Lecture

Question 1

What do external receptors sense/feel/transmit?

Answer 1

touch
pressure
hot/cold
light
sound
taste
pain

Question 2

What do internal receptors sense/feel/transmit?

Answer 2

Stretch - Baroreceptors, Hering Bruer
Osmolarity - Hypothalamus
Ion levels - hypercarbic drive
Chemicals - hypoxic drive

Question 3

List the 5 classifications of receptors and what they are responsible for transmitting

Answer 3

Mechanoreceptors - detect mechanical compression or stretching of the receptor or tissue
Thermoreceptors - detect change in temperature
Nociceptors - detect physical or chemical tissue damage
Electromagnetic - detect light on the retina
Chemoreceptors - detect taste, small, O2 level in arterial blood, osmolality of body fluids, CO2 concentration etc.

Question 4

How does a stimulus transform?

Answer 4

The stimulus excites the receptor and causes an immediate effect to the receptors membrane electrical potential - receptor potential

Question 5

What must be reached for transmission of impulse to occur?

Answer 5

Threshold potential

Question 6

What is the labeled line principle?

Answer 6

Each sensory signal is conveyed to an appropriate specific site in the CNS, this is what results in different sensations

Question 7

What are the 2 responses to repeated stimulus a receptor can have?

Answer 7

Adaptation and Sensitization

Question 8

What is adaptation? Give some examples.

Answer 8

Repeated stimulus of a receptor results in a weaker response.
Pressure receptors are quick to adapt
Baro- and chemoreceptors are slow

Question 9

What is sensitization? Give an example

Answer 9

Repeated stimulus results in a stronger response.

Nociceptors

Question 10

List the order of peripheral nerves from largest to smallest. Naming which are myelinated and which are not. Which are fastest, slowest.

Answer 10

A alpha
A beta
A gamma
A delta
B
C - only one unmyelinated

Question 11

What size nerves conduct the fastest?

Answer 11

Larger fibers conduct faster

Question 12

Sensory information enters the spinal cord via the?

Answer 12

Dorsal root

Question 13

Once sensory information enter the spinal cord via the DRG and dorsal horn, what are the 2 pathways it could take?

Answer 13

Dorsal column - Medial Lemniscal

Anterolateral System - Spinothalmic tract

Question 14

Where does the dorsal column - Medial Lemniscal System enter, ascend, first synapse, cross, terminate.

Answer 14

Enters: Dorsal Horn
Ascends: Dorsal White column
First synapse: Medulla
Crosses: Medulla
Terminates: Thalmus

Question 15

Where does the anterolateral system enter, ascend, first synapse, cross, terminate?

Answer 15

Enters: Dorsal Horn
Ascends: Anterior and lateral white column
First synapse: dorsal horn
Crosses: in the dorsal horn
Terminate: brainstem and thalamus

Question 16

Which system has larger fibers and conducts faster?

Answer 16

Dorsal column - medial lemniscal system

Question 17

Which system has smaller fibers that conduct slower?

Answer 17

Anterolateral system - spinothalmic tract

Question 18

What signals does the dorsal column medial lemniscal system conduct?

Answer 18

localized touch
fine touch
proprioception

Question 19

What signals does the anterolateral system - spinothalmic tract conduct?

Answer 19

pain
temperature
crude touch
pressure 
tickle
itch