Cardiovascular System – Comprehensive Notes on Anatomy,
Hypertension Pathophysiology, and Antihypertensive
Pharmacology | Medical School Study Guide 2025 | Complete
Exam Material
I. Anatomy and Physiology of the Cardiovascular System
The cardiovascular system, also known as the circulatory system, is a closed-loop system
responsible for transporting blood, nutrients, oxygen, hormones, and waste products
throughout the body. It consists of the heart, blood vessels (arteries, veins, capillaries), and
blood.2
A. The Heart
The heart is a muscular, four-chambered pump located in the mediastinum of the thoracic
cavity, slightly to the left of the midline.3
1. Chambers:
o Right Atrium (RA): Receives deoxygenated blood from the systemic circulation
via the superior vena cava (SVC), inferior vena cava (IVC), and coronary sinus.
o Right Ventricle (RV): Receives deoxygenated blood from the RA and pumps it to
the pulmonary artery, leading to the lungs for oxygenation.
o Left Atrium (LA): Receives oxygenated blood from the lungs via the pulmonary
veins.
o Left Ventricle (LV): Receives oxygenated blood from the LA and pumps it to the
aorta, distributing it to the entire systemic circulation. The LV has the thickest
muscular wall due to the high pressure required to perfuse the entire body.
2. Valves: Prevent the backflow of blood, ensuring unidirectional flow.
o Atrioventricular (AV) Valves: Located between atria and ventricles.
Tricuspid Valve: Between RA and RV (three cusps).
Mitral (Bicuspid) Valve: Between LA and LV (two cusps).
o Semilunar Valves: Located at the exit of the ventricles into the great arteries.
, Pulmonary Valve: Between RV and pulmonary artery.
Aortic Valve: Between LV and aorta.
3. Blood Vessels:
o Arteries: Carry oxygenated blood away from the heart (except pulmonary
arteries). They have thick, muscular, elastic walls to withstand high pressure.
Aorta: Largest artery, originating from the left ventricle.
Arterioles: Small arteries that control blood flow to capillaries and are
major sites of peripheral resistance.
o Capillaries: Microscopic, thin-walled vessels (single cell thick) where exchange of
gases, nutrients, and waste products occurs between blood and tissues.
o Veins: Carry deoxygenated blood back to the heart (except pulmonary veins).
They have thinner walls and larger lumens than arteries and contain valves to
prevent backflow, especially in the limbs.
Venules: Small veins that collect blood from capillaries.
Vena Cavae (Superior and Inferior): Largest veins, returning blood to the
right atrium.
4. Circulation Loops:
o Pulmonary Circulation: Deoxygenated blood from RV → pulmonary artery
→lungs (gas exchange) → pulmonary veins → LA (oxygenated blood).
o Systemic Circulation: Oxygenated blood from LV → aorta → systemic arteries →
capillaries (tissue exchange) → systemic veins → RA (deoxygenated blood).
o Coronary Circulation: A dedicated system of arteries (coronary arteries
originating from the aorta) and veins that supply blood to the heart muscle itself.
5. Electrical Conduction System: Generates and transmits electrical impulses, coordinating
heart contractions
o Sinoatrial (SA) Node: "Natural pacemaker," initiates electrical impulses.
o Atrioventricular (AV) Node: Delays impulse, allowing atrial contraction to
complete before ventricular contraction.
o Bundle of His, Bundle Branches, Purkinje Fibers: Transmit impulses rapidly
throughout the ventricles.
Hypertension Pathophysiology, and Antihypertensive
Pharmacology | Medical School Study Guide 2025 | Complete
Exam Material
I. Anatomy and Physiology of the Cardiovascular System
The cardiovascular system, also known as the circulatory system, is a closed-loop system
responsible for transporting blood, nutrients, oxygen, hormones, and waste products
throughout the body. It consists of the heart, blood vessels (arteries, veins, capillaries), and
blood.2
A. The Heart
The heart is a muscular, four-chambered pump located in the mediastinum of the thoracic
cavity, slightly to the left of the midline.3
1. Chambers:
o Right Atrium (RA): Receives deoxygenated blood from the systemic circulation
via the superior vena cava (SVC), inferior vena cava (IVC), and coronary sinus.
o Right Ventricle (RV): Receives deoxygenated blood from the RA and pumps it to
the pulmonary artery, leading to the lungs for oxygenation.
o Left Atrium (LA): Receives oxygenated blood from the lungs via the pulmonary
veins.
o Left Ventricle (LV): Receives oxygenated blood from the LA and pumps it to the
aorta, distributing it to the entire systemic circulation. The LV has the thickest
muscular wall due to the high pressure required to perfuse the entire body.
2. Valves: Prevent the backflow of blood, ensuring unidirectional flow.
o Atrioventricular (AV) Valves: Located between atria and ventricles.
Tricuspid Valve: Between RA and RV (three cusps).
Mitral (Bicuspid) Valve: Between LA and LV (two cusps).
o Semilunar Valves: Located at the exit of the ventricles into the great arteries.
, Pulmonary Valve: Between RV and pulmonary artery.
Aortic Valve: Between LV and aorta.
3. Blood Vessels:
o Arteries: Carry oxygenated blood away from the heart (except pulmonary
arteries). They have thick, muscular, elastic walls to withstand high pressure.
Aorta: Largest artery, originating from the left ventricle.
Arterioles: Small arteries that control blood flow to capillaries and are
major sites of peripheral resistance.
o Capillaries: Microscopic, thin-walled vessels (single cell thick) where exchange of
gases, nutrients, and waste products occurs between blood and tissues.
o Veins: Carry deoxygenated blood back to the heart (except pulmonary veins).
They have thinner walls and larger lumens than arteries and contain valves to
prevent backflow, especially in the limbs.
Venules: Small veins that collect blood from capillaries.
Vena Cavae (Superior and Inferior): Largest veins, returning blood to the
right atrium.
4. Circulation Loops:
o Pulmonary Circulation: Deoxygenated blood from RV → pulmonary artery
→lungs (gas exchange) → pulmonary veins → LA (oxygenated blood).
o Systemic Circulation: Oxygenated blood from LV → aorta → systemic arteries →
capillaries (tissue exchange) → systemic veins → RA (deoxygenated blood).
o Coronary Circulation: A dedicated system of arteries (coronary arteries
originating from the aorta) and veins that supply blood to the heart muscle itself.
5. Electrical Conduction System: Generates and transmits electrical impulses, coordinating
heart contractions
o Sinoatrial (SA) Node: "Natural pacemaker," initiates electrical impulses.
o Atrioventricular (AV) Node: Delays impulse, allowing atrial contraction to
complete before ventricular contraction.
o Bundle of His, Bundle Branches, Purkinje Fibers: Transmit impulses rapidly
throughout the ventricles.
