Circulatory and Respiratory Systems

In a month, a fingernail grows an eighth of an inch. HEALTH TIP OF THE DAY In a month, a fingernail grows an eighth of an inch.

The cardiovascular system moves blood through the body.

Physical Benefits

How the Blood Circulates The cardiovascular system consists of the heart, blood, and blood vessels. Your heart is the muscle that makes the cardiovascular system work.

Blood Vessels The Three Main Types of Blood Vessels Arteries Capillaries Veins

Blood Vessels Arteries are vessels that branch into progressively smaller vessels called arterioles, which deliver blood to capillaries. Arteries Blood vessels that carry oxygenated blood away from the heart

Blood Vessels Capillaries reach almost all body cells. Capillaries near the skin’s surface can dilate or constrict to adjust body temperature. Capillaries Small vessels that carry blood from arterioles and to small vessels called venules, which empty into veins

Blood Vessels The large veins, the vena cava, carry deoxygenated blood to the right atrium. Pulmonary veins carry oxygenated blood to the left atrium. Veins Blood vessels that return blood to the heart

Blood Components of Blood Red Blood Cells White Blood Cells Plasma Platelets

Blood About 55 percent of total blood volume consists of plasma, which is mainly water, but it also contains nutrients, proteins, salts, and hormones. Plasma The fluid in which other parts of the blood are suspended

Blood Red blood cells make up about 40 percent of normal blood. They contain hemoglobin. Hemoglobin The oxygen-carrying protein in blood

Blood White blood cells have one of three purposes: Surrounding and ingesting the organisms that cause disease White blood cells have one of three purposes: Forming antibodies that provide immunity against a second attack from that specific disease Fighting allergic reactions

Blood When the wall of a blood vessel tears, platelets collect at the tear and form a clot that blocks the flow of blood. Platelets Types of cells in the blood that cause blood clots to form

The Heart Inside the heart are four chambers separated by a wall of tissue called the septum. The two top chambers are called the atria. The two lower chambers are called ventricles.

The Heart

Circulatory System Problems Heart Disease High Blood Pressure

Cardiovascular System Problems Congenital heart defects Conditions of the heart that are present at birth. Abnormal sounds that are made as blood flows through the heart. Heart murmurs Formed as result of the valves in veins not closing tightly enough to prevent backflow of blood. Varicose veins A condition in which the ability of the blood to carry oxygen is reduced. Anemia An inherited disorder. The blood does not clot properly. Hemophilia A form of cancer in which any one of the different types of white blood cells is produced excessively and abnormally. Leukemia

The respiratory system provides oxygen to the blood and removes carbon dioxide from the body.

How Respiration Works The respiratory system consists of the lungs, trachea, and diaphragm. Your lungs automatically fill with air and are emptied in a rhythmic way.

Five Major Organs Trachea—windpipe Diaphragm—muscle that separates chest from abdomen Bronchi—airways that connect to the lungs Right lung Left lung

Problems of the Respiratory System Asthma Tuberculosis Bronchitis Emphysema Pneumonia