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Course: Health and medicine > Unit 7
Lesson 3: Diabetes- What is diabetes mellitus?
- What is diabetes mellitus?
- Breaking down diabetes
- Types of diabetes
- Pathophysiology - Type I diabetes
- Pathophysiology - Type II diabetes
- Diagnosing diabetes
- Treating type I diabetes
- Treating type II diabetes - Pharmacology
- Treating type II diabetes - A practical approach
- Acute complications of diabetes - Diabetic ketoacidosis
- Acute complications of diabetes - Hyperosmolar hyperglycemic nonketotic state
- Diabetic nephropathy - Mechanisms
- Diabetic nephropathy - Clinical presentation & treatment
- Diabetic retinopathy
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Pathophysiology - Type II diabetes
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Want to join the conversation?
- What about type 1.5 diabetes? Is this a form of diabetes mellitus where some beta cells are dysfunctional and some do produce insulin but all the cells that have the GLUT4 protein(which doesn't include the liver and brain) are resistant to the insulin that is produced and is thus a combination of type 1 and type 2 diabetes?(10 votes)
- Good Question... Type 1.5 diabetes is actually a subgroup of type 1 diabetes which occurs mostly in adults. The difference between Type 1 and Type 1.5, is that Type 1.5 most likely will take a longer time to get into effect. Which is why Type 1.5 is sometimes referred to as "Latent Autoimmune Diabetes" which broken down is "Late" Autoimmune Diabetes(7 votes)
- 4:50how can hypertension lead to type two diabetes?(3 votes)
- Does the extra glucose effect the heart in anyway? I ask this because wouldn't extra glucose make the blood heavier and lead the heart to pump more. Would that lead to heart disease?(2 votes)
- High blood pressure increases the risk of heart disease, and heart attack.
Hope this helps!(3 votes)
- If the cells are perpetually locked then how could someone get their energy(2 votes)
- The glucose being unable to enter the cells causes lethargy and fatigue. The fats can be used as energy source in this situation (it was briefly explained in the Pathophysiology - Type I diabetes).(3 votes)
- I read an article that says blood glucose rises 10-15 minutes after eating a meal. My question is how does this happen? Shouldn't it take a few hours for blood glucose to rise because it takes around 4 hours for food to go into the small intestine. And then nutrients like glucose will be absorbed into the blood after reaching small intestine. How does glucose get absorbed into blood via stomach.
Sorry this is a little confusing, but I am confused.(3 votes) - So if genetics are the biggest risk factor for type 2 diabetes. Can you be perfectly healthy but still develop type 2 diabetes?(1 vote)
- Well, a person can look and feel healthy can still get type 2 diabetes, but if that person gets diabetes than he/she is not perfectly healthy. See what I'm getting at?
Hope this helps!(3 votes)
- wait so can both diabetes be properly cured and that you wouldn't be able to develop it again(2 votes)
- i read pathophysiology books kathryn L. McCance page 734 it says Aldosteronoma leads to Diabetes Mellitus Type II , Can you explain its mechanism?(2 votes)
- Which type of diabetes is more dangerous? Type I or Type II ?(2 votes)
- Is there a way you can avoid being diabetic?(0 votes)
- A good diet, low in sugars that continually stress your liver and pancreas.
Many people contract diabetes because of poor diets.(3 votes)
Video transcript
- Diabetes Mellitus is
a group of disorders that's caused by improper
function of insulin, which is a hormone
produced by the pancreas. And insulin is responsible
for helping regulate blood sugar, or glucose
levels, in the blood. Now since it's a group of diseases, there are actually multiple
different underlying causes of diabetes mellitus. And one of these causes is
known as Type 2 Diabetes. Now, before we dive into the actual cause of Type 2 Diabetes, let's first
get a better understanding of how exactly insulin works. And there are two major steps. So, imagine that you just ate a big meal. Maybe like a bowl of pasta or something. And your body is currently
absorbing all of those nutrients from your digestive system
into your bloodstream. Now one of these nutrients is glucose, and as your body absorbs it, that glucose starts building up in the blood stream. And in this feeding or absorptive state, your body wants to store
this glucose in places like the liver and muscle cells so that it can be used for energy later when the body needs it. But unfortunately, glucose on its own can't get into these cells. In a sense, these cells are locked. But fortunately, the pancreas is able to help with this problem. So there are a couple types of cells in the pancreas that
sense blood sugar levels. And these cells are located
in the islets of Langerhans. And these green cells here
in the islets of Langerhans are meant to represent the Beta cells. And when the blood glucose increases, the Beta cells of the
pancreas sense this change, and they secrete a
hormone known as insulin into the blood. And what insulin does
is it acts like a key that can unlock these
cells so that the glucose can be stored in both the
liver and the muscle cells. So you can see that there are two steps in order for insulin to function properly. And the first is that these Beta cells of the endocrine portion of the pancreas have to be functioning in order to secrete the insulin into the blood. And then second, these cells
have to respond to the insulin in order to unlock them
so that the glucose can be taken out of the blood to
decrease the blood glucose levels. Now, diabetes mellitus can be caused by dysfunction at either
of these two steps. So if the Beta cells
aren't functioning properly or they're being destroyed,
such as in Type 1 Diabetes, there isn't enough insulin to be produced to unlock the cells. And what happens is that the glucose builds up in the bloodstream, and that person will
develop diabetes mellitus. However, similarly in step two, if the cells aren't properly responding to the insulin in the blood,
then they can't be unlocked. And the glucose will build
up in the blood vessels and you'll get hyperglycemia, and the person will
develop diabetes mellitus. So this is what I meant
earlier when I said that diabetes is a group of disorders, because multiple different mechanisms can result in diabetes mellitus. So, in general, Type 2 Diabetes is caused by dysfunction of this second step. And this is known as insulin resistance. So, in Type 2 Diabetes, the
Beta cells of the pancreas are functioning properly, and they're able to produce insulin, but
that insulin isn't able to have its proper effect on
the cells throughout the body. However, it is important to note that as the disease does progress, the pancreas can become effective and eventually decrease
its insulin production. But in general, Type 2 Diabetes is thought of as primarily due
to this insulin resistance. So what exactly causes the cells to become resistant to insulin? Well, unfortunately there's
no simple answer to this, and the cause of Type 2
Diabetes is very complex and includes many different factors that work together to cause the problem. So let's get a little
bit better idea of this. I'm gonna just erase
some of our work here, so we can get a little more room. So what are some of these risk factors? Well one of the most important ones is actually genetics. In fact, having a family history, say in someone's parents or grandparents, of Type 2 Diabetes is one
of the biggest risk factors for developing Type 2 Diabetes. Other factors include obesity, hypertension, and increasing age. And it's the interaction of
all these different factors plus more that end up resulting
in insulin resistance. But how can we maybe understand
this a little bit better? Well, one of the factors
that we understand maybe a little bit better
than some of the others is the effect of obesity. So let's bring back that
lock I described earlier. So if you think of obesity as kind of this perpetual feeding
state, or in a sense, that the body is
continuously being exposed to insulin released by the pancreas in an effort to bring
down the increased glucose from this perpetual feeding state. Over time, the receptors on
the cells, or these locks, become desensitized to the insulin. And they become resistant to its effect. So let's use an analogy to help understand this idea of resistance. So instead of a lock,
pretend this is a person. And this person decides
to put on a baseball cap. So when you first put on a baseball cap, you can feel it on your head, however, over time, say 10, 15 minutes, this constant stimulation
of the touch receptors results in a desensitization
to the feeling of the ball cap on your head, and it feels
like it's no longer there. So this is kind of similar
to the cells in the body. If they're constantly
exposed to this insulin, they'll stop responding to it, and the cell won't become unlocked. Now initially the pancreas is able to compensate for this resistance
by producing more insulin. However, eventually as time progresses, the pancreas cannot keep up to overcome the insulin resistance, and eventually the body
will lose its ability to lower the blood glucose
level with insulin. And this will result in hyperglycemia and the complications that
are associated with it. But this process can take time. In fact, from the time this
insulin resistance starts to when someone would develop
symptoms of Type 2 Diabetes can actually take multiple years. But at the same time, early
diagnosis and treatment is critical to prevent
the serious complications associated with diabetes. And for this reason, it's very important to screen people who are at risk, people who have some
of these risk factors. It's important to screen
them for Type 2 Diabetes, so they should regularly have
their blood glucose levels monitored for hyperglycemia, so that it can be detected
and treatment can be started even before he or she
will develop symptoms. So I hope this gives you
a better understanding of what causes Type 2 Diabetes. It's not caused by a problem
with the pancreas itself and the ability to produce insulin. Instead, it's caused by
this insulin resistance, by the cells throughout the body that are supposed to respond to insulin.