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Digestive histology 11- Pancreas

October 10, 2019


– Do you remember
the function of the pancreas? Remember the pancreas was that–
it looks just like this. And it had the pancreatic duct
that emptied into the duodenal papilla. So this is duodenum. Yeah, and there’s my
duodenal papilla. And also coming in
is the common bile duct. We’re all over this action. Because the pancreas has
exocrine tissue and endocrine tissue there are
two different structures that we’re going to see in here. For one thing we’re going to see
these kind of round islands. They’re going to look different
than the tissue surrounding them. Depending on the stain, they
might like look super different or they might look kind of
similar but slightly different. They’re made of cells and these
are called islets of Langerhans or pancreatic islets. They’re like little islands
in the pancreas. And these guys are your
endocrine structures and they produce insulin and
they also produce glucagon. But both of those hormones are
involved in glucose homeostasis. Surrounding the
pancreatic islets are a billion glandular
structures and these guys– and I’m drawing them like this. It’s not a single cell.
It’s actually–it’s a gland. It looks really similar to all
the other glandular tissue that we’ve been looking at
so far. But I really should’ve drawn
them all like this because these look like
individual cells and I am not going to
draw them all. But that’s what they are. These guys are called acini and they’re producing
the exocrine secretions, which are bicarbonate ions to
neutralize the stomach acid. Digestive enzymes to help digest
proteins and carbohydrates. And I don’t know, do they make
fat enzymes too? I don’t think so. I think the bile emulsifies
the fat and then we just
absorb it directly. So all of this stuff produced by
the exocrine structures, the acini, is dumped
into the duodenum. Most of the pancreas–I think
the number–it’s like in the 95% of all pancreatic
cells, can’t remember the exact number,
are exocrine cells. And a very small number of them
are actually endocrine cells found in the pancreatic islets. I expect you to be able to
identify the islets, to identify the structure
looking through the microscope to know I’m looking at
a pancreas, and to know what comes out of
each of them. So endocrine secretions coming
out of the pancreatic islets are going to be insulin,
glucagon, hormones. They go into the blood. So you also are going to have to
have blood. You have to have blood.
Here’s a little blood supply. Look. I’m going to
draw it like this. Do my exocrine structures dump
fluid into the blood? No. They dump it outside your body
to the lumen of the duodenum because it’s exocrine. That’s the definition of
an exocrine structure. Endocrine structures dump
into the blood. That’s the definition
of the endocrine structure. Done. Digestive histology. You guys are rock stars
and so am I. Now I’m going to go move around
dead bodies.

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15 Comments

  • Reply Jamal Jabareen November 23, 2014 at 3:21 pm

    thankkk youuuuuuuuuuuu

  • Reply Aletha Mathias February 14, 2015 at 6:36 am

    Thank you so much Ms Riggs!!! =)

  • Reply Tim De Boeck June 14, 2015 at 9:25 am

    good job! PS the acini do secrete lipase aswell so they do help in the breakdown of fats

  • Reply gopobo December 4, 2015 at 10:59 pm

    You are amazing, love your explanations. Keep up the good work!

  • Reply Hương Ngô January 6, 2016 at 6:02 pm

    What vivid lectures! they are very useful! Thank U so muchhhhhhhhhhhhhh!

  • Reply Hisham Khider March 2, 2016 at 6:53 pm

    Pancreas also produces lipase

  • Reply FavJam June 21, 2016 at 10:31 pm

    i don't know what i would do without your videos.
    you're awesome !

  • Reply ibrahim hamid October 10, 2016 at 8:00 pm

    you're awesome !

  • Reply ga d November 2, 2016 at 5:13 pm

    you are a star

  • Reply nazma ahmed April 22, 2017 at 10:42 am

    Amazing lady. Really helpful. Thank you

  • Reply Vet KALEEM May 28, 2017 at 11:14 am

    i used to do the same while studying as u r doing at the end of video😂😂

  • Reply Sudipan Roy December 11, 2017 at 1:03 pm

    need more details

  • Reply Soyasb98 Soyasb98 June 28, 2018 at 12:09 am

    U are really amazing mam❤️tq

  • Reply Hadiye A September 6, 2018 at 9:30 pm

    i think i love you

  • Reply Yaa Amoah-Tachie October 4, 2018 at 12:47 am

    thank you so very much!!!

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