Blood

An essential tissue

Structure and Function-Overall

  • Blood is a connective tissue and is composed of two parts: blood corpuscles which are subdivided into red blood cells, white blood cells, and platelets and plasma
  • Blood transports materials throughout the body (gasses, waste, hormones, enzymes, nutrients, blood cells, etc.)
  • Maintains body temperature
  • Controls pH
  • Removes toxins (performed by the kidneys)
  • Regulates body fluid electrolytes

Structure and Function of Plasma

  • Plasma is 90-92% water and 10-8% dissolved substances such as sodium, chlorine, potassium, and calcium ions
  • Plasma helps ensure that the medium in which blood cells are transported around the body is functional
  • Helps maintain optimal body temperature
  • Controls the pH of the blood and body tissues
  • Helps maintain an ideal balance of electrolytes in the blood and body tissues

Structure and Function of Erythrocytes (Red blood cells)

  • Main function is to carry oxygen which is accomplished by the prosthetic group whose main component is Haem which combines with oxygen to form oxyhaemoglobin
  • Young cells have a nucleus, mature cells do not
  • Small and biconcave
  • Lack organelles
  • Their structure allows them to be packed with hameoglobin
  • Small size allows them move through capillaries
  • Eventually broken down by the spleen into bilinubin, bilveridin, and iron which are transported to the liver to be re-cycled and form bile salts

Structure and Function of Leucocytes (White blood cells)

  • Larger than red blood cells with a very large nucleus and contains very little cytoplasm
  • Nucleus is doubled as if it were undergoing cell division which allows the genetic material to be doubled
  • Different types of white blood cells can be classified as granular or agranular and include B Cells, T Cells, basophils, and phagocytes
  • Travel through the blood and destroy bacteria, produce antigens, and fight malignant diseases
  • Produced in the bone marrow
  • Major component of the immune system

Structure and Function of Trombocytes (Platelets)

  • Platelets are disk-shaped cell fragments
  • Lodge in and seal any gaps that are in the lining of a blood vessel
  • Principal function is to prevent or stop bleeding by clotting
  • Disk shape allows them to clot effectively

Interaction with Organs and Systems

  • Blood is pumped by the heart and is transported by veins and arteries
  • Blood interacts with the digestive system when food is broken down in the small intestine and nutrients enter the bloodstream through tiny hair-like projections
  • Blood interacts with the endocrine system by transporting hormones from glands to organs and tissues within the body
  • Blood provides white blood cells to the immune system
  • Supports the respiratory system by transporting oxygen throughout the body
  • The kidneys process about 200 quarts of blood every day by removing waste products and extra water (2 quarts) that result from the breakdown of active tissue and food
  • The waste is expelled from the kidneys as urine

Sources Cited

National Kidney and Urological Diseases Information Clearinghouse [Internet]. 2009 Feb. Bethesda(MD):National Institute of Diabetes and Digestive and Kidney Diseases [cited 2014 Mar 11]. Available from: http://kidney.niddk.nih.gov/kudiseases/pubs/yourkidneys/#kidneys


Fact Monster [Internet]. 2007. Pearson Education, publishing as Fact Monster [cited 2014 Mar 11]. Available from: http://www.factmonster.com/ipka/A0774536.html


IvyRose Holistic [Internet]. [cited 2014 Mar 11]. Available from: http://www.ivy-rose.co.uk/HumanBody/Blood/Blood_StructureandFunctions.php


Introduction to Respiratory and Cardiovascular Physioloy [Internet]. 2014. University of the West of England [cited 2014 Mar 11]. Available from: https://hsc.uwe.ac.uk/rcp/cs-blood.aspx


White Blood Cells and Granulocytes [Internet]. American Red Cross; [cited 2014 Mar 11] . Available from: http://www.redcrossblood.org/learn-about-blood/blood-components/white-blood-cells-and-granulocytes