Cardiovascular System

Question 1

Where is the heart located?

Answer 1

On the mediastinum, lies in between the two lungs and plural membranes

Question 2

What is the outer and protective layer of the heart called? & What is its function?

Answer 2

the pericardium which is composed of tough outer fibrous layer. The fibrous sac encloses the heart and helps to retain its position on the mediastinum while still allowing freedom of movement.

Question 3

What is pericarditis?

Answer 3

It is the inflammation of the lining around the heart which causes chest pain and can affect cardiac output

Question 4

Name the 3 layers of the heart wall

Answer 4

Epicardium = outer layer (contains blood vessels)
Myocardium = middle layer (composed of cardiac muscle)
Endocardium = the innermost layer (composes of the valves, inner linings of the chambers and contains vessels & nerves - allows for smooth movement of the blood).

Question 5

Name the 4 chambers of the heart

Answer 5

Left Atria
Right Atria
(both receive blood flowing into the heart)

Left ventricle
Right ventricle
(with pump blood out of heart)

Question 6

What does the right side of the heart do?

Answer 6

Receives DE-OXYGENATED blood that has travelled around body - it pumps the blood to your lungs to collect a fresh supply of oxygen

Question 7

What does the left side of the heart do?

Answer 7

Receives OXYGEN-RICH blood from the lungs and pumps it through arteries to rest of body

Question 8

What are heart valves?

Answer 8

Blood flows around heart & body in 1 direction - heart valves control the direction of the blood flow - act like doors that open and close with very heartbeat - they prevnt backflow

Question 9

Name the 4 valves in the heart

Answer 9

Tricuspid valve
Pulmonary valve
Mitral valve
Aortic valve

Question 10

What are atrioventricular valves?

Answer 10

These valves are the mitral valve and the tricuspid valve. Both are situated between the atria and the ventricles - both prevent back flow from the ventricles into the atria during systole.

Question 11

What are the outflow valves? & Where are they positioned?

Answer 11

Right outflow valve called pulmonary valve opens into pulmonary trunk

Left outflow valve called aortic valve opens into the cardiac arch

Positioned at entrance to the outflow vessels which lead into the pulmonary and systemic circulation

Question 12

What prevents the valves from being damaged?

Answer 12

As ventricles start to contract the closing AV valves are subject to strong forces - the AV valves are tethered to the walls of the ventricles by “heart strings” - (chordae tendinae). The papillary muscles pull on AV valves via the chordae tendinae - slowing the closure & preventing trauma to valves.

Question 13

What are arteries? & Describe their structure

Answer 13

Vessels that conduct blood away from heart - arteries contain OXYGENATED blood.
Structure = Most arteries are thick walled & have small lumens - they are exposed to high pressure and friction forces.

Question 14

What are veins? & Describe their structure

Answer 14

Vessels that always bring blood back to the heart. Veins contain DEOXYGENATED blood.
Structure = most veins are thin walled & have large lumen - they are exposed to low pressures and minimal friction forces.

Question 15

What are the major arteries that attach to the heart?

Answer 15

Arch of aorta
Pulmonary trunk
Coronary arteries

Question 16

What are the major veins that attach to the heart?

Answer 16

Superior and inferior vena cava
The four pulmonary veins
Coronary sinus

Question 17

What are arterioles?

Answer 17

Small blood vessels that carry blood AWAY from heart. They control blood pressure and blood flow throughout body using their muscles to hence their diameter

Question 18

What are capillaries? & Describe the structure?

Answer 18

They are the smallest vessels which allow exchange of substances between the blood and interstitial fluid - they connect the arteries and the veins.
Structure = narrow diameters, RBC pass single file through lumen of vessel

Question 19

What is the role of the Autonomic nervous system?

Answer 19

It is to regulate changes in blood pressure, blood flow and blood volume to maintain enough cardiac output to always provide for all organs - ie to maintain homeostasis.

Question 20

What does atrial diastole mean in cardiac cycle?

Answer 20

When the atria are relaxed, low pressure and chambers fill with blood.

Question 21

What does atrial systole mean?

Answer 21

(ventricles are relaxed) This is where the atria contracts pressure increases, volume DECREASES and this opens the AV valves causing blood to flow out of the atria and into the ventricles

Question 22

What is ventricular diastole?

Answer 22

This is when the ventricles are relaxed (lower pressure in ventricles than atria) and blood flows from the atria into the ventricles through AV valves

Question 23

What is ventricular systole?

Answer 23

(atria is relaxed) Ventricles contract , pressure increases (volume decreases) outflow valves open and blood flows out of ventricles to the pulmonary artery (right) and aorta (left)

Question 24

Where is the apex of the heart normally pointed?

Answer 24

To the left of the midline

Question 25

Which structure does blood pass from the right atrium to the right ventricle?

Answer 25

Tricuspid valve

Question 26

Which wave in an ECG represents depolarisation of the ventricles?

Answer 26

T wave

Question 27

Which ECG waves represent atrial depolarisation?

Answer 27

P wave

Question 28

What is the stroke volume?

Answer 28

The volume of blood ejected from the left or right ventricle every beat 70ml approx

Question 29

How do you figure out cardiac output?

Answer 29

Cardiac output (CO) = stroke volume (SV) x heart rate (HR)

Question 30

Name 3 important factors that affect Stroke volume

Answer 30

- amount of ventricular filling before contraction (preload) - contractility of ventricle - resistance in the blood vessels the heart is pumping into (called after load)

Question 31

What is cardiac reserve?

Answer 31

The amount of extra blood the heart can pump per minute over and above its resting output. Average cardiac reserve is 4 - 5 times resting value

Question 32

What is a sinoatrial node? (SA) & where is it located?

Answer 32

Can also be known as sinus node Group of specialised cells in heart - generates electrical impulses that regulate the hearts rhythm and rate ie the pacemaker - located in the right atrial wall just below where the superior vena cava enters the chamber

Question 33

Name the two types of venules

Answer 33

- Post capillary venules - Muscular venules

Question 34

What are venules?

Answer 34

The smallest veins which receive blood from capillaries. Also play role in exchange of oxygen and nutrients for water products

Question 35

What are included in the atrioventricular valves?

Answer 35

Tricuspid and mitral valve

Question 36

What are included in the seminary valves?

Answer 36

Aortic valve and the Pulmonary valve

Question 37

What are the major veins that attach to the heart?

Answer 37

Superior and inferior vena cava, four pulmonary veins and coronary sinus

Question 38

What is a stent & why would people have them put in place ?

Answer 38

people’s arteries can become blocked due to cholesterol being built up on the side of the arteries walls. This causes them to become narrower and eventually become blocked which then cause the risk of a heart attack – to prevent this from happening people can have stents put in place which is an tiny mental tube that holds open the artery to allow blood to go through better.

Answer 39

cardiogram