THE CIRCULATORY SYSTEM

Also known as the cardiovascular system

Cardio means…

Vascular means…What life process does is the

circulatory system responsible for?

Introduction

The circulatory system is comprised of the heart, veins, capillaries, arteries, bloodwhich work together to supply the body tissues with nourishment and collect waste materials.

Functions of the circulatory system:

Distribute nutrients,

Transport and exchange oxygen and carbon dioxide,

Remove waste materials,

Distribute secretions of endocrine glands,

Prevent excessive bleeding,

Prevent infection, and

Regulate body temperature.

Heart

The heart is a funnel-shaped, hollow, muscular organ that is responsible for pumping blood to all parts of the body.

The heart is located near the center of the thoracic cavity between the lungs.

The cardiac muscle is an involuntary muscle.

You don’t have to think about making your heart beat!

In mammals and birds have a four chambers (right atrium, right ventricle, left atrium, and left ventricle).

Red portion of heart and red blood vessels carry oxygen-rich blood.

Blue portion of heart and blue blood vessels carry oxygen-poor blood.

Aorta

Pulmonary Veins

Inferior Vena Cava

Superior Vena Cava

Valve

Right Atrium

Right Ventricle

Left Ventricle

Pulmonary Arteries

Left Atrium

Valve

Septum

The Vascular System

The vascular system is made up of three types of blood vessels:• Arteries,

• Capillaries, and

• Veins

Photo from U. S. Federal Government courtesy of Wikipedia.

Blood Vessels

Arteries are blood vessels that carry blood, rich in oxygen, from the heart to other parts of the body.

The large arteries have thick walls of elastic-like tissue that enables them to withstand the high blood pressure created by the heart’s beating.

As the arteries extend away from the heart.

Capillaries are tiny, thin-walled blood vessels that connect arteries to veins and are located in all body tissues.

Capillaries are so small in diameter that blood cells pass through in a single file.

The semi-permeable membrane of capillary walls allows nutrients, oxygen, and water to diffuse from the blood to the tissues.

Waste products, like carbon dioxide, diffuse from the tissues into the blood.

Capillary Bed Interaction of molecules flowing in and out of blood at a

capillary bed.

The intercellular fluid is fluid between the capillaries and cells through which nutrients, gases and wastes diffuse.

Once blood passes through the capillary beds, it begins its return to the heart.

Veins are the blood vessels that return blood to the heart from all parts of the body.

Veins have valves that aid the return flow of blood and prevent the blood from reversing flow.

The valves also assist the return flow of blood to the heart when blood pressure is low.

Anatomy and Physiology of the Blood

Blood is an important component of the circulatory system.

Blood is a tissue.

Plasma, which makes up 50 – 65% of the total volume of blood, is a straw-colored liquid containing water (90%) and solids (10%).

The solids in plasma include inorganic salts and organic substances such as antibodies, hormones, vitamins, enzymes, proteins, and glucose (blood sugar).

The non-plasma, or cellular, portion of blood is composed of red blood cells, white blood cells, and platelets.

Photo from U. S. Federal Government courtesy of Wikipedia.

From left to right: Red blood cell (erythrocyte); Platelet (thrombocyte); White blood cell (leukocyte).

Red blood cells, called erythrocytes, are responsible for carrying oxygen from the lungs to various body tissues.

Red blood cells contain hemoglobin, which gives them their characteristic red color and helps them carry the oxygen.

Blood platelets, or thrombocytes, are oval-shaped discs that are formed in the bone marrow.

Blood platelets help prevent blood loss from injuries to blood vessels by forming clots.

White blood cells, or leukocytes, are divided into two general categories:

•Phagocytes -

Engulf pathogens

•Lymphocytes -

Make antibodies

Blood types are classified based on certain antigens and antibodies found on surface of red blood cells.

Universal Donor

Universal Receiver