Week 6 - sensory input

Question 1

Do we have 5 senses?

Answer 1

No more when defined by modality

Question 2

What is bad about the definition of the 5 senses?

Answer 2

• nose+ mouth different chemicals
• ear and finger mechanical pressure (hand also temp, damage)

Question 3

What are the signal modalities?

Answer 3

• mechanoreception
• thermoreception
• photoreception
• chemoreception
• nocieption

Question 4

Mechanoreception

Answer 4

Pressure, body position, sound, acceleration, gravity (pacinian corpuscles, msucle spindles, hair cells in organs of corti, semicircular canals, utricle and saccule)

Question 5

Thermoreception

Answer 5

Temp (free nerve endings in skin and core temp sensors in hypothalamus)

Question 6

Photoreception

Answer 6

Electomagnetic waves eg. Rod and cones

Question 7

Chemoreception

Answer 7

Specific materials/ molecules (eg. Olfactory receptors in your nose, gustatory receptors such as taste buds)

Question 8

Nociception

Answer 8

Cellular damage (eg. NK1 receptor for substance P )

Question 9

What can we not sense?

Answer 9

Carbon monoxide, raditation - alpha, nuclear decay

Question 10

What 2 receptors are there

Answer 10

A. Sensory neuron
B. Epithelial sensory receptor cell

Question 11

Where are the most receptors in your hand?

Answer 11

Fingertips

Question 12

How does the receptor work

Answer 12

• presure deforms capsule
• More permeable to spodium ion

Question 13

Which type of receptors are the pacinian sorpuscles and muscle spindles

Answer 13

Direct

Question 14

Example of mechanoreception

Answer 14

Hearing
- pressure waves transmitted into fluid in vestibular duct
- waves vibrate in connective tissue fibres in tectorial membrane when they match resnoant freq of fibres, membrane bathed in area of high potassium, ion conc

Question 15

Hair cells

Answer 15

• modified eptihelial cells
• cilia projected form apical side
• tallest cilium in each cell kinocilium and is linked to stereocilia
• when kinocilium is bent away from stereocilia, K+ channels open
• when bent toward stereocilia, channels close

Question 16

Bend to right

Answer 16

Action potentail frequency increases

Question 17

Bent to left

Answer 17

Feweer porduced

Question 18

Acceleration and gravity

Answer 18

Internal ear location of ability to sense acceleration and gravity
-> kupila is bending hair cells (jelly like)

Question 19

In what way is the utrile oriented?

Answer 19

3 dimentionally in x,y,z planes

Question 20

Hair cells

Answer 20

Epithelial sensory receptor cell

Question 21

Enodiing

Answer 21

4 types:
1. Stimulus modality
2. Stimulus intensity
3. Stimulus location
4. Stimulus duration

Question 22

Why do you see stars when punched

Answer 22

So much pressure, opens up photo receptor to pass down optic nerve, brain sees it as light

Question 23

Location

Answer 23

Ssomatosensory cortex, certain parts correspond to certain touch

Question 24

Intensity

Answer 24

Souldnt be O in sens neuron 2 - just no change in action potential, if intesnity increases, recruiting more orgnas

Question 25

Stimulus duration

Answer 25

• all receptors adapt
• tonic receptors adapt slowly
• phasic receptors adapt quickly