Page 1 of 62
BIOS252 / BIOS 252 Exam 1 (Latest 2025): Anatomy &
Physiology II - Chamberlain
4 Types of Sensory Information that sensory receptors provide
the CNS .....ANSWER.....Type (modality), Location, Intensity,
Duration
Sensory Receptors: Type of Stimulus (Modality)
.....ANSWER.....The differentiation between taste, smell, sight,
touch. And even further within the senses, such as bitter versus
salty taste. All of these sensory types produce identical action
potentials to the CNS, so how does the brain differentiate
between different senses? It does so by looking at WHERE the
action potential came from. If the stimulus came from the retina,
the brain assumes the stimulus is sight. You can prove this by
rubbing your eyes really hard. This touch sensation is interpreted
as sight!
,Page 2 of 62
Transduction .....ANSWER.....The conversion of one form of energy
to another. This occurs then sensory receptors convert heat, light,
chemicals, touch, sound to an action potential.
Sensation .....ANSWER.....Conscious awareness of the stimulus or
feeling.
Sensory Receptors: Location .....ANSWER.....There is also a
Labeled Line Code that works for location. The path of action
potentials take from the eyes will be different than the path that
action potentials take from the hand to get to the brain.
Also, every sensory receptor has a receptive field, the area in
which it detects stimulation. You can poke the middle or the edge
of this field and it would feel the exact same to the person. More
sensitive areas of the body (fingertips) need smaller receptive
fields than do the back sensory receptors.
,Page 3 of 62
Sensory Receptors: Intensity .....ANSWER.....Receptors
differentiate intensity of the stimulus by:
1. The frequency of firing of neurons
2. The number of neurons that are firing
3. The threshold of neurons that are firing (neurons with a high
threshold for stimulus will only be fired in a very intense (painful)
situation.
Sensory Receptors: Duration of Stimulus .....ANSWER.....Encoded
by changes in the firing frequency of a nerve fiber with the
passage of time. All sensors undergo sensory adaptation, where
the firing of a neuron gets slower over time if a stimulus is
prolonged.
Phasic Receptors .....ANSWER.....Sensory receptors that adapt
rapidly to stimuli; like how you don't feel your shirt after like 10
seconds of wearing it. This is the first level of filtering of
unnecessary stimuli. RF is the second.
, Page 4 of 62
Tonic Receptors .....ANSWER.....Sensory receptors that keep firing
action potentials even after a while and are slowly adapting to
stimuli. Why is this important or needed?
1. If your finger stopped hurting a milisecond after you put it in
fire, you would leave it in the fire. This is to really burn into your
memory this painful experience
2. Pain continues so that your body will want to do something
about it (treat the pain so you don't get infected or die). This
enacts an inflammation and/or immune response.
Mechano-recptors .....ANSWER.....Sensory receptors that respond
to physical deformation of the tissue or cell. Ex. Cutaneous (skin)-
touch, pain, vibration
Nociceptors .....ANSWER.....Specific pain receptors. The idea that
a stimuli of any sense can be painful if intense enough. These
BIOS252 / BIOS 252 Exam 1 (Latest 2025): Anatomy &
Physiology II - Chamberlain
4 Types of Sensory Information that sensory receptors provide
the CNS .....ANSWER.....Type (modality), Location, Intensity,
Duration
Sensory Receptors: Type of Stimulus (Modality)
.....ANSWER.....The differentiation between taste, smell, sight,
touch. And even further within the senses, such as bitter versus
salty taste. All of these sensory types produce identical action
potentials to the CNS, so how does the brain differentiate
between different senses? It does so by looking at WHERE the
action potential came from. If the stimulus came from the retina,
the brain assumes the stimulus is sight. You can prove this by
rubbing your eyes really hard. This touch sensation is interpreted
as sight!
,Page 2 of 62
Transduction .....ANSWER.....The conversion of one form of energy
to another. This occurs then sensory receptors convert heat, light,
chemicals, touch, sound to an action potential.
Sensation .....ANSWER.....Conscious awareness of the stimulus or
feeling.
Sensory Receptors: Location .....ANSWER.....There is also a
Labeled Line Code that works for location. The path of action
potentials take from the eyes will be different than the path that
action potentials take from the hand to get to the brain.
Also, every sensory receptor has a receptive field, the area in
which it detects stimulation. You can poke the middle or the edge
of this field and it would feel the exact same to the person. More
sensitive areas of the body (fingertips) need smaller receptive
fields than do the back sensory receptors.
,Page 3 of 62
Sensory Receptors: Intensity .....ANSWER.....Receptors
differentiate intensity of the stimulus by:
1. The frequency of firing of neurons
2. The number of neurons that are firing
3. The threshold of neurons that are firing (neurons with a high
threshold for stimulus will only be fired in a very intense (painful)
situation.
Sensory Receptors: Duration of Stimulus .....ANSWER.....Encoded
by changes in the firing frequency of a nerve fiber with the
passage of time. All sensors undergo sensory adaptation, where
the firing of a neuron gets slower over time if a stimulus is
prolonged.
Phasic Receptors .....ANSWER.....Sensory receptors that adapt
rapidly to stimuli; like how you don't feel your shirt after like 10
seconds of wearing it. This is the first level of filtering of
unnecessary stimuli. RF is the second.
, Page 4 of 62
Tonic Receptors .....ANSWER.....Sensory receptors that keep firing
action potentials even after a while and are slowly adapting to
stimuli. Why is this important or needed?
1. If your finger stopped hurting a milisecond after you put it in
fire, you would leave it in the fire. This is to really burn into your
memory this painful experience
2. Pain continues so that your body will want to do something
about it (treat the pain so you don't get infected or die). This
enacts an inflammation and/or immune response.
Mechano-recptors .....ANSWER.....Sensory receptors that respond
to physical deformation of the tissue or cell. Ex. Cutaneous (skin)-
touch, pain, vibration
Nociceptors .....ANSWER.....Specific pain receptors. The idea that
a stimuli of any sense can be painful if intense enough. These
