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Biol 373 Midterm #1 - Unit 3 Questions with
Detailed Verified Answers
Special senses Ans: Vision, hearing, taste, smell,
equilibrium
Somatic senses Ans: Touch, temperature, pain, itch,
proprioception
Proprioception Ans: Awareness of body movement +
position in space, can be conscious or unconscious. A
somatic sense.
What is the function of the receptor in sensory systems?
Ans: This sensory structure, part of all sensory systems,
is a transducer that converts the stimulus into an
intracellular signal, usually a change in membrane
potential.
Where does stimuli have to reach to become
"conscious"? Ans: Cerebral cortex (association areas)
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At each synapse along the way of a sensory system, the
nervous system can... Ans: ...modulate and shape the
sensory information
What "type" are all somatic sensory neurons? Ans:
Pseudounipolar...can be myelinated or not
What makes special sense receptors "special"? Ans:
Most special sense receptors are CELLS (i.e. hair cells),
not NEURONS. The cells release neurotransmitter onto
neurons to initiate an AP.
What special sense uses a neuronal receptor instead of a
cell receptor? Ans: Smell
What is the role of accessory structures? Ans: These
structures enhance the info-gathering capability of the
sensory system.
I.e. Lens and cornea of eye help focus incoming light
onto photoreceptors
4 groups of receptors based on their preferred stimulus
Ans: 1. Chemoreceptors - chemical ligands
2. Mechanoreceptors - mechanical energy/pressure
3. Thermoreceptors - temperature
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4. Photoreceptors - light
Transduction Ans: The conversion of stimulus energy
into info that can be processed by the nervous system.
Conversion of stimuli into graded potentials by stimulus
opening or closing ion channels.
Adequate stimulus Ans: Each sensory receptor has a
particular form of energy to which it is most responsive.
I.e. Light is the adequate stimulus of photoreceptors.
"Adequate" = "Preferred"
Why do you "see light" when you push on your eye?
Ans: The pressure on the eye stimulates
photoreceptors...although the adequate stimulus of
photoreceptors is light, any stimulus strong enough will
stimulate any type of receptor.
Threshold stimulus Ans: Minimum stimulus req'd to
initiate a receptor
Receptive field Ans: The area of surface monitored by a
particular receptor.
Convergence Ans: Multiple pre-synaptic (primary)
neurons synapse with a smaller number of post-synaptic
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(secondary) neurons. Allows multiple simultaneous
subthreshold stimuli to sum at the post-synaptic neuron.
What happens to receptive fields when convergence
occurs? Ans: When multiple primary sensory neurons
converge on a single secondary neuron, their individual
receptive fields merge into a single, large receptive field.
What does the size of a receptive field tell us? Ans: The
size of this field tells us how high the "resolution" is in
that area.
Smaller receptive field = higher resolution (i.e.
fingertips)
Larger receptive field = lower resolution
When would a receptive field become "larger"? Ans:
When there's a lot of convergence...when multiple
primary neurons synapse onto fewer secondary neurons,
their receptive fields merge into one.
What does high-convergence wiring result in (regarding
senses)? Ans: HIGH SENSITIVITY (increased chance of
an AP due to summation) but LOW RESOLUTION (can't
Biol 373 Midterm #1 - Unit 3 Questions with
Detailed Verified Answers
Special senses Ans: Vision, hearing, taste, smell,
equilibrium
Somatic senses Ans: Touch, temperature, pain, itch,
proprioception
Proprioception Ans: Awareness of body movement +
position in space, can be conscious or unconscious. A
somatic sense.
What is the function of the receptor in sensory systems?
Ans: This sensory structure, part of all sensory systems,
is a transducer that converts the stimulus into an
intracellular signal, usually a change in membrane
potential.
Where does stimuli have to reach to become
"conscious"? Ans: Cerebral cortex (association areas)
, Page | 2
At each synapse along the way of a sensory system, the
nervous system can... Ans: ...modulate and shape the
sensory information
What "type" are all somatic sensory neurons? Ans:
Pseudounipolar...can be myelinated or not
What makes special sense receptors "special"? Ans:
Most special sense receptors are CELLS (i.e. hair cells),
not NEURONS. The cells release neurotransmitter onto
neurons to initiate an AP.
What special sense uses a neuronal receptor instead of a
cell receptor? Ans: Smell
What is the role of accessory structures? Ans: These
structures enhance the info-gathering capability of the
sensory system.
I.e. Lens and cornea of eye help focus incoming light
onto photoreceptors
4 groups of receptors based on their preferred stimulus
Ans: 1. Chemoreceptors - chemical ligands
2. Mechanoreceptors - mechanical energy/pressure
3. Thermoreceptors - temperature
, Page | 3
4. Photoreceptors - light
Transduction Ans: The conversion of stimulus energy
into info that can be processed by the nervous system.
Conversion of stimuli into graded potentials by stimulus
opening or closing ion channels.
Adequate stimulus Ans: Each sensory receptor has a
particular form of energy to which it is most responsive.
I.e. Light is the adequate stimulus of photoreceptors.
"Adequate" = "Preferred"
Why do you "see light" when you push on your eye?
Ans: The pressure on the eye stimulates
photoreceptors...although the adequate stimulus of
photoreceptors is light, any stimulus strong enough will
stimulate any type of receptor.
Threshold stimulus Ans: Minimum stimulus req'd to
initiate a receptor
Receptive field Ans: The area of surface monitored by a
particular receptor.
Convergence Ans: Multiple pre-synaptic (primary)
neurons synapse with a smaller number of post-synaptic
, Page | 4
(secondary) neurons. Allows multiple simultaneous
subthreshold stimuli to sum at the post-synaptic neuron.
What happens to receptive fields when convergence
occurs? Ans: When multiple primary sensory neurons
converge on a single secondary neuron, their individual
receptive fields merge into a single, large receptive field.
What does the size of a receptive field tell us? Ans: The
size of this field tells us how high the "resolution" is in
that area.
Smaller receptive field = higher resolution (i.e.
fingertips)
Larger receptive field = lower resolution
When would a receptive field become "larger"? Ans:
When there's a lot of convergence...when multiple
primary neurons synapse onto fewer secondary neurons,
their receptive fields merge into one.
What does high-convergence wiring result in (regarding
senses)? Ans: HIGH SENSITIVITY (increased chance of
an AP due to summation) but LOW RESOLUTION (can't
