II. Cardiovascular System
The cardiovascular system, also known as the circulatory system, is responsible for pumping
and circulating blood throughout the body, delivering oxygen, nutrients, and hormones to cells,
and removing waste products.
A. Anatomy of the Heart
● The heart is a hollow, muscular organ located in the thoracic cavity, slightly left of the
midline.
● It has four chambers: two atria and two ventricles, separated by valves that ensure
one-way flow of blood.
The walls of the left ventricle are thicker than those of the right ventricle, as the left ventricle
pumps blood to the systemic circulation, while the right ventricle pumps blood to the pulmonary
circulation.
The heart is supplied by its own blood vessels, known as coronary arteries, which provide
oxygen and nutrients to the heart muscle.
B. Blood Vessels
Blood vessels are tubes that transport blood throughout the body.
Arteries are thick-walled vessels that carry oxygenated blood away from the heart to the rest of
the body. They branch into smaller arterioles, which regulate blood flow to tissues and organs.
Veins are thinner-walled vessels that carry deoxygenated blood back to the heart. They merge
into larger veins, and ultimately into the superior and inferior vena cavae, which return blood to
the heart.
Capillaries are the smallest blood vessels, with thin walls that allow for the exchange of oxygen,
nutrients, and waste products between blood and tissues.
C. Blood
Blood is a connective tissue composed of cells (such as red blood cells, white blood cells, and
platelets) suspended in a liquid matrix called plasma.
The cardiovascular system, also known as the circulatory system, is responsible for pumping
and circulating blood throughout the body, delivering oxygen, nutrients, and hormones to cells,
and removing waste products.
A. Anatomy of the Heart
● The heart is a hollow, muscular organ located in the thoracic cavity, slightly left of the
midline.
● It has four chambers: two atria and two ventricles, separated by valves that ensure
one-way flow of blood.
The walls of the left ventricle are thicker than those of the right ventricle, as the left ventricle
pumps blood to the systemic circulation, while the right ventricle pumps blood to the pulmonary
circulation.
The heart is supplied by its own blood vessels, known as coronary arteries, which provide
oxygen and nutrients to the heart muscle.
B. Blood Vessels
Blood vessels are tubes that transport blood throughout the body.
Arteries are thick-walled vessels that carry oxygenated blood away from the heart to the rest of
the body. They branch into smaller arterioles, which regulate blood flow to tissues and organs.
Veins are thinner-walled vessels that carry deoxygenated blood back to the heart. They merge
into larger veins, and ultimately into the superior and inferior vena cavae, which return blood to
the heart.
Capillaries are the smallest blood vessels, with thin walls that allow for the exchange of oxygen,
nutrients, and waste products between blood and tissues.
C. Blood
Blood is a connective tissue composed of cells (such as red blood cells, white blood cells, and
platelets) suspended in a liquid matrix called plasma.
