heart rate regulation

Question 1

cardiac control

Answer 1

when heart rate needs to increase or decrease, the brain gets involved

Question 2

autonomic nervous system (ANS)

Answer 2

involuntarily regulates heart rate and determines the firing rate of the SA node

Question 3

cardiac control centre (CCC)

Answer 3

receives info from sensory nerves and sends direction through motor nerves to change HR

Question 4

control mechanisms

Answer 4

neural control, intrinsic control, hormonal control

Question 5

neural control

Answer 5

• chemoreceptors in muscles and carotid arteries detects an increase in CO2 and lactic acid
• proprioceptors in bones and joints detect motor activity
• baroreceptors in vessel walls detects an increase in blood pressure

Question 6

intrinsic control

Answer 6

• increased temperature increases the speed of nerve transmissions which stimulates the SA node causing HR to increase
• increased venous return cause increased stretch of atrial and ventricular walls

Question 7

hormonal control

Answer 7

• adrenaline + noradrenaline released from adrenal glands increasing force of ventricular contraction
• stimulates the sympathetic nervous system which increases firing rate of SA node

Question 8

sympathetic nervous system

Answer 8

releases adrenaline sending stimulation to the SA node via the accelerator nerve increasing heart rate

Question 9

parasympathetic nerve

Answer 9

inhibits the effects of the sympathetic system via the vagus nerve lowering heart rate