Cardio - Lec 15: Compensatory Mechanisms in Disease States.

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Across
  1. 1. pressure overload leads to concentric hypertrophy, or the laying down of new sarcomeres in _____________ (wall becomes thicker).
  2. 3. Put these in order, starting with a). A) heart failure and a reduction in CO. B) arterial blood pressure falls. C) noradrenaline binds to alpha receptors and stimulates peripheral vasoconstriction, increasing TPR (increases workload on heart!) D) This is sensed by baroreceptors. E) noradrenaline also binds to beta receptors on heart myocardium to increase force and rate of contraction (also increases workload of heart!). F) baroreceptor reflex to brain results in increased sympathetic release of noradrenaline.
  3. 6. ____________ hypertrophy occurs in volume overload when new sarcomeres are added in series.
  4. 8. reduced perfusion of the skeletal muscles in heart failure can lead to ________ “wasting” due to atrophy of muscle fibres. Contributes to exercise intolerance along with everything else.
  5. 10. in heart failure due to eccentric and concentric hypertrophy, ____ ____ often increases due to increased sympathetic stimulation of SA node. Ths is to try and maintain CO in the face of a reduced SV. In short term helps compensate ,but longer term places further strain on myocardium and can lead to potentially fatal arrhythmias.
  6. 12. loss of cardiac reserve means that the heart has to work harder to undergo normal metabolic functions at rest. This means it can’t keep up with metabolic demand during __________. ___________ intolerance.
  7. 13. the increased peripheral resistance due to _______________ (caused by angiotensin, sympathetic stimulation etc) as well as increased blood volume (due to RAAS and ADH) place further strain on heart and accelerate damage to the myocardium.
  8. 15. in right sided heart failure fluid can build up in the abdomen (peritoneal effusion/ ascites) or AROUND the lungs (___________ effusion – more common in cats).
  9. 17. a reduced ______ ________ can occur in both eccentric and concentric hypertrophy. Eccentric due to reduced contractility and increased ESV. Concentric due to reduced EDV as heart too stiff/thick/uncompliant to accept adequate amount of blood.
  10. 20. fluid conservation in heart failure (caused by activation of RAAS and ADH due to low BP and baroreceptor reflex) leads to increased blood volume , favours oedema formation as fluid forced out into interstitium.
  11. 22. concentric hypertrophy of the heart reduces end ________ volume due to stiff uncompliant heart  therefore decreases stroke volume.
Down
  1. 2. increased sympathetic stimulation in heart failure (due to decreased arterial BP and baroreceptor reflex) also leads to stimulation of the hypothalamus – secretion of ____________ hormone (stored in post pit). Works to retain fluid in the kidneys (aquaporins). Increases preload and afterload.
  2. 4. oedema fluid build up in the lungs due to left sided congestive heart failure can lead to _________ (shortness of breath) and tachypnoea (rapid breathing), can cause lungs to become stiff, and reduces efficiency of gas exchange.
  3. 5. in left heart failure, pulmonary oedema causes hypoxia in lungs, causes reflex vasoconstriction (lungs are different) – leads to pulmonary ___________ and greater strain put on right heart. Therefore left heart failure can lead to right heart failure.
  4. 7. volume overload of the heart leading to eccentric hypertrophy (heart gets bigger but not thicker) leads to decreased ___________ of cardiomyocytes. (ventricle filled too much and not enough overlap between myosin and actin filaments)
  5. 8. ____________ hypertrophy occurs with pressure overload (new sarcomeres laid down in parallel. )
  6. 9. eccentiric hypertrophy leads to a reduced stroke volume through reduced contractility  less blood ejected from heart leading to increased end __________ volume.
  7. 11. in health, the ______ _________ law means that when there is increased volume in the heart  increases stretch of cardiomyocytes  increases contractility. Not the case in eccentric hypertrophy, not enough overlap, and contraction inefficient.
  8. 14. heart failure causes reduced ______ ______.
  9. 16. reduced blood flow (effective circulating volume) is sensed by the ___________, which release renin. RAAS activation – vasoconstriction (more TPR and work for the heart!) and fluid retention (increases preload).
  10. 17. volume overload (eg in dilated cardiomyopathy) leads to the addition of sarcomeres in _______. (eccentric hypertrophy)
  11. 18. ___________ overload leads to eccentric hypertrophy eg dilated cardiomyopathy.
  12. 19. sustained high concentrations of neuroendocrine hormones (aldosterone, angiotensin, renin, catecholamines) lead to structural ______________ of the heart mediated by transforming growth factor beta (TGF-b) and epidermal growth factor (EGF).
  13. 21. heart disease will NOT cause an increase in blood __________, but sustained high blood _______ can lead to heart disease.