast break down bone
(osteoblast trigger osteoclast)
kidney cells absorb more Ca
intestines more permeable to CaWolff’s Law
bone architecture depends on stress placed upon bone
interstitial growth
cartilage grwth
deposition of new matrix
chondrocyte
mature bone cell
