Cardiovascular System

Question 1

What is the function of the cardiovascular system?

Answer 1

Circulate and transport nutrients,oxygen, carbon dioxide, endocrine hormones and blood cells in the plasma. Helps in homeostasis with thermoregulation, pH and disease fighting.

Question 2

Key components of the cardiovascular system are:

Answer 2

Heart
Blood
Blood vessels

Pulmonary loop for oxygenation and the systemic loop to give oxygenated blood to the body and remove deoxygenated blood.

Question 3

Is the cardiovascular system open or closed?

Answer 3

Closed- we don’t want an open end, all the blood would leak out.

Question 4

Why are erythrocytes bi-concave?

Answer 4

Allow oxygen transport on haemoglobin.

Need to be squishy to fit through small capillaries.

Question 5

What is the circulating blood volume?

Answer 5

5 litres

Question 6

How much of blood is plasma and how much is erythrocytes?

Answer 6

3L plasma

2L RBCs

Question 7

What percentage of circulating blood is in the veins?

Answer 7

65%

Question 8

What contains the smallest proportion of our blood?

Answer 8

Capillaries 5%- but surface area is absolutely huge

Question 9

What percentage of blood is in heart and lungs?

Answer 9

20%

Question 10

What carries 10% of blood volume?

Answer 10

Arteries

Question 11

What to systems compete in a cut To maintain haemostasis?

Answer 11

Pro-coagulant

Anticoagulant

Question 12

Which side of the heart is low pressure circulation and thus is more fragile?

Answer 12

The right

Question 13

What is bridging on coronary arteries?

Answer 13

In systole the left anterior descending coronary artery gets squished but then recoiled 0.13 second later- thankfully or the heart it supplies would infarct if this artery didn’t have this flexibility.

Question 14

What is an end artery?

Answer 14

Terminal artery supplying the blood to a part of the body with no alternative route.

Question 15

Why does a heart attack hurt?

Answer 15

Blood supply interrupted -.> hypoxia -> nerve detect hypoxia and give pain to tell you it’s in trouble -> ischaemia

Question 16

Give 4 examples of end arteries then give the absolute best example.

Answer 16

Splenic artery
Coronary artery
Cerebral artery
Renal Artery

Central retinal artery- no other supply, vision lost in classical form and its permanently lost.

Question 17

What’s artery narrowing called?

Answer 17

Stenosis

Question 18

What’s a thrombus?

Answer 18

A clot?

Question 19

What’s an embolus?

Answer 19

Something in the circulatory system that may or may not be a derivative of blood that has moved in the circulation.

Question 20

What do the heart valves prevent?

Answer 20

Regurgitation of the blood

Question 21

What are the two main arteries that supply the heart and where is their route?

Answer 21

Route in aorta and split to left and right coronary arteries.

Question 22

Compare side effects of disturbance of blood supply to the right and left side of the heart?

Answer 22

Right- electrical problems

Left- mechanical muscle issues

Question 23

What is the natural pacemaker where is it found and what does it do?

Answer 23

SAN (Sino Atrial Node) in the right atria that starts the action potential in the heart.

Question 24

Why is the atria ventricular node called what it is?

Answer 24

It’s positioned between the atria and ventricle bulging from the septum in the right atria.

Question 25

Why do you need two nodes and pause between them firing? | What is the clinical condition when this communication and delay is stopped?

Answer 25

Stop contraction being simultaneous we need atria ventricular delay at the AV node. Ventricular Fibrillation

Question 26

Name the branches of the aortic arch.

Answer 26

The aortic arch which divides into: - Brachiocephalic trunk which divides to the subclavian artery and the right common carotid artery. - The left common carotid artery. - The left subclavian artery

Question 27

What is the pressure in the aorta in systole on average in a healthy young adult?

Answer 27

Systole- heart contracts and 120mmHg in aorta

Question 28

Is the tunica media thicker in the arteries or veins?

Answer 28

Arteries- they need thick muscular walls

Question 29

What is the pressure in the aorta in diastole and where does it come from if the heart is relaxed?

Answer 29

70-80mmHg Aorta wall recoiled maintaining reassure on the blood and moving it toward heart and smaller BVS. Elastic arteries act as pressure reservoirs and are called capacitor vessels because they store elastic energy from systole and become auxiliary pumps in diastole.

Question 30

Where is the natural weak point of the cardiovascular system that is prone to aneurysm?

Answer 30

Infrarenal abdominal aorta

Question 31

How do blood vessels contract?

Answer 31

Tunica adventitia has fenestrations that receive the noradrenaline signalling and transport it to the external tunica media which depolarises some of the superficial smooth muscle. The gap junctions propagate this depolarisation through the tunica media smooth muscle.

Question 32

A ring of smooth muscle fibres around a terminal arteriole at the junction with capillaries is called a?

Answer 32

Pre capillary sphincter - controls blood flow to capillary bed.

Question 33

Where in the body needs a protective mechanism for blood supply?

Answer 33

The brain 750ml/min

Question 34

What needs more blood in exercise?

Answer 34

Heart, Skin and skeletal muscle.

Question 35

What makes a capillary?

Answer 35

Single layer of endothelium and a basement membrane.

Question 36

How do you remember how the heart sits in the body?

Answer 36

I am RIGHT at the FRONT, I have been LEFT at the BACK Right side of heart front left is at the back

Question 37

Why are veins called capacitance vessels?

Answer 37

Ability of the blood vessel to increase the volume of blood it hold with out the pressure increasing. This is inversely proportional to elasticity.

Question 38

What is the primary pump for venous blood return?

Answer 38

Skeletal muscle contraction from calf muscle contraction.

Question 39

What is the secondary venous return pump?

Answer 39

Respiration, breath in gives negative throacic pressure causing blood to rush back to the right atrium in the thorax.

Question 40

Venous hypertension form failure of the calf muscle pumps leads to?

Answer 40

Venous ulceration

Question 41

What position requires venous pump pressure correction?

Answer 41

Standing up. Venous pressure would go up in the legs if the pumps didn't take effect. If the calf muscle doesn't pump the blood back up you get too much of the circulating blood volume in the legs and the brain temporarily gets a bit starved. You faint at this point so to encourage venous report stay supine with legs slightly elevated.