Cardiovascular physiology

28 Questions

Draw a labelled diagram of a cardiac action potential highlighting the sequence of changes in ionic conductances. Explain the terms 'threshold', 'excitability', and 'irritability' with the aid of a diagram. (02A2) (1995)
Briefly discuss the interaction of the action potential duration and conduction velocity in the ventricular myocardium and its effect on myocardial performance. (1993)

Draw a pressure volume loop for a left ventricle in a healthy adult and state the normal pressures and volumes. Outline the information which can be obtained from a pressure volume loop and how such a loop can be constructed. (02B9)(1996)
Draw and label a left atrial pressure trace against time. List the physiological factors which effect left atrial pressure and explain their effects. (95A3)
Quote Starlings law of the heart. Outline the factors that determine the right ventricular end diastolic volume. (1993)
Discuss the relationship between cardiac output and venous return. Include factors that determine the magnitude of both. (1990)

Explain the physiological processes involved in the development of interstitial oedema. (01B8)
Describe the substances released by the endothelium. Explain the role they play in regulating blood flow through the peripheral circulation. (01A6)
Draw both aortic root and a radial artery pressure wave forms on the same axes. Explain the differences between them. (99B8)
Explain the significance of plasma oncotic pressure in capillary fluid dynamics. (99A8)
Explain the local effects of a decrease on plasma colloid osmotic pressure in the skeletal muscle capillary bed. (97B1)
Briefly discuss the factors that influence the rate of blood flow through a capillary bed. (1994)
Describe the relationship between vascular tone and tissue oxygenation. (1994)
Briefly discuss the humoral factors that control blood pressure. (1993)
Give an account of the Starling forces within the capillary circulation. Include specific reference to the pulmonary and glomerular capillaries. (1991)

Describe the role of baroreceptors in the control of systemic arterial pressure. (03B10) (00B1)
Describe the autonomic innervation of the heart and the direct effect of autonomic stimulation on the heart. (99A7)
Describe the compensatory mechanism in a fit person moving from the supine to the erect position. (98B2)
On arising from the horizontal position, in a normal gravitational field, a series of reflex adjustments follows which results in a redistribution of blood volume and body water. DISCUSS the physics and physiology involved. (94B1)
Explain the cardiovascular responses to a Valsalva manoeuvre maintained for 30 seconds. What can be learnt about cardiovascular function from observing these responses? (94B2)
Briefly discuss the humoral factors that control blood pressure. (1993)
Write short notes on volume receptors. (1992)

Describe the effects of tachycardia on myocardial oxygen supply and demand in a normal heart. (03B9)
Explain the mechanisms that maintain cerebral blood flow on moving from a supine to a standing position. (03A12) (99B6) (96B4)
Describe the factors influencing hepatic blood flow. (03A10) (99A6)
Outline the factors that determine coronary vascular resistance. (02B11)
List the determinants of coronary artery blood flow. Briefly compare phasic coronary blood flow in the left and right coronary arteries. (1997)
The heart rate of a healthy 20 yr old goes from 55bpm to 130 bpm after receiving atropine IV. Describe the effects of tachycardia on myocardial O2 supply and demand in a normal heart. (95A4)