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35 Cards in this Set
- Front
- Back
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relationship btwn cells, organ systems, and homeostasis
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organ systems maintain homeostasis
homeostasis is essential for survival of cells cells comprise organ systems |
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negative feedback
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causes reversal of variable
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positive feedback
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reinforces a variable
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negative feedback in osmolality
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increased plasma osmolality
osmoreceptors detect hypothalamus synthesizes and PP secretes ADH kidneys retain more water and excrete less water plasma osmolality decreases |
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neg feedback in blood glucose
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decr blood glucose
alpha cells of panc detect alpha cells secrete glucagon glycogen converted to glucose in hepatocytes |
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glycogenolysis
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conversion of glycogen to glucose in hepatic cells, caused by glucagon
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MAP
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mean arterial pressure
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neg feedback of MAP
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decr MAP
baroreceptors in carotid arts and aortic arch detect brainstem activates SNS incr in HR and cardiac contractility and vasoconstriction |
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positive feed back in uterus
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incr stretch on uterine walls
stretch receptors detect hypothal synthesizes and PP secretes oxytocin stim of myometrial contractions |
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reasons homeostasis can't be maintained
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1. something prevents organ/system from doing its job
2. loss of neg feedback mechs 3. organ/system reaches physiological limit |
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neurgenic vs nephrogenic DI
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neur: decr ADH secr from PP
nephro: kidneys insensitive to ADH |
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when MAP decr, body is limited by how much HR and CC can increase and by how much vasoconstriction can occur. why?
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cardiac output based on HR and volume pumped by CC; HR can only make up for low volume if chambers are full-ish for effective CC
severe vasoconstriction kills tissue, other systems override vasoconst |
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relationship between physiological and pathological states
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physiologic to pathologic when homeostasis is disrupted
pathologic to physiologic due to therapeutics |
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Components of ECF (2 maj, 2 min)
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Major: plasma and interstitial fluid
Minor: third-space and lymph |
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what is third space?
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body cavities which usually do not collect fluid or which are nonfunctional with fluid
ex: pleural and peritoneal cavities |
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what is ICF
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intracellular fluid = collective fluid contained w/i cells
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ECF and ICF are rich in _
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ECF: Na+
ICF: K+ |
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protein concentrations are high in __ and __ and low in __
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proteins high in plasma and ICF
proteins low in interstitial fluid |
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how are electrolyte concentrations maintained across membranes?
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electrolytes maintained via osmosis nad diffusion
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E for simple and facilitated diffusion come from __
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concentration gradient (or chemical potential energy difference)
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diff between lipid soluble and insoluble diffusion
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soluble can openly cross membrane if small; channel proteins for insoluble
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Na/K pump is an example of __
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primary active transport
(ATP req to pump Na out and bring K in simult) |
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Secondary active transport types
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symport/co-transport (ex Na pumped out to produce gradient, so when it re-enters the energy produced pumps Ca out of cell)
antiport/countertransport (ex Na enters cell and glucose crosses through in channel protein w it) |
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bulk transport types
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1. endocytosis (/receptor-med)
2. exocytosis 3. pinocytosis |
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most abundant cation in body
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Na+
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Na+
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*ECF levels = 135-148 mEq/L
*helps maint osmostic P of ECF, RMP and action potential generation, facilitates absorp of glucose in SI |
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Where should K+ be/do?
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K+ in ICF, only small amounts in blood (3.5-5.5 mEq/L)
*damaged cells/enzymes can release K+ in blood *nerve conduction, muscle funct, acid-base balance, osmotic P reg., cardiac output/HR |
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hyperkalemia
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high K+ in blood
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Ca++ used/stored in __
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50% ionized (=useable), 50% protein bound
stored in bones/teeth used for musc contract, cardiac funct, enzyme activ, NT exocytosis, blood clotting |
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What regulates calcium via endocrine system?
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PHT (parathyroid) and CT (calcitonin)
*also, vit D, estrogens, and androgens |
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2nd most abundant cation
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Mg++
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where is Mg++ stored?
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50% bone
49% ICF 1% ECF |
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Mg is imp for _.
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*req for use of ATP for E (needed in enzyme systems like metabolism, prtn synth, NA synth, and musc contract
*req for Na/K pumps |
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Cl- is found __ and is imp for ___
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*Cl- mostly in ECF as NaCl or HCl (in stomach)
*maint cellular integritiy via osmo P and acid-base and H2O balance |
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What is HCO3- and why is it important?
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Bicarbonate
Imp in acid-base balance measure via ABG (arterial blood gas) |
