Question

Explain four factors that can increase blood pressure.

Explain why an embolus may cause a larger infarction than an atheroma with thrombus.

Compare PVCs, atrial flutter, atrial fibrillation, and total heart block.

Explain how cor pulmonale may develop.

Explain two causes of left-sided heart failure, one related to the heart and one systemic.

Describe the possible destination of an embolus from the mitral valve.

Explain the process by which a large volume of fluid in the pericardial cavity decreases cardiac output.

Answer 1

Four Factors that can increase blood pressure:

1. Cardiac output: Blood pressure increases with increased in cardiac output. Cardiac output is calculated by stroke volume multiplied by heart rate. So factors like sympathetic stimulation, thyroid hormone amd excess calcium ions can cause increased cardiac output by increasing either stroke volume or heart rate or both. Thereby blood pressure also increases

2. Peripheral vascular resistance: peripheral vascular resistance is the ability of a compartment to expand to accommodate more content. This is compliance of a blood vessel to expand according to the increased amount of blood flowing through it. Veins have more ability to expand than arteries. When vascular disease causes stiffening of arteries, due to atherosclerosis or arteriosclerosis, there will be increased resistance to blood flow. So blood pressure increases.

3. Volume of circulating blood: Volume of circulating blood is the amount of blood flowing through the body parts. When there is increased venous return,it will cause stretching of atrial wall. This will lead to increased firing of the pressure sensing baroreceptors located over the atrial wall. This will lead to sympathetic stimulation therby increased heart rate then increased blood pressure.

4. Viscosity of blood: It is the thickness of the blood due to the presence of plasma proteins and other elements in the blood. The more viscous blood shows more resistance to flow than normal blood. This resistance increases blood pressure.