ILO:

1. What is the structure and function of the heart and the major vessels?2. How does blood flow through the heart?

Cardiac excitation begins in the SA node, located in the right atrial wall.-The SA node's prepotential causes action potential to be triggered.-Each action potential triggered by the SA node propagates through the atria via gap junctions In the intercalated discs of atrial muscle fibers. This causes the atria to contract

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By conducting along the internodal pathways, the action potential reaches the AV node in the atrial septum near the opening of the coronary sinus.

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The impulse slows as it enters the AV node( 100msec delay), as the nodal cells are smaller than the conducting cells.

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The delay is important because it allows the atria to contract before the ventricles do.-Next, the impulse is conducted along the AV bundle and the bundle branches to the purkinje fibers and papillary muscles.

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The purkinje fibers distribute the impulse to the ventricular myocardium, and ventricular contraction begins.

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3. What is the control of the conductive system in the heart?

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4. What is the cardiac cycle and the pressures involved (graph)?-

1 - The atria contract, rising atrial pressures push blood into the ventricles through the right and left AV valves2 - Atrial systole ejects blood into ventricles, filling the last 30% of volume needed. The other 70% fills from passive flow from last cycle.3 - At the end of atrial systole, each ventricle holds the maximum amount of blood that it will hold -the end diastolic volume - about 130ml. The left AV valve closes4 - Now atrial systole has ended, ventricular systole begins. Isovolumetric contraction happens, as the pressure rises, the ventricles contract and generate tension until the pressure rises enough to make the semilunar valves open.5 - Once pressure in the ventricles exceeds the arterial trunks, the semilunar valves open and blood flows into the pulmonary and aortic trunks. This is ventricular ejection.During ventricular ejection, each ventricle ejects 70- 80 ml of blood - the stroke volume6 - As the end of ventricular systole approaches, ventricular pressures fall rapidly. The semilunar valves close. Pressure in the aorta rises again as the elastic walls recoil, producing a dicrotic notch. The amount of blood remaining in the ventricle when the semilunar valve closes is the end systolic volume7 - All heart valves are closed, ventricular myocardium is relaxing. Isovolumetric relaxation - the ventricle pressures are dropping, but no more blood is entering them.8 - When ventricular pressures fall below the atrial pressures, the atrial pressure forces the AV valves open. This causes passive flow of blood from atria into ventricles, even though both chambers are in diastole. The ventricle becomes about 70% full before cardiac cycle ends.

End-Diastolic Volume (EDV): The amount of blood in each

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End-Diastolic Volume (EDV): The amount of blood in eachventricle at the end of ventricular diastole (the start ofventricular systole). End-Systolic Volume (ESV): The amount of blood remainingin each ventricle at the end of ventricular systole (the startof ventricular diastole). Stroke Volume (SV): The amount of blood pumped out ofeach ventricle during a single beat. It can be expressed asSV = EDV - ESV. Ejection Fraction: The percentage of the EDV represented bythe SV.

5. What is the nerve supply to the heart?6. What is rheumatic fever?a. Incidence, Prevalence, Epidemiology, pathophysiology, causes, symptoms, diagnosis, treatments.7. What is the role of NHS interpreters?a. Number of different languages?b. Role of families?c. Cost?8. What is parentalism?a. Young interpreters?b. Accuracy?9. What is BNP a test for?BNP is a 32-amino acid polypeptide secreted by the ventricles of the heart in response to excessive

stretching of heart muscle cells.- The most commonly used decision threshold for BNP is 100 pg/ml.- BNP levels of more than 100 pg/ml have a greater than 95% specificity and greater than 98%

sensitivity when comparing patients without congestive heart failure (CHF) to all patients with CHF

10. Why is Mr Ahmed breathless?a. Why is he propped up by pillows?11. What is heart failure?a. Left and right sided heart failure?12. What are you listening for during an auscultation of the heart?13. Drugs Class, Side Effects, Mechanism of Action, Uses?a. Furosemide.b. Digoxin.c. Beta Blockers.d. Ace Inhibitors.e. Ramipril.f. Aspirin.g. GTN.h. Carvedilol.i. Warfarin.j. INRProthrombin time is a measure of how fast blood clots via the extrinsic pathway.INR is

Method: blood is drawn into a test tube containing sodium citrate, which binds the calcium

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Method: blood is drawn into a test tube containing sodium citrate, which binds the calcium and prevents coagulation.

- Plasma is isolated- Calcium is added, then tissue factor is added, and the clotting time is measured.- High INR= risk of bleeding- Low INR= risk of clotting- Warfarin results in low INR.

14. What are the types of mitral valve replacements?Tilting disc -

Ball and cage:

Bileaflet valve - most common

A recording and display of the electrical events in the heart.-When a portion of the heart has been damaged, an abnormal ECG is present-The P wave represents he depolarization of the atria-The QRS complex represents depolarization of the ventricles. It is larger because the ventricles are bigger than the atria

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15. What is an ECG?

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ventricles are bigger than the atria

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Extension of the PR interval to more than--

200 msec can indicate damage to the conductingpathways or AV node.

16. What is an echocardiogram?17. What is Starlings law?states that the stroke volume of the heart increases in response to an increase in the volume of blood filling the heart (the end diastolic volume) when all other factors remain constant. The increased volume of blood stretches the ventricular wall, causing cardiac muscle to contract more forcefully

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18. What is pulmonary oedema?19. What causes heart enlargement?20. Why was he given an oxygen mask?21. Why does he require antibiotics?

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