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WorksheetsPhysiology Principles exam 2 review
Total questions: 108
Worksheet time: 1hrs 22mins
_______ _______ _____ consists of the brain and spinal cord
(a)
_______ _______ ________ consists of nerves and ganglia
(a)
Cells that transmit information from sensory receptors to the CNS, and from the CNS to the effectors
Neurons
Axons
axon terminal
hormones
Neurons are EXCITABLE CELLS, and they generate electrical signals called ______ _______ that allow information transfer between cells
(a)
The plasma membrane does NOT have restricted permeability that creates differences in the solute compositions between the ECF and ICF
True
False
In the ECF, charged solutes are MOSTLY (a)
In the ICF, there is a combination of ions and charged molecules such as:
Proteins
collagen
amino acids
nucletoides
The body as a whole is ________ _________, and all body fluids are an electrically neutral
(a)
Sodium ions are NOT the major cation of the ECF, and their positive charges are NOT balanced by the chloride and bicarbonate anions
True
False
Potassium ions are the major component of the ICF, and their positive charges are balanced by the negative charges of proteins and nucleotides
True
False
Body fluid compartments are 100% electrically neutral, there is no slight imbalance of ions in both the ECF and ICF
True
False
there are slightly more anions than cations in the ICF and slightly more cations than anions in the ECF
True
False
Excess ions cluster near the _______ _______ due to the attraction of the excess opposite charge on the other side
(a)
ions clustering near the plasma membrane is a form of ________ _________, defined as a difference in charge distribution between two locations
(a)
when a potential difference occurs across a membrane, it is called a:
(a)
A membrane potential is a form of ________ _______, because it can be used to do work when opposite charges are allowed to come together
Energy transfer
Potential energy
ionization
diffusion change
membrane potential is a very small potential difference and is measured in _____
watts (wattage)
Millivolts (mV)
volts (V)
Size of the potential difference is NOT indicated by the magnitude of the membrane potential and is expressed relative to the ICF
True
False
Since ICF normally has more anions than ECF, membrane potential is a (a) number
some cells do not have membrane potentials, and those that do have the same membrane potentials
True
False
All human cells have membrane potentials in the range of -40 to -90 mV
True
False
The variability in membrane potential is due to:
differences in ion concentrations between the ICF and ECF
resting membrane potential is always zero
differences in membrane permeability to various ions
concentration of sodium ions inside the cell
membranes are COMPOSED of phospholipids and proteins, with phospholipids forming a bilayer, with proteins embedded in the bilayer
True
False
the bilayer is (a) to ions, so ion movement across membranes is dependent on specialized proteins in the membrane
there are several types of (a) that move across membranes, including ion channels and ion pumps
(a) form pores in the membrane, each channel is specific for particular ions
Gated ion channels and leak channels are the two basic types of ion channel
True
False
_____ ___ ______ can be opened and closed
(a)
____ ______ are ALWAYS open
(a)
presence of leak channels makes a membrane (a) to particular ions at all times
the number of leak channels does NOT determine how permeable the membrane is to a particular ion
True
False
All ions in the ECF and ICF do NOT contribute to a cell's membrane potential
True
False
What ions make a greater contribution to the membrane potential, due to their higher concentration in the body
Na+
OH-
K+
N-
membranes are quite permeable to K+, as they contain numerous (a) leak channels
membranes are relatively (a) to Na+, as there are few sodium-specific leak channels
Ions can move in both directions through an ion channel, but there is usually ___ __________ in a particular direction
(a)
Direction of net movement is determined by the combination of two factors:
differences in ion concentrations across the membrane (chemical driving force)
differences in charge distribution across the membrane (electrical driving force)
____________ __________ drive ions from areas of higher concentration to lower concentration
(a)
Differences in _____ ________ drive ions toward areas with higher opposite charge
(a)
combination of the chemical and electrical driving forces do NOT determine the net direction of movement for a particular ion
True
False
Under some conditions, there is no net movement of an ion through ___ _________. This occurs when an ion is at its equilibrium potential
(a)
an ion's _______ ________ is the membrane potential at which the chemical and electrical driving forces are equal to one another and in opposite directions
(a)
_______ _____ are those that produce large, rapid changes in membrane potential, called action potentials, when they are stimulated
(a)
Examples of excitable cells include:
neurosecretory cells
integumentary cells
neurons
most muscle cells
some endocrine cells
changes in membrane potential that occur during an action potential are NOT due to changes in membrane permeability to specific ions
True
False
changes in permeability are caused by the opening and closing of _______ __ _______
(a)
In the absence of stimulation, most excitable cells maintain a constant memrbane potential that is referred to as the________ _________ (Vm)
(a)
occurs when the membrane potential becomes less negative than the resting potental
(a)
occurs when the membrane potential becomes more negative than the resting potential
(a)
occurs when the membrane potential returns to the resting potential from a depolarized. or hyperpolarized state
(a)
There are two types of electrical signals that can occur in excitable cells:
action potentials
synapses
neurotransmission
graded potentials
Action potentials are LARGE, rapid changes in membrane potential. Action potentials (a) the release of neurotransmitters from axon terminals
Graded potentials are NOT smaller, longer duration changes which regulate action potential production
True
False
graded potentials are produced by neurons in response to (a) stimuli
There are many types of external stimuli, with each neuron responsive to a particular type of (a)
chemical synapses refers to graded potentials originating at specific sites on the dendrites
True
False
(a) is a point of contact between two excitable cells, a chemical synapse is a specific type of this.
A chemical synapse does NOT require two cells
True
False
_________ _________ is the cell that releases neurotransmitters at the synapse
(a)
_________ ________ is the cell that responds to the neurotransmitters by producing GRADED POTENTIALS
(a)
when the presynaptic neuron releases neurotransmitters, they do NOT bind to receptors in the postsynaptic membrane
True
False
receptors in postsynaptic membrane do NOT function as LIGAND-GATED ion channels, as they open in response to neurotransmitter binding
True
False
Each synapse is a specialized structure consisting of:
Axon terminal released one kind of neurotransmitter
postsynaptic membrane containing only receptors for that neurotransmitter
ion channels at that synapse open only in response to binding of that neurotransmitter to its receptors
graded potentials produced at a synapse can vary in (a)
the number of ion channels that open is proportional to the amount of neurotransmitter released from the axon terminal, so the magnitude of the graded potential is also (a) to the amount of neurotransmitter released
graded potentials are NOT decremental
True
False
ligand-gated ion channels are typically CATION channels
True
False
when ligand-gated channels open, CATIONS cross the membrane, creating a ________ _______ in membrane potential
(a)
movement of ions across the MEMBRANE does NOT create a localized current on BOTH sides of the membrane
True
False
current flow spreads away from the synapses, but the current weakens as it spreads, as. cations move through ____ _____ channels
(a)
a graded potential can be either hyper polarization or a depolarization, depending on the ion channels in the _________ _________
(a)
if CATIONS flow in, (a) occurs (graded potential)
if CATIONS flow OUT, a (a) occurs
a single graded potential is a very small change in membrane potential, and it. can only spread a very small distance
True
False
every synapse is NOT a location where a graded potential can be produced
True
False
each postsynaptic neuron receives stimulation from multiple (a) neurons (graded potentials)
a single presynaptic neurons can form SEVERAL synapses with a (a) neuron (graded potentials)
a typical postsynaptic neuron can have thousands of synapses on its dendrites and cell body (graded potentials)
True
False
graded potentials can NOT be produced simultaneously at different synapses
True
False
when a graded potential spreads from a synapse, it can interact with graded potentials that. have spread from other synapses
True
False
when graded potentials interact they are (a) , meaning the change in membrane potential produced by each graded potential will sum together
when graded potentials from different synapses sum together
(a)
when graded potentials from the same synapse sum together
(a)
graded potentials are either depolarizations or hyperpolarizations
True
False
DEPOLARIZATIONS can come together to induce action potentials, this is called:
Inhibitory postsynaptic potentials
excitatory postsynaptic potentials
membrane difference
potential energy
HYPERPOLARIZATIONS can inhibit action potential induction, this is called:
membrane potential
excitatory postsynaptic potentials
potential energy
inhibitory postsynaptic potentials
action potentials are NOT induced at a specific location called the AXON HILLOCK
True
False
axon hillock is located at the (a) between the cell body and axon
All action potentials produced by an excitable cell are NOT identical, varying in strength and duration
True
False
action potentials are ALL-OR-NONE (once an action potential begins, it cannot be stopped and will move through its characteristic changes in membrane potential
True
False
action potentials propagated along axon to axon terminals occur without (a)
action potential is induced when when the membrane potential depolarizes to value called
membrane potential
threshold potential
potential energy
equilibrium
threshold typically requires a +15 mV depolarization, so if the resting potential were -70 mV, then threshold would be (a) mV
events that occur at threshold during an action potential can be stopped
True
False
changes in membrane potential occurring during action potentials can be divided into three phases
Depolarization (rising phase)
Repolarization (Falling phase)
Afterhyperpolarization (undershoot)
During DEPOLARIZATION, membrane potential depolarizes from threshold to about +30 mV
True
False
During repolarization, membrane potential changes from +30 mV to -70 mV
True
False
During afterhyperpolarization, membrane potential is more negative than -70 mV, so membrane potential is slightly HYPERPOLARIZED
True
False
entire action potential is NOT VERY brief and CANNOT be completed in as little as 2 msec
True
False
action potential is induced and maintained by LOCAL CHANGES in sodium and ion (a)
changes in permeability are DUE to the OPENING and CLOSING of ________-_______ ___ channelswithin the membrane
(a)
voltage-gated ion channels do NOT open and close in response to changes in membrane potential
True
False
Na+ (sodium) and K+ (potassium) are involved in producing an action potential
True
False
(action potentials) K+ channel has two states:
open
closed
(action potentials) stimulus that opens the K+ channel is (a) , but the channel is slow to respond to the stimulus
(action potentials) K+ channels don't start opening until the end of depolarization, so all channels are OPEN by the middle of REPOLARIZATION
True
False
(action potentials) K+ channel is in OPEN state for some time, then returns to CLOSED state
True
False
(action potentials) K+ channels close slow , so channels start closing at the middle of REPOLARIZATION, all channels are closed at the end of AFTERHYPERPOLARIZATION
True
False
