Cardiovascular System

Question 1

What are the 3 major blood vessels?

Answer 1

• Arteries
• Capillaries
• Veins

Question 2

What happens in the capillary bed?

Answer 2

The exchange of gases takes place

Question 3

What are the 3 layers of arteries and veins?

Answer 3

• Tunica Adventitia (outermost)
• Tunica Media (middle)
• Tunica intima/endothelium (innermost)

Question 4

What is the role of the tunica adventitia?

Answer 4

Is made of connective tissue fibres which reinforce the walls of the vessels allowing it to withstand high pressure

Question 5

What is the role of the tunica media?

Answer 5

Is made up of smooth muscle cells and is thicker in the arteries then in the veins

Question 6

What is the role of the tunica intima or endothelium?

Answer 6

Is a single layer of cells which lines the entire cardiovascular system

Question 7

What are the features of arteries?

Answer 7

• Always take blood away from the heart
• Thick muscle layer
• Under autonomic nervous control
• Stretches under force of blood pressure then elastic recoil maintains pressure wave
• Larger arteries have their own little arteries

Question 8

What are the features of arterioles?

Answer 8

• Smaller than arteries
• Basic structure is the same
• Arteriolar network is important for the maintenance of pressure and temperature control

Question 9

What are the features of capillaries?

Answer 9

• Walls are composed of a single layer of cells to allow for quick exchange of glucose, O2 and waste
• The layer is so thin so that molecules such as oxygen, water and lipids can diffuse through them and enter the tissue

Question 10

What is the capillary bed?

Answer 10

It is the network of capillaries supplying an organ. the more metabolically active the cells, the more capillaries it will require to supply nutrients

Question 11

What are venules?

Answer 11

• Small veins collecting blood from capillary network
• Very little muscle therefore dependent on external muscle activity to return blood towards the heart
• Contains valves to prevent back flow

Question 12

What are veins?

Answer 12

• Thinner layer of muscle then in arteries therefore external muscle activity needed to help retire blood to the heart
• Valves to prevent back flow

Question 13

What is the pulmonary circuit?

Answer 13

Carries blood to the lungs to be oxygenated and then back to the heart. In the lungs CO2 is removed from the blood and oxygen taken up by the haemoglobin in the red blood cells

Question 14

What is the systemic circuit?

Answer 14

Carries blood around the body to deliver the oxygen and returns the de-oxygenated blood to the heart

Question 15

What is the hepatic portal circulation?

Answer 15

The veins of the gastrointestinal tract carry blood to the liver through the hepatic portal vein. The liver removes toxins, stores sugars and processes the products of digestion before they reach the other body tissues. Blood from the liver then returns to the heart through the inferior vena cava

Question 16

What is foetal circulation?

Answer 16

Specialised blood vessels carry the foetal blood to the placenta where exchange occurs and then returns it to the foetal body. 2 umbilical arteries and 1 umbilical vein accomplish this purpose

Question 17

What are the 4 chambers of the heart?

Answer 17

• Left and right atria

- Left and right ventricle

Question 18

What are the 4 valves of the heart?

Answer 18

• Tricuspid and bicuspid

- Aortic and pulmonary valves

Question 19

What are the 3 layers of the heart?

Answer 19

• Pericardium
• Myocardium
• Endocardium

Question 20

What is the role of the 2 atria?

Answer 20

Thin walled chambers that receive blood form the veins

Question 21

What is the role of the 2 ventricles?

Answer 21

Thick walled chambers that forcefully pump blood out of the heart

Question 22

What are the valves between the atria and ventricles called?

Answer 22

Atrioventricular valves

Question 23

What are the valves at the bases of the aorta and pulmonary artery called?

Answer 23

Semilunar valves

Question 24

What are the left and right AV valves called?

Answer 24

• Bicuspid valve = left

- Tricuspid valve = right

Question 25

What are the actions of papillary muscles and the chordae tendinae?

Answer 25

Open the valves and keep the valve flaps in place as the chambers contract

Question 26

What is the first ‘Lub’ sound caused by?

Answer 26

The closure of the AV valves as the ventricles contract

Question 27

What is the ‘dub’ sound caused by?

Answer 27

The closure of the semilunar valves when the ventricles undergo diastole or relaxation

Question 28

What is systole?

Answer 28

Contraction phase

Question 29

What is atrial systole?

Answer 29

Atria contract, forces remaining blood into the ventricles, ventricles remain relaxed

Question 30

What is ventricular systole?

Answer 30

Ventricles contract a the same time, blood pressure increases, AV valves forced shut (so no back flow), semi lunar valves forced open, blood pushed into aorta and pulmonary artery

Question 31

What is diastole?

Answer 31

Relaxation phase

Question 32

What happen in diastole?

Answer 32

Atria fill with blood, pressure rises, atrioventricular valves open, blood passes by gravity into ventricles, semi lunar valves closed

Question 33

What is the sinoatrical (SA) node?

Answer 33

Pacemaker

Question 34

What is the atrioventricular (AV) node?

Answer 34

Here the impulse is delayed briefly so that the contracting atria have enough to pump all the blood into the ventricles

Question 35

What is the AV bundle?

Answer 35

Passes impulses down into the ventricles

Question 36

What are the bundle branches?

Answer 36

Ensure all areas of the heart receive the impulses

Question 37

What is the purkinje fiber?

Answer 37

Pass impulse into the muscle cells

Question 38

What is an electrocardiogram (ECG)?

Answer 38

A graphic record of the heart electrical activity