Blood main functions and component

Human blood is a mixture of numerous individual components. All these components have one or even several tasks and ensure that our organism functions smoothly. Here is an overview of the components and main functions of human blood.

Our blood – Components

blood cells


Blood Collection FingerRed blood cells. Erythrocytes are the most abundant cells in the blood. Main function: transport of oxygen from the lungs to the various body tissues and removal of carbon dioxide from the body tissue to the lungs.


Platelets. The smallest cells of the blood. main function: attaches to the injured tissue and closes it.


Generic term for the white blood cells (lymphocytes, monocytes and granulocytes) in our blood. main function: part of the immune system. Combating foreign cells by e.g. phagocytosis in blood, body tissue and lymph fluid. A detailed description can be found hier.


The fibrinogen in our blood is converted into fibrin during blood coagulation by various processes, which together with the thrombocytes forms the so-called thrombus.


plasma proteins

The plasma proteins are formed in the liver under vitamin K influence.


The albumin in our blood binds water to itself in the blood vessels and thus prevents its escape into the surrounding tissue. A lack of albumin leads to edema (accumulation of fluid in the tissue).


Main tasks in our blood: Important function in blood coagulation, defence against foreign bodies, etc…


Cell- and protein-free blood fluid in blood and tissue fluid. Ultrafiltrate contains only small molecular substances dissolved in water, e. g: Glucose, vitamins, lactate, salts, electrolytes, etc. …

Our blood – Functions

Transport function

Our blood is not only the main transporter for the substances in the following list. It also transports heat through our body.

  • oxygen (O2) bound to hemoglobin (HB)
  • CO2 in the form of bicarbonate (= HCO3): CO2 + H2O ⇔ H2CO3 ⇔ H+ + HCO3
  • Nutrients (protein, carbohydrates, fat, mineral substances, vitamins, etc.)
  • Waste materials (e.g. urea)
  • Hormones
  • Water

Blood clotting

  1. Lesion of a blood vessel.
  2. contact blood ⇔ connective tissue.
  3. Thrombocytes Deposition on connective tissue + bursting of thrombocytes.
  4. plate factor becomes free.
  5. Coagulation cascade is set in motion. The different plasma proteins (factor XII – III) and Ca++ finally activate prothrombin to thrombin.
  6. cleavage of fibrinogen into fibrin = protein filaments.
  7. These protein filaments form a network in which erythrocytes remain trapped.
  8. A sealing plug = thrombus is formed.

This post is also available in: German

William C. Hilberg
As an author, Mr. Hilberg has published several papers on health issues that have gained international recognition. He is close to nature and loves the seclusion and activity as a freelance journalist. In his function as editor William C. Hilberg manages the entire content of PENP. Our team greatly appreciates his expertise and is proud to have him on board.