circulatory system

A.    Blood

Have you ever seen people who are doing donor

Blood? Or you yourself have ever done? Blood donors are

the process of taking blood from the body to a certain amount for

transferred to the body of another person with the same blood type.

Blood is one of the components of the circulatory system (circulatory

blood) is very important. Blood and circulatory system have

function as follows.

1. Circulating nutrients (nutrients) of the digestive system

food to all body cells

2. Transport oxygen from the lungs to cells throughout the body, and

transport of carbon dioxide from the body cells to the lungs

3. Transport of metabolic waste from the body cells to the organs of excretion

(expenses)

4. Transport of hormones from endocrine glands to cells or tissues

target

5. Helps the body's fluid balance

6. Help in regulating body temperature

1. Composition of Blood

You must have seen the blood. Did you know the composition of blood

The? The composition of the blood can be obtained by rotating the blood

in a tube at high speed. Blood screening process

is called centrifugation. From the results of centrifugation, the blood will

separated into two parts, namely a solid bottom and parts

the liquid. The liquid at the top is a blood plasma (55%),

while the bottom there is blood cells (45%).

a. Blood plasma

Blood plasma fills about 55% of the total blood volume. wrong

the function of blood plasma that regulate blood osmotic balance

in the body. In humans, blood plasma is composed of water (90%) and

soluble materials (10%). Here is the composition of blood plasma and its

function.

b. Blood Cells

There are about 45% of the blood cells in the blood. Blood cells

composed of red blood cells (erythrocytes), white blood cells (leukocytes),

and platelets (thrombocytes). To better understand the composition of the cells to

blood in the human body

1) Red blood cells

Red blood cells (erythrocytes) carry or circulate function

oxygen and carbon dioxide. The ability of the oxygen and carbon

dioxide by red blood cells is due to hemoglobin.

Hemoglobin is a protein that has a strong holding capacity

O2 and CO2.

2) The white blood cells

White blood cells (leukocytes) function in immune defense and

body. Leukocytes will defend the body against disease.

This function is supported by the ability of leukocytes to move

amoeboid (such as Amoeba) and the nature of phagocytosis (prey or

consuming).

Based on the presence or absence of granules in the cytoplasm,

leukocytes are divided into leukocytes not bergranula (agranulosit) and

bergranula leukocytes (granulocytes).

a) Agranulosit

Agranulosit are leukocytes without granules in

cytoplasm. There are two types of agranulosit, ie lymphocytes and monocytes.

Lymphocytes are leukocytes that can not move and have one

the cell nucleus. Lymphocyte function in the form of antibodies. Lymphocyte-sized

between 8-14 μm. Monocytes are larger than lymphocytes, which

14-19 μm. Monocytes have a heart shaped like a kidney.

b) Granulocytes

Granulocytes are leukocytes that have granules in

cytoplasm. Based on the properties of its granules, granulocytes

divided into three, namely neutrophils, basophils, eosinophils

3) Platelet

Platelets are also called thrombocytes. Platelets form

round, oval, even irregularly shaped. Platelets are not

has a core and smaller than erythrocytes.

The number of platelets in each millimeter around 250000-400000

cubic blood. Platelets can live for eight days. Platelets

function in the process of blood clotting. Regarding the role of platelets

in the clotting of blood, the matter will be discussed further.

2. Blood Clotting Mechanism

Have you ever fallen off a bike and hurt your knee? Wound

it will bleed. However, what happens to the

wound after a few days? The wound will close and

dry.

When blood vessels are damaged or cut off due to injury, blood

will flow out of the blood vessels. However, the blood

will stop flowing out due to the process of blood clotting.

How does the mechanism of blood clotting?

In blood plasma platelets are to be broken if

touching the rough surface. If platelets rupture, enzyme

thromboplastin contains will come out mixed with plasma

Blood. In addition to platelets, in blood plasma are protombin. Protombin will

enzyme is converted into thrombin by thromboplastin. Changes protombin

a thrombin triggered by calcium ions (Ca2 +). Protombin is a

plasma protein formation requires vitamin K.

Thrombin will serve as enzymes that can alter

fibrinogen into fibrin. Fibrinogen is a protein contained

in plasma. The fibrin is a protein in the form of threads

not soluble in plasma. Fibrin threads that form will

interlocked so that the red blood cells and their plasma will be netted

and forming clots. The new network will be formed replacing

Clumps and wounds will close

3. Blood and Blood Transfusion

Is your blood type? Do the same with brothers or

your sister? Blood group on each person not necessarily the same. It is

due to some blood groups in humans. What are the

in human blood type is?

Based on the composition and aglutininnya aglutinogen, blood

Human blood can be divided into A, B, AB, and O.

ABO blood classification discovered by an expert immunologist Austria,

Karl Landsteiner (1868-1943). Blood classification is based on

aglutinogen the presence of two types, namely aglutinogen aglutinogen A and B.

Aglutinogen and aglutinin is the protein content in the blood.

Aglutinogen is a form of protein antigen, whereas aglutinin

a protein such as an antibody.

In addition to the ABO system, there are other regional classifications, namely

system of rhesus (rh). The system is based on the presence or absence

rhesus aglutinogen in the blood. Landsteiner discovered the system rh

was on probation for Macaca rhesus macaques. At rh system, if

person's blood contains the person aglutinogen rhesus

including positive rhesus (rh +). As if it does not contain

aglutinogen rhesus negative person including rhesus (rh-).

ABO blood classification plays a role in blood transfusion. Transfusion

Blood is the removal of blood from a person's body into the body

others. The person receiving the blood is called the recipient or recipients.

As for those who give blood is called the donor or donor.

It should be noted in a blood transfusion is the kind of

aglutinogen aglutinin donor and recipient. Aglutinin have the ability

to agglutinate erythrocytes. Thus, if the donor aglutinogen

mixed with aglutinin recipient, recipient blood will clot.

Blood donors were mixed in the recipient's body will be treated as

antigen by the body. To give you a better understanding of blood transfusion

note

4. Disorders and Blood-Related Diseases

There are several disorders and diseases associated with

Blood. The disorder can be caused by physiological factors and

genetic factors.

a. Anemia

Anemia is a lack of hemoglobin in the form of disease,

Fe, and erythrocytes in the body. Under normal circumstances, the Hb

Blood is 12-16 grams%. The number of normal erythrocytes at 5.3 million /

mm3 of blood. A person suffering from anemia have symptoms of pallor,

lethargy, headache, and menstrual disorders.

b. Leukemia

In leukemia, white blood cell production exceeds normal limits. Case

This is caused by the abnormal growth of tissue

produce blood cells. Leukemia can be caused by a viral infection,

exposed to radioactive rays, exposed to chemicals, as well as hereditary factors

(Genetic). Patients with leukemia have a characteristic pale, listless, fever, and

bleeding.

c. Thalassemia

Thalassemia is a disease caused by disruption

production of hemoglobin and erythrocytes. Thalassemia is a disease

genetic or hereditary. Symptoms of thalassemia varies greatly,

include anemia, an enlarged spleen, abnormal bone shapes, and

growth disorders.

d. Sickle Cell Anemia

Sickle cell anemia is a disease characterized by the shape

red blood cells resembling a crescent moon. Shaped red blood cells

The crescent moon is easy to overlap on the blood vessels.

As a result, the blood cells clog blood vessels and occurs

hemolysis (rupture). In addition, the resulting lack of crescent shape

holding capacity for oxygen.