Fun Reading

#36 Biology of Human Blood

Hey guys,

This is my Science assignment about Biology of Human Blood. I hope you all like it. 

Biology of the Human Blood

Human blood is one of the most important fluids in our body. About 7% of human body mass is from our blood. Adults have 4.5 to 6 quarts of blood. Blood carries out very important functions which are transporting oxygen and nutrients throughout our body and blood also carries waste products to the excretory organs to be disposed. In addition, blood plays a vital role in human immune system and maintains our body temperature. Blood consists of 4,000 components. The most important components of our blood are plasma, platelets, red blood cell and white blood cell.

Constituents of the Blood and Their Functions

Blood Cells

The Beginning of Blood Cells

Every cell in our human body was give rise by certain stem cells. Hematopoietic Blood Cell or Hemacytoblasts are stem cells that give rise to all the other blood cells through the process of haematopoiesis. They are derived from mesoderm-the middle layer of the germ layers in very early embryo- and are located in the bone marrow. Hemacytoblasts give rise to lymphoid and myeloid. Myeloid cells include monocytes, macrophages, neutrophils, basophils, eosinophils, erythrocytes, dendritic cells, and megakaryocytes or platelets. Lymphoid cells include T cells, B cells, and natural killer cells.

I. Red Blood Cell

- Red blood cells or erythrocytes which are a type of myeloid cells are very small cell without nuclei. Red blood cells make up of 40% of the total volume of the blood.

-Erythrocytes are produced in the bone marrow.

-They are biconcave in shapes with a large surface area to volume ratio.

- Red blood cells transport oxygen from our lungs to all parts of body for cells to carry out respiration.

-Red blood cells contain haemoglobin. Haemoglobin is a type of protein which helps to carry gas and haemoglobin gives the blood the colour of red.

II. White Blood Cell

-White blood cells or leucocytes have nucleus and protect our body from diseases and response to immune system.

-They are irregular in shape and their shape can change.

-Leucocytes consist of phagocytes and lymphocytes.

-Lymphocytes produce antibodies to kill germs. The antibodies produced will surround the microorganisms and 'kill' it.

-Phagocytes carry out phagocytosis carry out phagocytosis by surrounding the bacterium, swallowing it, digesting it thus killing it.

III. Platelets

-Platelets or thrombocytes are small fragments of cells from larger cells in the bone marrow.

-Platelets help in clotting of blood to stop bleeding.

-They do this by adhering to the walls of blood vessels, thereby plugging the rupture in the vascular wall. They also can release coagulating chemicals which cause clots to form in the blood that can plug up narrowed blood vessels.

Plasma

Plasma form 55% of the volume of blood. Plasma is a pale yellowish liquid made up of 90% water and 10% soluble substances such as sugar (glucose), amino acids, blood proteins and mineral salts.