Question 1

What is the term for the stretching of vessels that were previously open but not to their full capacity?

Accepted Answer

Distention refers to the stretching or expansion of vessels that were previously open but not to their full capacity.

Question 2

What is the term for an increase in myocardial contractility?

Accepted Answer

Positive inotropism refers to an increase in the force of contraction of the heart muscle (myocardium), which enhances myocardial contractility.

Question 3

How will hypoxia affect the pulmonary capillary bed and pulmonary vascular resistance?

Accepted Answer

Hypoxia causes the pulmonary capillary bed to constrict, which in turn increases the pulmonary vascular resistance. This is a unique response of the pulmonary circulation to low oxygen levels, contrasting with systemic vessels that typically dilate in response to hypoxia to increase blood flow and oxygen delivery.

Question 4

Which of the following can occur with PPV?
I. Decreased cardiac output
II. Decreased arterial blood pressure
III. Increased pulmonary vascular resistance

Accepted Answer

Positive Pressure Ventilation (PPV) can lead to decreased cardiac output due to increased intrathoracic pressure, which reduces venous return to the heart. This can also lead to decreased arterial blood pressure for the same reason. Additionally, PPV can increase pulmonary vascular resistance by compressing pulmonary vessels.

Question 5

What effect would hypercapnia and metabolic acidemia have on the pulmonary vascular system?

Accepted Answer

Both hypercapnia (increased CO2 levels in the blood) and metabolic acidemia (decreased pH from non-respiratory causes) lead to vasoconstriction in the pulmonary vascular system. This is part of the body's mechanism to redirect blood flow to areas of the lung with better ventilation and gas exchange.

Question 6

Which of the following affect ventricular afterload?
I. Volume and viscosity of blood ejected
II. Peripheral vascular resistance
III. Cross-sectional area of vascular space into which blood is ejected

Accepted Answer

Ventricular afterload is influenced by several factors, including the peripheral vascular resistance (II), which is a major determinant, and the cross-sectional area of the vascular space into which blood is ejected (III), as both directly affect the pressure against which the heart must work to eject blood. The volume and viscosity of blood ejected (I) also play a role, as they can affect the resistance encountered by the ejected blood.

Question 7

Which of the following is derived when MAP is divided by CO?

Accepted Answer

Vascular resistance is derived when Mean Arterial Pressure (MAP) is divided by Cardiac Output (CO). This calculation is fundamental in understanding the resistance that must be overcome to push blood through the circulatory system.

Question 8

Which of the following conditions is associated with right heart failure?

Accepted Answer

Cor pulmonale is a condition specifically associated with right heart failure, typically resulting from pulmonary hypertension. It involves the enlargement and potential failure of the right ventricle of the heart as a response to increased resistance in the pulmonary circulation.

Question 9

Which pulmonary disorder results secondary to left ventricular failure?

Accepted Answer

Pulmonary edema is a condition that often results secondary to left ventricular failure. When the left ventricle fails, it cannot effectively pump blood out of the ventricle into the systemic circulation. This leads to an increase in pressure in the left atrium and subsequently in the pulmonary veins and capillaries. The increased pressure in the pulmonary capillaries forces fluid out of the capillaries and into the alveoli, leading to pulmonary edema.

Quiz 5: The Anatomy and Physiology of the Circulatory System