Membrane Test 1

Front 1

T/F about neurons?
they are all classified as multipolar due to their numerous dendrites

Back 1

false

Front 2

T/F about neurons?
supporting cells are formed by fission of the perikaryon

Back 2

false

Front 3

T/F about neurons
their processes contain numerous microtubules and neurofilaments

Back 3

true

Front 4

T/F about neurons?
they produce the reticular fibers of the endoneurium

Back 4

false

Front 5

T/F about neurons?
when stimulated, they divide rapidly to form new neurons

Back 5

false

Front 6

lysosomes function in which of the following ways:
a) destruction of bacteria
b) degradation of worn-out or excess organelles
c) playing a role in the reabsorbtion of bone and secretion of thyroid hromones
d) a, b, c
e) a, c

Back 6

all three are correct

Front 7

microglia:
a) form the glia limitans
b) are phagocytic
c) derive, in most cases, from astrocytes
d) are smaller, but much more numerous than oligoden.
d) make up most of the cells found in scar tissue in the cns

Back 7

b) glia are phagocytic

Front 8

at the peak of the AP described in class, which of the following gradients change(s) direction?
a) Na concentration grad
b) K concentration grad
c) negatively charged anion gradient
d) electrical gradient
e) all of the above

Back 8

d) electrical gradient

Front 9

the primary morph diff between a PNS neuron and a CNS neuron is that:
a) only CNS neurons have a lg euchromatic nuclei
c) only PNS neurons have neurofilaments, because axons must be several ft long
e) none of above

Back 9

e) none of above

Front 10

an experimental procedure that lowers the monomer concentration of actin in a cell will be most likely to directly:
a) cause increased endocytosis
b) increase number of actin microfilaments
c) cause microfilament depolarization
d) decrease the concentration of cytoplasmic Ca++
e) increase intermediate filament polymerization

Back 10

c) cause microfilament depolymerization
check this one!

Front 11

the primary site of action of signal peptidase is:
a) smooth ER
b) RER
C) the cis golgi network
d) the trans golgi network
e) vesicles that shuttle between cis- and trans-golgi network

Back 11

b) RER, but need to verify

Front 12

which one of the potentials is not electrotonic in nature?
a) EPSP
b) IPSP
c) AP
d) generator potential
e) receptor potential

Back 12

c) AP

Front 13

increasing which membrane parameter(s) will result in a faster AP conduction velocity?
a) length constant
b) time constant
c) both a and b
d) neither a or b

Back 13

need to verify

Front 14

which statement is false about how materials move in and out of cells?
a) materials can be taken up by cells via pinocytosis
b) lysosomes must synthesize all of the hydrolases that they contain since proteins cannot gain access to them by any other mech
c) materials such as proteins can move through nuclear pores by a mechanism called gated transport
d) substances synth by the RER can be transported from the RER lumen into the golgi apparatus using transport shuttle vesicles
e) prot can be transp across some cell memb such as those surr peroxisomes and mitochondria

Back 14

b) lysosomes must synth
verify

Front 15

a neuron is stimulated with an elec impulse that depolarizes its membrane potential exactly to threshold for AP production. at this threshold stimulus level what are the directions and relative magnitudes of the Na and K currents elicited by the stim?
a) inward Na current is greater than the outward K current
b) inward Na current is less than the outward K current
c) outward Na current is greater than inward K current
d) inward Na current equal to outward K current
e) outward Na current is equal to inward K current

Back 15

need to verify

Front 16

muscle is surr by conn tissue layers. nerves and blood vessels are found in the conn tissue layer called the:

Back 16

need to verify:
aren't blood vessels not found in the CT that surrounds muscle?

Front 17

approx what % of a cell's total RNA consists of ribosomal RNA?

Back 17

85%

Front 18

when a smooth muscle contracts
a) the degree of tension may have been influenced by elec or hormonal signals
b) troponin C binds Ca and the myosin binding site on the actin myofilament is exposed
c) the thick and thin myofilaments depolymerize thus becoming shorter
d) nucleus maintains its elongated shape b/c the nuclear lamins provide a stiff intranuclear matrix and prevent nucleus from changing shape
e) length of both sarcomere and I-band decreases

Back 18

need to verify

Front 19

in skeletal muscle a group of myofibers contracts at the same time because they:
a) are a syncytium
b) are all innervated by same neuron
c) are phys connected at the Z-line by intermediate filaments
d) communicate w/ each other through gap junctions
e) all of above

Back 19

b) are all innervated by same neuron

Front 20

which is true about peroxisomes?
a) contain some enzymes that generate hydrogen peroxide and others that destroy excess HP
c) inner membrane contains proteins involved in e transport
d) matrix has a pH optimum at about pH 5
e) microtubules of the cell radiate outward from peroxisomes found adj to nuc

Back 20

a) contain enzymes that generate HP and destroy excess HP

Front 21

mEPP produced by release of _____ into synaptic cleft

Back 21

one synaptic vesicle

Front 22

which follows linear kinetics

Back 22

simple diffusion

Front 23

what effect will addition of KCL to the inside of the typical cell have on its resting potential: (assume Cl does whatever is req'd to remain in equil and ignore any role of the NaK pump

Back 23

hyperpolarization ??? or no change?

Front 24

a super threshold stim is applied to a merkel disc located in a subj finger. what info reaches the SC that allows the cns to judge the amplitude of the applied stim?
a) generator potential amp
b) receptor pot amp
c) receptor pot freq
d) action pot amp
e) action pot freq

Back 24

verify: ap freq?

Front 25

how do you measure the magnitude of the stimulus from an intracell electrode?

Back 25

frequency of AP's

Front 26

simple diffusion and carrier mediated transport share what chars?
a) can be passive
b) follow saturation kinetics
c) req that oil to water partition coeff must be greater than 1
d) follow linear kinetics
e) indep of electrochem gradient of solute

Back 26

a) can be passive
carrier mediated transp follows saturation kinetics, simple follows linear

Front 27

which is true about cells?
a) invariably contain only one nucleus
b) all of internal cell memb attach directly to surface memb
c) all cell organelles are surr by single cell memb
d) molecular motor proteins can be involved with mvmt of vesicles along microtubules

Back 27

d) molec motor proteins involved with mvmt of vesicles along micro tub (ribosomes don't have membranes)

Front 28

what effect would adding NaA to external medium to increase ec Na concentration by X2 have on resting and action potential?

Back 28

depends. won't affect amp of AP, but may sl depolarize resting memb pot

Front 29

which is true about mitochondria?
a) enzymes involved in coupling of electron transp to ATP synthesis are only found in the outer mitochon membrane
b) DNA found in mito was transported into mitochon from nucleus
c) mitochon are specialized to contain acid hydrolases
d) cristae increase membrane surface are of the inner mitochon memb
e) all cells need energy so they have same number of mito per cell

Back 29

d) cristae inc memb surf area of inner mitochon memb

Front 30

EC recording:
velocity to right
- then + electrodes
draw oscilloscope tracing

Back 30

upper defl first then lower defl

Front 31

which ch in the membrane is resp for creating the resting pot in typical cell

Back 31

non-gated K+ ch

Front 32

which is true about nucleus?
a) it is surr by a metabolically active single cell memb
b) protein components of ribosomes are synthesized in a sp region of the nucleolus
c) nuclear lamins make up fibrous lamina that is found just inside nuc envelope
d) nuclei rich in heterochromatin are ext active in synthesis of ribosomal units
e) ribosomal precursors gain access to cytoplasm by vesicular transp mech

Back 32

c) nuclear lamins
(no prot synth in heterochrom)
(no ves transp through nuc)

Front 33

what is resp for repolarizing an unmyelinated axon back to resting pot during an AP

Back 33

VG K+ ch

Front 34

glycosaminoglycans are large molecules that are formed from
a) repeating disaccharide subunits
b) glycosylated proteins
c) RNA protein complexes
d) type III colagen
e) repeats of tetrapeptide proline-lysine-glycine-histidine

Back 34

a) repeating disacch subunits

Front 35

which of following organelles normally contain DNA?
a) mitochon and nucleus
b) peroxisomes and nucleus
c) mitochon and RER
d) nissl substance and RER
e) nucleus and transp vesicles

Back 35

a) mitochon and nuc

Front 36

which of following do NOT normally ferry material to lysosomes so that the contents can be digested within lysosomes?
a) phagosomes
b) autophagosomes
c) endocytotic vesicles
d) pinocytic vesicles
e) microbodies

Back 36

e) microbodies

Front 37

E(Na) = +66 mV
E (K) = -70 mV
E(Cl) = -60 mV
Em = -55 mV
threshold -45 mV
a postsyn potential is initiated in a typical CNS neuron at its resting pot by increasing postsyn memb permeability to chloride (Pcl). this permeability change will produce ____ by means of ____ chloride current in the postsyn cell

Back 37

c) IPSP, inward

Front 38

E(Na) = +66 mV
E (K) = -70 mV
E(Cl) = -60 mV
Em = -55 mV
threshold -45 mV

a postsyn potential is initiated in the CNS by closing a normally open K+ channel in the postsyn memb. this permeability change will produce ____ by _____ the outward K+ current in the postsyn cell

Back 38

an EPSP.....decreasing

Front 39

which is true about mitochon?
a) outer membrane sur mitochon contains enzymes involved in elec transport and coupling of electron transp to ATP synthesis
b) porin particles are found in the mitochon matrix and selectively bind to ca ions
c) cristae are folds of the outer mitochon memb that project into the cytoplasm
d) mitochondria in muscle cells are only found around nucleus
e) fcns of mitochon include synth of ATP and some steps in steroid hormone synthesis

Back 39

need to verify (not a)

Front 40

activit of Na+ K+ pump is regulated mainly by:
a) Na in
b) Na out
c) K in
d) K out
e) Ain

Back 40

need to verify (not d)

Front 41

what prevents AP from generating other AP's that propagate backwards from left to right?

Back 41

Na VG channels are in refractory period (inactivated)

Front 42

which of the following is not a process for uptake of material to be digested within lysosomes?
a) endocytosis
b) phagocytosis
c) autophagy
d) pinocytosis
e) mitosis

Back 42

e) mitosis

Front 43

which are of n. sums the cell's elec inputs and decides whether the cell fires an AP

Back 43

initial or integrative segment of the axon (axon hillock)

Front 44

a miniature end plat potential is due to the
a) release of one molec of ACh
b) opening of one postsyn receptor
c) release of one syn vesicle
d) rel of 200 syn vesicles
e) random opening of sev postsyn ch without rel of NT from presyn memb

Back 44

c) rel of one syn vesicle
(2 molec are needed to open the channel)

Front 45

during a single (twitch) contraction of a skel myofiber,
a) the rel of inorganic phosphate from the myosin head is a rate limiting step of the process
b) a nerve impulse causes rel of NE into syn cleft of the motor end plate
c) the interaction of actin and myosin is inhib by titin binding to the myosin
d) some of the sarcomeres contract while others in the same myofiber remain in relaxed conformation
e) myosin binds to actin and ATP at the same time

Back 45

a) rel of inorg phosphate from myosin head is a rate lim step of process

Front 46

if a memb is permeable to both Na and Cl, the memb pot is +60 mV, and nernst pot for both Na and Cl is -60 mV, which of the following pairs of fluxes should occur?
a) na efflux, cl influx
b) na efflux, cl efflux
c) na influx, cl influx
d) na influx, cl efflux
e) no flux of either b/c in equil

Back 46

a) na efflux, cl influx

Front 47

how are motor units recruited as the force a muscle produces increases?
a) CNS recruits a few large motor units to make up most of force and then recruits small units to fine tune amt of force generated
b) CNS inc number of muscle fibers in each MU to adjust amt of force generated
c) small motor units recruited at lowest forces adn remain recruited as larger MUs are recruited to inc muscle force
d) small MU recruited at lowest forces and fire con't as larger MUs recruited to increase muscle force
e) small MU recruited at lowest forces and drop out as larger MU take over force prod

Back 47

c) small MU recruited at lowest forces and remain recruited while larger MUs recruited to inc muscle F

Front 48

smooth muscle:
a) myosin forms highly ordered microfilaments that are conn to these dense bodies in cytoplasm
b) nuclei found near sarcolemma at periphery of cell
c) cells are fusiform shaped and can be linked to each other by gap junctions
d) contraction is inhib by rel of Ca from sarcoplasmic reticulum
e) cells contain specialized NMJ's called motor end plates

Back 48

c) cells are fusiform shaped and can be linked by GJ's

(a is cardiac, smooth muscle is not highly ordered)
(b is skeletal)
(e is skeletal)

Front 49

golgi apparatus is
a) usually basal to nucleus in epithelial cells
b) rarely active in cells of muscle tiss
c) involved in add'n of carbs to var of proteins
d) site where core sugars made of mannose resuides added to nascent polypeptides
e) studded with ribosomes in cells that produce many secretory prot

Back 49

c) involve with add'n of carbs to var of proteins

Front 50

at NMJ endplate the EPP is produced by:
a) opening of separate receptor-gated ch in postsyn membrane for Na and K
b) opening of single class of receptor gated ch in postsyn membrane for Na only
c) opening of single class of R-gated ch in postsyn memb for K only
d) opening vg ch in postsyn memb for Na and K
e) opening of single class of receptor gated ch in postsyn memb for Na and K

Back 50

e) single class for both Na and K

Front 51

neural crest is origin of a diverse set of cells and tissues including:
a) most of PNS
b) lining of gastrointest tract
c)neurons of brain
d) smooth muscle of gut wall
e) strat squamous epithelium of epidermis

Back 51

a) PNS

Front 52

E(Na) = +120 mV
E(K) = -70 mV
E(cl) = -60 mV
Em = -55 mV (resting)
an IPSP would be prod by closing a single normally open ch in the memb that is permeable to:
a) Na
b) K
c) Cl
d) K and Cl

Back 52

a) Na

Front 53

which of following is char of EPSP?
a) all or none
b) propagation
c) sep Na and K ch
d) refractory pd
e) summation

Back 53

e) summation

Front 54

if Cl is initially in electrochem equil across memb and Na nernst pot is more positive than memb pot, an increase in EC Cl concentration will have what effect on memb pot, and the resulting change in memb pot will have what effect on Na influx?
a) hyperpolarization, inc in Na influx
b) hyperpol, dec in Na influx
c) depol, inc Na influx
d) depol, dec Na influx
e) no effect on memb pot or Na influx

Back 54

a) hyper, inc Na influx

Front 55

which is true about perioxsomes
a) catalase within perox destroys HP
b) perox (including both lg and small) are only found in liver, brain, kidney cells
c) perox are surr by 2 cell memb
d) perox enzymes are transp into perox by vesicular transport

Back 55

a) catalase destroys HP

Front 56

actin microfilaments are most likely found:
a) in centrosome, initiating formation of spindle
b) in contractile ring divinding daughter cells during cytokenesis
c) in central core of cilia
d) in reticular lamina underlying epithelial cells
e) as an integral component of connexons

Back 56

b) in contractile ring dividing daughter cells during cytokinesis

Front 57

which is false about syn transmission in n.?
a) although maj of syn in human rely on rel of chem, elec synapses can occur
b) a var of NT can function in various syn
c) rel of vesicles from presyn ending can stim a nerve impulse to be generated from postsyn surface
d) syn trans invariably results in formation of a nerve impulse
e) numerous syn can occur at any given n.

Back 57

d) syn trans invar resuls in formation of n. impulse

Front 58

select most acc statment about CNS:
a) meninges penetrate deeply into n. tissue, dragged inward along with major blood vessels
b) numerous tight junctions bet endothelial cells of CNS blood vessles constitute most impt fcnal component of BBB
c) fibroblasts of the pia send out numerous cytoplas extensions that meet astrocyte foot processes and thus form most impt structural component of connective tissue in CNS
d) CSF exits CNS via numerous lymphatics that course through arachanoid
e) perisoteum is another name for dura mater that is closely applied to bone of cranium and spinal cord

Back 58

b) numerous tight junctions bet endothelial cells of cns blood vessels make BBB

Front 59

when the typical cell is at resting pot of -90 mV, (no AP's syn pot, etc) Na leaks ______ and K leaks ____ the cell

Back 59

Na leaks into
K leaks out of

Front 60

an end plate potential at NMJ is produced by inc permeability of the muscle cell memb to :
a) Na only
b) K only
c) ACh only
d) K and Na
e) Na, K, and ACh

Back 60

d) Na and K
2 ACh molec bind to alpha subunits of receptor, opens ionic ch which move the Na and K

Front 61

choose most acc stmt:
a) sk muscle cells surr, individually, by a basal lamina
b) in adult, cardiac muscle cells are able to divide in response to injury
c) sk muscle fibers are connected by gap junctions
d) smooth muscle cells contain sarcomeres
e) in skel muscle, myosin binds to actin in the absence of Ca

Back 61

need to verify

Front 62

which of the following is true about glia:
a) astroglia surr nerve cell bodies in autonomic ganglia
b) they prov support, elec insulation, and or aid in metab exchange for n. they are assoc with
c) schwann c are found in assoc with myelinated n. but not with unmyl ones
d) they are formed by div of pre-existing n.
e) form epineurim

Back 62

b) provide supp elec insul and or aid in metab exch
(schwann cells endoneurium?)

Front 63

ependymal cells:
a) line the central canal of the SC as well as form surfaces of arachnoid villi
b) ahve motile cilia on apical surf (except for the ependymal cells of choroid plexus)
c) synthesize type IV collagen fibers bound in bet all glial cells of cns
d) cover capillaries that penetrate cns
e) joined tog by tight junctions (except for ependymal cells of choroid plexus)

Back 63

a) line central canal of SC and form surf of arach villi
(they have microvilli on apical surf)

Front 64

anterograde mvmt of organelles in axonal processes is most dir due to:
a) mvmt gen by kinesin in assoc with mictotubules
b) ap produced by influx of K
c) stim of myosin by inc Ca levels
d) site specific polymerization of microtubules
e) pot energy diff bet perikarryon and end of axon

Back 64

a) mvmt generated by kinesin in assoc with microtubules

Front 65

which of following is embryolog source of schw cells?
a) notochord
b) neural tube
c) paraxial mesoderm
d) neural crest
e) ectodermal placodes

Back 65

neural crest

Front 66

the actin-myosin syst in non-muscle cells differs from that in skeletal muscle in tha
a) no non-muscle cells contain tropomyosin
b) myosin in non-muscle cells is activated by phosphorylation by spec enzymes called kinases
c) actin-myosin activity in non-muscle cells is insensitive to intracellular ca
d) in non-muscle cells, vimentin, rather than alpha-actinin, anchors actin filaments
e) actin-myosin of non-muscle cells cannot gen force or mvmt

Back 66

e) actin-myosin of non muscle cells cannot gen force/mvmt

Front 67

which is not true about mitochon?
a) they have only a single unit membrane
b) involved in prod of Atp
c) contain circular DNA that encodes for certain mitochon RNAs
d) present in all cells except mature RBCs
e) have cristae that serve to inc memb area of organelle

Back 67

a) they actually have a double membrane

Front 68

which of the following is part of autonomic nervous syst?
a) nerve cell bodies loc in wall of intesting
b) motor end plates
c) purkinje cells in cereb
d) pacinian corpuscles in finger
e) all of above

Back 68

a) nerve cell bodies in wall of intest

Front 69

peroxisomes would be expected to contain which of the following subst?
a) DNA, RNA, and enzymes nec to synth prot
b) DNA but not RNA so they can not synth prot
c) enzymes used in citric acid cycle
d) var of acid hydrolases
e) catalase and var of oxidases

Back 69

e) catalase and var of ox

Front 70

actin-myosin syst in non-muscle cells differs from that in sk muscle in that:
a) no non-muscle cells contain tropomyosin
b) myosin in non-muscle cells is activated by phosphorylation by spec enzymes called kinases
c) actin-myosin activity in non-musc cells is insensitive to intrac. Ca
d) in non-muscle cells vimentin, rather than alpha actinin anchors the actin filaments
e) actin-myosin of non-muscle cells cannot gen force/movement

Back 70

e) can't gen force or mvmt

Front 71

which of following organelles do not contain microtubules as a major struct element?
a) basal bodies
b) centrioles
c) mitotic spindles
d) cilia
e) microvilli

Back 71

microvilli---- microfilaments

Front 72

which of following would least likely be located in region of axon synapse?
a) mitochon
b) vesicles containing NT
c) microtubules
d) cisternae of RER
e) all of above would be found

Back 72

d) cisternae of RER

Front 73

which of following enzymes is found in lysosomes?
a) ATP synthetase
b) catalase
c) urate oxidase
d) glycosyl transferaseses
e) proteases, lipases, glycosidases

Back 73

e) proteases, lipases, glycosidases

Front 74

which of following stmts concerning intermediate filaments is FALSE?
a) intermed fil can be either very stable or labile
b) lamins are intermed fil proteins that form part of nuclear skeleton
c) intermed fil contract in resp to elevated levels of cytoplasmic ATP
d) vimentin forms non-polar filaments
e) glial cells contain intermed fil different from those found in n.

Back 74

c) contract in response to elev levels of cytopl ATP

Front 75

ribosomes:
a) have 2 subunits, each of which contains one or more sp of RNA and more than 20 distinct prot
b) bind to membranes of rough ER via specific binding domain on S16 protein of small subunit
c) only participate in synth of glycoprot if large subunit has a core segment of 6 mannose residues attached to it
d) are prod in cis-golgi region
e) move along mRNA with energy prov by a dynein motor prot

Back 75

????? (think it's not d or e)

Front 76

ribosomes:
a) consist of small and large subunits both of which contain specific prot and RNAs
b) bound to memb of RER contain a diff set of prot than do ribosomes "free" in cytopl
c) localized to nucleolus synth the protein needed to make new ribosomes
d) traverse the memb of cis-golgi saccules to synth most glycoprot
e) localized in mitochon and perox contain only a lg subunit, as is the case for most bacterial ribosomes

Back 76

a) consist of sm and lg subunits, containing spec prot and RNAs

Front 77

which of following is fcn of peroxisomes?
a) digestion of ingested bacteria
b) destruction of areas of cytopl no longer needed by cell
c) breakdown of HP formed in cell by var chem rxns
d) formation of actin arrays rel to cell mvmt
e) lysis of basal lamina

Back 77

c) breakdown of HP (by catalase) actually gen HP also

Front 78

which of following is most acc match of an organelle with est size?
a) nuclear pore -- 1 micrometer in dia
b) actin microfilament -- 15-20 nanometers in dia
c) mitochon --- 1-8 microm in length
d) small ribosomal subunit -- .1 micrometer in dia
e) axonene of cilia -- 25 nm in dia

Back 78

c) mitochon (1 to 7 microm long)
actin microfil is 5-7 nm in dia
sm subunit listed is greater than entire thing

Front 79

choose best to describe sk muscle:
a) sk muscle c. contain multiple nuclei per cell b/c cytokinesis did not occur aftter karyokinesis
b) cytopl of muscle cells is deeply basophilic due to large aggregates of RSR
c) sk muscle cells each contain only one myofibril per cell
d) sk muscle c. bound together by intercalculated discs
e) n. and specific sk muscle fibers it innervates is called a motor unit

Back 79

e) motor unit

Front 80

two mech by which intracell Ca is maintained low rel to EC Ca concentration are:
a) diffusion of Ca through memb ch and diffusion of Ca directly through lipid bilayer of memb
b) maintenance of Ca Gibbs donnan equil and complete imperm of memb to Ca
c) existence of large elec and chem grad for efflux of Ca
d) primary active transport of Ca and secondary active Na/Ca exchange
e) passive facilitated diffusion of Ca and negative memb pot

Back 80

d) primary active transp of Ca and cotransport of Na and Ca

Front 81

which of following stmts true about plasma memb surr cell?
a) plasma memb can be resolved as a single dense line using light microscope
b) althoug memb surr cell organelles differ in molec struct, plasma memb surr cell always has same kind and amts of lipids and prot
c) trilaminar appearance of unit mem as seen in electron microscope is due to deposition of osmium on hydrophilic groups of the lipid bilayer
d) memb is primarly composed of bilayer of prot molec
e) oligosaccharide chains project out from prot at both extracell and intracell memb surfaces

Back 81

c) trilaminar appearance due to osmium on hydrophillic groups of lipid bilayer

Front 82

rapid depol during upstroke after threshold is prod by inc memb permeab. by about a factor of 1000
a) to Na
b) to K
c) to Cl
d) equally to Na and K
e) equally to Na and Cl

Back 82

to sodium

Front 83

when cariac muscle contracts, the
a) A band of sarcomere widens
b) I band of sarcomere widens
c) A band of sarcomere narrows
d) I band of sarcomere narrows
e) myofilaments shorten in length

Back 83

d) I band of sarc narrows

Front 84

alien:
ENa = -60 mV
EK = +50 mV
ECl = -70 mV
have same anion as we do and its conc is high on inside of cell. resting pot for alien is -60 mV. threshold is -40 mV.
what are relative conc of Na, K, Cl in the alien cell?
a) Na and Cl high outside, K high inside
b) Na and K high outside, Cl high inside
c) Na and K high inside, Cl high outside
d) K and Cl high outside, Na high inside
e) Na, K, Cl all high outside

Back 84

d) K and Cl high outside, Na high inside

Front 85

alien:
Ena = =-60
EK = +50
ECl = -70
Em resting = -60
thresh -40
which ions are at equil in the alien cell?
a) Na
b) K
c) Cl
d) A-
e) none

Back 85

a) Na

Front 86

alien:
Ena = =-60
EK = +50
ECl = -70
Em resting = -60
thresh -40
in alien cell, which dir is Cl moving across membrane when cel at resting pot?
a) inward
b) outward
c) no net current

Back 86

a) inward

Front 87

alien:
Ena = =-60
EK = +50
ECl = -70
Em resting = -60
thresh -40
what effect will inc ext Na conc have on resting pot of alien cell?
a) hyper
b) depol
c) no effect

Back 87

b) depol

Front 88

select most acc stmt
a) axons contain ribosomes, so the extensive prot biosynth req'd for axonal tranport can be maintained
b) syn ves are not synth/prod in presyn nerve terminal, rather they are transp from cell body by axonal transp
c) each n. has mult axons to ensure neuron prop signal to as many postsyn cells as poss
d) dendrites are myelinated
e) fcn of dend spines is to inc presyn surface for syn es fusion leading to NT rel

Back 88

b) syn vesicles are synth then transported

Front 89

if a cell has a pos memb pot and EC conc of a solute X greater than its internal conc, which of following stmet NOT true?
a) X is a neutral solute (non ionized) and not in chem equil
b) X is an anion which is electrochem equil
c) x is a cation which is not in equil
d) active transport of X is taking place
e) membrane is impermeable to X

Back 89

b) x is an anion which is in electrochem equil

Front 90

what is a motor unit?
a) an alpha motor neuron and all of the muscle fibers it innervates
b) group of muscle fibers innervated by sev alpha motor neurons working tog for production of muscle force
c) all of muscle fibrils in a single muscle fiber
d) sarcoplasmic reticulum, terminal cisternae, T-tubule system of a muscle fiber
e) muscle spindle, golgi tendon organ, assoc alpha motor neurons

Back 90

a) alpha motor neuron and all muscle fibers it innervates

Front 91

waving motion of cilia and flagella dependent on:
a) depolymerization of microtubules
b) changes in config of dynein
c) hydrolysis of GTP by cental pair of microtubules
d) incomplete coverage of axoneme by plasma memb
e) actin-myosin interactions

Back 91

b) changes in config of dynein

Front 92

which of following ch is respon for rapid depolarization at start of upstroke of ap?
a) non gated Na ch
b) non gated K ch
c) VG Na ch
d) VG K ch
e) VG Ca ch

Back 92

c) VG Na ch

Front 93

alien frog:
Ek= +50
Kna = -65
Ecl = -80
Em = -65
which if any ions in alien frog are in equil?
a) Na
b) K
c) Cl
d) K, Cl, and Na
e) none

Back 93

a) Na

Front 94

alien frog:
Ek= +50
Kna = -65
Ecl = -80
Em = -65
with the alien memb at restin pot of -65 mV in which directions are net Na and net Cl currents flowing across cell memb?
a) no Na current cl inward
b) Na inward cl inward
c) Na inward cl outward
d) Na outward cl inward
e) Na outward cl outward

Back 94

a) no Na current, cl inward

Front 95

alien frog:
Ek= +50
Kna = -65
Ecl = -80
Em = -65
with the alien memb at resting pot of -65, increasing memb permeability to which of following ions will produce depolarization?
a) Na only
b) K only
c) Cl only
d) both Na and Cl
e) none of the above will prod depolar

Back 95

e) none of above