Senses

Question 1

Rods

Answer 1

High sensitivity - saturate in daylight
Slower response + longer integration time
Low acuity
Achromatic

Question 2

Cones

Answer 2

Low sensitivity - saturate in intense light
Fast response + short integration time
High acuity
Trichromatic

Question 3

Phototransduction in dark

Answer 3

Depolarisation (-40mV)
cGMP binds ion channels
Allows positive ions to enter

Question 4

Phototransduction in light

Answer 4

Hyperpolarisation (-70mV)
[cGMP] decreases
No ions enter
Ions leaving still

Question 5

On centre receptive fields

Answer 5

Light in middle excites
Dark in middle inhibits

Question 6

Off centre receptive fields

Answer 6

Dark in middle excites
Light in middle inhibits

Question 7

M pathway

Answer 7

Magnocellular
Movement pathway

Question 8

P pathway

Answer 8

Parvocellular
Fine detail + colour analysis

Question 9

Simple cells

Answer 9

Respond best bars of light/dark
Respond to specific orientation
Elongated excitatory + inhibitory bars

Question 10

Complex cells

Answer 10

No off area
Detect moving bars of light
Axis parallel
Shape receptive field

Question 11

Basilar membrane - apex

Answer 11

Thin + floppy
Sensitive to low frequency vibrations

Question 12

Basilar membrane base

Answer 12

Thick + taught
Sensitive to high frequency vibrations

Question 13

Cochlear structure

Answer 13

Inner Hair Cells (IHC) - 1 layer
Outer Hair Cells (OHC) - 3 layers

Question 14

Cochlear activation

Answer 14

1. Basilar membrane movement
2. Movement of tectorial membrane
3. Tectorial membrane presses on cilia of IHC

Question 15

Motor of OHC

Answer 15

Distortion of cilia
Change in membrane potential
Cell stretches + contracts
Low sound

Question 16

Prestin

Answer 16

Motor protein
Long + short state depending on voltage change

Question 17

Depolarisation

Answer 17

When cilia displaced
Entry of K by stria vascularis
Ca entry
80mV in scala media

Question 18

Deafness

Answer 18

Change sin genes expressed in hair + supporting cells
Cx26 deletion

Question 19

Vestibular system

Answer 19

1. Depolarisation of hair cells
2. Neurotransmitter release
3. Activation of afferent nerve

Question 20

Spiral ganglion neurone

Answer 20

Forms afferent nerve
Innervates one hair cell

Question 21

Cochlear implant

Answer 21

Stimulates electrodes for SGN to restore hearing

Question 22

Brainstem (Medial Superior Olive)

Answer 22

Receives input from both ears
Give rise to place code
Neurones fire when inputs from L + R are simultaneous

Question 23

Wernicke’s area

Answer 23

Language comprehension

Question 24

Brocas area

Answer 24

Language production

Question 25

Altitude + equator

Answer 25

High barometric pressure Solar radiation causes convection Column of air higher

Question 26

Sleep + high altitude

Answer 26

Periodic breatihng Instability between hypoxia + hypocapnia Increased O2 intake drives CO2 down

Question 27

Adaptation to high altitude (HCO3-)

Answer 27

Moved from CSH -> blood to increase CO2 Blood becomes more alkaline Kidneys secrete HCO3-

Question 28

Acute mountain sickness treatment

Answer 28

Acetazoldamide Carbonic anhydrase inhibitor Increase HCO3-

Question 29

High altitude pulmonary edema symptom

Answer 29

Coughing up blood Pulmonary capillary rupture

Question 30

Birds + gas exchange system

Answer 30

Air passes in one direction Countercurrent exhange Powerful heart Insensitivity of cerebral blood vessels to hypocapnia

Question 31

Elephants gas exchange system

Answer 31

No pleural cavity Abdominal pressure > pleura which would cause microvessles that produce fluid to rupture Instead have dense + loose connective tissue