HUMAN BLOOD CIRCULATION SYSTEM

STRUCTURE OF THE HUMAN BLOOD CIRCULATION TOOL

Circulatory system in humans is composed of the heart as the center of circulation, blood vessels and blood itself.

1. Heart
   
   

The heart has four chambers that are divided perfectly the two porch (atrium) and the two chambers (ventricles) and is located in the left chest cavity above the diaphragm. Heart wrapped in sack pericardium consisting of two pieces:
a. panistalis lamina in the outer
b. visceral lamina attached to the wall of the heart

The heart has atrioventikuler valve (valvula bikuspidal) found on the porch and chambers that serve to prevent the flow from the chamber into the foyer during systole and semilunaris valves (aortic and pulmonary valve) which function to prevent backflow from the aorta and left pulmonary artery into the chamber during diastole .

2. Blood vessel

Blood vessels consist of arteries and veins. Artery directly related to the venous capillaries and venules in sections that are connected by the endotheliumnya.
Arteries and veins are located side by side. Arterial walls are thicker than the walls of the vein. The walls of arteries and veins have three layers of the inner layer consisting of endothelium, the middle layer composed of smooth muscle with elastic fibers and the outermost layer consists of connective tissue coupled with elastic fibers. Smallest branches of arteries and veins are called capillaries. Capillaries have a diameter which is very small and has only one single layer of endothelium and a basal membrane.
Differences of each structure of blood vessels associated with differences in their respective functional vasculature.

KINDS OF BLOOD VESSELS
Blood vessels are divided into:

A. The arteries

1. Place the blood flow that is pumped from the chamber
2. Vessel which is tough and elastic
3. Pressure vessels are stronger than the veins
4. Have a valve (valvula semilunaris) which is right outside the heart
5. Consisting of:

5.1 of vessels from the aorta into the left ventricle through the body
5.2 is branching arteries arterioles
5.3 Capillaries:
a. Smaller diameter than the arteries and veins
b. The walls consist of a single layer of endothelium and a membrane basalt

6. The walls consist of three layers namely:
   6.1 inner layer consisting of endothelium
   6.2 The middle layer consists of smooth muscle with elastic fibers
   6.3 The outermost layer is composed of elastic connective tissue fibers
   
   

B. Turn vessels (veins)

1. Situated near the surface of the skin so easily recognizable
2. Vessel wall is thinner and not elastic.
3. Pressure vessels are weaker in comparison arteries
4. There is a valve that is shaped like a crescent moon (semi lunaris valvula) and keep the blood does not reverse direction.

5. Consists of:

5.1.Superior vena cava in charge of carrying blood from the upper body toward right atrium of the heart.

5.2.The inferior vena cava in charge of carrying blood from the lower body to right atrium of the heart.

5.3.Vena cava in charge of bringing the pulmonary blood from the lungs into the left porch the heart.

KIND OF BLOOD CIRCULATION
Human blood circulation is a closed blood circulation because the blood that flowed from and to the entire body through blood vessels and blood flow through the heart as much as two times the so-called dual circulation consisting of:

1. Circulatory long / large / systemic

Is a circulatory flow of oxygen-rich blood from the chamber (ventricle) into the left heart and then circulated throughout the body tissues. Oxygen exchange with carbon dioxide in body tissues. Then the carbon dioxide-rich blood is carried through the veins into the right atrium (atria) of the heart.

2. Circulatory short / small / pulmonary

Is the blood circulation that drains blood from the heart to the lungs and back to the heart. Carbon dioxide-rich blood flows from the right ventricle to the lungs via the pulmonary artery, the pulmonary alveoli are exchanging blood with oxygen-rich blood which would then be channeled into the porch left the heart via the pulmonary veins.
The process of blood circulation is affected also by the speed of the blood, cross-sectional area of ​​blood vessels, blood pressure and muscle work contained on the heart and blood vessels.

In the capillaries there is spingter prakapiler regulate blood flow to the capillaries:

1. When spingter prakapiler relaxes the capillaries that branched from the main blood vessels open and blood flowing into the capillary.

2. When spingter prakapiler contract, will be closed and the capillary blood flow through the capillaries will be reduced.

In the vein when the muscles contract the vein will be squeezed and flaps that are on the network will act as a one-way valves that keep blood flowing to the heart only.

BLOOD CIRCULATION SYSTEM DISORDERS

Abnormalities or diseases of the circulatory system include:

1. Arteriosclerosis is hardening of the arteries due to fatty deposits form plaque (scale) of fibrous connective tissue and smooth muscle cells in infiltration by lipids (fats) formation of fatty deposits in arteries
2. Anemia is a low level of hemoglobin in the blood or a reduced number of erythrocytes in the blood
3. Varicose veins are blood vessel dilation in the calf
4. Hemeroid (pile) dilation of blood vessels around the anus
5. Ambolus namely blockage of blood vessels due to a moving object.
6. Thrombus that blocked blood vessel that does not move objects.
7. Hemofili is a blood disorder that causes blood to clot difficult (derived by heredity)
8. Leukemia (blood cancer) is increasing in an uncontrolled number of erythrocytes.
9. Erithroblastosis fetalis namely the destruction of erythrocytes baby / fetus due to agglutination of antibodies derived from the mother.
10. Thalassemia is anemia caused by the breakdown of hemoglobin-forming genes that are declining.
11. Hypertension is high blood pressure due to arteriosclerosis