The Cardiovascular System

Overview

The cardiovascular system, also known as the circulatory system, is a network of organs and vessels that transport blood throughout the body.

Functions

• Transports oxygen and nutrients from the lungs and digestive system to the body's tissues • Removes waste products, such as carbon dioxide, from the body's tissues • Regulates body temperature • Maintains blood pressure

Components

Heart

• Muscular organ that pumps blood throughout the body • Divided into four chambers: left and right atria, and left and right ventricles

Blood Vessels

• Arteries: carry oxygenated blood away from the heart • Veins: carry deoxygenated blood back to the heart • Capillaries: allow for exchange of oxygen and nutrients with the body's tissues

Blood

• Liquid tissue that transports oxygen, nutrients, and waste products • Composed of plasma, red blood cells, white blood cells, and platelets

Blood Circulation

Pulmonary Circulation

• Deoxygenated blood from the body enters the right atrium • Blood is pumped to the lungs, where it picks up oxygen and releases carbon dioxide • Oxygen-rich blood returns to the left atrium

Systemic Circulation

• Oxygen-rich blood from the lungs enters the left ventricle • Blood is pumped to the body's tissues, where it delivers oxygen and nutrients • Deoxygenated blood returns to the right atrium

Regulation

• Autonomic nervous system: regulates heart rate and blood pressure • Baroreceptors: sense changes in blood pressure and signal the brain to make adjustments

Disorders

• Atherosclerosis: buildup of plaque in the arteries, leading to heart disease and stroke • Hypertension: high blood pressure • Heart failure: inability of the heart to pump enough blood to meet the body's needs

Cardiovascular System

• Network of organs and vessels that transport blood throughout the body

Functions

• Transports oxygen and nutrients from lungs and digestive system to body's tissues
• Removes waste products, such as carbon dioxide, from body's tissues
• Regulates body temperature
• Maintains blood pressure

Components

Heart

• Muscular organ that pumps blood throughout the body
• Divided into four chambers: left and right atria, and left and right ventricles

Blood Vessels

• Arteries: carry oxygenated blood away from the heart
• Veins: carry deoxygenated blood back to the heart
• Capillaries: allow for exchange of oxygen and nutrients with body's tissues

Blood

• Liquid tissue that transports oxygen, nutrients, and waste products
• Composed of plasma, red blood cells, white blood cells, and platelets

Blood Circulation

Pulmonary Circulation

• Deoxygenated blood from body enters right atrium
• Blood is pumped to lungs, where it picks up oxygen and releases carbon dioxide
• Oxygen-rich blood returns to left atrium

Systemic Circulation

• Oxygen-rich blood from lungs enters left ventricle
• Blood is pumped to body's tissues, where it delivers oxygen and nutrients
• Deoxygenated blood returns to right atrium

Regulation

• Autonomic nervous system: regulates heart rate and blood pressure
• Baroreceptors: sense changes in blood pressure and signal brain to make adjustments

Disorders

• Atherosclerosis: buildup of plaque in arteries, leading to heart disease and stroke
• Hypertension: high blood pressure
• Heart failure: inability of heart to pump enough blood to meet body's needs

Heart Anatomy

• Located in the thoracic cavity, between the lungs, in the mediastinum
• Weighs approximately 250-300 grams in adults
• About the size of a fist

Layers of the Heart Wall

• Epicardium: outermost layer, a thin layer of connective tissue
• Myocardium: middle layer, thick layer of cardiac muscle
• Endocardium: innermost layer, thin layer of epithelial tissue

Chambers of the Heart

• Right Atrium: upper chamber that receives deoxygenated blood from the body
• Right Ventricle: lower chamber that pumps blood from the right atrium to the lungs
• Left Atrium: upper chamber that receives oxygenated blood from the lungs
• Left Ventricle: lower chamber that pumps blood from the left atrium to the rest of the body

Valves of the Heart

• Tricuspid Valve: between the right atrium and ventricle, allows blood to flow from atrium to ventricle
• Pulmonary Valve: between the right ventricle and pulmonary artery, allows blood to flow from ventricle to lungs
• Mitral Valve: between the left atrium and ventricle, allows blood to flow from atrium to ventricle
• Aortic Valve: between the left ventricle and aorta, allows blood to flow from ventricle to the rest of the body

Blood Flow Through the Heart

• Deoxygenated blood enters the right atrium
• Blood flows through the tricuspid valve into the right ventricle
• Blood is pumped through the pulmonary valve into the pulmonary artery and to the lungs
• Oxygenated blood returns to the left atrium
• Blood flows through the mitral valve into the left ventricle
• Blood is pumped through the aortic valve into the aorta and to the rest of the body