Essay On Human Heart

ANATOMY AND PHYSIOLOGY

SECTION A

Explain the function of the heart, and the structure of arteries, veins and Capillaries

As per the Cardiologist, Dr. Laurence Phillips, The human heart is an organ that pumps blood throughout the body via the circulatory system, it supplies oxygen and nutrients to the various parts of the body and removes waste and carbon dioxide. The tissues and organs of the body need a constant supply of nutrients in order to be active and healthy. If the heart is not able to supply blood to the organs and tissues they will die.

There are 3 main kinds of blood vessels – arteries, veins and capillaries.

• Arteries carry bright red oxygenated blood away from the heart at high pressure. They divide again and again,

The structure of the walls of veins are very thin. They contain mainly fibrous tissues and have far less muscles and elastic tissue than arteries. The lumen passage is large; the veins are pumped by the skeletal muscle. The valve in the veins prevents back flow of blood (Biology notes for IGCSE). (L. Tucker 2015).

Explain the Cardiac cycle

• The heartbeat, or cardiac cycle is the muscular contractions of the heart wall.

• Both the right and left Atrium contract, forcing the contents down into the ventricles.

• The Atria relaxes, but the ventricles contract and empty their contents in the arteries

• The ventricles relax and the heart is at rest.

• While resting the heart dilates and fills with blood. (L. Tucker 2015).

The Biologist Louise Tucker explains the pulmonary circulation as follows:

It is the circulation of blood from the heart to the lungs and back. Deoxygenated blood travels from the heart to the lungs in the pulmonary artery. The blood gets rid of carbon dioxide and replaces it with oxygen. It then returns to the heart via the pulmonary veins (lungs to heart) and is ready to be pumped around the

Describe the conditions high and low blood pressure.

Blood pressure is a measure of the force exerted on your arteries by your heart as it pumps blood around your body. Everyone’s blood pressure goes up and down during the day. Physical activity, stress and excitement can all raise our blood pressure temporarily – this is quite normal. But permanently high blood pressure can have an impact on the health of your heart and is linked with raised cholesterol levels (Flora Pro Activ, 2016).

According to the U.S .National Library of Medicine, the circulatory system is a vast network of organs and vessels that is responsible for the flow of blood, nutrients, hormones, oxygen and other gases to and from cells. Without the circulatory system, the body would not be able to fight disease .or maintain a stable internal environment, such as body temperature.

The NLM also states that the circulatory system, (also known as cardiovascular system), which allows the flow of blood through the body, is made up of three independent systems that work together: the heart (cardiovascular); lungs (pulmonary); and arteries, veins, coronary