Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
34 Cards in this Set
- Front
- Back
steady state
|
a condition that doesn't change with time.
- energy - may be required e.g. ion gradients |
|
equilibrium
|
- opposing forces are balanced and their is no net movement between compartments
- type of steady state equilibriium - energy - not required for equilibrium. |
|
components of a control system
|
- sensor - measures variables you're trying to control.
- integrating center - compares the input to the set point - effectors- change the system |
|
negative feedback systems
|
- brings it back into normal range
|
|
reason temp. regulation is needed
|
- maintain rxn. rates at optimal level.
|
|
pathologic consequences of temp. deviations.
|
excessive heat - 43 deg. C or up is fatal
- excessive cold - less than 77 deg. farhenheit is fatal. |
|
core vs. peripheral temp.
|
- core = brain, thoracic/abdominal cavities
- imp. to control these areas temp. |
|
control system
|
- sensors (thermoceptors)
peripheral - monitor shell temp. - central - hypothalamus of brain and abdominal cavities - integrating center - hypothalamus - compares set point to input (thermoceptors) |
|
responses to the cold
|
- decreased blood flow to the skin
- inc. symp. ns. activity --> skin vasoconstriction --> dec. blood flow--> decreased heat loss |
|
shivering response to the cold
|
- hypthalamus --> motor neuron actiivty --> skeletal muscle contraction
|
|
responses to cold increased metabolic rate
|
- increased epinepherine and thyroid hormone release
- increased fat breakdown brown fat - lot of mitochondria in it and this produces more metabolic activity and more heat. |
|
responses to heat -
|
behavioral adjustments
- increased blood flow to skin - decreased s.n.s. activity --> skin vasodilation --> increased blood flow --> increased heat loss - sweating - evaporatin cools off the skin. |
|
pathological conditions of temp. range
|
- fever - increase in setpoint, the bodies thermostat goes up
- mechanism - infection, traums --> macrophages --> increased pyrogens --> increased prostaglandins in hypothalamus --> increased setpoint. |
|
hyperpyrexia
|
- greater than 41 deg. cel. is life threatening.
|
|
hypothermia
|
- less than 35 deg. cel. is mild
- less than 28 degres cels. is severe - less than 25 deg. cels. is fatal. - CNS effects - confusion - cardiac effects - arrhythmias due to faulty ion channels in heart. |
|
heat exhaustion
|
- profuse sweating --> fluid loss --> dec. blood volume --> dec. blood pressure --> fainting.
|
|
heat stroke
|
- immediately life threatening
- GI vasoconstriction --> ischemia --> endotoxins from intestines released into the blood - signs - increased body temp., often no sweating; - CNS: delirium, coma, siezures |
|
phospholipids
|
3 carbon backbone, 2 fatty acids, phsophate adn alcohol
- amphipathic - polar and non polar regions - headgroup alcohol group is polar - fatty acids - non polar regions. |
|
cholesterol
|
- decreases membrane fluidity and may alter membrane protein function.
|
|
membrane protein
|
integral - in the membrane and they cross or embedded)
- peripheral - loosely associated |
|
carbohydrates
|
- can be attached to protein or lipid
- glycolipids and glycoproteins - almost always face outside of cell. |
|
membrane transport
|
- simple diffusion - occurs by random thermal motion.
- rate increased with concentration - direct relationship between concentration and solute concentration. |
|
factors determining diffusion through cell membrane
|
- size - smaller passes easier
- polarity - non polar pass more readily - osmosis - (diffusion of water) - H2O moves from area of high H2) conc. to low H2O concentration, and stops moving when hydrostatic pressure exactly opposes osmotic pressure. |
|
osmolarity
|
- cell osmolarity is approx. 300 mosm.
- hypoosmotic - solution has lower number of solutes. - hyperosmotic - solution has a higher number of solutes. |
|
tonicity
|
- the molar concentration x the number of osmotically active impermeant molecules
THIS IS WHAT DETERMINES IF CELL SHRINKS OR GROWS. NOT osmolarity |
|
tonicity in review
|
- hypotonic solution - solution has less solute than cell
- H2O moves into the cell and it grows isotonis solution - no movement and cell volume remains the same. - hypertonic solution - cell has less solute than solution so water moves out and the cell shrinks. |
|
clinical relevance of tonicity
|
- hypnatremia/ water intoxication - low tonicity and H2O moves in.
- kidney and liver disease - late stage alcoholism - tonicityof peritoneal fluid is much higher than blood so fluid flows out and pot belly follows. |
|
facilitated diffusion
|
- carrier proteins (transporters or exchangers) -
passive - moves from area of high to low conc. of molecules - substrate size - can move large molecules that wouldn't pass otherwise - transport max. velocity (Vmax) - max. velocity you can have at any given conc. because their are only so many receptors. competition - if 2 substrates compete the rate for each goes down. |
|
ion channels
|
- rapid movement after gate opens
- passive - - substrate size - small molecules - specificity - selective ( varies) - flux rates - very high rate of ion streaming. - 3 main types - activated by NT's, voltage or stretch. |
|
active transport
|
- primary - directly breaking down ATP to move molecules
NaATPase goes against conc. gradient. - secondary - indirectly using energy stored in conc. gradient created from primary active transport two types - symport - move molecules in the same direction - antiport - move molecules in opposite direction |
|
vesicular transport
|
- endocytosis
- pinocytosis - small particles/ fluid taken in - phagocytosis - large particles - receptor mediated endocytosis - ligand that binds surface protein and that molecules are then taken up into vesicle (ex. ion receptor) - exocytosis - intracellular vesicle diffuses thru plasma membrane. - exocytosis - intracellular vesicle diffuses thru plasma membrane |
|
second messenger systems
|
- intracellular - takes EC signal and transmits it inside via receptors
- amplificaiton - make signal stranger because theyre catalytic. - speed - fast responses (seconds to minutes) |
|
adenylyl cyclase/ cyclic AMP
|
- G protein signal to adenylyl cyclase creates cAMP (2nd messenger)
- PDE - breaks down cAMP - |
|
phospholipase C/inositol triphosphate (IP3)
|
Protein lipase C --> activates DAG or it creates IP3 which causes the cascade (DAG activates protein kinase c makes atp into ADP)
- di acyyl glycerol is the 2nd messenger (lipid soluble) -->activates protein kinase C -- IP3 is the other 2nd messenger -- synthetic enzyme --> hormone |