THE HUMAN SPLEEN

 

INTRODUCTION: The spleen is located in the upper left quadrant of the abdominal cavity, just below the diaphragm, behind the stomach. The lower rib cage protects the spleen from physical trauma and it is one of the organs in the human body that plays various roles in immunity as discussed in our previous articles. In the fetus, the spleen produces red blood cells, a function assumed by the red bone marrow after birth. After birth the spleen is very much like a large lymph node, except that its functions affect the blood that flows through it rather than lymph.

FUNCTIONS OF THE SPLEEN: The functions of the spleen after birth are:

1. Contains plasma cells that produce antibodies to foreign antigens.

2. Contains fixed macrophages (RE cells) that phagocytize pathogens or other foreign material in the blood. The macrophages of the spleen also phagocytize old red blood cells and form bilirubin and by way of portal circulation, the bilirubin is sent to the liver for excretion in bile.

3. Stores platelets and destroys them when they are no longer useful.

SIGNIFICANCE OF THE SPLEEN: The spleen is not considered a vital organ, because other organs compensate for its functions if the spleen must be removed, in a surgical procedure known as spleenectomy. The liver and red bone marrow will remove old red blood cells and platelets from circulation. The many lymph nodes and nodules plus the liver, will phagocytize pathogens and have lymphocytes to be activated and plasma cells to produce antibodies. It should however be noted that, a person without a spleen is somewhat more susceptible to certain bacterial infections such as pneumonia and meningitis.

RELATED;

1.  THE ENDOCRINE PANCREAS

2.  THE PITUITARY GLAND

3.  THE LIVER

4.  METABOLIC PROFILE OF ORGANS

5.  IMMUNITY

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