L45. CVS Cardiac Cycle/Blood Pressure Flashcards Preview

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Flashcards in L45. CVS Cardiac Cycle/Blood Pressure Deck (37)
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1
Q

What are heart muscle cells called?

A

Cardiomyocytes

2
Q

Describe the differences in myocardium between the left and right ventricle.

A

Right ventricle - thinner myocardium

Left ventricle - thicker myocardium

3
Q

Name 2 AV valves and give their location.

A

Right atrium to right ventricle - tricuspid valve

Left atrium to left ventricle - bicuspid valve

4
Q

Name 2 semilunar valves and give their location.

A

Right ventricle to pulmonary artery - pulmonary valve

Left ventricle to aorta - aortic valve

5
Q

Is heart valve movement active or passive?

A

Passive

6
Q

What is systole?

A

Ventricular contraction

7
Q

What is diastole?

A

Ventricular relaxation

8
Q

Name the muscles that are connected to the valve cusps. What do they do?

A

Papillary muscles

Prevent backflow by limiting valve movement

9
Q

What causes the “lub” sound?

A

AV valves closing

10
Q

What causes the “dub” sound?

A

SL valves closing

11
Q

Give the definition of stroke volume.

A

Volume of blood ejected per heartbeat.

12
Q

What is the end diastolic volume?

A

Volume in ventricle before contraction.

13
Q

What is the end systolic volume?

A

volume in the ventricle after ejection.

14
Q

Is all blood ejected from the ventricle in each heartbeat?

A

No

15
Q

How is stroke volume calculated?

A

End diastolic volume - end systolic volume

16
Q

How is heart rate determined in terms of anatomy?

A

The rate that the cardiac pacemaker (sino-atrial node - top of right atrium) fires action potentials.

17
Q

Which nervous system determines action potential firing, thus heart rate?

A

Autonomic nervous system

18
Q

Which nerves release noradrenaline?

A

Sympathetic nerves

19
Q

Which nerves release acetylcholine?

A

Parasympathetic nerves (vagus nerve)

20
Q

Name 2 neurotransmitters and their effects on heart rate.

A

Noradrenaline increases heart rate

Acetylcholine decreases heart rate

21
Q

Name 2 types of adrenoreceptors and the main type of adrenoreceptor in the heart.

A

Alpha and beta adrenoreceptors

Heart contains mostly beta-1 receptors.

22
Q

Briefly describe how action potentials cause the heart to contract.

A

Action potentials spread as a wave of depolarisation from the SA node through the cardiac conduction system. This triggers the heart to contract.

23
Q

What does bradycardia mean?

A

Heart rate is too slow.

24
Q

How is cardiac output calculated?

A

stroke volume x heart rate

25
Q

Describe what is outlined in “Starling’s Law”.

A

As the heart chambers become increasingly filled, the force of muscle contraction increases.

26
Q

Describe systolic blood pressure.

A

Pressure in the aorta during contraction.

27
Q

Describe diastolic blood pressure.

A

Pressure in the aorta during relaxation.

28
Q

How is pulse pressure calculated?

A

systolic BP - Diastolic BP.

29
Q

How is mean arterial blood pressure calculated?

A

Diastolic BP + 1/3 pulse pressure

30
Q

What equipment is used to measure arterial blood pressure?

A

Inflatable blood pressure cuff and stethoscope

31
Q

What do mechanoreceptors in the heart do?

A

Detect the degree of stretch in blood vessel walls.

32
Q

What innervates the carotid sinus?

A

Nerve of hering ( a branch of the glossopharyngeal nerve)

33
Q

What is the Valsalva manoeuvre and what does is result in?

A

attempting to expire on a closed glottis.

Increases blood pressure

34
Q

Give the values for hypertension.

A

140mmHg systolic / 90mmHg diastolic or higher

35
Q

Name 2 drugs used to treat hypertension.

A

clonidine and alpha methyldopa

36
Q

Give the values for hypotension.

A

90 mmHg systolic / 60 mmHg diastolic

37
Q

What is postural hypotension?

A

Abnormal drop in blood pressure after standing up.