Brainscape's Knowledge GenomeTM

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


See full index

PPoS > The Cardiac Cycle > Flashcards

The Cardiac Cycle Flashcards

1
Q

What is the R of healthy valves + why is it important?

A

v. little R (flexible) so small P gradient across them nec for them to open + close

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

What opens + shuts valves in the heart?

A
  • P diff

- only small P gradient nec to open valve

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

What are the structure of the AV valves + sig?

A
  • floppy but anchored to walls of vent by papillary muscles + chordae tendineae so don’t blow back into atria when P in vent rises during systole
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does the AV valve cause?

A
  • add atrial P wave that can be seen ext. as it causes pulse of blood into jugular vein that can be seen at neck
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is an echo?

A
  • damage to anchoring structures e.g. after MI causes AV valve everting back into atrium so during systole some blood pumped backwards in wrong direction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is stroke vol?

A
  • diff between how much blood in vent when full (120ml) vs empty (50ml) + therefore amount of blood pumped out by vent each beat
    ~ 70ml
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is stroke work?

A
  • area of P-V loop

- how much work heart is doing

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

What does jugular vein do?

A

brings blood from head to SVC + then to R atrium

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

What is JVP?

A
  • biphasic
  • low P bc its venous
  • assessed by viewing dilation of jugular veins in neck
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the a wave of JVP?

A
  • R atrial contraction (systole)

- P inc in R atrium + contraction causes pulse in jugular vein

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

What is X descent of JVP?

A

atrial relaxation

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

What is the C wave of JVP?

A
  • interruption of X descent caused by transmitted carotid pulse
  • carotid artery close to jugular vein + pulse transmitted through tissue to cause carotid pulse in jugular
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is v wave of JVP?

A
  • R atrial filling during vent systole

- when R atrium contracts, push tricuspid (closed) - goes up towards atria which gives pulse in atria

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

What is y descent of JVP?

A
  • atrial emptying during vent diastole
  • before atrial contraction
  • tricuspid open
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What affects shape + size of v wave?

A

bulging, regurgitation + stenosis of tricuspid

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

What is peripheral arterial pulse?

A
  • largely monophasic

- high P

17
Q

What influences peripheral arterial pulse?

A
  • shape of peak + descending phase influenced by factors of vessels themselves such as:
  • reflected waves,
  • compliance,
  • resonance,
  • interference
  • damping
  • why shape + mag of pulse varies along arterial tree
18
Q

How does venous + arterial P diff?

A
  • absolute venous P (+ pulse P) low (4-8mmHg)

- arterial P (+ pulse P) high (80-120mmHg)

19
Q

What happens to jugular vein 5cm above RA?

A
  • collapse bc not enough P to keep it inflated + due to hydrostatic influences
20
Q

How do veins few cm above heart differ to veins closer to heart?

A
  • CVP low so due to gravity, veins few cms above heart collapse bc P inside them -ve + are flat
  • as move towards heart, P hgih enough so veins are rounded so height of this point above heart is readout of CVP
21
Q

Why is IJV sig?

A
  • see point of collapse
  • P waves in R atrium back up into IJV + so can discern changes in collapse point
  • also changes in pulse of IJV visualise changes in P in RA with diff pathologies affecting tricuspid valve + in heart failure
22
Q

How do you measure JVP?

A
  • support patient at 45 degree angle - can now see point where IJV collapses
  • JVP is height of collapse of IJV above manubriosternal angle (about 3cm in healthy person, should have 0cm H2O + go from slightly distended to completely flat)
23
Q

At what point is JVP pathoglogical?

A
  • > 3cm

- means CVP/RA P too high

24
Q

Why does the patient need to be at an angle to measure JVP?

A
  • if patient upright, point of collapse lower as jugular below level of clavicle + can’t be seen
  • if person lying down, no point of collapse
25
Q

Why is IJV preferred over ext. jugular for measuring venous P?

A
  • IJV anatomically closer to R atrium while ext. doesn’t drain directly into SVC
  • IJV valveless so pulsations can be seen whereas EJV not
  • vasoconstriction 2ndary to hypotension (as in congestive heart failure) can make EJV small + barely visible
  • EJV superficial + prone to kinking
26
Q

How does JVP differ waves differ in tricuspid stenosis?

A
  • valve narrow + inc R
  • a wave enhanced - working harder to get blood through valve as a result so RA P inc during contraction
  • v wave diminished as vent P wave tends not to be so effectively transmitted back through stenotic inflexible tricuspid valve
27
Q

How does JVP differ waves differ in tricuspid regurgitation?

A
  • a wave diminished as atria not as effective so P doesn’t inc much
  • v wave enhanced as vent contraction ejects blood through incompetent tricuspid valve back into atria
  • JVP inc in this stage
28
Q

How does damping change shape of arterial P wave?

A
  • stretch aorta - lots of energy in ejection goes into stretching aorta
29
Q

How does reflection change shape of arterial P wave?

A
  • elastic aorta means some stretch given back as reflected wave
  • reflected waves can interfere with forward compression wave so pulse wave is altered
  • if interference summative, pulse P can actually inc in magnitude but if its out of phase can depress forward P wave
30
Q

List primary heart sounds

A
  • S1: initiation of vent systole + closure of AV valves (low freq)
  • S2: Closure of SL valves (higher freq, shorter)
31
Q

List extra heart sounds

A
  • S3: opening of AV valves + rapid refilling

- S4: atrial systole (rarely heard unless EDP raised)

32
Q

When can S3 + S4 be heard?

A
  • when EDP raised (usually during heart failure)

- heard as gallop rhythm

33
Q

What causes heart murmurs?

A
  • turbulence in blood

- not always pathological, occur in young + in exercise

34
Q

What are causes of heart murmurs?

A
  • valve stenosis (too narrow)

- valve regurgitation (incompetent)

35
Q

What causes diastolic murmurs?

A
  • mitral stenosis as vent fills + occurs after S2

- aortic incompetence leads to early murmur with softening + prolongation of 2nd sound

36
Q

What causes systolic murmurs?

A
  • aortic stenosis (high P)
  • mitral incompetence leads to pan-systolic lush
  • occurs after S1

PPoS (11 decks)

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