Nervous System Physiology FINAL EXAM GUIDE
2025
|MOST COMMON QUESTIONS WITH CORRECTLY
VERIFIED ANSWERS|ALREADY A+
GRADED|GUARANTEED PASS
The membrane of cells is highly permeable to ___ ions due to its ____ - potassium
equilibrium potential
What is the equilibrium potential of K and Na? - K = -90mV
Na = 66mV
What does Na-K ATPase do? - exchanges 3 Na out and 2 K in to maintain resting potential
of -70mV
What determines the transmembrane potential? - membrane permeability to Na and K
What types of channels are passive? How do they open/close? - leaky channels
always open
What are types of active channels? How do they open/close? - gated channels
open/close in response to stimuli
At resting potential, are most gated channels open or closed? - closed
What types of gated channels are found on neuron cell bodies and dendrites? -
chemically gated channels
What types of gated channels are found in neural axons, skeletal muscle sarcolemma, and
cardiac muscle? - voltage-gated channels
What types of gated channels are found in sensory receptors? - mechanically gated
channels
,What characterizes the depolarization of a graded potential? - Na moves in
change in potential is proportional to stimulus
What characterizes the repolarization of a graded potential? - potassium leaves the cell
increasing the negativity of the resting potential results in what? - hyperpolarization
What are the 4 basic characteristics that all graded potentials share? - effect decreases
with distance
effect spreads passively
depolarization or hyperpolarization
stronger the stimulus, greater the change in transmembrane potential and the larger the area
affected
Does the action potential change based on the size of the stimulus? - no
What is the all or none principle when it comes to action potentials? - AP is either
triggered or not
What are the 4 basic steps of an action potential - depolarization to threshold
activation of voltage gated Na channels
inactivation of Na channels and activation of voltage gated K channels
Return to normal permeability
Is an action potential possible during the absolute refractory period? - no
Is an action potential possible during the relative refractory period? - yes, but need a very
large stimulus
What is the time frame of the refractory period? - from beginning of AP to the return to
rest
What is propagation of action potentials? - moves AP generated in axon hillock along
entire length of axon
What types of axons are myelinated? - Type A and Type B
What is the order of axons from largest diameter to smallest diameter? - A --> B --> C
Which type of axons carry rapid information to/from the CNS? - Type A
,Which type of axon fiber is responsible for position, balance, touch, and motor impulses? -
Type A
Which type of axon fiber is responsible for sensory information and peripheral effectors? -
Type B
Which type of axon fiber is responsible for involuntary muscle and gland controls? - Type
C
Where is the effect of a neurotransmitter located? - on a postsynaptic membrane -
depends on the receptor
What are the 2 classes of neurotransmitters? - excitatory and inhibitory
Excitatory Neurotransmitters:
What do they cause?
Effect on AP? - depolarization
promote AP
Inhibitory Neurotransmitters
What do they cause?
Effect on AP? - hyperpolarization
suppress AP
A synaptic delay occurs between what? - arrival of AP at synaptic terminal and its effect
on the postsynaptic membrane
What occurs when a neurotransmitter cannot recycle fast enough to meet the demands of an
intense stimuli? - synaptic fatigue
What are neuromodulators? - chemicals that are released by synaptic terminals that may
impact neurotransmission
Effects of neuromodulators: - long-term but slow to appear
What are the 3 ways in which neurotransmitters and neuromodulators work? - direct
effects on membrane channels
indirect effects via G proteins
Indirect effects via intracellular enzymes
, What is summation? - combination of EPSP and/or IPSP to trigger an AP
What is temporal summation? - rapid, repeated stimuli at one synapse
What is spatial summation? - many stimuli, many synapses
Sympathetic
Preganglionic/Postganglionic myelination and length - Pre-Ganglionic = myelinated, short
Post-Ganglionic = unmyelinated, long
Parasympathetic
Preganglionic/Postganglionic myelination and length - Pre-Ganglionic = myelinated, long
Post-Ganglionic = unmyelinated, short
How do you get different responses when the parasympathetic and sympathetic innervate the
same effectors? - Differentiate responses due to neurotransmitter differences and
receptor differences
What are the adrenergic membrane receptors? - Alpha 1, Alpha 2, Beta 1, Beta 2, Beta 3
What type of adrenergic receptor has an excitatory effect on the target cell? - alpha 1
What type of adrenergic receptor has an inhibitory effect on the cell? - alpha 2
Which type of adrenergic receptors trigger a metabolic change in the target cell? - beta
Which type of adrenergic receptor increases metabolic activity and heart rate? - beta 1
Which type of adrenergic receptor triggers relaxation of smooth muscles along respiratory tract
and causes vasodilation to heart and skeletal muscles? - beta 2
Which type of adrenergic receptor leads to lipolysis? - beta 3
What releases NO as the neurotransmitter? - nitroxidergic synapses
Neuromuscular and Neuroglandular junctions all release ____ as neurotransmitter - ACh
2025
|MOST COMMON QUESTIONS WITH CORRECTLY
VERIFIED ANSWERS|ALREADY A+
GRADED|GUARANTEED PASS
The membrane of cells is highly permeable to ___ ions due to its ____ - potassium
equilibrium potential
What is the equilibrium potential of K and Na? - K = -90mV
Na = 66mV
What does Na-K ATPase do? - exchanges 3 Na out and 2 K in to maintain resting potential
of -70mV
What determines the transmembrane potential? - membrane permeability to Na and K
What types of channels are passive? How do they open/close? - leaky channels
always open
What are types of active channels? How do they open/close? - gated channels
open/close in response to stimuli
At resting potential, are most gated channels open or closed? - closed
What types of gated channels are found on neuron cell bodies and dendrites? -
chemically gated channels
What types of gated channels are found in neural axons, skeletal muscle sarcolemma, and
cardiac muscle? - voltage-gated channels
What types of gated channels are found in sensory receptors? - mechanically gated
channels
,What characterizes the depolarization of a graded potential? - Na moves in
change in potential is proportional to stimulus
What characterizes the repolarization of a graded potential? - potassium leaves the cell
increasing the negativity of the resting potential results in what? - hyperpolarization
What are the 4 basic characteristics that all graded potentials share? - effect decreases
with distance
effect spreads passively
depolarization or hyperpolarization
stronger the stimulus, greater the change in transmembrane potential and the larger the area
affected
Does the action potential change based on the size of the stimulus? - no
What is the all or none principle when it comes to action potentials? - AP is either
triggered or not
What are the 4 basic steps of an action potential - depolarization to threshold
activation of voltage gated Na channels
inactivation of Na channels and activation of voltage gated K channels
Return to normal permeability
Is an action potential possible during the absolute refractory period? - no
Is an action potential possible during the relative refractory period? - yes, but need a very
large stimulus
What is the time frame of the refractory period? - from beginning of AP to the return to
rest
What is propagation of action potentials? - moves AP generated in axon hillock along
entire length of axon
What types of axons are myelinated? - Type A and Type B
What is the order of axons from largest diameter to smallest diameter? - A --> B --> C
Which type of axons carry rapid information to/from the CNS? - Type A
,Which type of axon fiber is responsible for position, balance, touch, and motor impulses? -
Type A
Which type of axon fiber is responsible for sensory information and peripheral effectors? -
Type B
Which type of axon fiber is responsible for involuntary muscle and gland controls? - Type
C
Where is the effect of a neurotransmitter located? - on a postsynaptic membrane -
depends on the receptor
What are the 2 classes of neurotransmitters? - excitatory and inhibitory
Excitatory Neurotransmitters:
What do they cause?
Effect on AP? - depolarization
promote AP
Inhibitory Neurotransmitters
What do they cause?
Effect on AP? - hyperpolarization
suppress AP
A synaptic delay occurs between what? - arrival of AP at synaptic terminal and its effect
on the postsynaptic membrane
What occurs when a neurotransmitter cannot recycle fast enough to meet the demands of an
intense stimuli? - synaptic fatigue
What are neuromodulators? - chemicals that are released by synaptic terminals that may
impact neurotransmission
Effects of neuromodulators: - long-term but slow to appear
What are the 3 ways in which neurotransmitters and neuromodulators work? - direct
effects on membrane channels
indirect effects via G proteins
Indirect effects via intracellular enzymes
, What is summation? - combination of EPSP and/or IPSP to trigger an AP
What is temporal summation? - rapid, repeated stimuli at one synapse
What is spatial summation? - many stimuli, many synapses
Sympathetic
Preganglionic/Postganglionic myelination and length - Pre-Ganglionic = myelinated, short
Post-Ganglionic = unmyelinated, long
Parasympathetic
Preganglionic/Postganglionic myelination and length - Pre-Ganglionic = myelinated, long
Post-Ganglionic = unmyelinated, short
How do you get different responses when the parasympathetic and sympathetic innervate the
same effectors? - Differentiate responses due to neurotransmitter differences and
receptor differences
What are the adrenergic membrane receptors? - Alpha 1, Alpha 2, Beta 1, Beta 2, Beta 3
What type of adrenergic receptor has an excitatory effect on the target cell? - alpha 1
What type of adrenergic receptor has an inhibitory effect on the cell? - alpha 2
Which type of adrenergic receptors trigger a metabolic change in the target cell? - beta
Which type of adrenergic receptor increases metabolic activity and heart rate? - beta 1
Which type of adrenergic receptor triggers relaxation of smooth muscles along respiratory tract
and causes vasodilation to heart and skeletal muscles? - beta 2
Which type of adrenergic receptor leads to lipolysis? - beta 3
What releases NO as the neurotransmitter? - nitroxidergic synapses
Neuromuscular and Neuroglandular junctions all release ____ as neurotransmitter - ACh
