Friday, July 18, 2014

Physiology of pancreas as the secretor of insulin

The pancreas, in addition to its digestive functions, secretes two important hormones, insulin and
glucagon, that are crucial for normal regulation of glucose, lipid, and protein metabolism.

Although the pancreas secretes other hormones, such as amylin, somatostatin, and pancreatic polypeptide, their functions are not as well established. The main purpose of this chapter is to discuss the physiologic roles of insulin and glucagon and the pathophysiology of diseases, especially diabetes mellitus, caused by abnormal secretion or activity of these hormones.

Physiologic Anatomy of the Pancreas. The pancreas is composed of two major types of
tissues: the acini, which secrete digestive juices into the duodenum, and  the  islets of Langerhans, which secret insulin and glucagon directly into the blood.

The human pancreas has 1 to 2 million islets of Langerhans, each only about 0.3
millimeter in diameter and organized around small capillaries into which its cells
secrete their hormones.

The islets contain three major types of cells, alpha, beta, and
delta cells, which are distinguished from one another by their morphological and
staining characteristics.
Physiology of pancreas

The beta cells, constituting about 60 per cent of all the cells of the islets, lie mainly
in the middle of each islet and secrete insulin and amylin, a hormone that is often
secreted in parallel with insulin, although its function is unclear.

The alpha cells, about 25 per cent of the total, secrete glucagon. And the delta cells, about 10 per
cent of the total, secrete  somatostatin. In addition, at least one other type of cell,
the PP cell, is present in small numbers in the islets and secretes a hormone of uncer-
tain function called pancreatic polypeptide.

The close interrelations among these cell types in the islets of Langerhans allow
cell-to-cell communication and direct control of secretion of some of the hormones
by the other hormones.

For instance, insulin inhibits glucagon secretion, amylin
inhibits insulin secretion, and somatostatin inhibits the secretion of both insulin and
glucagon.

 References:
© Copyright Guyton and Hall Textbook of Medical Physiology

14 comments:

  1. thanks for a good informative article
    http://knowrare.blogspot.com

    ReplyDelete
  2. We focus on the endocrine aspects of health concerns.
    We are a core of the fitness community now as well...and especially for bodybuilders.
    http://area1255.blogspot.com/2014/06/5-ways-to-increase-dht-naturally.html
    http://area1255.blogspot.com/2014/06/5-important-ways-to-detoxify-your-body.html
    http://area1255.blogspot.com/2014/06/signs-and-symptoms-of-low-nmda-receptor.html

    Those are our three main health related "gemstones".

    ReplyDelete
  3. Thanks for the pageviews:

    http://lgpOnTheMove.blogspot.com

    ReplyDelete
  4. Very Informative article... and also thanks for the page views
    http://cj-ramki.blogspot.in

    ReplyDelete
  5. This comment has been removed by a blog administrator.

    ReplyDelete
  6. my blog ref on here http://apknl.blogspot.ru :D

    thanks ye ... :)

    ReplyDelete
  7. Nice Article. Why don't take out some time for MOVIES? Watch Latest Movies in HD here: http://showflix.blogspot.com

    ReplyDelete
  8. For whatever reason my blog is getting readers from your site. No problem. I happen to have diabetes so I am part of the community anyway. http://classicalmodernmusic.blogspot.com/ Music can't hurt folks with diabetes!
    All best,
    Grego

    ReplyDelete
  9. I too received a surprising number of viewers linking from this page. Unlike the hoity-doities above, I say bring it on! This week's blog is particularly good, so yippee about having more viewers!

    Here is a direct link:
    http://mikelweisser.blogspot.com/2014/07/draft-yavapai-democratic-womens-club.html

    ReplyDelete
  10. No idea why, but the blog looks legit and pretty good, too.
    Anyone interested in musings about bikes and bike rides - written by an overweight middle-aged woman with hyperinsulinism, whose life has been transformed by getting a little exercise... and loving it! Please come on over. If you like what you see, please subscribe so you don't miss a thing. Right now I'm in the middle of a series about our cycling holiday on the Isle of Skye - lots of gorgeous scenery!
    velovoice.blogspot.co.uk

    ReplyDelete
  11. I am getting visitors from here too! Oh well, at least you seem to be a respectable blog, not a weird spam/porn site! :)

    ReplyDelete
  12. Nice to read your post, really nice blog

    http://cricketsbest.blogspot.com

    ReplyDelete