CIRCULATORY SYSTEM

Circulatory System

Provides the force and channels for distribution of blood which carries food and oxygen to cells and removes wastes

Circulation

“The Double Pump” Blood passes through the heart twice each time it

completes a circuit1. Right side of the heart receives deoxygenated

blood from body tissues and pumps it to the lungs2. Left side of the heart receives oxygenated blood

from the lungs and pumps it to all body tissues

Human Circulatory System

Closed system of circulation in which blood is always enclosed in tubular blood vessels

Blood does not come in direct contact with body tissue cells

Body cells must come in close contact with blood to exchange materials, therefore, blood vessels are found in almost every part of the body

Human circulatory system is made up of the blood vessels, the blood, and the heart

Blood Vessels

1. Arteries Thick walled tubes composed of elastic muscle

tissue Carries blood away from the heart Aorta – principle artery protruding from the

heart

Blood Vessels

2. Veins Thin walled tubes Carries blood back to the heart from body

tissues Vena Cava – principle vein going into the heart

Blood Vessels

3. Capillaries Fine network of tubes surrounding body tissues Composed of thin walls only one cell layer thick to

allow for diffusion of materials quickly across the membrane

Oxygen and nutrients move from the capillaries into the body cells

Carbon Dioxide and other waste products move from the body cells into the capillaries

Blood Vessel Disorders

Aneurysm Bulging blood vessel that can rupture and cause a

stroke, internal bleeding, and even death

Varicose Veins Valve failure resulting in backflow of blood Causes enlargement of superficial veins in legs or

rectum (hemorrhoids)

Varicose Veins

Blood

70 kg person has ~ 5L of blood

Blood is a “fluid” tissue (individual cells working together for a common purpose)

Blood: The Transport Medium

The importance of blood• Transport of gases (oxygen and carbon dioxide)• Transport of waste• Transport of nutrients• Fighting disease and infection• Blood clotting

Red Blood Cells

Platelets

Diseases and Disorders of the Circulatory System

Coronary Artery Disease Coronary arteries provide blood to heart muscle tissue Arteries can become partially blocked with plaque Plaque is a build-up of fat, cholesterol, calcium and

other substances that are found in blood Symptoms – tired, dizzy, pain or burning sensation in

arms or chest Angiogram is used to diagnose this disease

Diseases and Disorders of the Circulatory System

Heart Attack Arteries can become completely blocked with plaque or with a blood

clot Heart muscle cells no longer receive the oxygen and nutrients they need

to function Heart stops pumping and heart tissue starts to die Symptoms – chest pain or pressure, shortness of breath, nausea,

anxiety, sweating, dizziness Blood test and electrocardiogram (ECG) are used to diagnose a heart

attack Heart attacks are very serious and life-threatening

http://www.heartsite.com/html/cad.html

Summary of Heart Structure

Superior Vena Cava

Right Atrium

Right Ventricle

Inferior Vena Cava

Aorta

Left Atrium

Left Ventricle

Septum

PulmonaryArtery