Page 154 - 84 human physiolofy part-1

Chapter 8

cyanotic heart defects deoxygenated blood from the right ventricle flows into the systemic circulation.
Cyanotic defects include tetrogy of fallot and transposition of the great arteries.

Homeostasis

Homeostasis in the body is only possible if the cardiovascular system is working properly. This
means that the system needs to deliver oxygen and nutrients to the tissue fluid that surrounds the cells
and also take away the metabolic waste. The heart is composed of arteries that take blood from the
heart, and vessels that return blood to the heart. Blood is pumped by the heart into two circuits: the
pulmonary and systemic circuits. The pulmonary circuit carries blood through the lungs where gas
exchange occurs and the systemic system transports blood to all parts of the body where exchange with
tissue fluid takes place. The cardiovascular system works together with all other systems to maintain
homeostasis.

The Lymphatic System

The lymphatic system is closely related to the cardiovascular system. There are three main ways
that they work together to maintain homeostasis: the lymphatic system receives the excess tissue fluid
and returns it to the bloodstream, lacteals take fat molecules from the intestinal villi and transport them
to the bloodstream and both systems work together to defend the body against disease.

Interesting Facts

• Heart Disease is the number one killer in American women.
• 16.7 million deaths are result forms of cardiovascular disease, heart disease and stroke.
• Stress, birth control pills and alcohol are just some risk factors of developing heart disease.
• Recent research suggests that taking a small dose of aspirin daily may help prevent a heart attack
(because aspirin inhibits platelet clumping).
• The length of all your blood vessels lined up is about 60,000 miles long! Farther than the distance
between California and Asia which is about 13,000 miles! blah

Ways To A Healthy Heart

• Eating healthy, good nutrition
• Fitness and Exercise
• Having a healthy lifestyle, don't smoke
• Watch cholesterol and blood pressure
• Reduce the fat, sodium, and calories in your diet.
• The total length of capillaries in an average adult human is approximately 25,000 mi (42,000
km).

Aging

The heart muscle becomes less efficient with age, and there is a decrease in both maximum cardiac
output and heart rate, although resting levels may be more than adequate. The health of the

154 | Human Physiology