ch6-10 Flashcards
the movement of water across a plasma membrane occurs by
simple diffusion through membrane channels
which of these statements about the facilitated diffusion of glucose is TRUE
carrier proteins in the cell membrane are required for transport
if a poison such as cyanide stopped the production of ATP, which of the following trasport processes would cease
the movement of Na+ out of the cell
red blood cells crenate in
a hypertonic solution
plasma has an osmolality of about 300 mOsm. The osmolality of an isotonic saline is equal to
300 mOsm
which of these statements comparing a 0.5 m NaCl solution and a 1.0 m glucose solution is true
they have the same osmolality
they have the same osmotic pressure
they are isotonic to each other
ALL OF THESE ARE TRUE
the most important diffusable ion in the establishment of the membrane potential is
K-
which of these statements regarding an increase in blood osmolality is true
it can occur as a result of dehydration
in hyperkalemia, the resting membrane potential
it moves closer to 0 millivolts
which of these statements about the NA/K pump is true
K is actively transported out of the cell
which of these statements about carrier mediated facilitated diffusion is true
it is used for cellular uptake of clood glucose
which of these is not an example of cotransport
movement of Na and K through the action og the Na K pumos
the resting membrane potential of a nueron or muscle cell is
somewhat less negative than the potassium equilibrium potential
suppose that gates ion channels for Na of Ca opened in the plasma membrane of a muscle cell. the membrane potential of that cell would
move toward the equilibrium potential for that ion
become less negative than the resting potential
move further away from the potassium resting potential
ALL OF THESE
which of the following questions regarding second messengers is false
they are needed to mediate the action of nonpolar regulatory molecules
the supporting cells that form the myelin sheath in the peripheral nervous system are
Schwann cells
a collection of neuron cell bodies located outside the CNS is called
a ganglion
which of these neurons is pseudounipolar
sensory neurons
depolarization of an axon is produced by
inward diffusion of Na+
repolarization of an axon during an action potential is produced by
outward diffusion of K+
as the strength of a depolarizing stimulus to an axon is increased
the frequency with which the action potential are produced increases
the conduction of action potentials in a myelinated nerve fiber is
saltatory
without decrement
faster than in an unmyelinated axon
ALL OF THESE
which of these is not a characteristic of synaptic potentials
they are all or non in amplitude
which of these os not a characteristic of action potentials
Na and K gates open at the same time
a drug that inactivates acetylcholinesterase
increases the ability of ACh to stimulate the muscle contraction
postsynaptic inhibition is produced by
hyperpolarization of the postsynaptic membrane
hyperpolarization of the postsynaptic membrane in response to glycine or GABA is produced by the opening of
Cl- channels
the absolute refractory period of a neuron
occurs during depolarization and the first part of the repolarization phase
which of these statements about catecholamines is folase
their effects are increased by the action of the enzyme catechol- O- methyltransferase
the summation os EPSPs from a numerous presynaptic nerve fibers converging onto one postsynaptic neuron is called
spatial summation
which of these statements about ACh receptors is FALSE
G-proteins are needed to open ion channels for nicotinic receptors
