Endocrine Pancreas (Nursing)

00:01 The next endocrine organ we're gonna look at is one we've already seen has an exocrine function in the GI tract, and that is the pancreas.

00:10 So we already said the majority of the pancreas is really exocrine pancreas.

00:15 Now, 95% of the volume is dedicated to producing digestive enzymes that will help digestion by being secreted into the duodenum.

00:27 About 5%, though, is going to be devoted to an endocrine function.

00:32 And so the endocrine pancreas will be arranged into these little spheres, called the islets of Langerhans.

00:38 They're going to produce hormones like insulin, glucagon, somatostatin, and something called pancreatic polypeptide.

00:47 The acinar cells are part of the exocrine system.

00:51 And so they're going to be arranged around little glands that feed into ducts.

00:56 And as we mentioned, in the GI portion, those ducks are also going to secrete bicarbonate, because they're about to enter the duodenum and face a very acidic pH coming from the stomach.

01:08 So it's going to help neutralize things.

01:10 And that neutralizing will help these digestive enzymes work properly.

01:15 In contrast, the endocrine portion is going to go into the bloodstream.

01:20 And so here we have the islets of Langerhans, where these endocrine cells live.

01:26 We have beta cells, which are the most prominent ones, and they're going to produce insulin.

01:34 We also have alpha cells, though, in slightly lower numbers, and they're going to have an opposite effect by secreting glucagon.

01:42 So these will have opposite effects on blood glucose levels, whereas insulin will try to lower it, glucagon will actually try to raise blood glucose levels.

01:53 And so, for example, during exercise, it's going to decrease blood sugar, it's going to be used up during the process of exercising.

02:03 And that's going to stimulate the alpha cells of these eyelets to produce glucagon to in turn, tell the liver to break down glycogen stores glycogenolysis as it's called, to increase blood sugar to compensate for it.

02:19 Of course, the other way to increase or decrease compensate for decreased blood sugar is eating and getting more blood sugar into your body in the first place.

02:28 And when you do that, you will increase that blood sugar above the baseline levels.

02:33 And that will tell the beta cells, "Oh, we better get rid of this free floating sugar, so we're going to secrete insulin." And that's going to stimulate adipose cells and other types of cells to take that glucose out of the bloodstream and back into their cells.

02:52 Now, when we talk about blood glucose, we're also going to be talking about the pathology, the most closely related to it which is diabetes mellitus.

03:00 And you've probably heard that there are various types of diabetes sometimes roughly referred to type I and type II.

03:08 And when you hear type I, that's usually something that is a result of an autoimmune attack directly on those beta cells of the pancreas that produce insulin.

03:19 And because of that, it's usually an earlier onset.

03:24 And because these beta cells have been destroyed, there's really no way to compensate for it.

03:30 Therefore exogenous insulin needs to be given in order to compensate for the lack of insulin production.

03:38 Type II which is the more prevalent type is more so that the cells aren't responding to insulin.

03:47 And there's a lot of factors that go into type II diabetes.

03:52 But it could be a combination of this insulin resistance, so the cells not recognizing insulin as well as it should.

04:00 And over time, it may be also a deficiency in insulin as well.

04:05 And because it's usually an acquired thing although there can be dispositions to get it earlier in life, it's usually an older onset than type I.

04:14 And it does have more of a relation to obesity and overall metabolic health.

04:20 And again, there is a familial predisposition to getting type II more easily and sometimes earlier in life.

04:30 And because there are still beta cells, they're not actually outright destroyed by an autoimmune attack, like with type I's.

04:38 There are other ways that it can be treated, such as controlling diet, oral hypoglycemic agents.

04:45 And then in extreme cases, unfortunately, it will be almost the same as type I diabetes where exogenous insulin will just need to be given.

04:57 Diabetes has a wide range of complications, because we're talking about blood glucose.

05:03 So really anything blood touches which is just about everything can be affected by these problems with blood glucose regulation.

05:11 That includes the back part of the eye that senses vision, which is the retina so you could have retinopathies.

05:18 Whenever you see a pathy, it just means disease of.

05:22 Also have effects on the kidney and that will be called nephropathy, affects nerves, especially peripheral nerves, very commonly in the feet and that will be neuropathy.

05:36 And then most seriously, it can affect the cardiovascular system, swells specifically the coronary arteries and cerebrovascular disease.

05:46 And because those areas are supplying, areas like the heart and the brain, damage to those can have probably the worst risk for overall health and well-being.