Overview
This lecture covers the structure and function of the circulatory system, highlighting the role of the heart, blood vessels, and blood in transporting oxygen, nutrients, and wastes throughout the body.
Main Components of the Circulatory System
- The circulatory system consists of the heart, blood vessels (arteries, veins, capillaries), and blood.
- Its main role is to deliver oxygen and nutrients to cells and remove waste products.
- The system is also called the cardiovascular system.
The Heart: Structure and Function
- The heart is a muscular organ divided into four chambers: left atrium, right atrium, left ventricle, right ventricle.
- The left atrium receives oxygenated blood from the lungs and passes it to the left ventricle.
- The left ventricle pumps oxygen-rich blood into the aorta, the body's main artery.
- The right atrium receives deoxygenated blood from the body through the vena cava.
- The right ventricle pumps deoxygenated blood to the lungs via the pulmonary artery for oxygenation.
Heart Valves and Blood Flow
- Four major valves control blood flow: mitral, tricuspid, aortic, and pulmonary valves.
- The mitral valve prevents backflow into the left atrium.
- The tricuspid valve stops blood from flowing backward into the right atrium.
- The aortic valve separates the left ventricle from the aorta.
- The pulmonary valve is between the right ventricle and the pulmonary artery.
Major Blood Vessels
- The aorta is the largest artery, carrying blood from the heart to the body.
- The superior vena cava collects blood from the upper body, and the inferior vena cava from the lower body, both returning it to the heart.
Importance and Function
- The circulatory system sustains life by providing nutrients and oxygen to cells and removing waste products.
- It works with other body systems to transport essential materials and wastes.
Circulatory System and Disease
- Leukemia is mentioned as a cancer of the blood or blood-forming tissues.
Key Terms & Definitions
- Aorta — the largest artery in the body, distributes oxygenated blood.
- Vena Cava — largest vein returning blood to the heart.
- Oxygenated Blood — blood rich in oxygen, pumped from the lungs to the body.
- Deoxygenated Blood — blood low in oxygen, returning from the body to the lungs.
- Mitral Valve — prevents backflow into the left atrium.
- Tricuspid Valve — prevents backflow into the right atrium.
- Aortic Valve — separates left ventricle from aorta.
- Pulmonary Valve — separates right ventricle from pulmonary artery.
Action Items / Next Steps
- Review the path of blood flow through the heart and major vessels.
- Memorize the functions of the four heart valves.
- Prepare for questions on the importance of the circulatory system and its diseases.