Sensory Receptors

Question 1

Describe the structure of cutaneous receptors

Answer 1

Found in the skin (dermis/ epidermis)

Question 2

Functions of sensory receptors

Answer 2

Inform brain of internal/ external environment
Nerve endings
Convert different stimuli into frequency of action potentials (transducers)

Question 3

Explain 3 types of sensory receptors

Answer 3

Mechanoreceptors- skin sensation of touch/ pressure
Propriceptors- joints/ muscles, body positions
Nociceptors- heat and tissue damage, pain

Question 4

Explain frequency coding stimulus intensity

Answer 4

Need a larger stimulus, causes a larger receptor potential and higher frequency of action potentials

Question 5

What are proprioceptors

Answer 5

Mechanoreceptors that signal body or limb position
Control our voluntary movements
Generate spinal reflex movements
Perceive limb and body position and movement in space (kinaesthesia)

Question 6

Name 3 types of propriceptors

Answer 6

Muscle spindles- muscle length, rate of length change
Golgi tendon organs- tension on tendons
Joint receptors- joint angle, rate of angular movement

Question 7

Explain skin Mechanoreceptors & proprioceptors

Answer 7

Involves opening ion channels
Stimulus causes graded membrane potientials
Strength of stimulus = larger receptor potiential= higher frequency/ larger action potiential

Question 8

What is a pacinian corpuscle

Answer 8

Encapsulated ending of a sensory receptor tat acts as a receptor for pressure and vibration

Question 9

How do muscle stretch stimulate spindle stretch receptors

Answer 9

1. Resting AP frequency depends on length
2. AP frequency is proportional to velocity
3. AP frequency at new steady state

Question 10

Explain alpha/ gamma motor neurons

Answer 10

A- fire causing extramural fibre contraction
Y- fire causing intramuscular fibre ends contraction