Lesson video

Hi, I'm Mrs. Hudson, and today I'm going to be teaching you a lesson called type 1 and type 2 diabetes.

This is a biology lesson and it comes under the unit titled "Coordination and Control "Hormones and the Human Endocrine System." The outcome of today's lesson is, I can describe the causes and treatments for type 1 and type 2 diabetes.

There are some keywords that are going to be used frequently during today's lesson, and they are, hormone, insulin, gland, pancreas, and diabetes.

So let's have a look in a little bit more detail at what each of those words mean.

A hormone is a chemical substance produced by a gland that travels in the bloodstream to a specific organ.

Insulin is a hormone secreted by the pancreas when blood glucose is too high, lowering blood glucose levels.

Gland is an organ or tissue that produces and secrete substances such as hormones.

The pancreas is a glandular organ in the body that detects changes in blood glucose concentration and secretes insulin.

And finally, diabetes is a disease in which the body is unable to regulate blood glucose concentration.

Today's lesson is going to be split up into three different parts.

In the first part of the lesson, we're going to be looking at glucose regulation and insulin, and then we're going to move on to look at type 1 diabetes.

And then finally in the third part of the lesson, we will look at type 2 diabetes.

But let's get going first of all with glucose regulation and insulin.

Glucose is a sugar that travels in the bloodstream and is delivered to most body cells for aerobic respiration.

Aerobic respiration is a chemical reaction that releases energy and is a vital process that keeps organisms alive.

And this here is the beginning of the word equation for aerobic respiration.

So the reactants are glucose and oxygen, and then they chemically react together to produce carbon dioxide and water.

And during that chemical reaction, energy is released.

So glucose is a reactant for aerobic respiration.

And aerobic respiration releases energy, which is then used to drive other metabolic processes in the body and keeps us alive.

So glucose is a very important reaction that cells need.

Throughout the day blood glucose levels rise and fall, the body constantly monitors the levels of blood glucose and will secrete hormones to return the levels to normal.

So here we've got an infographic that is showing you the natural increases and decreases of blood glucose throughout the day.

And between those two lines is showing you the ideal range of blood glucose levels.

And we can see here that the arrow is pointing to a point on the graph where blood glucose is increasing and that could be after eating breakfast.

And then the blood glucose is decreasing after not eating for a period of time, and then it goes back up again.

So it could be eating lunch has caused the blood glucose to increase.

And then we can see that it goes down and then increases again, and then it will decrease rapidly.

And that could be caused by exercising after dinner, which causes blood glucose to decrease.

So blood glucose can increase because of eating, but it can decrease due to fasting.

So not eating for a period of time or exercising.

So this diagram here is showing you the glands of the endocrine system.

Can you remember which gland in the endocrine system this is? This is the pancreas.

So well done if you remember that.

The pancreas is the organ in the body that detects changes in blood glucose concentration.

If blood glucose concentration is too high, the pancreas will detect this change and secrete a hormone called insulin.

So here the pancreas detects that change, so the blood glucose is too high and it secretes insulin, which is a hormone.

Insulin travels in the blood plasma to its target cells, which are the liver and muscle cells.

So here we've got the pancreas, which is a gland again.

It's detecting those two high blood glucose levels and it secretes the hormone insulin.

The insulin travels in the blood plasma, which is the yellow part of the blood, which is the liquidy part, and it is delivered to the target cells, which are the liver and muscle cells.

Insulin acts on the liver to reduce blood glucose concentration by increasing the amount of glucose absorbed from the blood into the cells and converting excess glucose into glycogen which is stored in the liver and muscle cells.

So if this was the liver here, when insulin arrives at the liver, it causes the liver to absorb glucose from the blood.

And then that glucose, which is now absorbed into the liver, is converted into a substance called glycogen that is stored in the liver and muscle cells.

And both of these things reduce the amount of glucose that is in the blood.

By removing glucose from the blood and converting it into glycogen to be stored, the blood glucose concentration decreases back to normal.

So here we've got glucose, which is in the blood plasma and it is converted into glycogen, which is stored in the liver and muscle cells.

And that process decreases the blood glucose concentration.

The pancreas is constantly working to keep blood glucose levels within and an ideal range.

If blood glucose remains too high or too low for long periods of time, it can cause severe health complications.

So it's really important for the pancreas to constantly monitor blood glucose concentrations so that it can secrete the correct hormone to keep levels within that ideal range.

So here again, we've got our natural increases and decreases of blood glucose and those two lines representing the ideal range of blood glucose.

So here we can see that blood glucose is increasing at all of these arrows.

Insulin will be secreted causing blood glucose to return back to normal, which we can see because after it's increased then the levels will come back down to within the normal range.

So now we're going to look again at the sequence of events that happens if blood glucose concentration is too high.

So here we've got high blood glucose concentration and that is detected by the pancreas.

The pancreas then secretes insulin which travels in the blood plasma to the liver and muscle cells.

The insulin triggers the liver to absorb more glucose and convert it into stored glycogen.

And then blood glucose concentration decreases back to normal levels.

So we can see there's four steps there showing you what happens when blood glucose concentration is too high.

Let's check our understanding of this so far.

So are these statements true or false? The liver detects changes in blood glucose concentration.

The hormone insulin is secreted when blood glucose is too high.

Insulin causes the liver to turn glycogen into glucose and eating causes blood glucose levels to increase.

So the first statement is false.

It's not the liver that detects changes in blood glucose, it is the pancreas.

The second is true.

Insulin causes a liver to turn glycogen into glucose is also false, and this is because insulin causes glucose to be turned into glycogen and stored in the liver.

And finally, eating causes blood glucose levels to increase.

This is also true.

Well done if you manage to get those right.

We're ready now to move on to the first task of the lesson.

So in the first part, using the diagram, explain how the pancreas regulates blood glucose levels.

And there are the numbers one, two, three and four which each correspond to the different parts of the diagram to say what is happening at each stage.

I'm sure you're gonna do a really great job.

Pause the video now.

Give as much detail as you can in your answers and then press play when you're ready for me to go through them.

Let's see how we did.

So at 0.

1, high blood glucose concentration is detected by the pancreas.

And number two, the pancreas secretes insulin which travels in the blood plasma to the liver and muscle cells.

Number three, insulin triggers the liver to absorb more glucose and convert it into stored glycogen.

And then finally, number four, blood glucose concentration decreases back to normal levels or you could say ideal levels.

If you need to pause a video to add anything into your answers and any extra detail, then please do, but we're going to carry on now with the rest of the lesson.

Great job.

So we know about glucose regulation using insulin.

Let's have a look now at type 1 diabetes.

Diabetes is a disease in which the body is unable to regulate blood glucose concentration.

There are two types of diabetes, type 1 and type 2.

And first of all, we are going to look at type 1 diabetes.

Type 1 diabetes is a disorder in which the pancreas fails to produce enough insulin.

It usually appears in childhood or teenage years.

When blood glucose levels increase, the body is unable to decrease blood glucose levels back to normal.

Scientists think that genes or environmental factors such as viruses are responsible for causing type 1 diabetes.

So what happens when somebody has type 1 diabetes is that the pancreas will detect high blood glucose levels, but it will fail to produce sufficient insulin.

So there will be an insufficient amount of insulin produced and that means that the body is less able to convert glucose into glycogen, so therefore blood glucose levels will remain higher than they should do.

Type 1 diabetes is characterised by having uncontrolled high blood glucose levels.

And remember, high blood glucose levels are caused by the fact that the pancreas cannot produce enough insulin.

So if we look first at a non-diabetic person's blood glucose levels, you can see that those levels are remaining within the ideal range.

So blood glucose increases and insulin is secreted causing blood glucose to return back to normal.

Whereas somebody with type 1 diabetes, blood glucose will increase, but insufficient insulin is secreted.

So blood glucose stays higher for longer and becomes high in the long term.

So after a long period of time what will happen is that the resting glucose levels will be higher and they remain above the ideal range for longer because there isn't enough incident to reduce blood glucose levels.

Type 1 diabetes is usually treated by injecting with insulin.

People with type 1 diabetes will need to check their blood glucose levels throughout the day.

They can help keep their blood glucose levels lower by eating a diet low in carbohydrates and sugar and exercising.

Because type 1 diabetics don't produce enough insulin, the main treatment is that they will inject insulin into their body and then they have to regularly monitor their blood glucose levels throughout the day.

So here we've got an image showing you a device that can be used for regular monitoring of blood glucose levels and the device will analyse a small amount of blood to give you the blood glucose concentration.

So throughout the day you can tell what your blood glucose concentration is.

And then the treatment will be the injection of insulin to lower blood glucose concentration.

But because you are injecting insulin which lowers blood glucose, you then need to carefully monitor glucose levels throughout the day.

There have been some more modern advancements in technology that help diabetic people to monitor their blood glucose levels.

So there are machines that you can wear, attached to your body for a two week cycle that constantly monitor your blood glucose levels.

And there are also now pumps which monitor blood glucose levels and deliver insulin depending on what your blood glucose level is.

Let's check our understanding of this so far.

So which is true for type 1 diabetes, A, the pancreas secretes too much insulin, B, the pancreas does not secrete enough insulin, or C, the liver cells do not respond to insulin.

This is B.

The pancreas does not secrete enough insulin in people with type 1 diabetes.

Well done if you got that right.

Next question, what is the usual treatment for type 1 diabetes? A, eat a high carbohydrate and sugar diet, B, exercise as little as possible, or C, injections with insulin.

This is C, injections with insulin.

We're ready now to move on to task B of the lesson.

So in the first part of task B, you need to describe what causes type 1 diabetes and the effect this has on the body.

And then number two, how is type 1 diabetes monitored and treated? Sure, you're gonna do a fantastic job.

Pause the video and press play when you're ready for me to feed back the answers.

Let's see how we did.

So for question one, describe what causes type 1 diabetes and the effect this has on the body.

The exact cause of type 1 diabetes is unknown, but scientists think that there is a genetic cause and also an association between environmental factors such as viruses and the onset of type 1 diabetes.

People with type 1 diabetes do not produce enough insulin, which means that blood glucose concentration remains high.

And then for number two, how is type 1 diabetes monitored and treated? People with type 1 diabetes have to regularly check their blood glucose levels and inject themselves with insulin.

Eating a low sugar and carbohydrate diet and exercising regularly can help keep blood glucose levels lower.

There's quite a lot of information on that slide.

If you need to pause a video to check your answer against this, then please do, and add in any extra detail.

But we're going to move on now to the final part of today's lesson.

Great job so far.

We know about regulating glucose levels with insulin.

We've talked about type 1 diabetes.

So let's look now in a bit more detail about type 2 diabetes.

People with type 2 diabetes produce insulin, but their cells no longer respond to it and become insulin resistant.

It's usually develops over many years and typically presents during adulthood.

So here the pancreas is detecting the high blood glucose concentration, but people with type 2 diabetes, they still produce insulin.

However, the liver and muscle cells do not respond to that insulin and therefore their body is less able to convert glucose to glycogen.

So the key difference between type 1 diabetes and type 2 diabetes is that people with type 1 diabetes do not produce enough insulin, but people with type 2 diabetes do produce insulin, but their liver and muscle cells do not respond to that insulin.

Type 2 diabetes is characterised by uncontrolled high blood glucose levels in a similar way to type 1 diabetes.

Type 2 diabetes, however, usually develops over many years and obesity is a risk factor for developing it.

Some people are genetically predisposed to develop type 2 diabetes.

So eating a diet high in sugar, fat and carbohydrates can lead to obesity.

And obesity is a risk factor for developing type 2 diabetes.

The main treatment for type 2 diabetes is to follow a low sugar and carbohydrate diet and partake in regular exercise.

When carbohydrates are digested, they are broken down into sugar, therefore limiting carbohydrates will keep blood glucose levels lower.

So two main treatments for type 2 diabetes are having a low carbohydrate diet, rich in protein and vegetables, which we can see in this picture here.

So lots of meat, eggs, vegetables, avocados, and then also partaking in regular exercise can help to combat type 2 diabetes by reducing blood glucose levels.

If a person does not respond to controlling their diet and exercise, then they may have to be prescribed medicine to help cells respond better to insulin.

Help the pancreas make more insulin.

Slow down the digestion and absorption of carbohydrates.

And reduce the amount of glucose that the liver releases.

And this year is showing you a medication called metformin, which is a medication that people who have type 2 diabetes may take.

So if diet and exercise alone doesn't help to control blood sugar levels, then medicine may be prescribed.

Let's quickly check our understanding, which are true for type 2 diabetes? A, the pancreas does not secrete enough insulin.

B, cells in the liver and muscles do not respond to insulin.

Or C, leads to high blood glucose concentration.

So this is B, in type 2 diabetes, cells in the liver and muscles do not respond to insulin.

But also C is correct because type 2 diabetes does lead to high blood glucose concentration.

A is incorrect, because people with type 2 diabetes do produce insulin, it's just that their cells don't respond to it.

Type 1 diabetes is where the pancreas does not secrete enough insulin.

So well done if you've got that right.

Next question, what is the usual treatment for type 2 diabetes? A, eat a low carbohydrate and sugar diet.

B, regular exercise.

Or C, injections with insulin.

This is A and B.

Injections with insulin are not usually a method of treatment for type 2 diabetes because cells of the body do not respond to insulin, so it wouldn't be as an effective treatment.

The table below summarises type 1 and type 2 diabetes and we've got the stage when it typically presents the ability of the pancreas to produce insulin, sensitivity of cells to insulin and the treatment.

So let's go through what that looks like for type 1 and type 2 diabetes.

So type 1 diabetes usually presents in childhood or early teens, whereas type 2 diabetes usually presents itself later in life during adulthood.

In type 1 diabetes, the pancreas does not produce enough insulin.

In type 2 diabetes, the pancreas does produce a sufficient amount of insulin and then the sensitivity of cells to the insulin.

In type 1 diabetes, cells are responsive to insulin, whereas in type 2 diabetes, cells are not responsive to insulin.

So therefore looking at the treatments because cells are responsive to insulin, then the treatment for type 1 diabetes is injection with insulin because body just simply doesn't have enough of it.

Whereas in type 2 diabetes, you wouldn't inject with insulin, instead, the first treatment plan would be for an individual to lose weight through a low carbohydrate diet and regular exercise.

Type 2 diabetes can be reversed through this method.

However, if somebody is not able to control their blood glucose levels through diet and exercise alone, they may be prescribed certain medications.

This graph shows the difference between the glucose levels of a diabetic and a non-diabetic.

So we can see here we've got blood glucose concentration in milligrammes per deciliter on the y-axis and time on the x-axis.

And over time we can see in a non-diabetic person that blood glucose levels will be at rest, normal and then they may eat something and they increase, but then the body responds by producing insulin and quickly that blood glucose level decreases back to normal levels.

And this here is showing you levels in a diabetic person and first of all what we can see is that the diabetic person has a higher fasting glucose level.

So at rest their glucose level is higher than somebody who is non-diabetic.

There is a large increase in glucose after a meal.

So you can see after they've eaten something, their blood glucose increases by more than a non-diabetic person.

And then you can also see that blood glucose takes longer to decrease back to baseline levels.

So in a non-diabetic person, the insulin takes effect quite quickly and blood glucose levels return to normal.

Whereas in a diabetic person we can see there that the blood glucose is taking much longer to get back to the baseline level.

Let's check our understanding.

Are these statements describing type 1 or type 2 diabetes? Thoughts to be caused by genes and environmental factors.

Cells do not respond to insulin.

Treated by injecting with insulin.

Pancreas does not secrete enough insulin and usually presents in adulthood.

So type 1 or type 2 diabetes? Right? Looking at the first statement, that is type 1 diabetes thought to be caused by genes and environmental factors such as viruses.

Cells do not respond to insulin.

That is type 2.

Treated by injecting with insulin.

That is type 1.

The pancreas does not secrete enough insulin is also type 1.

And usually presents in adulthood.

That is type 2.

So well done if you manage to get all of those correct.

We're ready now to move on to the final task of our lesson.

In part one, you need to describe what causes type 2 diabetes and the effect this has on the body.

And then number two, how is type 2 diabetes treated? Then moving on to question three, two people are given a meal at 9:00 a.

m.

and their blood glucose is monitored in the following hours.

Which person is more likely to have diabetes and why? So you need to use the graph and decide which person is more likely to have diabetes and explain why.

I'm sure you're going to do a fantastic job.

Pause the video and then press play, ready for me to feedback the answers.

Let's see how we did.

So number one, the causes of type 2 diabetes and the effect it has on the body.

Type 2 diabetes is linked to obesity.

People with type 2 diabetes produce insulin, but their cells do not respond to it increasing blood glucose levels.

For number two.

How is type 2 diabetes treated? People with type 2 diabetes are encouraged to lose weight through a low carbohydrate diet and regular exercise.

If this does not work, they may be given medication that helps our cells to respond to insulin, stimulates insulin production in the pancreas or reduce the amount of glucose absorbed by the small intestines.

And then for question three, which of these people is more likely to have diabetes? So first of all, you should have said that person B is more likely to have diabetes.

And the reasons why? They have a higher fasting glucose level.

They experience a greater rise in blood glucose concentration after eating a meal.

And it takes longer for person B's blood glucose to decrease and it doesn't return back to normal within three hours.

Really great job if you manage to get all of that information into your answers.

If you need to pause a video to go back to add any extra detail in, then please do, but we're going to summarise everything that we have learned so far in the next slide.

A great job in today's lesson, we've been looking at type 1 and type 2 diabetes.

And first of all, we said that diabetes is a disease where the body cannot regulate blood glucose levels and that the pancreas is a gland that secretes the hormone insulin to lower blood glucose levels.

So type 1 diabetes is when the pancreas does not secrete enough insulin and this means that not enough glucose is converted to glycogen in the liver and blood glucose becomes high.

Treatment involves injecting with insulin and following a low carbohydrates diet.

We then looked at type 2 diabetes and we said type 2 diabetes is when liver and muscle cells no longer respond to insulin.

And this means not enough glucose is converted into glycogen and blood glucose levels remain high over long periods of time.

Treatment involves following a low sugar and carbohydrate diet and following an exercise regime.

So we know the differences between type 1 and type 2 diabetes and we understand how the body normally works to regulate blood glucose levels.

I've really enjoyed today's lesson.

I hope you have too and I look forward to seeing you next time.