Sensory Systems Part 1

Question 1

What is sensory transduction?

Answer 1

How properties within our external and internal environment become encoded as nerve impulses

Question 2

What structures carry out sensory transduction?

Answer 2

Specialised structures namely SENSORY RECEPTORS

Question 3

Sensory receptors range from single cells to

Answer 3

Complex sense organs

Question 4

What type of receptors are there? List six

Answer 4

Chemoreceptors, mechanoreceptors, photoreceptors, electroreceptors, magnetoreceptors, thermoreceptors

Question 5

What do all receptors do to incoming stimuli?

Answer 5

They transduce incoming stimuli into changes in membrane potential

Question 6

In three short points what happens when a receptor protein detects a stimulus?

Answer 6

Results in the opening or closing of ion channel
Change in membrane potential
Signal sent to integrating centre/ CNS

Question 7

The sensory receptors can be classified by the location of the stimulus. What three categories would these be?

Answer 7

1. Telereceptors 2. Exteroreceptors 3. Interoreceptors

Question 8

What is a telereceptor?

Answer 8

An organ such as the eye that can receive sense stimuli from a distance

Question 9

Give two examples of telereceptors

Answer 9

vision, hearing

Question 10

What is an exteroceptor?

Answer 10

A sensory receptor which receives external stimuli

Question 11

Give two examples of exteroceptors

Answer 11

pressure and temperature

Question 12

What is an interoceptor?

Answer 12

a sensory receptor which receives stimuli from within the body

Question 13

Give two examples of interoceptors

Answer 13

blood pressure and blood oxygen

Question 14

What is stimulus modality?

Answer 14

One aspect of a stimulus. for example, hot or cold, pressure

Question 15

Give three locations in which mechanoreceptors are found

Answer 15

Special senses (ear), muscles and joints, skin and viscera

Question 16

Give an example of a mechanoreceptor found in the ear

Answer 16

cochlear hair cells

Question 17

give an example of a mechanoreceptor found in the muscles and joints

Answer 17

muscle spindles

Question 18

give an example of a mechanoreceptor found in the skin and viscera

Answer 18

pacinian corpuscles

Question 19

give two locations in which chemoreceptors are found

Answer 19

special senses such as the nose and the skin and viscera

Question 20

give an example of the chemoreceptors found in the nose

Answer 20

olfactory receptors

Question 21

give an example of a chemoreceptor found in the skin and viscera

Answer 21

nociceptors

Question 22

what is a nociceptor/nociception?

Answer 22

A nociceptor is a sensory neuron (nerve cell) that responds to potentially damaging stimuli by sending signals to the spinal cord and brain. This process, called nociception, usually causes the perception of pain.

Question 23

give an example of where photoreceptors are found

Answer 23

in the eye

Question 24

give an example of the photoreceptors in the eye

Answer 24

retinal rods and cones

Question 25

give two locations where thermoreceptors are found

Answer 25

in the skin and in the cns

Question 26

give an example of the thermoreceptors found in the skin

Answer 26

warm and cold receptors

Question 27

give an example of thermoreceptors found in the cns

Answer 27

temperature sensing hypothalamic neurons

Question 28

What happens when a chemical stimulus hits a chemoreceptor?

Answer 28

the chemical stimulus is identified by the receptor protein, goes through the signal transduction pathway, opens ion channel causing a change in the membrane potential and the signal is sent to the cns

Question 29

what are the two types of sensory receptor cells?

Answer 29

a sensory neuron itself or an epithelial sensory receptor cell

Question 30

where is the site of inititiation of an action potential in the efferent and in the interneuron?

Answer 30

In the efferent and interneurons, action potentials are inititated at the axon hillock located at the start of the axon next to the cell body

Question 31

Where is the site of initiation of an action potential in an afferent neuron?

Answer 31

Action potentials are initiated at the peripheral end of an efferent nerve fiber next to the receptor, a long distance from the cell body

Question 32

What is the adequate stimulus

Answer 32

the preferred (most sensitive) stimulus modality, for example, pressure on the eyelid - perceive light

Question 33

What are polymodal receptors?

Answer 33

Many receptors can be excited by other stimuli if sufficiently strong. for example, nociceptors; polymodal receptors for multiple types of pain

Question 34

where are all stimuli converted into action potentials?

Answer 34

In a primary afferent neuron

Question 35

Sensory receptors and sensory neurons must encode four types of information? what are the four?

Answer 35

1. stimulus modality 2. stimulus location 3. stimulus intensity 4. stimulus duration

Question 36

What of the four factors does the sensory receptor encode for?

Answer 36

the stimulus modality and location