6.2 The Blood System

Question 1

The heart triggers its own contractions, so it is…

Answer 1

myogenic

Question 2

Name of the specialised muscle cells that act as the primary pacemaker

Answer 2

Sinoatrial Node (SA node)

Question 3

Describe the myogenic nature of the heart and all the nodes and bundles it involves

Answer 3

When the atria are full, the sinoatrial node fires, contracting the atria. The signal is passed on to the Atrioventricular nodes, which pass the signal on to the Bundle of His, which makes the ventricles contract.

Question 4

Which body part realises if the body needs more/less oxygen and a higher/lower heart rate?

Answer 4

Brain stem / Medulla Oblongata

Question 5

What is a Systole? What is a Diastole?

Answer 5

Systole = contraction
Diastole = relaxation

Question 6

Which 2 nerves from the medulla can send impulses do increase or decrease the heart rate?

Answer 6

Sympathetic Nerve -> increase
Parasympathetic Nerve / Vagus Nerve -> Decrease

Question 7

Another name for Nor-adrenaline. What does it do?

Answer 7

Nor-epinephrine
Increases heart rate

Question 8

How do arteries work?

Answer 8

Bring blood at high pressure from ventricles to the body, Have muscle and elastic fibres for stability and elastic recoil to push blood forward, respectively.

Question 9

How do veins work?

Answer 9

Bring blood at low pressure from body to atria, have valves and a wide lumen, when nearby muscles or arteries contract, the blood in the veins gets pushed towards the heart

Question 10

Causes and consequences of occlusion of the coronary arteries? What is the name of this Zustand?

Answer 10

Name: Atherosclerosis

Causes: fat deposits that block proper blood flow

Consequences: can be so severe that the parts of the heart do not get enough oxygen and then die