Circulatory System Notes
Overview
The circulatory system, also known as the cardiovascular system, is responsible for
transporting blood, nutrients, oxygen, carbon dioxide, hormones, and other substances
throughout the body. It consists of the heart, blood vessels, and blood.
Components
1. Heart
○ Structure: A muscular organ divided into four chambers: two atria (upper
chambers) and two ventricles (lower chambers).
○ Function: Pumps blood through the body. The right side pumps
deoxygenated blood to the lungs (pulmonary circulation), and the left side
pumps oxygenated blood to the rest of the body (systemic circulation).
2. Blood Vessels
○ Arteries: Carry oxygenated blood away from the heart. The largest artery
is the aorta.
○ Veins: Carry deoxygenated blood back to the heart. Major veins include
the superior and inferior vena cava.
○ Capillaries: Tiny blood vessels where exchange of gases, nutrients, and
waste occurs between blood and tissues.
3. Blood
○ Components:
■ Red Blood Cells (Erythrocytes): Carry oxygen from the lungs to the
body and bring carbon dioxide back to the lungs.
■ White Blood Cells (Leukocytes): Part of the immune system, they
help fight infections.
■ Platelets (Thrombocytes): Assist in blood clotting to prevent
bleeding.
■ Plasma: The liquid part of blood, composed mostly of water, along
with proteins, electrolytes, and other substances.
Functions
Overview
The circulatory system, also known as the cardiovascular system, is responsible for
transporting blood, nutrients, oxygen, carbon dioxide, hormones, and other substances
throughout the body. It consists of the heart, blood vessels, and blood.
Components
1. Heart
○ Structure: A muscular organ divided into four chambers: two atria (upper
chambers) and two ventricles (lower chambers).
○ Function: Pumps blood through the body. The right side pumps
deoxygenated blood to the lungs (pulmonary circulation), and the left side
pumps oxygenated blood to the rest of the body (systemic circulation).
2. Blood Vessels
○ Arteries: Carry oxygenated blood away from the heart. The largest artery
is the aorta.
○ Veins: Carry deoxygenated blood back to the heart. Major veins include
the superior and inferior vena cava.
○ Capillaries: Tiny blood vessels where exchange of gases, nutrients, and
waste occurs between blood and tissues.
3. Blood
○ Components:
■ Red Blood Cells (Erythrocytes): Carry oxygen from the lungs to the
body and bring carbon dioxide back to the lungs.
■ White Blood Cells (Leukocytes): Part of the immune system, they
help fight infections.
■ Platelets (Thrombocytes): Assist in blood clotting to prevent
bleeding.
■ Plasma: The liquid part of blood, composed mostly of water, along
with proteins, electrolytes, and other substances.
Functions
