respondto stimuli

Question 1

what are the pacinian corpuscles

Answer 1

Pacinian corpuscles are a type of receptor found deep in the skin
They are present in the skin of fingers, soles of the feet as well as in joints, tendons and ligaments.
They respond to changes in pressure
When these receptors are stimulated by pressure on the skin it leads to the establishment of a generator potential

Question 2

talk to me about how a generator potential is formed from pressure on the Pacinian corpuscle

Answer 2

The section of axon surrounded by layers of membrane contains stretch-mediated sodium ion channels which open when sufficient pressure is applied
When pressure receptors are stimulated by pressure on the skin an electrical potential difference across the axon membrane is established - the generator potential

Question 3

process of generating potential

Answer 3

Sodium ions enter the axon via facilitated diffusion
This influx of ions changes the electrical potential difference across the membrane
This leads to depolarisation
This establishes a generator potential
The generator potential triggers impulses (action potentials) that travel along the sensory neurone to the central nervous system

Question 4

name the two types of eye receptors and their function

Answer 4

The eye contains two types of receptor cell:
Rod cells which are sensitive to light intensity
Cone cells which are sensitive to different wavelengths of visible light (colour)

Question 5

what is visual acuity

Answer 5

Visual acuity
Acuity is the ability to distinguish two separate points, otherwise known as ‘visual clarity’