2- Receptors

Question 1

Define receptors ?

Answer 1

specialized structures present at peripheral end of AFFERENT neuron & sensitve to & can detect change in environment

Question 2

Function of receptor ?

Answer 2

Respond to stimuli & transform them to electrical energy

Question 3

physiological classification (5) ?

Answer 3

1) mechanoreceptors
2) thermoreceptors
3) nociceptors
4) electromagnetic receptors
5) chemoreceptors

Question 4

Histological classification (2) ?

Answer 4

Free nerve ending
Expanding nerve ending

Question 5

mechanoreceptors ex (5)?

Answer 5

• skin tactile (dermis & epidermis )
• deep tissue (muscle & tendon)
• hearing
• arterial pressure
• vestibular receptors (equilibrium)

Question 6

Rods & Cones are example of which type of receptor ?

Answer 6

electromagnetic

Question 7

chemoreceptors (4) examples ?

Answer 7

• taste
• smell
• arterial oxygen
• osmolality

Question 8

free nerve ending for ?

Answer 8

Pain
Temperature
Crude touch

Question 9

Markels disc: ———- adapting & ———- receptive field ?

Answer 9

Slow , small

Question 10

Meissner courpuscle : —- adapting & —— receptive field ?

Answer 10

Rapid , small

Question 11

pacininan corpuscle: —— adapting & —— receptive field ?

Answer 11

Rapid , large

Question 12

Ruffinis ending : —— adapting & —— receptive feild ?

Answer 12

Slow , large

Question 13

excitability of receptor by Mechanisms of ?

Answer 13

Receptor Potentials

Question 14

Receptor Potentials excited by (4) ?

Answer 14

1) Mechanical deformation
(2) Application of a chemical
(3) Change of the temperature
(4) Electromagnetic radiation

Question 15

define adequate stimulus?

Answer 15

Each type of the receptors is sensitive to a specific stimulus

Question 16

Response of the receptors to non specific stimuli
Ex: hitting the eyes strongly causes flashes of light
This is know as ?

Answer 16

Muler’s law of specific nerve energy.

Question 17

frequency of action potential in the nerve directly proportional to the logarithm of rate of increase in intensity is known as ?

Answer 17

Weber-fechner law (compression function)

Question 18

Weber-fechner law (compression function) allows
————- range detection of intensity of stimuli
in spite of the———————-?

Answer 18

Wide range , limited number of action potential.

Question 19

Define adaptation ?

Answer 19

Decrease response in spite of constant (stimulation)

Question 20

MOA of adaptation in mechanoreceptors ?

Answer 20

due to
1- the Lamellae ( surrounds nerve ending)
2- Adaptation by inactivation of Na+ channels in the nerve membrane.
3- Dec sensitivity 1st ranvier node
4- dissipation of energy to surrounding tissue.

Question 21

Ex of rapid adapting receptors ?

Answer 21

Skin
Posture (in muscle & tendons )

Question 22

Ex of slow (tonic) adapting receptors?

Answer 22

Mechanoreceptors
Pain receptors

• macula in the vestibular apparatus.
  -Pain
• baroreceptors
• chemoreceptors of the carotid and aortic bodies

Question 23

Ex of moderate adapting receptors?

Answer 23

Temperature receptors
Smell receptors
Taste receptors
Pressure receptors