Special senses

Question 1

Humans perception is limited by?

Answer 1

1. receptor types
2. sensitivity
3. central processing

Question 2

Control centre in the brain?
2 things it controls

Answer 2

Cerebral cortex
1. Sensation
2. Perception

Question 3

Receptor definition

Answer 3

structure within afferent neuron that responds to stimulus

Question 4

Sensory transduction

Answer 4

conversion of stimulus to electrical energy

Question 5

Peripheral nervous system

Answer 5

nerve fibres carrying info between CNS and other parts of the body
Afferent neurons have sensory receptors at the end of peripheral endings

Question 6

Adequate stimulus

Answer 6

the stimulus that the receptor is specialised to respond to

Question 7

Types of receptors and their adequate stimulus
Peter Malark Obviously Never Takes Chemicals

Answer 7

1. Photoreceptor (light)
2. Chemoreceptors (chemicals)
3. Mechanoreceptor (pressure)
4. Osmoreceptor (concentration of solutes)
5. Thermoreceptors (temps)
6. Nocireceptors (pain)

Question 8

Intensity of stimulus determined by?

Answer 8

1. number of receptors
2. frequency of action potentials

Question 9

Response changes - body adjusts to stimulus in 3 ways:

Answer 9

1. Receptor Adaptation
2. Neuron Habituation
3. Neuron Sensitivity

Question 10

Receptor Adaptation
What is it and 2 types

Answer 10

Receptors decrease extent of depolarisation
Repetition of stimulus results in fewer action potentials
1. Tonic Receptors
- adapt slowly or not at all

2. Phasic Receptors
   - adapt rapidly (watch)

Question 11

Sensory discrimination
Large vs Small

Answer 11

Large diffuse receptive fields = least sensitive
Small dense receptive fields = most sensitive

Question 12

Somatic senstation
What?
Where is it processed?
Types of tactile receptors (5)

Answer 12

Sensation of body surfaces
Somatic processing: spinal cord & brain
1. Hair
2. merkels disc
3. pacinian corpuscle
4. ruffini endings
5. meissners corpuscles

Question 13

Pain Sensation
describe
3 Categories of Nocireceptors

Answer 13

more than a direct response. behaviour and emotions play a role
it is personal and multidimensional
1. Mechanical noceceptors
2. Thermal noceceptors
3. Polymodal noceceptors (damaging stimuli)

Question 14

EYE
2 main muscles in contraction & relaxation
what occurs in bright light

Answer 14

Circular muscles
Radial muscles

In bright light the circular muscles contract and radial muscles relax, and the pupil constricts

Question 15

Eye accomodation
what is it?
explain process

Answer 15

Observation of nearby objects
The ciliary muscles contract -> suspensory ligaments slacken -> lens more convex -> light rays more refracted

Question 16

Rods VS Cones

Answer 16

Rods:
- more sensitive
- low acuity
- shades of grey
- photopigment

Cone:
- less sensitive
- sharp
- colours
- 3 photopigments (red, green & blue)

Question 17

Visual Acuity Test
formula?

Answer 17

VD = d/D
(d = 6 meters)
(D = distance at which eyes should be able to read it)

Question 18

EAR
3 main sections

Answer 18

1. External ear
2. Middle ear
3. Inner ear

Question 19

Pitch, Intensity and Timbre

Answer 19

Pitch = frequency changes
Intensity = amplitude changes
Timbre = overtones

Question 20

External Ear Structures (3)

Answer 20

1. Pinna
2. External auditory meatus (canal)
3. tympanic membrane (eardrum)

Question 21

Middle Ear Structures (3)
MIS

Answer 21

Ossicles
1. Malleus
2. Incus
3. Stapes

Question 22

Inner Ear (1 main & NB compartment)

Answer 22

Cochlea
1. Organ of Corti

Question 23

Pitch discrimination

Answer 23

Depends on where it vibrates maximally on the basilar membrane

Question 24

Loudness discrimination

Answer 24

Depends by how much the basilar membrane vibrates

Question 25

Conductive deafness What & possible causes

Answer 25

Sound waves are not conducted through external and middle ear Blockage ruptured ear drum ear infection restricted ossicular movements

Question 26

Sensorineural deafness What & where possible defects may lie

Answer 26

Sound waves are transmitted to inner ear but not translated to nerve signals 1. Organ of corti 2. in auditory nerves 3. in ascending auditory pathways

Question 27

Equilibrium Vestibular aparatus and their roles (2)

Answer 27

1. Semi-circle canals - rotation / angular acceleration 2. Otolith canals - upside down sloth (position of head to gravity)

Question 28

Taste receptors? protrusions on tongue? 5 primary tastes

Answer 28

Chemoreceptors Papillae 1. sweet 2. sour 3. bitter 4. umami 5. salty

Question 29

Smell (olfactory mucosa) 3 cell types

Answer 29

1. olfactory receptors cells - afferent neuron 2. basal cells - detect odours 3. supporting cells - secrete mucous