Brainscape's Knowledge GenomeTM

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


See full index

103-theme 3 > how the cardiovascular system fails > Flashcards

how the cardiovascular system fails Flashcards

1
Q

what is stroke and what are the different types? 3

A
  • rapid loss of brain functions due to loss of perfusion to parts of the brain
  • hemorrhagic- cerebral blood vessel rupture
  • ischaemic- cerebral blood vessel blockage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what can cause a blood vessel to burst? 8

A
  • high pressure
  • high blood pressure or downstream blockage
  • turbulent flow
  • large diameter/ high wall tension
  • low compliance/ high stiffness
  • trauma
  • atherosclerosis
  • diabetes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

explain vessel wall tension? 3

A
  • tension in a cylinder is the force (tangential to the circumference of the cross section) that is trying to rip the wall apart
  • in a cylinder it is proportional to P x radius
  • the larger the vessel, the greater the wall tension (there is more trying to tear the vessel apart)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is laminar flow?

A
  • slow at the edges
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is turbulent flow? 2

A
  • can be caused by high speed, branching and low viscosity

- turbulence can be caused by junctions, mixing and obstacles (atherosclerosis, endothelial damage)

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

what are the activities of the endothelium? 6

A
  • blood vessel tone= local control of perfusion and vasodilation due to NO secretion
  • fluid filtration for tissues surrounding the blood vessel (blood brain barrier, CSF, kidney, GI secretions)
  • haemostasis: especially fibrinolysis
  • white cell recruitment: atherosclerosis
  • angiogenesis
  • hormone trafficking= transcytosis (transportation across the inside of a cell)(insulin)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is an acute myocardial infarction? 6

A
  • a region of heart tissue that is dying or dead
  • usually caused by a blocked coronary artery
  • onset takes minutes
  • reduces hearts capacity to pump
  • large or multiple can lead to heart failure
  • can be fatal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is atherosclerosis? 4

A
  • a disease process
  • results in the furring of arteries
  • asymptomatic but can lead to other disorder
  • results from hyperlipidaemia, immune action of unknown aetiology
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is coronary heart disease? 5

A
  • a disease process resulting in obstruction of arteries supplying the heart tissue
  • angina/ asymptomatic
  • primary cause is atherosclerosis
  • treat with drugs for hyperlipidaemia, angina or hypotension
  • treat with stenting or surgically replacing clogged vessels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

explain plaque rupture? 2

A
  • when the fibrous cap of a plaque bursts open
  • atheroma are relatively safe even if they occlude 50% of a vessel, but if the plaque ruptures in a coronary artery it can cause a thrombus or MI
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are the sympathetic activity during a MI? 4

A
  • sympathetic nervous system releases adrenaline and noradrenaline during acute MI
  • this is in response to pain and haemodynamic abnormalities
  • sympathetic activities also help to compensate during heart failure
  • it leads to increased heart rate and contractility, increased peripheral resistance and increased risk of arrhythmia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the forces on water molecules in a capillary?

2

A
  • net pressure= hydrostatic pressure (out) and osmotic pressure (in)
  • pushes water out at arterial end and pulls in at venous end
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is pulmonary oedema? 4

A
  • fluid accumulates in lungs (especially alveoli)
  • causes impaired gas exchange and the process of O2 diffusion is lengthened
  • this is caused by left heart failure- damming of blood vessels leads to hydrostatic pressure increase in the pulmonary circulation
  • symptoms= dyspnoea/orthopnoea (trouble breathing lying down) which leads to hypoxia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are ascites? 2

A
  • accumulation of fluid in the peritoneal cavity

- many causes including heart failure

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

what is peripheral oedema? 2

A
  • swelling of tissues

- many causes including chronic low output heart failure

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

what is compensation?

in heart faliure?

A
  • maintaining homeostasis of a physiological function despite stressors of malfunctions- happens via endogenous physiological feedback
  • in heart failure, to maintain adequate cardiac output despite damage, there needs to be an increase in plasma volume and increase in sympathetic activity
17
Q

what is decompensated heart failure? 3

A
  • a medical emergency
  • the failure of the heart to maintain adequate blood circulation after long-standing vascular disease (previously compensated)
  • respiratory distress
18
Q

what is cardiac remodelling? 5

A
  • growth of cardiac muscle, changes in shape, size and function
  • caused by injury (MI, heart failure, valve response)
  • the result is hypertrophy or dilation
  • compensatory initially-pathological later
  • treated by ACE inhibitors or spironolactone
19
Q

explain ventricular hypertrophy? 4

A
  • response to work
  • athlete’s heart
  • eccentric= dilate due to volume overload
  • concentric= thicken due to pressure overload
20
Q

what is ADH? 4

A
  • antidiuretic hormone
  • causes kidneys to reabsorb more water and decreases diuresis (losing water via kidneys into the urine)
  • secreted from posterior pituitary gland
  • peptide
21
Q

what is aldosterone? 5

A
  • causes kidney to reabsorb more NaCl (and thus more H2O)
  • directly decreases natriuresis (excretion of sodium in urine)
  • which decreases diuresis
  • secreted from the adrenal cortex
  • steroid
22
Q

what does angiotensin II do? 7

A
  • increases pressure
  • vasoconstriction
  • increased fluid retention
  • increased aldosterone secretion by adrenal cortex
  • increases Na+ retention
  • increases ADH secretion by posterior pituitary
  • contributes to ventricular hypertrophy and remodelling
23
Q

describe the renin-angiotensin-aldosterone system (RAAS)? 5

A
  • angiotensinogen
  • enzyme renin
  • angiotensin I
  • enzyme ace
  • angiotensin II (active vasoconstrictor)
24
Q

what do diuretics do?

name 3 different types

A

lead to loss of fluid at nephron

  • thiazide like
  • indapamide
  • blocks reabsorption at DCT
  • loop
  • furosemide
  • blocks reabsorption in the thick
  • K+ sparing
  • spironolactone
  • inhibits aldosterone receptors in cortical collecting duct
25
Q

what is heart faliure?

A
  • when cardiac output is insufficient for meeting needs of the body and lungs
26
Q

what is chronic low output heart failure? 2

A
  • cardiac output is low, usually due to accumulated damage to the heart
  • chronic condition with poor 5-year survival rate
27
Q

what is left heart failure? 5

A
  • respiratory systems
  • right heart pumps into lungs but left atrium is too full
  • increased hydrostatic pressure in pulmonary circulation
  • ‘congestive’- pulmonary vasculature is congested
  • in extreme conditions- fluid leaks out of blood vessels and into the lungs
28
Q

what is right heart failure? 2

A
  • increased central venous pressure

- leads to peripheral oedema

29
Q

what is heart failure symptoms and signs? 4

A
  • fatigue (especially during exertion)
  • peripheral oedema
  • dyspnea
  • orthopnea
30
Q

what is fluid retention? 3

A
  • the thing that unites all forms of heart failure
  • compensation= initially homeostatic
  • eventually does more harm than good= dyspnea, ascites, ankle oedema
31
Q

what is cardiogenic shock? 6

A
  • critically low perfusion due to low cardiac output
  • medical emergency, usually fatal
  • insufficient perfusion of tissues, especially the heart
  • progresses by positive feedback
  • includes SBP < 90 mmHg
  • aggressive intravenous fluid and oxygen +airway maintained
32
Q

what are the normal treatments for chronic heart failure? 4

A
  • ACE inhibitors
  • diuretics
  • beta blockers
    these all interfere with the body’s response to low cardiac output
33
Q

what is the homeostasis for cardiac output? 9

A
  • increased sympathetic activity (fast response)
  • increased heart rate and heart contractility
  • vasoconstriction
  • kidney accumulates fluid (slow response)
  • decreased glomerular filtration rate
  • increased central venous pressure
  • increased venous return
  • increased preload

the goal of pharmacotherapy for heart failure is to stop both of these processes

34
Q

explain what the kidney is evolved to cope with? 3

A
  • haemorrhage no heart failure, these look the same to the kidney
  • heart failure- normal pressure, ends with shock
  • haemorrhage- loss of fluid leads to loss of pressure, ends with shock
35
Q

explain the process of decompensated heart failure? 8

A
  • kidney increases plasma volume to compensate for poor perfusion of renal tissue
  • the kidney responds as if there is haemorrhage which leads to fluid overload
  • the heart is unable to pump the extra fluid
  • fluid damming leads to increased venous pressures
  • increased back pressure further damages the heart
  • positive feedback loop
  • the capillaries leak fluid into the tissues
  • the lungs cannot perform gas exchange
36
Q

what are the treatment goals of low output HF? 3

A
  • prevent acute decompensated heart failure
  • counteract cardiac remodelling
  • minimize symptoms

103-theme 3 (18 decks)

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