Brainscape's Knowledge GenomeTM

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


See full index

Cardiology SB > Physiology > Flashcards

Physiology Flashcards

1
Q

what is the spread of excitation in the heart

A

1 - Across the atria mainly cell-to-cell conduction via gap junctions
2 - From SA node to AV node: mainly cell-to-cell conduction via gap junctions; but there is also some internodal pathways
3 - The conduction is delayed in the AV node.
4 - The Bundle of His and its branches and the network of Purkinje fibers allow rapid spread of action potential to the ventricles
5 - Ventricular muscle: cell-to-cell conduction
Diastole

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

what stimulation decreases the HR

A

Parasympathetic

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

what is classified as bradycardia

A

HR less than 60

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

what is classified as tachycardia

A

HR more than 100

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

what does a negative chronotropic effect do

A

slows down HR (parasympathetic)

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

what does a positive chronotropic effect do

A

increases HR (sympathetic)

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

what is an ECG a record of

A

depolarization and repolarization cycle of cardiac muscle obtained from the skin surface

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

what values shut together

A

Tricuspid and Mitral

Pulmonary and aortic

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

how long does diastole and systole last for

A

diastole - 0.5sec

systole - 0.3sec

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

what happens in systole

A

the heart ventricles contract and pump blood into the: aorta (LV) and pulmonary artery (RV)

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

what happens in diastole

A

the heart ventricles are relaxed and fill with blood

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

what is the process of Isovolumetric Ventricular Contraction

A
  • Ventricular pressure rises
  • When ventricle pressure exceeds atrial pressure the AV values shut
  • produces first heart sound (‘lub’)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

when does the aortic/pulmonary value open

A

When the ventricular pressure exceeds aorta/pulmonary artery pressure

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

what does the T wave on an ECG represent

A

ventricular repolarisation

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

what happens after the aortic/pulmonary value open

A

Ventricles relax

ventricular pressure start to fall

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

what happens when the ventricular pressure falls below aortic/pulmonary pressure

A

aortic/pulmonary valves shut

this produces the second heart sound (dub)

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

what does the Closure of aortic/and pulmonary valves signal

A

isovolumetric ventricular relaxation

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

what happens when the ventricular pressure falls below atrial pressure

A

AV valves open and the heart starts a new cycle

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

what are the 5 stages of the cardiac cycle

A 
1 - Passive Filling
2 - Atrial Contraction
3 - Isovolumetric ventricular Contraction
4 - Ventricular Ejection
5 - Isovolumetric ventricular Relaxation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how does arterial pressure not fall to zero during diastole

A

elastic tissue

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

when does JVP appear

A

after right atrial pressure waves

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

what is the a wave on the JVP

A

atrial contraction

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

what is the c wave on the JVP

A

bulging of tricuspid valve into atrium during ventricular contraction

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

what is the v wave on the JVP

A

rise of atrial pressure during atrial filling: release as AV valves open

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

what happens in diastole (in relation to ions)

A

sodium enters the cell
Calcium exits the cell
Calcium enters the SR

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

what does stretch do in relation to calcium

A

increases the affinity of troponin for Ca++

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

when is the optimal length in cardiac muscle achieved

A

by stretching the muscle

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

what happens if venous return to right atrium increases

A

EDV of right ventricle increases

Starling’s Law leads to increased SV into pulmonary artery

29
Q

when does EDV of left ventricle increase and what does this cause

A

Venous return to left atrium from pulmonary vein increases

Starling’s Law leads to increased SV into aorta

30
Q

what does sympathetic stimulation do

A

increases the force of contraction (positive inotropic effect)

31
Q

what is the effect of sympathetic stimulation on ventricular contraction

A

1 - Force of contraction increases
2 - peak ventricular pressure rises
3 - Rate of pressure change (dP/dt) during systole increases
4 - reduced the duration of systole
5 - Rate of ventricular relaxation increases
6 - reduces duration of diastole

32
Q

how is force of contraction increased in sympathetic stimulation and what mediates it

A

activation of Ca++ channels - greater Ca++ influx

cAMP

33
Q

how is the rate of ventricular relaxation increased in sympathetic stimulation

A

increased rate of Ca2+ pumping

34
Q

what does the Frank-Straling curve shifted to the right

A

heart failure

35
Q

what should systolic and diastolic BP not exceed

A

s - 140mmHg

d - 90mmHg

36
Q

what is the effect of the parasympathetic stimulation on the heart

A

decreases HR
decreases CO
decreases MAP

37
Q

what is the effect of the sympathetic stimulation on the heart

A

increases HR-increases CO-increases MAP

increases contractile strength of heart-increases SV-increases CO-increases MAP

38
Q

what is the effect of the sympathetic stimulation on the arterioles

A

increases vasoconstriction-increases TPR- increases MAP

39
Q

what is the effect of the sympathetic stimulation on the veins

A

increases vasoconstriction-increases Venous return-increases stroke volume-increases cardiac output- increases MAP

40
Q

what causes postural hypotension

A

failure of Baroreceptor responses to gravitational shifts in blood, when moving from horizontal to vertical position

41
Q

what are the two main factors affect Extracellular Fluid volume

A

Water excess or deficit

Na+ excess or deficit

42
Q

what affect does angiotensin II have on the systemic system and how does it achieve this

A

vasoconstriction -increases TPR and BP

increases ADH and thirst -increases Plasma Volume and BP

43
Q

what does aldosterone do

A

acts on the kidneys to increase sodium and water retention increases plasma volume
therefore, increases BP

44
Q

where does aldosterone come from

A

adrenal cortex

45
Q

where does ACE come from

A

lung vascular endothelium

46
Q

what stimulates the release of rennin from the juxtaglomerular apparatus in the kidneys

A

1 - Renal artery hypotension -caused by systemic hypotension (↓ blood pressure)
2 - stimulation of renal sympathetic nerves
3 - Decreased [Na+] in renal tubular fluid

47
Q

where is ADH synthesised and where is it stored

A

hypothalamus

posterior pituitary

48
Q

what is ADH also known as

A

vasopressin

49
Q

what is plasma osmolality monitored by

A

osmoreceptors in the brain in close proximity to hypothalamus

50
Q

when is the release of ADH stimulated

A

when there is an increased plasma osmolality

51
Q

mechanism of action of ADH

A

1 - increase reabsorption of water
2 - increase extracellular and plasma volume
3 - increases CO and BP

52
Q

affect of ADH on blood vessels

A

vasoconstriction - increase TPR and BP

important in hypovolaemic shock e.g. haemorrhage

53
Q

what does contraction and relaxation of vascular smooth muscle cause

A

vasoconstriction - increases TPR and MAP

vasodilatation - decreases TPR and MAP

54
Q

what is the effect of increase sympathetic discharge on vascular smooth muscle

A

vasoconstriction

55
Q

what factors causes relaxation of arteriolar smooth muscles resulting in VASODILATATION

A 
Decreased local PO2
Increased local PCO2
Increased local [H+] (decreased pH)
Increased extra-cellular [K+]
Increased osmolality of ECF
Adenosine release (from ATP)
56
Q

where is NO produced and from what

A

vascular endothelium from the amino acid L-arginine through enzymatic action of Nitric Oxide Synthase (NOS)

57
Q

what is the mechanism of action of NO

A

1 - diffuses from the vascular endothelium into the adjacent smooth muscle cells
2 - activates the formation of cGMP
3 - serves as a 2nd messenger for signalling smooth muscle relaxation

58
Q

what causes increased venous return

A

increase venomotor tone
increased skeletal muscle pump
increased resp pump
increased blood volume

59
Q

what does increased venous return causes

A

increased atrial pressure-increase EDV-increased SV

60
Q

what does increased venomotor tone causes

A

increased venous return, SV and MAP

61
Q

what does increased vasomotor tone causes

A

increases TPR and MAP

62
Q

how does contraction of muscles aid venous return

A

large veins lie in between skeletal muscle
One-way venous valves allow blood to move towards the heart
Muscle Activity increases VENOUS RETURN to heart

63
Q

how does sympathetic stimulation increase HR

A

INCREASING THE RATE OF FIRING OF SA NODE and DECREASES AV NODAL DELAY
Increases force of contraction

64
Q

what happens when slope of pacemaker potential increases

A

pacemaker potential reaches threshold quicker

frequency of action potentials increases

65
Q

what does adequate tissue perfusion depend on

A

adequate blood pressure and adequate cardiac output

66
Q

where do the right and left coronary arise from

A

the base of the aorta

67
Q

what is the mechanism of adenosine

A

potent vasodilator
cause vasodilation of coronary arteries
increase blood flow to cardiac muscle

68
Q

what does shortening diastole cause

A

very fast heart rate ↓ coronary flow

Cardiology SB (15 decks)

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