Cardiovascular

Question 1

Describe outer layers of heart?

Answer 1

Fibrous pericardium (outer)

Tough, stiff tissue that attaches to central tendon of diaphragm, mediastinum and sternum via sternopericardial ligaments
Protects and prevents heart from expanding/overfilling

Serous pericardium (inner) two layers; parietal and visceral, separated by pericardial cavity

Thin, lubricated tissue that allows movement and prevents friction

Question 2

Why does the heart contain fibrous outer layer and is tightly anchored to the body, where as the lungs do not?

Answer 2

Heart produces more movement, with more strength

Question 3

What are the main 4 vessels that carry blood in / out of heart?

Answer 3

Deoxygenated
Vena cava- body to right atrium
Pulmonary artery- right ventricle to lungs
Oxygenated
Pulmonary vein- lungs to left atrium 
Aorta- left ventricle to body

Question 4

The difference between left and right side of the heart?

Answer 4

Left side is for systemic circulation, larger muscle and thick walls as more pressure is exerted to pump blood around entire body

Right side is for pulmonary circulation, which has less muscle and thinner walls due to only needing to produce enough pressure to pump blood to nearby lungs

Question 5

What happens if there is lack of blood supply to the lungs

Answer 5

compromise of blood supply to the lungs immediately decreases the partial pressure of oxygen in the blood, known as hypoxemia. This can lead to a decrease in tissue oxygenation throughout the body, known as hypoxia.

Question 6

Which valve separates the left atrium and ventricle?

Answer 6

Bicuspid valve

Question 7

Which valve separates the right atrium and ventricle?

Answer 7

Tricuspid valve

Question 8

Explain internal nervous conducting system within the heart

Answer 8

Sinoatrial(SA) node generates an impulse causing both atria to contract
Impulse reaches the atrioventricular (AV) node which delays the depolarisation allowing time for the blood to fill the ventricles
The Impulse reaches “bundle of his” which carry the impulse through the fibrous skeleton to the Purkinje fibres, which take the impulse around the ventricular wall causing the ventricles to contract

Question 9

Explain systolic v diastolic

Answer 9

Systolic blood pressure is the highest pressure reached when the ventricles contract and blood is ejected from heart (systole phase)

Diastolic blood pressure is the lowest pressure between beats when the heart is fully relaxed after contraction (diastole phase)

Question 10

What is unique about cardiac muscle

Answer 10

The myocardia are a specialised type of muscle cell with intercalated disks (gap junctions) between fibres, which allow an impulse to be generated and conducted within the muscle, without the need for direct innervation, known as “myogenic”

Question 11

What are the purpose of the conducting fibres (bundle of his, purkinje fibres)

Answer 11

Coordinated contraction of entire ventricle wall, from the inferior aspect, ensuring that blood is forced upward toward the arteries

Question 12

Describe the passage of blood in UEX

Answer 12

Arch of aorta- subclavian artery- axillary artery- brachial artery- radial, median & ulnar arteries

Question 13

Describe vascular supply to LEX

Answer 13

Thoracic aorta becomes abdominal aorta at T12, which bifurcates at L4, becoming common iliac artery, then external iliac artery, becomes femoral artery at inguinal ligament, becomes popliteal artery at knee, and ant/post tibial artery just below knee

Question 14

Explain systole v diastole

Answer 14

Systole- peak ventricle contraction (highest pressure in artery)

Diastole- ventricles relax, blood is static (lowest pressure in artery)

Question 15

What ventricle are we assessing when taking blood pressure?

Answer 15

Left, the left ventricles supply blood to the body (systemic)

Question 16

What is the heartbeat regulated by?

Answer 16

Rate and force of impulse generation is moderated by the autonomic nervous systems’ chemical mediators.
SNS speeds the heart rate by releasing catecholamines, PNS slows heart rate by releasing acetylcholine.
Unregulated, the heart would beat at 100 BPM

Question 17

What is a pulse?

Answer 17

The pulse is felt as a throbbing of an artery, usually palpable superficially where an artery can be compressed against bone

The force of blood exiting the heart (systole) creates a pressure wave that travels rapidly through the body, creating the pulse

Question 18

Define blood pressure

Answer 18

Overall force exerted on arterial walls via blood, measures pressure exerted by left side of heart, as this provides systemic circulation

Question 19

What pulses can we palpate?

Answer 19

UEX
Axillary
Brachial
Radial

Trunk
Abdominal aorta

LEX 
Femoral 
Popliteal 
Tibial (posterior)
Dorsalis pedis

Question 20

What do we measure by palpating pulse?

Answer 20

Rate (BPM)
Rhythm (regularity)
Volume (strength)
Equality (at each body location)

Question 21

Where would you auscultate the aortic valve?

Answer 21

2nd intercostal space, right sternal edge

Question 22

Where would you auscultate the pulmonary valve?

Answer 22

2nd intercostal space, left sternal angle

Question 23

Where would you auscultate the bicuspid valve?

Answer 23

5th intercostal space, left sternal edge (mid clavicular line)

Question 24

Where would you auscultate the tricuspid valve?

Answer 24

5th intercostal space, left sternal angle

Question 25

Why does systolic blood pressure need to be significantly higher than diastolic?

Answer 25

Higher pressure within the ventricles causes the atrial and pulmonary valves to open, blood leaves the ventricles into the pulmonary trunk and aorta.

Liquid flows from high to low pressure, if the pressure in both chambers were equal the valves wouldn’t open and the blood wouldn’t flow through

Question 26

Explain how sphygmomanometer works

Answer 26

The pressure of the cuff creates turbulent flow which can be heard, the pressure compresses the artery until it closes, at which point you will hear silence indicating systolic pressure

The pressure is then gradually released, once the artery becomes fully open again the blood flow will be laminar and therefore silent, indicating diastolic pressure

• find radial pulse and place stethoscope over it lightly
• pump pressure until hear silence (systolic) then continue pumping to an extra 30 to ensure artery is completely closed
• release pressure until hear silence (diastolic)

Question 27

Why don’t we hear valves over the valves?

Answer 27

We listen where we hear blood flow best which isn’t always precisely on the valve it’s moving through. The valves are underneath bone which makes it impossible to hear directly over.

Question 28

Explain the process by which the heart receives deoxygenated blood from the body and transports it to the lungs

Answer 28

Deoxygenated blood enters the right atrium via the superior and inferior veins cava

Blood enters the right ventricle via the tricuspid valve

Blood enters the pulmonary artery via the pulmonary valve

The pulmonary artery bifurcates into left and right, which transport the deoxygenated blood to each lung

Question 29

Explain the process by which the heart receives oxygenated blood from the lungs and transports it to the body

Answer 29

The lungs oxygenate the blood, which enters the left atrium via the pulmonary veins.

Blood flows into the left ventricle via the bicuspid valve

Blood flows into the aorta via the aortic valve, and on to the rest of the body via arteries

Question 30

Describe lub heart sound?

Answer 30

Ventricles contract, bicuspid and tricuspid valves close

Long, low, soft sound

End of ventricular diastole, start of ventricular systole

Question 31

Describe dub heart sound?

Answer 31

Ventricles relax, pulmonary and aortic valve close

Short, sharp, high pitch sound

End of ventricular systole, start of ventricular diastole

Question 32

What might aortic stenosis sound like?

Answer 32

Noise on ventricular contraction/systole (lub, noise, dub)

Narrowing of valve, unable to open enough, turbulence

Question 33

What night aortic regurgitation sound like?

Answer 33

Noise during diastole (after lub dub)

Backflow of blood due to valve not fully closing

Question 34

What is a murmur? What can it indicate?

Answer 34

Whooshing sound

Valvular Regurgitation (blood forced through a normally closed valve)

Valvular Stenosis (blood flow through a normally open valve that is abnormally narrowed)

Question 35

Compare muscular to elastic arteries

Answer 35

The muscular and elastin layer is especially thick in elastic arteries, which are large and found close to the heart. The pulse pressure is higher closer to the heart so the elastin ensures that the arteries are distendable. This is to provide a dampening effect, reducing the effect of high pulse pressure on the artery during systole. Tunica adventitia contains vasa vasorum (own blood supply) as the arteries are too large to be without.

The smooth muscle within the tunica media is especially thick in muscular arteries, which are found further from the heart. They are smaller than elastic arteries and contain no elastin in the tunica media because blood pressure is lower further from the heart, this lower pressure means more muscle is needed to pump the blood back up to the heart

Question 36

How are the arteries and veins regulated

Answer 36

Tunica media is the smooth muscular layer of arteries that can cause constriction or dilation depending on its tone. This is known as vasomotor tone and is controlled only by the sympathetic nervous system

Question 37

What factors combine to form blood pressure

Answer 37

Heart rate + Stroke volume (cardiac output)
Peripheral resistance (vessel length/diameter, blood viscosity)

BP= HR x SV x PR

Question 38

How does exercise over a long term reduce blood pressure?

Answer 38

We can grow capillaries in response to increased demand caused by exercise, effectively increasing valcularisation

Question 39

Explain valves during systole and diastole phases?

Answer 39

Systole- bicuspid and tricuspid valve close simultaneously. Blood runs through the open pulmonary and aortic valves, blood leaves the heart

Diastole- pulmonary and aortic valves close simultaneously. Blood runs through the open bicuspid and tricuspid valves, the ventricles fill