UPDATED / NURS 8022 All Exams 1, 2 & 3 2024/2025
With Complete Solutions And Rationales
Negative Feedback - CORRECT ANSWER - Promotes stability; cancels out the
original response. Ex: High FSBS, increased insulin by the pancreas
Positive Feedback - CORRECT ANSWER - Promotes a change in one direction;
instability, DISEASE. Ex: Blood clotting, platelet cascade
Proteins - CORRECT ANSWER - Provide selectivity to a membrane
Integral proteins - CORRECT ANSWER - channels, pores, carriers, enzymes,
receptors, second messengers
Peripheral proteins - CORRECT ANSWER - Enzymes, intracellular, signal
mediatiors
ATP - CORRECT ANSWER - Converted to ADP to produce energy; chemical
bonds between 2nd and 3rd phosphate groups have abundant energy
Simple/passive diffusion - CORRECT ANSWER - Occurs down a concentration
gradient; from HIGH to LOW concentration
Simple/passive diffusion - CORRECT ANSWER - Diffuse from high to lower
pressure; diffusion will not occur if the membrane is non permeable to the
molecule
Factors that affect the net rate of diffusion - CORRECT ANSWER - 1.
Concentration difference (high to low)
2. Electrical Potential (EMF)- charge difference on each side of the membrane
matters TOO!
3. Pressure difference (higher pressure results in increased energy)
Osmosis - CORRECT ANSWER - Passive transport of fluid across a membrane;
from an area of low solute concentration to high solute concentration (high
FLUID to low FLUID)
Primary Active Transport - CORRECT ANSWER - Molecules are "pumped"
against ("uphill") a concentration; DIRECT USE OF ENERGY
,Secondary Active Transport - CORRECT ANSWER - Trasport is driven by the
energy STORED in the concentration gradient of another molecule (Na+);
INDIRECT USE OF ENERGY
Na+- K+ ATPase - CORRECT ANSWER - Carrier protein located on the plasma
membrane of alll cells; enzyme that converts ATP to ADP to release energy
-Important role in regulating osmotic balance
-Requires one to two thirds of cells energy
Ca2+ ATPase - CORRECT ANSWER - Maintains a low cystosolic Ca2+
concentration
H+ ATPase - CORRECT ANSWER - - Found in parietal cells of gastric glands (HCl
secretion) and intercalated cells of renal tubules (controls blood pH)
- Concentrates H+ ions up to 1 million-fold
Remember: Sodium Potassium Pump - CORRECT ANSWER - sodium is
pumped out of the cell; potassium is pumped in...
Secondary Active Transport; Co-transport - CORRECT ANSWER - Co-transport:
Substance is transported in the same direction as the "driver" ion (Na+)
Counter transport - CORRECT ANSWER - Substance is transported in the
opposite direction as the driver ion Na+
How do cardiac glycosides increase cardiac contractility? - CORRECT ANSWER
- Increase intracellular Ca2+
ungated Ion Channels - CORRECT ANSWER - determined by size, shape,
distribution of charge
Gated Ion Channels - CORRECT ANSWER - -volgate (e.g.) Voltage dependent
Na+ channels)
-Chemically (e.g. Nicotinic AcH receptor channels)
Ion Channels - CORRECT ANSWER - Conductance depends on probability that
channel is open.
,Equilibrium Potential - CORRECT ANSWER - the diffusion potential that
exactly balances or opposes the tendency for diffusion down the concentration
difference.
If a membrane were permeable to only K+ then... - CORRECT ANSWER - K+
would diffuse down its concentration gradient until the electrical potential
across the membrane countered diffusion. (moving from inside the cell down
its concentration gradient to the outside of the cell).
Potassium Nernst Potential - CORRECT ANSWER - Also called equilibrium
potential; if the membrane were only permeate to K+; the Vm would be -94mv.
Sodium Nernst Potential - CORRECT ANSWER - If the membrane were only
permeable to Na+ then the Vm would be +61mv.
The Goldman Hodgkin Katz Equation - CORRECT ANSWER - The resting
membrane potential is closest to the equilibrium potential for the ion with the
highest permeability!
Depolarization - CORRECT ANSWER - The process during the action potential
when sodium is rushing into the cell causing the interior to become more
positive. (less negative)
Hyperpolarization - CORRECT ANSWER - The movement of the membrane
potential of a cell away from rest potential in a more negative direction.
Threshold potential - CORRECT ANSWER - Membrane potential at which
occurrence of the AP is inevitable
Overshoot - CORRECT ANSWER - Portion of the AP where the membrane
potential is positive (cell interior is positive)
Undershoot - CORRECT ANSWER - Also called hyper polarizing after potential;
the portion of the AP, followed by repolarization where at membrane potential
is more negative than at rest.
Inward current - CORRECT ANSWER - Flow of positive charge into the cell
These currents depolarize the membrane potential (or make it less negative
and more positive)
Ex: Na+ flow into the cell during the UPSTROKE of the AP
, Outward Current - CORRECT ANSWER - Flow of positive charge out of the
cell; these currents hyper polarize the membrane potential (making the
membrane more negative and less positive)
Example: flow of K+ out of the cell during the depolarization phase of AP,
creating down stroke
depolarization - CORRECT ANSWER - NA+ moves in
Repolarization - CORRECT ANSWER - K+ moves out
Mylenation - CORRECT ANSWER - Myelin decreased ion flow through the
membrane
Schwann Cells - CORRECT ANSWER - Surround the nerve axon forming a
myelin sheath
Node of Ranvier - CORRECT ANSWER - Sheath interrupted every 1-3mm
Where do action potentials occur? - CORRECT ANSWER - At the Nodes of
Ranvier
Electrical synapse - CORRECT ANSWER - allow current to flow from one
excitable cell to the next through space between cells called gap junctions
Chemical synapse - CORRECT ANSWER - have a gap between the presynaptic
membrane and the postsynaptic cell membrane called the synaptic cleft
AP in presynaptic cells causes... - CORRECT ANSWER - Ca2+ channels to open
Neurotransmitter is released... - CORRECT ANSWER - and diffuses across the
synaptic cleft
Neutrotransmitter binds to... - CORRECT ANSWER - receptors on postsynaptic
membrane
Excitatory - CORRECT ANSWER - Will cause depolarization of postsynaptic cell
(more positive)
Inhibitory - CORRECT ANSWER - Will cause hyper polarization of the
postsynaptic cell (making the cell negative)
Neuromuscular Transmission - CORRECT ANSWER - specialized synapse
between a motor neuron and a muscle fiber
With Complete Solutions And Rationales
Negative Feedback - CORRECT ANSWER - Promotes stability; cancels out the
original response. Ex: High FSBS, increased insulin by the pancreas
Positive Feedback - CORRECT ANSWER - Promotes a change in one direction;
instability, DISEASE. Ex: Blood clotting, platelet cascade
Proteins - CORRECT ANSWER - Provide selectivity to a membrane
Integral proteins - CORRECT ANSWER - channels, pores, carriers, enzymes,
receptors, second messengers
Peripheral proteins - CORRECT ANSWER - Enzymes, intracellular, signal
mediatiors
ATP - CORRECT ANSWER - Converted to ADP to produce energy; chemical
bonds between 2nd and 3rd phosphate groups have abundant energy
Simple/passive diffusion - CORRECT ANSWER - Occurs down a concentration
gradient; from HIGH to LOW concentration
Simple/passive diffusion - CORRECT ANSWER - Diffuse from high to lower
pressure; diffusion will not occur if the membrane is non permeable to the
molecule
Factors that affect the net rate of diffusion - CORRECT ANSWER - 1.
Concentration difference (high to low)
2. Electrical Potential (EMF)- charge difference on each side of the membrane
matters TOO!
3. Pressure difference (higher pressure results in increased energy)
Osmosis - CORRECT ANSWER - Passive transport of fluid across a membrane;
from an area of low solute concentration to high solute concentration (high
FLUID to low FLUID)
Primary Active Transport - CORRECT ANSWER - Molecules are "pumped"
against ("uphill") a concentration; DIRECT USE OF ENERGY
,Secondary Active Transport - CORRECT ANSWER - Trasport is driven by the
energy STORED in the concentration gradient of another molecule (Na+);
INDIRECT USE OF ENERGY
Na+- K+ ATPase - CORRECT ANSWER - Carrier protein located on the plasma
membrane of alll cells; enzyme that converts ATP to ADP to release energy
-Important role in regulating osmotic balance
-Requires one to two thirds of cells energy
Ca2+ ATPase - CORRECT ANSWER - Maintains a low cystosolic Ca2+
concentration
H+ ATPase - CORRECT ANSWER - - Found in parietal cells of gastric glands (HCl
secretion) and intercalated cells of renal tubules (controls blood pH)
- Concentrates H+ ions up to 1 million-fold
Remember: Sodium Potassium Pump - CORRECT ANSWER - sodium is
pumped out of the cell; potassium is pumped in...
Secondary Active Transport; Co-transport - CORRECT ANSWER - Co-transport:
Substance is transported in the same direction as the "driver" ion (Na+)
Counter transport - CORRECT ANSWER - Substance is transported in the
opposite direction as the driver ion Na+
How do cardiac glycosides increase cardiac contractility? - CORRECT ANSWER
- Increase intracellular Ca2+
ungated Ion Channels - CORRECT ANSWER - determined by size, shape,
distribution of charge
Gated Ion Channels - CORRECT ANSWER - -volgate (e.g.) Voltage dependent
Na+ channels)
-Chemically (e.g. Nicotinic AcH receptor channels)
Ion Channels - CORRECT ANSWER - Conductance depends on probability that
channel is open.
,Equilibrium Potential - CORRECT ANSWER - the diffusion potential that
exactly balances or opposes the tendency for diffusion down the concentration
difference.
If a membrane were permeable to only K+ then... - CORRECT ANSWER - K+
would diffuse down its concentration gradient until the electrical potential
across the membrane countered diffusion. (moving from inside the cell down
its concentration gradient to the outside of the cell).
Potassium Nernst Potential - CORRECT ANSWER - Also called equilibrium
potential; if the membrane were only permeate to K+; the Vm would be -94mv.
Sodium Nernst Potential - CORRECT ANSWER - If the membrane were only
permeable to Na+ then the Vm would be +61mv.
The Goldman Hodgkin Katz Equation - CORRECT ANSWER - The resting
membrane potential is closest to the equilibrium potential for the ion with the
highest permeability!
Depolarization - CORRECT ANSWER - The process during the action potential
when sodium is rushing into the cell causing the interior to become more
positive. (less negative)
Hyperpolarization - CORRECT ANSWER - The movement of the membrane
potential of a cell away from rest potential in a more negative direction.
Threshold potential - CORRECT ANSWER - Membrane potential at which
occurrence of the AP is inevitable
Overshoot - CORRECT ANSWER - Portion of the AP where the membrane
potential is positive (cell interior is positive)
Undershoot - CORRECT ANSWER - Also called hyper polarizing after potential;
the portion of the AP, followed by repolarization where at membrane potential
is more negative than at rest.
Inward current - CORRECT ANSWER - Flow of positive charge into the cell
These currents depolarize the membrane potential (or make it less negative
and more positive)
Ex: Na+ flow into the cell during the UPSTROKE of the AP
, Outward Current - CORRECT ANSWER - Flow of positive charge out of the
cell; these currents hyper polarize the membrane potential (making the
membrane more negative and less positive)
Example: flow of K+ out of the cell during the depolarization phase of AP,
creating down stroke
depolarization - CORRECT ANSWER - NA+ moves in
Repolarization - CORRECT ANSWER - K+ moves out
Mylenation - CORRECT ANSWER - Myelin decreased ion flow through the
membrane
Schwann Cells - CORRECT ANSWER - Surround the nerve axon forming a
myelin sheath
Node of Ranvier - CORRECT ANSWER - Sheath interrupted every 1-3mm
Where do action potentials occur? - CORRECT ANSWER - At the Nodes of
Ranvier
Electrical synapse - CORRECT ANSWER - allow current to flow from one
excitable cell to the next through space between cells called gap junctions
Chemical synapse - CORRECT ANSWER - have a gap between the presynaptic
membrane and the postsynaptic cell membrane called the synaptic cleft
AP in presynaptic cells causes... - CORRECT ANSWER - Ca2+ channels to open
Neurotransmitter is released... - CORRECT ANSWER - and diffuses across the
synaptic cleft
Neutrotransmitter binds to... - CORRECT ANSWER - receptors on postsynaptic
membrane
Excitatory - CORRECT ANSWER - Will cause depolarization of postsynaptic cell
(more positive)
Inhibitory - CORRECT ANSWER - Will cause hyper polarization of the
postsynaptic cell (making the cell negative)
Neuromuscular Transmission - CORRECT ANSWER - specialized synapse
between a motor neuron and a muscle fiber
