T9 - Control Systems

Question 1

Name the part of the nervous system that controls
heart rate

Answer 1

Autonomic nervous system

Question 2

State what type of receptors detect blood pressure

Answer 2

Baroreceptors

Question 3

State where baroreceptors are found

Answer 3

Aorta and carotid arteries

Question 4

State what type of receptors detect blood pH

Answer 4

Chemoreceptors

Question 5

State where chemoreceptors are found

Answer 5

Aorta and carotid arteries

Question 6

Explain what causes blood pH to increase

Answer 6

Reduction in CO at rest due to low rate of respiration.

Question 7

Explain what causes the blood pH to decrease

Answer 7

Increase in CO during exercise due to higher rate of
respiration

Question 8

Name the part of the brian that coordinates heart rate

Answer 8

Cardiovascular centre in medulla oblongata

Question 9

Name the nerve that stimulates the heart rate to
increase

Answer 9

Sympathetic (accelerator) nerve

Question 10

Name the neurotransmitter released at the SAN by the sympathetic nerve

Answer 10

Noradrenaline (norepinephrine)

Question 11

Name the nerve that stimulates the heart rate to
decrease

Answer 11

Parasympathetic (vagus) nerve

Question 12

Name the neurotransmitter released at the SAN by the parasympathetic nerve

Answer 12

Acetylcholine

Question 13

Explain how the autonomic nervous system increases heart rate

Answer 13

Aortic and carotid baroreceptors detect low blood pressure, or chemoreceptors detect low blood pH and send nerve impulses to cardioacceletory centre in medulla oblongata.
Medulla oblongata stimulates sympathetic nerve to
release noradrenaline at the SAN, which depolarises more frequently

Question 14

Explain how the autonomic nervous system decreases heart rate

Answer 14

Aortic and carotid baroreceptors detect High blood pressure, or chemoreceptors detect high blood pH and send nerve impulses to cardioacceletory centre in medulla oblongata.
Medulla oblongata stimulates parasympathetic nerve to release acetylcohline at the SAN, which depolarises less frequently

Question 15

Explain how the release of adrenaline increases heart rate

Answer 15

The cardioacceleratory centre in the medulla oblongata sends nerve impulses to adrenal gland via sympathetic nervous system, which stimulates release of more adrenaline.
Adrenaline travels in the blood to the heart, and
stimulates the SAN to depolarise more frequently