L24 - Somatic movement

Question 1

What is a special sense?

Answer 1

Has its own organ to understand sensory information

Question 2

What are the special senses? [5]

Answer 2

*Vision
*Hearing
*Balance
*Taste
*Smell

Question 3

What are the somatic receptors?

Answer 3

*Mechanoreceptors
*Nociceptors
*Thermoreceptors
*Chemoreceptors

Question 4

What do mechanoreceptors detect?

Answer 4

Uses mechanically gated ions channels
*Touch
*Pressure
*Vibration
*Proprioception

Question 5

Does the brain have receptors?

Answer 5

NOp

Question 6

What does somatic mean?

Answer 6

“of the body”

Question 7

Where are the somatic receptors?

Answer 7

Distributed throughout the body

Question 8

What do nociceptors detect?

Answer 8

Noxious stimuli
*found all over the body except the brain
*things that damage/ potentially damage tissue

3 types of stimuli are thermal, mechanical and chemical

Question 9

Example of a chemoreceptor?

Answer 9

Holding breath increases the pH, detected by the chemoreceptors inside forces you to break your breath

Question 10

Why type of neurons are sensory neurons?

Answer 10

Unipolar, single process that splits into input (ONE OF THE TYPES OF STIMULI) and output (in CNS) areas

Question 11

Sensory station in the brain?

Answer 11

Thalamus

Question 12

What are proprioceptors and touch stimulated by?

Answer 12

Stimulated by physical forces that distort the plasma membrane
*Nerve endings contain mechanically gated ion channels

Question 13

Types of mechanoreceptors

Answer 13

*Proprioceptors - muscle spindles
*Baroreceptors - blood pressure, in the urinary bladder
* Tactile receptors - touch, pressure, vibration

Question 14

Skin has what kind of receptors?

Answer 14

Tactile receptors

Question 15

Closer to skin…

Answer 15

The more sensitive to touch on the skin

Question 16

What are encapsulated nerve endings?

Answer 16

Covers the receptors are covered with a membranous structures that makes the receptor sensitive to a type of touch

Question 17

Receptors that are sensitive to deep touch

Answer 17

Bulbous corpuscles (looks like muscle spindles)

Question 18

What are tactile discs?

Answer 18

Sensitive to vibration

Question 19

Nerve endings on the base of hair i.e hair units

Answer 19

*activated when the hair is displaced

Question 20

What is skin that does not have hair called?

Answer 20

Glabrous skin

Question 21

What are free nerve endings?

Answer 21

Bare nerve endings, sensitive to temperature and noxious stimuli

Question 22

Are there noxious receptors in tissue around the brain?

Answer 22

Yes

Question 23

What is signal transduction

Answer 23

Sensory receptors detect their specific stimulus –> ions channels open, change in MP results in a receptor potential –> threshold, AP

converting a stimulus of one form into an AP is a signal transduction

Question 24

Receptive field

Answer 24

If an axon branches out over a wide area, they have a big receptive field and only one axon is activated

More localised touch in smaller receptive fields, better 2 pt discrimination

Question 25

Phasic

Answer 25

Neurons are usually silent --> stimulus causes increase in f of APs, new steady state so no more APs until change again --> APs until new steady state *fast adapting

Question 26

Tonic

Answer 26

Continually active APs, change causes different rate of APs to be fired until steady state again --> back to og firing of APs *slow adapting

Question 27

4 types of info

Answer 27

*Modality - Type of receptor activated *Intensity- no. of APs fired in afferent neurons *Duration - time period over which stimulus exists *Location - brain mapped where sensory receptors are so would know where the stimulus occured

Question 28

What structure of the brain knows where stimulus occurs - sensory receptors of the body

Answer 28

Postcentral gyrus precenntral gyrus know the position of motor structures