Brainscape's Knowledge GenomeTM

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


See full index

2 - CVS > deck_624681 > Flashcards

deck_624681 Flashcards

1
Q

At rest, what are the relative venous and arterial pressures?

A

Venous pressure = lowerArterial pressure = higher

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

What happens when TPR falls?

A

arterial pressure will fallvenous pressure will rise

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

What happens when TPR rises?

A

arterial pressure will risevenous pressure will fall

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

What happens when cardiac output rises?

A

arterial pressure will risevenous pressure will fall

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

What happens when cardiac output falls?

A

arterial pressure will fallvenous pressure will rise

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

What is demand-led pumping?

A

When the body needs more blood, it causes the heart to beat more in order to facilitate the need

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

What is stroke volume?

A

The difference between the end diastolic volume and the end systolic volume– the amount of blood ejected by the heart

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

Describe ventricular filling

A

In diastole, the ventricles are connected to the veins so blood can enter. The ventricle fills until the walls stretch enough to produce an intra-ventricular pressure equal to venous pressure, due to the stretchiness of the walls.

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

What does the degree of ventricular filling depend on?

A

Venous Pressure (higher venous pressure, the more the heart fills in diastole)Stretchiness of the wallsIntraventricular pressure

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

What is the ventricular compliance curve?

A

The relationship between venous pressure and ventricular volume

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

What does Starlings Law of the Heart state?

A

If the myocardium is stretched before contracting it contracts harder– the more the heart fills up, the more it contracts– the harder the heart contracts the bigger the stroke volumeIncreased venous pressure causes an increase in the stroke volume

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

What is “pre-load”?

A

End diastolic stretch

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

What is “after-load”?

A

The force necessary to expel blood into the arteries

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

Define contractility

A

The slope of the curve showing the relationship between venous pressure and stroke volume

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

What is the force on contraction determined by?

A

End diastolic volumeContractility

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

What can have an effect on contractility?

A

Sympathetic activityNeurotransmittersHormonesDrugs which act on the myocardium

17
Q

What affect does increasing the venous pressure have on the stroke volume?

A

Increases stroke volume – more blood is entering the ventricles

18
Q

What happens when it is easy to eject blood from the heart?

A

The volume output increases and there will be a small pressure increase in the arteries

19
Q

What happens when it is difficult to eject blood from the heart?

A

The volume output decreases and the arterial pressure will increase

20
Q

What will a fall in the TPR do to the stroke volume?

A

It will increase the stroke volume

21
Q

How is the heart rate controlled?

A

Autonomic outflow is determined by signals from baroreceptors

22
Q

Where are baroreceptors situated in the heart and what do they do?

A

Carotid sinus at the bifurcation of the common carotid artery and in the walls of the aorta. They detect changes in the arterial pressure

23
Q

What section of the brain controls the heart?

A

Medulla oblongata

24
Q

What is the effect on sympathetic and parasympathetic activity when the arterial pressure falls?

A

Increases heart rate by:– reducing parasympathetic activity– increasing sympathetic activityIncreases contractility by:– increasing sympathetic activity

25
Q

What does a rise in venous pressure do?

A

CARDIAC OUTPUT RISES– increase stroke volume (Starlings Law) – increase heart rate

26
Q

What does a fall in arterial pressure do?

A

CARDIAC OUTPUT RISES– increase stroke volume (sympathetic activity and direct effect)– increase heart rate

27
Q

What do baroreceptors ensure?

A

If arterial pressure falls, heart rate and stroke volume will both rise

28
Q

How does the ANS affect cardiac output?

A

By changing heart rateBy changing contractility

29
Q

What is the mean filling pressure?

A

The mean pressure in the arteries and veins when the heart stops

30
Q

What happens to the arterial and venous pressure when the heart stops?

A

Arterial pressure fallsVenous pressure rises

31
Q

Why at the top end of a starling curve, does the stroke volume fall with increasing pressure?

A

The elastic fibres in teh myocardium have been stretched past a certain point where they do not return to their original shape

32
Q

What factors/illnesses increase the central venous pressure?

A

hypervolaemia, heart failure, tension pneumothorax, cardiac tamponade

33
Q

What factors/illnesses decrease the central venous pressure?

A

hypovolaemia, shock

2 - CVS (28 decks)

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