Theme 1: The Cardiovascular System

Question 1

Label this diagram of the heart

Answer 1

A - brachiocephalic artery
B - superior vena cava
C - right pulmonary artery
D- right pulmonary veins
E - right atrium
F - atrioventricular (tricuspid) valve
G - chordae tendineae
H - right ventricle
I - inferior vena cava
J - left common carotid artery
L - left subclavian artery
L - aorta
M - left pulmonary arteries
N - left pulmonary veins
O - left atrium
P - semilunar valves
Q - atrioventricular (mitral) valve
R - left ventricle
S - septum

Question 2

How many valves does the heart have?

Answer 2

Heart had 4 values

Question 3

What is the purpose of heart valve

Answer 3

To ensure blood circulates and minimising back flow

Question 4

What are the heart valves covered by?

Answer 4

Endocardium

Question 5

What is the valve that separates the left atrium to left ventricle called?

What’s the valve that separates the right atrium to the right atrium called?

Answer 5

Left > left is called *Biscuspid** (sometimes called mitral valve)

Right > right is called triscupid valve

Question 6

What are the muscular structures that connects the valves to the heart myocardium

Answer 6

Papillary muscles

Question 7

What valves are located in the opening of the aorta and pulmonary artery.

Answer 7

Semilunar valves (beacasue of their crescent moon shaped structures)

Question 8

What is the 3 layers heart wall made up of?

Answer 8

The endocardium - the inner lining facing the heart chambers, is protection to the heart chambers and valves

The myocardium - is cardiac muscle, is the thickest of the three layers and made up from cardiac myocytes (c

The epicardium - the outer lining that faces the pericardium, provides protection and support for the heart (is also called visceral serum pericardium)

Question 9

What is the pericardium?

Answer 9

Fibroelastic sac that surrounds the heart

Helps reduce energy the force from extrernal pressures that could impact the hearts function

Helps reduce friction during contraction

Question 10

What’s the first stage of circulation?

Answer 10

Pulmonary circulation - where deoxygenated blood is dedicated the the right side of the heart

1. Blood returns from the bloody from the superior and inferior vena cava and enters the Right Atrium
2. When the atrium contacts, blood is forced into the right ventricle through the the tricuspid valve and after another contraction, blood is ejected out of the pulmonary artery to the lungs

Question 11

What is the second stage of circulation?

Answer 11

systemic circulation - when oxygenated blood needs to be sent to the rest of the body

1. When the blood is oxygenated in returns to the left side of the heart via the PULMONARY VEINS
2. The left atrium fills with blood and pumped through the mitral valve to the left ventricle, when the left ventricle contacts
3. Blood is ejected through the aorta, which is then circulated around the rest of the body.

Question 12

What is the second stage of circulation

Answer 12

** systemic circulation ** - where oxygenated blood is sent to the rest of the body.

1. Oxygenated blood returns from the lungs through the pulmonary veins
2. The left atrium then fills with blood and is pumped through the mistrial valve to the left ventricle
3. Then blood is ejected through the aorta and then around the rest of the body.

Question 13

Why is the right side of the heart thinner?

Answer 13

The right side is thinner that that the right due to receiving deoxygenated blood, the right is thicker to eject blood at a higher pressure to ensure the blood reaches the body.

Question 14

What are the common arteries in the neck?

Answer 14

Carotoid/ jugular

Question 15

What are the three steps that make up cardiac conduction pathway

Answer 15

1. Sinoatrial node depolarisation (atrial contraction)
2. Atrioventricular node depolarisation (ventricular contraction)
3. Repolarisation (relaxation of atriums and ventricles)

Question 16

What is sinoatrial node depolarisation?

Answer 16

It is atrial contractions

The sinoatrial (SA) node is located where the superior vena cava enters the heart

Specialist cells called pacemaker cells generate their own action potentials which distributes across the myocardium in both atriums,

Causing the atrium to contact, ejecting blood into the ventricles - this is stoped by atrioventricular fibrous membrane, meaning the SA node will not pass through the ventricles just to the AV node.

Question 17

What is atrioventricular node depolarisation?

Answer 17

Ventricle contraction

The action potential from the SA node will travel through the AV node, this creates a small pause between atrial and ventricular contraction (DUm…DUM..)

When the action potential goes through the AV node it goes through the budle of his the is split into a left and right pathway

This supply’s action potentials to their subsequent ventral myocardium via additional purkinje fibres.

Both ventricles contract and eject blood through their dedicated great arteries

Question 18

What is depolarisation in the cardiac conduction pathway?

Answer 18

Relaxation of the atriums and ventricles

This stage resets all the cardiac cells ready for another action potential by the SA node.

Question 19

What are the three major factors that influence a pulse?

Answer 19

Strength
Rhythm
Rate

Question 20

What can the strength of a pulse tell us?

Answer 20

It’s information about how the blood is flowing though the blood vessels under pressure,

• strong pulse - this is normal and can be identified when only light pressure is required to palpate the pulse, is a sign that cardiac output is effective
• a weak pulse - this is a sign that cardiac output is reduced, sign of cardiovascular failure will be in combination of cold skin, pale and reduce capillary refuel time.
• a bounding pulse - there is an increased cardiac output due to vasodialation, not ideal and the capillaries will become leaking allowing fluid into interstitial spaces
  (Don’t need to apply pressure to feel, it will feel like its bouncing through the skin.
  Can be a sign of infection and sepsis

Question 21

What does the rhythm of the heart rate tell us?

Answer 21

The regularity and how synchronised the heart it

The health of the conduction pathway

If not regular, ECG and escalation is needed.

Question 22

What does the rate of the heart rate tell us>

Answer 22

How many beats per miniature there is,

If rate is higher (tachycardia)

If rate is slower (brachycardia)

Question 23

What are the landmark places to take a pulse?

Answer 23

Radial - on wrist

Carotid - on neck

Brachial - elbow (blood pressure)

Question 24

What can blood pressure be influenced by?

Answer 24

How heard the heart is contracting and ejecting blood

How dilated or constricted the blood vessels are

How much blood volume we have

Question 25

What does systolic blood pressure and what is diastolic blood pressure?

Answer 25

Systolic - highest number at the tip and the heart ejecting the blood out of the aorta into the systemic circulation pathway Diastolic - represents the heart re filling with blood.

Question 26

What is blood pressure measured?

Answer 26

Millimetres of mercury mmHG

Question 27

What are baroreceptors?

Answer 27

Baroreceptors contain specialised cells that monitor the blood pressure passing through the aortic arch. As blood passes through the aortic arch, the blood vessel stretch which is and that’s what the baroreceptors monitor

Question 28

What part of the brain interprets the signals from the baroreceptors

Answer 28

The medulla

Question 29

What group of hormones is triggered by the sympathetic nervous system by baroreceptors

Answer 29

Catecholamines which include adrenaline and nor-adrenaline > they trigger beta 1 receptors on the skeletal muscle surrounding blood vessels to contract. > causing myocardium to contract harder and increase blood pressure

Question 30

What are the three major types of blood vessel that help transport blood around the body?

Answer 30

** Arteries + veins + capillaries ** 1. Arteries - primarily transport oxygenated blood (apart from pulmonary and umbilical arteries 2. Veins - primarily transport deoxygenated blood (apart from pulmonary and umbilical) 3. Capillaries - these blood belles allow the transfer of oxygen, nutrient and other essential components to body tissues.

Question 31

What is the inside of a blood vessel called?

Answer 31

Lumen

Question 32

Which blood vessel has a wider lumen?

Answer 32

The veins have wider lumens

Question 33

What are the three layers in arteries and veins?

Answer 33

1. **tunica interna** The inner layer of which consist of smooth endothelial lining held together by a base meme to membrane. 2. **tunica media** Elastic tissue and smooth muscle, can contact to increase systemic vascular resistance, is connected to branches from the autonomic nervous system where is stimulated *arteries have a thicker tunica media* 3. **tunica externa** The outer layer, made up of collagen fibres to provide stability and support for the blood vessels, *arteries have a thick tunica externa due to anchoring themselves onto organs* capillaries only have this layer.

Question 34

What’s the cruicial difference between arteries and veins?

Answer 34

Veins contain valves to prevent back flow

Question 35

What the significance of coronary arteries?

Answer 35

Main function to supply blood to the heart.

Question 36

What’s the difference between preload and afterload in stroke volume?

Answer 36

Preload refers to the amount of blood already in your ventricles when you are ready to pump it out Afterload refers to the pressure against you heart has to plumb that blood

Question 37

How does blood pressure varies across the lifespan?

Answer 37

Children have a lower blood pressure, adults have higher blood pressure as they get older until they are older adults where it will reduce again.