Human Body System(Circulatory)

Austin And Jordan

Circulatory System Function

Circulatory system functions is a network of organs and vessels that is responsible for the flow of blood, nutrients, oxygen and other gases, and hormones to and from cells. Without the circulatory system, the body would not be able to fight disease or maintain a stable internal environment known as homeostasis.

Definitions in the Circulatory System

Arteries have a thick outer layer of longitudinal collagen and elastic fibers to avoid leaks and bulges. Also the narrow lumen maintains the high pressure inside the arteries.

Veins are made up of thin layers with a few circular elastic fibres and muscle fibres. Veins also have thin walls which allows the near by muscles to press against them so that they become flat. This helps the blood to be pushed forwards towards the heart.

Capillaries are made up of a wall that is only one cell layer thick and results in the distance for diffusion in and out of the capillary being very small so that diffusion can occur rapidly. They also contain pores within the their wall which allow some plasma to leak out and form tissue fluid.

Define Blood Route

Humans have two-circuit circulatory systems. one circuit is for pulmonary circulation and the other circuit is for systemic circulation. As each atrium and ventricle contract, blood is pumped into certain major blood vessels. From there continues through the circulatory system.

Define Blood Composition

Blood-consists of about 22 percent solids and 78 percent water.

Plasma-When the blood cells are suspended.

Erythrocytes-Carry oxygen from the lungs to the rest of the body.

Leukocytes-Help fight infections and aid in the immune process. Types of white blood cells.

Platelets-Help in blood clotting.

2 Disorders in the Circulatory System

Arteriosclerosis- When fatty deposits in the arteries causes the walls to stiffen and thicken the walls. The causes are too much fat, cholesterol and calcium. This can restrict blood flow or in severe cases stop it all together, resulting in a heart attack or stroke.

Hypertension- Commonly called high blood pressure. Causes the heart to work harder and can lead to such complications as a heart attack, a stroke, or kidney failure.

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