The control of heart rate

Question 1

Medulla oblongata

Answer 1

Cardiac control centre
- linked through 2 nervous systems

Question 2

Sympathetic nervous control

Answer 2

• stimulation of SA node via the accelerator nerve
• heart beat is faster, increases heart rate

Question 3

Parasympathetic nervous control

Answer 3

stimulation via the vagus nerve
- decreases heart rate

Question 4

Neural control (chemo,baro,proprio)

Answer 4

Chemoreceptors
- sense chemical changes and are located in the medulla oblongata.
- when exercising there is a decrease in PH levels.

Question 5

Baroreceptors

Answer 5

• detect changes in blood pressure
• blood pressure increases = sympathetic stimulation
• blood pressure decreases = parasympathetic stimulation

Question 6

Proprioceptors

Answer 6

• positioned in muscles and detect changes in movement and tension in muscles
• increased tension = more blood needed to contract the muscle.

Question 7

Hormonal control of the heart

Answer 7

• release of adrenaline which acts on the SA node by stimulating a greater rate of contraction.

Question 8

Intrinsic control of the heart

Answer 8

1. Temperature changes
2. Venous Return