Physiology Homework 5 Questions All
Solved.
You are walking barefoot in your bedroom and step on a tack. (Ouch!) In response you lift and
withdraw your foot from the painful stimulus.
The sensory afferent that carries the pain information that produced this reflexive response is
part of which branch of the nervous system? - Answer peripheral
The myelin surrounding the sensory afferent's axon would come from which type of glial cell?
a) astrocyte
b) ependymal cell
c) microglia
d) oligodendrocyte
e) satellite cell
f) Schwann cell - Answer f
Which region of a neuron typically serves as the integrative region?
a) axon
b) dendrite
c) node of Ranvier
d) presynaptic terminal
e) trigger zone - Answer e
In a typical neuron, where would you expect to observe a graded potential? Choose ALL that
apply.
a) dendrite
b) presynaptic terminal
c) trigger zone - Answer a and c
In a typical neuron, where would you expect to find Hodgkin-Huxley voltage-gated Na+ channels
(based on the typical function of these channels)? Choose ALL that apply.
a) dendrite
b) presynaptic terminal
, c) trigger zone - Answer b and c
What is the correct sequence of events in a stretch-sensitive sensory neuron?
• action potential(s)
• action potential propagation
• graded potential (receptor potential)
• neurotransmitter release
• opening of mechanically-gated ion channels
• opening of voltage-gated calcium channels
• opening of voltage-gated sodium channels
• sensory stimulus (muscle stretch)
summation of graded potentials - Answer muscle stretch, opening of mechanically gated ion
channels, receptor potential, summation of graded potentials, open of voltage gated sodium
channels, action potentials, action potential propagation, opening of voltage gated calcium
channels, neurotransmitter release
What is the correct sequence of signal transduction? (There can be missing steps, but the
sequence must be correct.)
a) sensory stimulus -> graded potential in afferent -> action potential(s) in afferent ->
neurotransmitter release by afferent
b) neurotransmitter release by afferent -> action potential(s) in efferent -> neurotransmitter
release by efferent -> graded potential in muscle-> muscle contraction
c) graded potential in efferent -> action potential(s) in efferent -> neurotransmitter release by
efferent -> muscle contraction
d) All of the above are correct.
e) None of the above are correct. - Answer d
If a 20msec stimulus resulted in 10 action potentials on top of a graded potential, what would
happen if the stimulus increased to 30msec? - Answer it would be a graded potential
The following neural activity (each line = one action potential) was recorded after a 20
millisecond stimulus.
There are three action potentials
Solved.
You are walking barefoot in your bedroom and step on a tack. (Ouch!) In response you lift and
withdraw your foot from the painful stimulus.
The sensory afferent that carries the pain information that produced this reflexive response is
part of which branch of the nervous system? - Answer peripheral
The myelin surrounding the sensory afferent's axon would come from which type of glial cell?
a) astrocyte
b) ependymal cell
c) microglia
d) oligodendrocyte
e) satellite cell
f) Schwann cell - Answer f
Which region of a neuron typically serves as the integrative region?
a) axon
b) dendrite
c) node of Ranvier
d) presynaptic terminal
e) trigger zone - Answer e
In a typical neuron, where would you expect to observe a graded potential? Choose ALL that
apply.
a) dendrite
b) presynaptic terminal
c) trigger zone - Answer a and c
In a typical neuron, where would you expect to find Hodgkin-Huxley voltage-gated Na+ channels
(based on the typical function of these channels)? Choose ALL that apply.
a) dendrite
b) presynaptic terminal
, c) trigger zone - Answer b and c
What is the correct sequence of events in a stretch-sensitive sensory neuron?
• action potential(s)
• action potential propagation
• graded potential (receptor potential)
• neurotransmitter release
• opening of mechanically-gated ion channels
• opening of voltage-gated calcium channels
• opening of voltage-gated sodium channels
• sensory stimulus (muscle stretch)
summation of graded potentials - Answer muscle stretch, opening of mechanically gated ion
channels, receptor potential, summation of graded potentials, open of voltage gated sodium
channels, action potentials, action potential propagation, opening of voltage gated calcium
channels, neurotransmitter release
What is the correct sequence of signal transduction? (There can be missing steps, but the
sequence must be correct.)
a) sensory stimulus -> graded potential in afferent -> action potential(s) in afferent ->
neurotransmitter release by afferent
b) neurotransmitter release by afferent -> action potential(s) in efferent -> neurotransmitter
release by efferent -> graded potential in muscle-> muscle contraction
c) graded potential in efferent -> action potential(s) in efferent -> neurotransmitter release by
efferent -> muscle contraction
d) All of the above are correct.
e) None of the above are correct. - Answer d
If a 20msec stimulus resulted in 10 action potentials on top of a graded potential, what would
happen if the stimulus increased to 30msec? - Answer it would be a graded potential
The following neural activity (each line = one action potential) was recorded after a 20
millisecond stimulus.
There are three action potentials
