Brainscape's Knowledge GenomeTM

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


See full index

ESA 2 - RJS > CVS > Flashcards

CVS Flashcards

0
Q

What affects the rate of diffusion?

A

Area
Diffusion resistance - Nature of barrier, molecules and distance
Concentration gradient

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

What do we have a cardiovascular system?

A

Supplies cells in the body with metabolic needs because simple diffusion would be too slow

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

What must be kept at an appropriate rate to ensure concentration gradients during diffusion?

A

Flow of blood else gradients driving exchange will dissipate

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

How much blood does the cardiovascular system have to deliver?

A

Between 5 and 25 L/min

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

Which organs must the blood flow be maintained at a constant rate?

A

Brain and kidneys

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

What is the blood flow required to the brain and kidneys?

A

Brain - 0.75 L/min

Kidneys - 1.2 L/min

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

What are the components of the circulation?

A

Pump - heart
Distribution vessels - arteries
Flow control - resistance vessels (arteriolar, pre-capillary sphincters)
Capacitance - store of blood (veins)

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

What is the role of resistance vessels in the circulation?

A

Allows for restricted flow to parts of the body that are easily perfused and drives blood to parts that are not easily perfused
E.g. Arteriolar, pre-capillary sphincters

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

What is the role of capacitance vessels in circulation?

A

Ability to cope with changes in cardiac output. Stores blood which can be called upon to cope with temporary imbalances
E.g. Veins

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

What is the difference between elastic arteries and muscular arteries?

A

Elastic arteries - expand slightly with each heart beat (greater amount of elastic fibres)
Muscular arteries - regulate amount of blood reaching an organ/tissue, regulates blood pressure, branch into arterioles

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

Describe the flow of structures in the circulation system from heart to capillaries
I.e. The order in which they occur

A

Large elastic/conducting arteries —> medium muscular/distributing arteries —> arterioles —> metarterioles —> capillaries

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

Describe the flow of structures in the circulation system from capillaries to heart
I.e. The order in which they occur

A

Capillaries —> post capillary venules —> venules —> medium veins —> large veins

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

How is the diameter of arteries and arterioles controlled?

A

By autonomic nervous system

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

What are the two types of capillary walls?

A

Continuous & fenestrated

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

What can capillaries be surrounded by?

A

Pericytes - contractile cells

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

What are sinusoids and where are they found?

A

Capillaries that have a larger diameter and may contain special lining cells and incomplete basal lamina - increase permeability
Found in liver, spleen, bone marrow

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

What is the difference in restructure between vein and artery?

A

Similar structure except that wall is thinner and lumen wider and irregular
Veins contain semilunar paired valves - blood flow in 1 direction

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

What occurs to the veins if blood pressure is not maintained?

A

They collapse

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

What are the two factors that most effect blood flow in veins?

A

‘Muscle-pump’ action in the leg and pressure factors in the abdominal and thoracic cavities

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

What are the valves located in the left ventricle?

A

Tricuspid and pulmonary

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

What are the two values located in the right ventricle?

A

Mitral and aortic

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

What are the six properties of cardiac muscle allow heart to operate as a pump?

A 
Striations
Branching
Centrally positioned nuclei
Intercalated discs - electrical and mechanical coupling with adjacent cells
Gap junctions
T tubules inline with Z bands
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How are action potentials generated in the heart?

A

Pacemaker cells (SA node) generate electrical activity which leads to activity in other cells

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

How long is cardiac contraction (systole)?

A

280ms

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

What is systole?

A

Period in which the myocardium is contracting

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

What is diastole?

A

Relaxation in-between contractions

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

How long does diastole last?

A

700ms

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

How does atrial systole occur?

A

SA node fibres an action potential - spreads over atria - atrial systole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What happens at the AV node?

A

Action potential is delayed for 120ms before spreading down septum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What causes the movement of blood from atrium to ventricle?

A

Intraventricular pressure falls below atrial pressure - rapid filling phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How do the atrioventricular valves close?

A

Build of pressure exerted in ventricles causes slight back flow but blood seeps behind the valve flaps slamming them shut with pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How is the muscle in the ventricles organised to facilitate pumping of blood?

A

Organised into figure of 8 bands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the difference between the right and left side of the heart?

A

Left side has thicker myocardium

Right side has pacemaker cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Describe isovolumetric contraction

A

When ventricles contract but there are no values open

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is isovolumetric relaxation?

A

When ventricles relax before atrioventricular valves open

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

When do the pulmonary/aortic valves open and close?

A

Open - when ventricular pressure exceeds diastolic pressure in pulmonary/aortic arteries - systole
Close - when arterial pressure is greater than ventricular pressure, slight back flow - end of systole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

When do the tricuspid/mitral valves open and close

A

Open - atrial pressure greater than ventricular pressure - early diastole
Close - when ventricular pressure exceeds atrial pressure, slight back flow - ventricular systole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are the origins of the heart sounds?

A

First sound - AV valves closing - lup

Second sound - semi-lunar valves closing (ventricular-arterial valves) - dup

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are the left coronary arteries?

A

Left anterior decending
Left marginal
Circumflex

39
Q

What are the right coronary arteries?

A

Right marginal

Right anterior ventricular

40
Q

In an ECG what signal does a depolarisation towards an electrode cause?

A

Upward signal

41
Q

In an ECG what signal does a depolarisation moving away from an electrode cause?

A

Downward signal

42
Q

In an ECG what signal does a repolarisation moving away from an electrode cause?

A

Upward signal

43
Q

In an ECG what signal does a repolarisation moving towards an electrode cause?

A

Downward signal

44
Q

What does the amplitude of an ECG signal depend on?

A

How much muscle is depolarising

How directly towards the electrode the excitation moves

45
Q

When reading an ECG what do you look at?

A

Rate, rhythm, axis, P-wave, P-R segment, QRS complex, Q-T interval, T wave

46
Q

What is the P-wave of an ECG?

A

Atrial depolarisation

47
Q

What is the Q peak in an ECG?

A

Excitation spreads down halfway down septum and across axis of heart

48
Q

What is the R peak of ECG?

A

Depolarisation spreads through ventricular muscle

49
Q

What is the S peak of the ECG?

A

Depolarisation spreads upwards through ventricles

50
Q

What is the T wave of an ECG?

A

Repolarisation on epicardium surface of ventricles

51
Q

What are amplifiers in terms of an ECG?

A

One positive and one negative electrode - negative electrode takes signal and inverts it, adding it to positive input

52
Q

What are the ECG changes of atrium fibrillation?

A

No P waves

Irregularly spaced QRS complex

53
Q

What are the ECG changes consistent with first, second and third degree heart blocks?

A

First degree - prolonged P-R interval
Second degree - erratic P-R interval
Third degree - no relationship between P wave and QRS complex

54
Q

What is the cause of axial deviation and what are the consistent ECG changes?

A

Caused by changes in amount of muscle

Moves normal rhythm out of lead II - alters axis

55
Q

What are the changes consistent with bundle branch block?

A

Lengthens and changes shape of QRS complex
Rabbit ears
Damage to conducting pathways

56
Q

What are the ECG changes consistent with myocardial infarction?

A

ST elevation
Inverted T waves
Pathological Q waves - caused by scar tissue

57
Q

In which vessels is blood flow fastest?

A

Where total cross sectional area is least, e.g. aorta

Slowest in capillary beds

57
Q

What are the layers of an artery?

A 
Tunica intima
Internal elastic lamina
Tunica media
External elastic lamina
Tunica externa
58
Q

What are the layers of a vein?

A

Tunica intima
Tunica media
Tunica externa

59
Q

What are the layers of the pericardium?

A

Fibrous layer

Serous layer - divided into parietal and visceral layers

62
Q

What is the sensory nerve supply to the pericardium?

A

Phrenic nerve (C3-C5)

63
Q

What is valve stenosis?

A

Narrowing of the valve

64
Q

What is valve incompetence and what does it result in?

A

Valve not closing properly causing regurgitation

65
Q

What occurs during an ventricular action potential?

A

Opening of voltage gated Na channels - Na influx
Transient outflow of K+
Plateaux caused by opening of VOCC (L-type) - Ca influx
Ca channels inactive, voltage gated K+ open - K efflux

66
Q

What occurs during an SA node action potential?

A

Gradual influx of Na through HCN channels (cAMP-dependent) - Funny current (If)
Opening of t-type voltage operated Ca channels - become inactive
Opening of voltage operated K channels cause depolarisation

67
Q

Describe the mechanism by which the tone of blood vessels controlled?

A

Ca binds to calmodulin which binds to myosin light chain kinase (MLCK) which phosphorylates myosin head through conversion of ATP to ADP

68
Q

How does sympathetic activity change the SA node action potential?

A

Increase cAMP causes increased gradient of If due to more channels open and more Na influx

69
Q

Which nerve provides parasympathetic innervation of the SA node?

A

Vagus nerve

70
Q

Where do sympathetic pre-ganglionic nerves synapse?

A

Paravertebral chain

71
Q

What are the two exceptions to the usual ANS innervation?

A

Sweat glands - sympathetic innervation but release ACh to muscarinic receptors
Chromaffin cells in adrenal medulla - specialised postganglionic sympathetic neurones that release adrenaline into the bloodstream

72
Q

Describe the mechanism of parasympathetic innervation of the SA node

A

M2 receptors - inhibit adenylyl cyclase - decreased cAMP - decreased opening of HCN channels, not main effect
Beta-gamma subunit increases open probability of K channels so causes hyperpolarisation so takes longer to reach threshold

73
Q

Describe the mechanism of sympathetically led positive inotropy

A

Noradrenaline - B1 receptors - + adenylyl cyclase - increased cAMP - increased PKA
PKA phosphorylates L-type VOCC channels to increase open probability - increased Ca entry
Increased Ca induced Ca release from SR (ryanodine receptors)
Increased force of contraction

74
Q

Describe the sympathetic drive of vasculature

A

Increased sympathetic drive - vasconstriction
Normal - vasomotor tone
Decreased sympathetic drive - vasodilation

75
Q

Which receptors are involved in sympathetic innervation of vasculature?

A

Alpha 1 adrenoceptors

76
Q

Describe the effect of metabolites on vasculature

A

Produced by active tissue (e.g. adenosine, K, H)

Strong vasodilatory effect

77
Q

What controls sympathetic and parasympathetic drive of the heart?

A

Baroreceptors - sensitive to stretch therefore detect arterial pressure
Located in carotid sinus and aortic arch

78
Q

Flow is determined by resistance but what is resistance determined by?

A

Nature of fluid and vessel

79
Q

What is flow?

A

Volume of fluid passing a given point per unit of time

80
Q

What is velocity?

A

Rate of movement of fluid particles along tube

81
Q

At a given flow, velocity is inversely proportional to what?

A

Cross sectional area

82
Q

Describe in laminar flow

A

Concentric rings of gradient of velocity (from middle to edge), highest in centre

83
Q

What causes turbulent flow?

A

Increased mean velocity or narrowed
Increases flow resistance
Generates sound

84
Q

What is viscocity of blood?

A

The extent to which adjacent layers resist sliding over one another due to laminar flow

85
Q

What does Poiseulles law state?

A

Decreasing the radius by 1/2 will increase vessel resistance by 16 times
F proprotional to r4

86
Q

What is special about the distensible tubes?

A

As vessel stretches, resistance falls

But as pressure drops, walls will eventually collapse - flow ceases before pressure falls to zero

87
Q

What is the pressure and resistance of arteries?

A

Low resistance
High pressure - due to high resistance of arterioles
Distensible walls make flow less pusitile

88
Q

What is TPR?

A

Total peripheral resistance - sum of all resistance from all vessels

89
Q

What are the factors affecting systolic pressure?

A

How heart the heart pumps
Total peripheral resistance
Stretchiness of arteries

90
Q

What are the factors affecting diastolic pressure?

A

Systolic pressure

TPR

91
Q

What is TPR proportional too?

A

Inversely proportional to body’s need for blood

92
Q

What does Starling’s Law of the Heart state?

A

The more the muscle is stretched the more is will contract (the bigger the stroke volume)
Therefore increased venous pressure will equal increased stroke volume

93
Q

What occurs during ventricular filling?

A

Ventricle will fill until intra-ventricular pressure = venous pressure
*Ventricular compliance curve (venous pressure vs volume)

94
Q

What does the Starling Curve show?

A

Stroke volume vs venous pressure (slope = contractility - ability of muscle to generate force for any given fibre length, caused by increased Ca)
Curve tapers off at high venous pressure because heart stretch is limited by pericardial sac and it will impinge on coronary arteries

95
Q

What determines the force of contraction?

A

End diastolic volume (starling’s law)

Contractility (increase sympathetic activity)

ESA 2 - RJS (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions