Advanced Exercise Physiology – Cardiovascular Physiology (Lecture 1)

Flashcards cover course policies, cardiovascular anatomy, physiology, blood flow, cardiac cycle, vessel characteristics, blood components, and clinical concepts introduced in Lecture 1.

What are the three main components of the cardiovascular system?

The heart, the vasculature (arteries, veins, capillaries), and the blood.

Which chambers of the heart are the receiving chambers?

The right and left atria.

Which chambers of the heart are the pumping chambers?

The right and left ventricles.

List the order of blood flow through the heart starting with the superior/inferior vena cava.

Superior/Inferior vena cava → Right atrium → Tricuspid valve → Right ventricle → Pulmonary semilunar valve → Pulmonary artery → Lungs → Pulmonary veins → Left atrium → Mitral (bicuspid) valve → Left ventricle → Aortic semilunar valve → Aorta → Systemic circulation.

Which side of the heart handles pulmonary circulation and what type of blood does it pump?

The right side; it pumps de-oxygenated blood to the lungs.

Which side of the heart handles systemic circulation and what type of blood does it pump?

The left side; it pumps oxygenated blood to the entire body.

Why is the left ventricular wall thicker than the right?

It must generate higher pressure to pump blood throughout the systemic circulation.

Name the atrioventricular (AV) valves.

Right side: Tricuspid valve; Left side: Mitral (bicuspid) valve.

Name the semilunar valves.

Pulmonary semilunar valve and aortic semilunar valve.

What is the primary function of heart valves?

To ensure one-way blood flow and prevent backflow between chambers/vessels.

Define cardiac output (CO) and give its formula.

The volume of blood ejected by a ventricle in one minute; CO = Heart Rate (HR) × Stroke Volume (SV).

What is the average resting cardiac output for a healthy adult?

Approximately 5 L min⁻¹.

During maximal exercise, how much can cardiac output increase in an average person?

It can rise to about 20–25 L min⁻¹.

Which variable (HR or SV) accounts for most of the cardiac output increase in endurance-trained athletes?

Stroke Volume (SV) increases markedly in trained athletes.

Describe the Windkessel effect.

Elastic recoil of large arteries maintains continuous blood flow and prevents large drops in arterial pressure during diastole.

Which vessels possess the most smooth muscle and therefore control vasoconstriction/vasodilation?

Muscular arteries and especially arterioles.

Explain the difference between arterial and venous pressure.

Arterial pressure is high and pulsatile (e.g., 120/80 mm Hg), whereas venous pressure is low (often < 30 mm Hg) because blood is far from the pump.

Why do veins contain one-way valves?

To prevent backflow and aid return of low-pressure blood to the heart.

What two ‘pumps’ assist venous return during exercise?

The skeletal-muscle pump and the respiratory (thoracic) pump.

What percentage of total blood flow does the heart muscle itself receive at rest?

About 4 % of resting cardiac output and ~10 % of resting oxygen consumption.

Name the vessels that supply oxygenated blood to the myocardium.

The coronary arteries.

Define systole and diastole.

Systole: period of ventricular contraction and ejection; Diastole: period of ventricular relaxation and filling.

What is an isovolumetric contraction phase?

Early systole when ventricles contract with all valves closed, causing pressure to rise with no change in volume.

What is an isovolumetric relaxation phase?

Early diastole when ventricles relax with all valves closed, causing pressure to fall with no change in volume.

During which phase does the mitral valve open, and why?

It opens when ventricular pressure falls below atrial pressure, allowing rapid inflow of blood.

What triggers closure of the aortic semilunar valve?

When ventricular pressure drops below aortic pressure at the end of systole.

Approximately how long is one cardiac cycle at a heart rate of 75 bpm?

About 0.8 seconds.

Which blood component carries oxygen, and what molecule enables this?

Red blood cells (erythrocytes) via hemoglobin.

What is the role of leukocytes?

White blood cells defend the body against infection and help with inflammation control.

What is the function of thrombocytes (platelets)?

To aid blood clotting and contribute to plaque formation in atherosclerosis.

How does dehydration affect blood viscosity and blood pressure?

Dehydration decreases plasma volume, thickens (increases viscosity of) blood, increases resistance, and can raise blood pressure.

Differentiate elastic (conducting) arteries from muscular (distributing) arteries.

Elastic arteries (e.g., aorta) have more elastic tissue and dampen pulsatile flow; muscular arteries have more smooth muscle and regulate blood distribution via vasomotion.

Why is blood velocity lowest in the capillaries?

Because the total cross-sectional area is largest, allowing time for nutrient and gas exchange.

Explain the relationship between vessel diameter and resistance.

Resistance is inversely proportional to the fourth power of radius; small decreases in diameter greatly increase resistance (Poiseuille’s law).

What is meant by ‘central’ versus ‘peripheral’ blood pressure?

Central BP refers to pressure in the aorta near the heart; peripheral BP is measured in distant arteries (e.g., brachial) and is usually higher.

Give two reasons high arterial blood pressure is dangerous for micro-vasculature.

It can damage delicate capillaries in organs like the brain, heart, and kidneys, leading to aneurysm or stroke, and accelerates atherosclerosis.

During exercise, how does the sympathetic nervous system affect blood vessels supplying active muscles?

It causes vasodilation in active skeletal muscle arterioles (often via local metabolic factors) and vasoconstriction in non-essential regions.

Which textbook was highly recommended by the instructor for ECG learning?

ECG Workout by Jane Huff.

According to course policy, are quizzes in lecture eligible for make-up?

No; missed quizzes receive a zero with no make-up exceptions.

What is the primary determinant of maximal heart rate?

Age.

Why is the atrial contraction (‘a-wave’) important during ventricular filling?

It provides the final ~10 % of ventricular filling volume before systole.