Sensory Receptors

Question 1

Transducer

Answer 1

Convert many different forms of energy into frequency of action potentials

Question 2

Types of sensory receptors

Answer 2

Mechanoreceptors
Proprioreceptors
Nociceptors
Thermoreceptors
Chemoreceptors
Photoreceptors

Question 3

Mechanoreceptors

Answer 3

Pressure, stretch, deformation

Question 4

Proprioreceptors

Answer 4

Joint and muscle for limb position

Question 5

Nociceptors

Answer 5

Pain

Question 6

Thermoreceptors

Answer 6

detect cold and warmth

Question 7

Chemoreceptors

Answer 7

chemical changes (PH)

Question 8

Photoreceptors

Answer 8

Wavelengths of light

Question 9

The receptor potential is____ to stimulus intensity

Answer 9

Graded

Question 10

Skin receptors

Answer 10

Paccinian corpuscle - vibration
Ruffini Corpuscle - vibration
Merkel Receptor- pressure and texture
Meissner’s- stroking

Question 11

Rapidly adapting receptors

Answer 11

Pacinian and Meissner’s

Question 12

Slow adapting

Answer 12

Merkel’s disc and Ruffini endings

Question 13

Receptor that does not adapt

Answer 13

Nociceptors

Question 14

Receptive fields

Answer 14

Ability to tell 2 points apart on the skin

Question 15

Neuronal convergence

Answer 15

Lots of convergence and a large secondary receptive field indicate a relatively insensitive area

Question 16

Low acuity

Answer 16

High levels of convergence

Question 17

High acuity

Answer 17

Low levels of convergence

Question 18

Lateral Inhibition

Answer 18

Pathway closest to the stimulus inhibits neighbors to sharpen up sensory information

Question 19

Muscle Spindles

Answer 19

Monitor muscle length and rate of change of muscle length

Question 20

Golgi Tendon Organs

Answer 20

monitor tension on tendon

Question 21

Joint receptors

Answer 21

monitor joint angle, rate of angular movement and tension on the joint

Question 22

What do the receptors do

Answer 22

send sensory information to the brain for voluntary control
Drives spinal cord reflexes
Kinaesthesia (body position)

Question 23

Structure of Muscle spindles

Answer 23

6-8 Specialised intrafusal fibres and lie parallel to muscle fibres

Question 24

Primary

Answer 24

1a
Wrap around centre
send information to CNS about velocity and length

Question 25

Secondary

Answer 25

II
Flower sparay
innervate nerve endings
Provide information on muscle length

Question 26

Muscle contraction

Answer 26

1. Muscle spindles detect stretch in mucsle
2. Sensory neurons conduct actionpotential to spinal cord
3. Sensory neurons synapse directly with alpha motor neurons
4. Alpha motor neurons conduct action potential to muscle causing it to contract

Question 27

Two kinds of intrafusal fibres

Answer 27

Nuclear bag

Nuclear chain

Question 28

Gamma motor neurons

Answer 28

Efferent
innervate and cause contraction of the contracile ends of intrafusal fibres
Maintain spindle sensitivity

Question 29

Golgi Tendon Organ

Answer 29

Tendon bundles at ends of muscle
Muscle fibre contraction increases the tension in the tendons
This stretches the nerve endings of the GTO and initiates APs in group 1b afferent from GTO

Question 30

Purpose of GTO

Answer 30

Restores tension in spindle and resets the sensitivity of the central sensitivity part

Question 31

Alpha motor neuron innervate

Answer 31

extrafusal

Question 32

Gamma motor neuron innervate

Answer 32

intrafusal

Question 33

Light Load

Answer 33

Hand raised and 1a afferent fibres increase firing rate

1b afferent doesn’t change

Question 34

Heavy Load

Answer 34

Heavy object causes firing of 1b

Question 35

The stretch of the GTO causes____

Answer 35

reflex inhibition (relaxation)