Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Y1 - HPP1 > Cardiovascular System I > Flashcards

Cardiovascular System I Flashcards

1
Q

What are the functions of the cardiovascular system?

A

Transport - O2, nutrients, glucose, AA, fatty acids
Washout of metabolic waste products - CO2, urea, creatinine
Distributes hormones to tissues
Hormone secretion
Temp regulation - Heat from core to skin
Reproduction - Provides hydraulic mechanism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe the location of the heart and its surroundings

A

Located in the thorax centre

Surrounded by pericardium (fluid protection)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the pericardium

A

Subdivided into visceral layer (outside) and parietal pericardium (water between layers)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the parietal layer

A

Lines inner portion of pericardial sac, deep meshwork of collagen fibers
Restrains heart and prevents sudden dislocation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the 3 layers of the heart?

A

Epicardium, myocardium, endocardium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the epicardium

A

Outer layer/visceral pericardium, has exposed mesothelium, underlain by layer of loose connective tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the myocardium

A

A muscle

Muscular wall of heart, has cardiac muscle tissue/blood vessels/nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the endocardium

A

Inner layer, squamous epithelium lines internal spaces of heart/covers valves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the left and right atria separated by?

A

Interatrial septum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the ventricles separated by?

A

Interventricular septum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is a unidirectional flow of blood controlled?

A

Atria and ventricles separated by AV valves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the other valves lying between the atria and ventricles

A

Tricuspid valves - Between right atria and ventricle

Bicuspid valve - Between left atria and ventricle (mitral valve)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the structure and function of the valves

A

Each valve has 2-3 flaps of connective tissue covered by endothelium
String-like chordae tendineae connect valve flaps to conical papillary muscles found on ventricular floor to prevent valve from bulging (prolapsing) into the atria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the difference between tricuspid and bicuspid

A

Tricuspid valves have 3 cusps but bicuspid valves have 2 cusps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the 2 types of semilunar valves?

A

Pulmonary and aortic semilunar valves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe pulmonary SL valves

A

Prevents backflow of blood from pulmonary artery to right ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe aortic SL valves

A

Prevents backflow of blood from aorta to left ventricle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe how the blood flow is divided

A

Blood vessels divided into pulmonary circuit (between heart and gas exchange surfaces of lungs) and systemic circuit (between heart and body)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are cardiac cells?

A

Types of heart cells involved with heartbeat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the 2 types of cardiac cells?

A

Mechanical and Electrical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are mechanical cardiac cells?

A

Contractile cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are electrical cardiac cells?

A

Conducting system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe mechanical cardiac cells

A

Form bulk of atrial/ventricular wall, perform mechanical work (Contraction - If stimulated)
Short, fat, branching, uninucleated myocytes striated
Cardiac myocytes joined by intercalated discs consist of
- Gap junctions to electrically couple the cells
- Desmosomes to mechanically couple the cells
99% cardiac myocytes contractile, 1% autorhythmic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe electrical cardiac cells

A

Consists of:
Sinoatrial node (SAN) - Initiate stimuli
Atrioventricular node (AV) - Delays stimuli
Bundle of His - Conducting bundle
Purkinje fibres - Conducting/distributing bundle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Describe how electrical impulses are conducted through the heart

A

Each heartbeat begins in SAN - Adjacent to superior vena cava opening to RA
SA node cells autorhythmic, depolarise, generate AP when membrane potential = -40mV
Impulse generated through AV node, slow conduction so takes longer for impulse to pass through AV node to Bundle of His - Delay allows atria to contract before ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Describe further notes about the conduction of electrical impulses through the heart

A

AV node continues as Bundle of His to ventricles
Bundle branches to right/left bundle branches, then to Purkinje fibres
Impulse spreads through ventricles, initiate ventricular contraction
Contraction = Systole
Relaxation = Diastole
Atria and ventricle contract in sequence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the 4 stages of the cardiac cycle?

A

Mid-to-late diastole
Systole
Systole - Ventricular ejection
Isovolumetric relaxation

28
Q

Describe mid-to-late diastole

A

Low pressure in diastolic atria, blood flows from veins to right atria
Ventricles are in diastole
Tricuspid and mitral valves open
70% of blood in atria flows into ventricles, atrial systole forces 30% blood to ventricles

29
Q

Describe systole

A

Ventricles fill with blood, pressure rises forcing AV valves to close increasing ventricular pressure more.
When ventricular pressure is greater than atrial pressure, mitral valves close. ventricles closed chamber with fixed volume of blood

30
Q

What is isovolumetric contraction?

A

Pressure in ventricles rises quickly reaching 80mmHg in 50ms

31
Q

Describe systole - Ventricular ejection

A

When ventricular pressure greater than aortic, forces SL valves to open pumping blood to ventricles

32
Q

Describe isovolumetric relaxation

A

Increased pressure in arteries close SL valves, begins ventricular diastole, contracting ventricular fibres so ventricle pressure drops.
When ventricle pressure below aortic, AV valves close, aortic pressure drops

33
Q

What is stroke volume?

A

Size of left ventricle, degree of myocardial fiber shortening

34
Q

What does myocardial shortening depend on?

A

Preload and afterload

35
Q

What is load?

A

Force acting on/generated by heart muscle

36
Q

What is preload?

A

Force acting on muscle before contraction (force stretching muscle before contraction)
Determines passive tension of muscle/initial length (part of total load muscle needs to overcome to shorten)

37
Q

What is afterload?

A

Force added to preload that offers resistance to muscle shortening

38
Q

What is total load?

A

Preload + Afterload

39
Q

Define preload

A

Degree of stretching of myocardial fibers in ventricular diastole proportional to EDV

40
Q

What is the link between EDV and preload?

A

The greater the EDV the greater the preload

41
Q

What is the importance of preload?

A

Determines the ability of muscle fibres to shorten (develop tension), hence the higher the preload the higher the tension developed and greater stroke volume

42
Q

What is EDV?

A

End-diastolic volume

Amount of blood in vent at end of VD

43
Q

What is ESV?

A

End-systolic volume

Amount of blood in vent at end of VS

44
Q

What is the relationship between EDV and force of contraction (Starling’s law)?

A

Stroke volume of heart increases in response to an increase in volume of blood filling the heart (at end of diastole volume) when all other factors stay constant

45
Q

What is SVR?

A

Systemic vascular resistance

46
Q

Describe SVR

A

Inverse relationship between cardiac output/SVR > If CO too low (eg hemorrhage) SVR is elevated (vasoconstriction)
If CO too high (septic shock) SVR will be low (vasodilation)

47
Q

Describe SVR in terms of an anemic patient

A

They may have compensatory tachycardia due to bleeding/decreased O2 carrying capacity and elevated SVR

48
Q

What happens when aortic regurgitation is present?

A

Back flow of blood causes increased cardiac output and lower SVR

49
Q

Define afterload (cardiac output)

A

Amount of tension made by vent in contraction to open SV valves

50
Q

Describe afterload in terms of systole and systolic volume

A

Greater afterload, shorter duration of ventricular ejection and larger end-systolic volume (stroke volume decreases with increased afterload)

51
Q

When does afterload increase?

A

By factors that increase peripheral resistance, high afterload may lead to myocardial damage and heart failure

52
Q

Describe the autonomic control of cardiac output

A

Heart innervated by SNS/PSNS and autonomic control is largely outside the influence of voluntary control (PS pathway usually dominant)

53
Q

What occurs due to the inhibition of sympathetic nerves?

A

Decreased heart rate from 70-60 bts/min due to uncontrolled PS activity

54
Q

What occurs due to the inhibition of parasympathetic nerves?

A

Increase in heart rate to 160 beats/min

55
Q

Define intropy

A

An agent that alters force of muscular contractions

56
Q

Describe the difference between negative and positive inotropic agents

A 
Negative = Weaken force of contraction
Positive = Increase strength of contraction
57
Q

Describe heart pathology

A

Ventricular hypertrophy increases inotropic state
MI decreases inotropic condition
Many inotropes alter preload/afterload

58
Q

Describe the difference between negative and positive chronotropic agents

A 
Negative = Decrease heart rate
Positive = Increase heart rate
59
Q

Give examples of negative and positive chronotropic agents

A 
Negative = Beta blockers, Ach
Positive = Adrenergic agonists, atropine
60
Q

What do parasympathetic nerves supply?

A

SA/AV nodes, atrial muscle, AV bundle

61
Q

Describe parasympathetic nerves

A

Release ACh - Act on M2 receptors
Activate M2 receptors - Decreased force of contraction (Neg ino), Cardiac slowing (bradycardia - Neg chro), Inhibition results inc in heart rate to 160 bts/min

62
Q

What do sympathetic nerves supply?

A

SA node, conducting tissue, myocardium

63
Q

Describe sympathetic nerves

A

Effects Sym activation on heart mediated by catecholamines actions on B1-receptors
Sym stimulation result - Inc force of contraction (Pos ino), Inc heart rate (Pos chro), Inhibition results dec heart rate from 70-60 bts/min

64
Q

Describe baroreceptors

A

Stretch sensitive receptors, tonically active, enhanced by stretching after dilation of vessels

65
Q

Describe the baroreceptor reflex pathway

A

Activity of SNS/PSNS regulated by cardiovascular centres in brain in response to info from baroreceptors (Main found in carotid sinus and aortic arch)

Y1 - HPP1 (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions