The Heart

Question 1

What are the 4 valves of the heart?

Answer 1

1. Aortic semilunar (left)
2. Pulmonary semilunar (right)
3. Tricuspid (right)
4. Bicuspid (left)

Question 2

What does the SA ( sinoatrial node ) do?

Answer 2

Triggers atrial contraction

Question 3

1. What is the function of the atrioventricular node?

2. What is the function of the atrioventricular bundle?

Answer 3

1. Transmits electrical signals from the atria into the ventricles.
2. Divides into Lt and Rt branches, the branches break up into fine fibres ( Purkinje )

Question 4

How is heart rate controlled?

Answer 4

• Regulated by autonomic nervous system.
• Vasomotor centre found in Medulla Oblongata in the brains sends nerve impulses to SAN.
• This is influenced by hormones, particularly adrenaline from the endocrine system.