Portal circulation: easy and brief description

Portal circulation: any part of the systemic circulation in which blood passage through two sets of capillary before draining to the heart

Types :

1. Arterial  portal system, EX: renal portal system

Heart >  artery > 1^st set capillary (at renal glomeruli) > arteriole > 2^nd set capillary (at capillary plexus surrounding the proximal and distal convoluted tubule of nephron )  > vein > heart

2. Venous portal system : EX: hepatic portal system

Heart > artery > 1^st set capillary (GIT) > vein  > 2^nd set capillary (liver) > vein > heart . 

What is the importance of portal circulation? 

Ans: if we want to transfer  blood of a particular region to other particular region for purpose then we need portal circulation 

Example: Gut and liver

gut blood vessels rich in nutrient , and nutrient need to metabolized  in liver so, gut veins are not directly drain into IVC , at first it goes to liver then drain into IVC 

Example:  Hypothalamus and pituitary 

The releasing hormones of hypothalamus must transfer to the anterior pituitary and anterior pituitary is stimulated and secretions

of anterior pituitary circulate through systemic circulation