sensory reception1

Question 1

what are sensory receptors?

Features of a stimuli-what it the type of stimulus/ energy of a stimuli known as?

Answer 1

nerve endings which can convert different forms of energy into Action potentials informing the CNS of changes in internal and external environment.
sensory receptors usually respond to one type of stimuli but will respond to an intense form of another stimuli.
Sensory modality: type of stimulus
adequate stimuli : type of energy

Question 2

different types of sensory receptors?

Answer 2

mechanoreceptors: respond to changes in pressure, stretch and deformation
nocireceptors: respond to intense pain
proprioreceptors: mechanoreceptors found in the muscle and joints which inform the CNS of changes in body movement

Question 3

what is adaptation?
different types of adaptation in receptors?
which receptors must not have adaptation?

Answer 3

When sensory receptors are able to signal only the onset of a stimulus.
Stimulus causes receptor potential to reach threshold and AP fired. then receptor potential decreases very quickly so AP no longer fired.
Rapid-adapting receptors: such as pacinian and meissnar’ s
Slow-adapting receptors: such as Merkels
Nocireceptors must not have adaptation- pain must be detected

Question 4

pacinian corpuscle

Answer 4

myelinated neurone with naked nerve ending which is surrounded by a capsule of layers of connective tissues which are separated by fluid.
When stimulates, stretches which causes Na+ channels to open and AP generated. Then adapts by redirecting fluid. When stimulated stops, layers spring back into shape, this causes new AP to be generated- ON and OFF signal

Question 5

what is the section of a sensory neurone which can be stimulated known as? what does it and convergencewhat define?

Answer 5

they define whether two areas of skin can be distinguished.
receptive area: the section of the sensory nerve where it can be stimulated
convergence: when multiple pre-synaptic nerves fire onto a smaller number of post-synaptic nerves so that there is a sum-up of sub-threshold stimuli.

Question 6

what are acuity and lateral inhibition?

Answer 6

acuity: ability to locate a stimulus on the skin
lateral inhibition: when stimuli of the edge of sensory receptor are neglected over stimuli in centre of sensory receptor

Question 7

What is the capsule in pacinian corpuscle an example of?

Answer 7

A non-neuronal accessory