Cardiovascular System: Anatomy & Clinical Insights
Course-Medicine(M.B.B. S/MD)
Date-12/01/2025
Introduction of cardiovascular system:
The cardiovascular system also knowns as circulatory system, is the body’s vital transport network. It
consists of the heart, blood vessels, and blood, it is responsible for transporting blood throughout
the body via a network of vessels. It delivers essential nutrients and oxygen to tissues and removes
carbon dioxide and other metabolic waste products. This system operates as a closed loop, with
blood being pumped by the heart—a muscular organ. It comprises two main pathways: the
pulmonary circuit, which handles gas exchange in the lungs, and the systemic circuit, which supplies
the rest of the body. Both circuits include arteries, capillaries, and veins.
Components of the cardiovascular system:
1.Heart
2.A closed system of vessels: Mainly of three types:
Arteries: The Arteries are responsible for carrying blood away from Heart, toward organs.
Veins: The Veins are responsible for carrying blood toward Heart, from body’s organ.
Capillaries: Capillaries are tiny vessels that branch off from arteries to deliver blood to all
body tissues.
The body has two primary circulatory pathways. The systemic circulation is the major route that
delivers blood to all the body’s organs, tissues, and cells.
In opposite, the pulmonary circulation is responsible for transporting blood between the heart
and lungs. This is where the blood picks up oxygen and expels carbon dioxide during gas
exchange.
Anatomy of Heart:
The primary function of the heart is to serve as a muscular pump propelling blood into and
through vessels to and from all parts of the body.
Structure:
1.Shape and Location:
The normal human heart is slightly larger than then a clenched fist.
Dimension of heart: 13 × 9 × 6 cm (5 × 3.5 × 2.5 inches)
Weight:300grams
Shape: Coned shaped (with the broad base directed upward and to the right and the apex pointing
downward and to the left).
, Location: Chest(thoracic) cavity behind the Sternum (Breast Bone), in front of trachea, esophagus
and descending aorta, between the lungs and above diaphragm
2.Heart Layers:
The Heart is a muscular organ made up of three main layers, each with a distinct structure and
function:
Img-1(Showing three distinct layer of heart)
1. Epicardium (Outer Layer):
Also known as the visceral layer of the serous pericardium.
Composed of mesothelial cells, connective tissue, and fat.
Protects the heart and reduces friction during contractions.
Contains blood vessels, lymphatics, and nerves that supply the heart.
� Clinical Relevance of epicardium- Endocarditis:
Endocarditis is an inflammation of the endocardium, often caused by bacterial infection.
It typically affects the heart valves, leading to the formation of vegetations (clumps of
bacteria, fibrin, and immune cells).
Symptoms include fever, heart murmurs, fatigue, and in severe cases, embolic events or
heart failure.
Risk factors: dental procedures, prosthetic valves, IV drug use, or congenital heart defects.
2. Myocardium (Middle Layer)
The thickest and most muscular layer.
Made up of cardiac muscle cells (cardiomyocytes).
Responsible for the pumping action of the heart.
Thicker in the left ventricle due to higher pressure needed to pump blood throughout the
body.
� Clinical Relevance of myocardium- Myocardial Infarction (Heart Attack):
The myocardium is the muscle layer responsible for pumping blood.
A myocardial infarction (MI) occurs when blood flow to part of the myocardium is blocked,
usually by a clot in a coronary artery.
This leads to ischemia and necrosis of cardiac muscle cells.
Symptoms: chest pain, shortness of breath, sweating, and nausea.
Course-Medicine(M.B.B. S/MD)
Date-12/01/2025
Introduction of cardiovascular system:
The cardiovascular system also knowns as circulatory system, is the body’s vital transport network. It
consists of the heart, blood vessels, and blood, it is responsible for transporting blood throughout
the body via a network of vessels. It delivers essential nutrients and oxygen to tissues and removes
carbon dioxide and other metabolic waste products. This system operates as a closed loop, with
blood being pumped by the heart—a muscular organ. It comprises two main pathways: the
pulmonary circuit, which handles gas exchange in the lungs, and the systemic circuit, which supplies
the rest of the body. Both circuits include arteries, capillaries, and veins.
Components of the cardiovascular system:
1.Heart
2.A closed system of vessels: Mainly of three types:
Arteries: The Arteries are responsible for carrying blood away from Heart, toward organs.
Veins: The Veins are responsible for carrying blood toward Heart, from body’s organ.
Capillaries: Capillaries are tiny vessels that branch off from arteries to deliver blood to all
body tissues.
The body has two primary circulatory pathways. The systemic circulation is the major route that
delivers blood to all the body’s organs, tissues, and cells.
In opposite, the pulmonary circulation is responsible for transporting blood between the heart
and lungs. This is where the blood picks up oxygen and expels carbon dioxide during gas
exchange.
Anatomy of Heart:
The primary function of the heart is to serve as a muscular pump propelling blood into and
through vessels to and from all parts of the body.
Structure:
1.Shape and Location:
The normal human heart is slightly larger than then a clenched fist.
Dimension of heart: 13 × 9 × 6 cm (5 × 3.5 × 2.5 inches)
Weight:300grams
Shape: Coned shaped (with the broad base directed upward and to the right and the apex pointing
downward and to the left).
, Location: Chest(thoracic) cavity behind the Sternum (Breast Bone), in front of trachea, esophagus
and descending aorta, between the lungs and above diaphragm
2.Heart Layers:
The Heart is a muscular organ made up of three main layers, each with a distinct structure and
function:
Img-1(Showing three distinct layer of heart)
1. Epicardium (Outer Layer):
Also known as the visceral layer of the serous pericardium.
Composed of mesothelial cells, connective tissue, and fat.
Protects the heart and reduces friction during contractions.
Contains blood vessels, lymphatics, and nerves that supply the heart.
� Clinical Relevance of epicardium- Endocarditis:
Endocarditis is an inflammation of the endocardium, often caused by bacterial infection.
It typically affects the heart valves, leading to the formation of vegetations (clumps of
bacteria, fibrin, and immune cells).
Symptoms include fever, heart murmurs, fatigue, and in severe cases, embolic events or
heart failure.
Risk factors: dental procedures, prosthetic valves, IV drug use, or congenital heart defects.
2. Myocardium (Middle Layer)
The thickest and most muscular layer.
Made up of cardiac muscle cells (cardiomyocytes).
Responsible for the pumping action of the heart.
Thicker in the left ventricle due to higher pressure needed to pump blood throughout the
body.
� Clinical Relevance of myocardium- Myocardial Infarction (Heart Attack):
The myocardium is the muscle layer responsible for pumping blood.
A myocardial infarction (MI) occurs when blood flow to part of the myocardium is blocked,
usually by a clot in a coronary artery.
This leads to ischemia and necrosis of cardiac muscle cells.
Symptoms: chest pain, shortness of breath, sweating, and nausea.
