Homeostasis/Membrane Potential

Question 1

the body’s tendency to maintain relatively constant internal enviro

Answer 1

homeostasis

Question 2

homeostasis is not equilibrium, but it is in a _____ state

Answer 2

dynamic steady

Question 3

what is the response loop?

Answer 3

stim–>sensor–>input–>integrate–>output–>target–>response

Question 4

what is local control and what is an example?

Answer 4

restricted to tissue/cell involved; lower O2

Question 5

wat is reflex control and what is an example of it?

Answer 5

long-distance, systemic path using nervous/endocrine system; maintaining BP

Question 6

___ feedback stabilizes variable, ___ feedback reinforces, ____ control anticipates change

Answer 6

negative; positive; feedforward

Question 7

which feedback loop is homeostatic?

Answer 7

negative

Question 8

example of neg feedback?

Answer 8

glucose regulation

Question 9

ex. of positive feedback?

Answer 9

uterine contractions

Question 10

ex. of feedforward

Answer 10

salivation

Question 11

what is buffer zoe between outside world and cells of body?

Answer 11

extracell fluid

Question 12

what is the ECF-ICF dividing wall?

Answer 12

cell membrane

Question 13

what are the 3 main types of lipids?

Answer 13

phospho, sphingo, chol

Question 14

membrane phosph can form these 3 things:

Answer 14

bilayer, micelles, liposomes (aqueous centre)

Question 15

functions of cell membrane?

Answer 15

physical isolation, reg. exchange with enviro, communication between cells and enviro, structure support

Question 16

these spatially organize signalling cules at mem to promote kinetically favourable interactions necessary for signal transduction

Answer 16

lipid rafts

Question 17

ICF is ___ of body fluid, ECF is ___

Answer 17

2/3; 1/3

Question 18

plasma is ___% of ECF volume, interstitial fluid is __%

Answer 18

25; 75

Question 19

__% BW of water

Answer 19

60 (more in M)

Question 20

mvmt of water across mem in response to solute concentration gradient

Answer 20

osmosis (diffusion, channels) –>membrane permeable to water but NOT solutes

Question 21

the # of particles in given volume of solution (NOT molecules)

Answer 21

osmolarity

Question 22

what is molarity?

Answer 22

number of moles of solute per L of solution

Question 23

solution that contains > particles/vol than other is ___, the one with less is ___

Answer 23

hyperosmotic; hyposmotic

Question 24

solution’s ability to affect cell vol if cell placed in solution and allowed reach equilibrium (osmolarity and nature of solutes)

Answer 24

tonicity

Question 25

___ cell loses water at equilibrium; ___ cell gains water

Answer 25

hypertonic; hypotonic

Question 26

cell mem impermeable to ____, permeable to ____

Answer 26

charged cules, large water soluble cules; small uncharged, water via aquaporins

Question 27

what properties of molecule influence mvmt across mem?

Answer 27

size, lipid solubility

Question 28

two types of passive trans?

Answer 28

simple, facilitated diffusion

Question 29

2 types active?

Answer 29

prim and sec

Question 30

3 types vesicular trans?

Answer 30

phago, endo, exo

Question 31

two types epithelial trans?

Answer 31

para, transcell

Question 32

diffusion is faster when:

Answer 32

[ ] gradient high, short distance, ^ temp, small cules

Question 33

what is Fick's law?

Answer 33

Rate of diff = SA x [ ] gradient x mem permeability

Question 34

types of gated channel proteins?

Answer 34

mechanically gated, volt gate, chem gate

Question 35

types of open gated channels?

Answer 35

K+, aquaporins

Question 36

ex. of facilitated diffusion by carrier proteins?

Answer 36

glucose

Question 37

Xtracell have ^ ___ and v ___

Answer 37

Na; K

Question 38

Na-K ATPase is example of:

Answer 38

primary active antiport

Question 39

example of secondary symport?

Answer 39

Na-glucose

Question 40

3 characteristics of both passive and active carrier transport

Answer 40

specificity, competition, saturation

Question 41

____ endocytosis requires ____ coated pits

Answer 41

receptor-mediated; clathrin

Question 42

trans from lumen-->ECF is called ___, reverse called ___

Answer 42

absorption (trans and para); secretion

Question 43

uses vesicles to cross epithelium when cules too large for reg. epithelial trans

Answer 43

transcytosis

Question 44

xample of transcytosis?

Answer 44

absorption of maternal antibodies from breast milk

Question 45

membrane potential results from:

Answer 45

separation of charges across mem

Question 46

ECF and ICF in state of electrical ____

Answer 46

disequilibrium

Question 47

neurons have resting potential of:

Answer 47

-60 to -70MV (unequal distribution of ions)

Question 48

4 most abundant ions?

Answer 48

Na, Cl, (extracell) K, A- (intracell)

Question 49

how is Vm maintained?

Answer 49

K+ background channel, Na-K pump

Question 50

what is Nernst equilibrium potential?

Answer 50

function of concentration x electrical charge

Question 51

how to calc driving force?

Answer 51

Eion-Vm

Question 52

Na-K pump pushes __ Na out of cell, __ K inside

Answer 52

3; 2