Nervous System- Eyes & Heart

Question 1

What are the 2 divisions of the autonomic nervous system?

Answer 1

1) Sympathetic NS (speeds up activities i.e. fight or flight response)
2) Parasympathetic NS (inhibits and slows down activities)

Question 2

Which region of the brain controls heart rate?

Answer 2

Medulla Oblongata

Question 3

What is the common end point of the sympathetic and parasympathetic nervous system?

Answer 3

Sinoatrial node

Question 4

Which receptors detect changes in pH and where are they found?

Answer 4

Chemoreceptors in the Carotid Arteries

Question 5

What receptors detect blood pressure?

Answer 5

Baroreceptors

Question 6

What is a generator potential?

Answer 6

The conversion of the energy of a stimulus into a nerve impulse (in sensory receptors)

Question 7

What is the structure and function of a pacinian corpuscle?

Answer 7

1) Responses to mechanical pressure
2) Found in ligaments and joints
3) The neurone is located in the centre of layers of tissue
4) Contain stretch mediated Na+ ion channels

Question 8

How is a generator potential created?

Answer 8

1) In the resting state, stretch mediated Na+ ion channels are narrow
2) Under pressure, the membrane of the neurone is stretched which causes channels to widen
3) Influx of Na+ ions cause change in polarity
4) Generator potential created which creates action potential

Question 9

What are the 2 types of light receptor and where are they found?

Answer 9

1) Rods
2) Cones
Found in the retina

Question 10

What are some characteristics of rod cells?

Answer 10

1) Cannot distinguish between different wave lengths of light
2) Multiple rod cells connected to one neurone
3) Function at low light intensity
4) They break down redopsin to generate an action potential
5) Rod cells have poor visual acuity

Question 11

What are some characteristics of cone cells?

Answer 11

1) 3 types of cone cells each responding to a different wave length
2) Interpretation of colour depends on the proportion of each type of cone cell being stimulated
3) 1 cone cell is connected to 1 bipolar cell
4) High light intensity required to create a generator potential
5) Cone cells break down Iodopsin to create a generator potential
6) High visual acuity
7) Fovea has a high concentration of cone cells

Question 12

SYNOPTIC QUESTION

Why do rod cells take time to recover?

Answer 12

Resynthesis of redopsin, as action potentials cannot be regenerated.