Lecture 3

Question 0

What are the characteristics of receptors? (4)

Answer 0

Differential sensitivity (receptor detects only specific stimuli)
Modality (types of sensation)
Labeled line principle (transmit only 1 kind of stimuli)
Adaptation of receptors (all adapt to sensation over time; some adapt faster)

Question 1

What are the sensory receptor types? What is an example of each?

Answer 1

1. Mechanoreceptors (free and encapsulated endings; Meissner’s Kraus’ and Pacinian corpuscles)
2. Thermoreceptors - cold/warm
3. Nocireceptors - pain
4. Electromagnetic receptors - rods/cones (eyes)
5. Chemoreceptors - taste, smell, O2 and CO2

Question 2

What are ways you can stimulate receptors?

Answer 2

Mechanical deformation - stretch memb. / open ion channels
Apply chemical to membrane - opens ion channels
Temperature change = changes the permeability of the memb.
Electromagnetic radiation = light indirectly/directly opens ion channels

Question 3

When comparing tonic and phasic receptors, which are faster to adapt?

Answer 3

Phasic receptors

Question 4

Which receptor transmits only if stimuli is present for a long time? (tonic or phasic)

Answer 4

Tonic

Question 5

Which receptor detects continuous stimuli? (tonic or phasic)

Answer 5

Tonic

Question 6

Which receptor is stimulated only when there is a change in strength and transmits info about the rate of that change? (tonic or phasic)

Answer 6

Phasic

Question 7

Muscle spindles, Golgi tendon organs, macula & vestibule receptors, baroreceptors, and chemoreceptors are what type of receptors?

Answer 7

Tonic receptors

Question 8

What are the two main nerve fiber types?

Answer 8

A & C

Question 9

Which nerve fiber type is large and myelinated?

Answer 9

A

Question 10

Which nerve fiber type has low velocity signal transduction, and makes up 1/2 of the PNS sensory fibers and all of the post ganglionic autonomic fibers.

Answer 10

type C (small and unmyelinated)

Question 11

What are the four sub-types of type A nerve fiber?

Answer 11

Ia (A alpha) - muscle spindle
Ib (A alpha) - golgi-tendon
II (A beta,gamma) - cutaneous tactile
III (A delta) - temp, crude, pricking pain

Question 12

What is the sub-type of type C nerve fiber?

Answer 12

IV (C) - itch, pain, temp, crude touch

Question 13

What are the two types of summation?

Answer 13

Spatial and Temporal

Question 14

A cluster of nerve endings creating a big local potential, describes what type of summation?

Answer 14

Spatial; More fibers = more strength

Question 15

Which type of summation is described as increased strength in potential due to an increase in frequency?

Answer 15

Temporal

Question 16

A functional group of neurons that process and integrate information, describes what?

Answer 16

Neuronal Pool

Question 17

What is a stimulatory field?

Answer 17

An area within the neuronal pool stimulated by an incoming fiber

Question 18

The output fibers stimulated by the incoming fiber in a neuronal pool are in what zone? But, if they are not excited by the incoming fiber then they are in which zone?

Answer 18

Discharge; facilitated

Question 19

An amplified signal that spreads, would be which kind of pathway?

Answer 19

Diverging pathway

Question 20

True/False: An inhibitory circuit is one fiber that splits and can be either inhibited or excited.

Answer 20

True

Question 21

This circuit is oscillatory, uses positive feedback and may discharge repetitively for a long time, which circuit is this?

Answer 21

Reverbatory Circuit

Question 22

What is a converging pathway?

Answer 22

Multiple fibers –> 1

Single/multiple sources