- [Voiceover] The pancreas is interesting,
because the pancreas is actually part
of two different organ systems.
It's part exocrine and part endocrine.
The exocrine function of the pancreas
is going to help with the digestive system.
While the endocrine function well obviously
that's the endocrine system.
The pancreatic hormones, which is glucagon,
insulin, somotastain;
they're going to help to keep your blood glucose levels
in proper balance.
What you're going to find into the pancreas
are these little islets.
Inside these islets or inside these little spaces
are the alpha and beta cells.
Alpha secretes the hormone glucagon.
Beta secretes the hormone insulin.
Well insulin, you might have heard of that one,
is meant to lower blood sugar levels.
Glucagon is meant to raise blood sugar levels.
That means they're meant to do the opposite thing.
Glucagon, the hormone produced by the pancreas,
is meant to raise your blood sugar.
The way it raises blood sugar
is by taking glycogen, a stored type of sugar
which is found in your liver,
and converting it into glucose.
Now glucose is a simple sugar.
So the hormone glucagon can raise your blood sugar.
Insulin though is meant to lower your blood sugar.
Instead of trying to increase amount
it's dropping amounts of sugar in your blood.
It causes various cells to help absorb the sugar,
to take up the sugar and store it.
So glucagon and insulin.
This graph is trying to show the relationship
of meals to glucagon and insulin and blood glucose levels.
So along the bottom you're going to see the time and hours.
Zero time is when the meal pretty much was.
After you eat a meal,
'kay notice how your blood sugar levels go up.
Where your blood sugar levels go up,
the pancreas is making insulin.
But if it's making insulin is going to inhibit glucagon.
You really only want one of these two hormones at a time.
So this increase in insulin caused the liver
to help take up glucose.
The muscle cells try to use more glucose.
Adipose are going to use more glucose.
The idea is you're dropping, dropping, dropping
your blood sugar.
Also notice it goes a little bit too low.
Well that low blood glucose would then inhibit insulin.
So hey hold on, stop insulin you went to far.
It'll stimulate glucagon,
which then helps convert some stored carbohydrates,
glycogen, and converts them back into glucose.
Now we kind of start to level off again.
The whole process is a constant give and take.
It never completely perfectly flatlines.
It's always a little bit of a wave going up and down.
Our next gland is the adrenal gland.
You're going to have a cortex and a medulla here.
The adrenal cortex is the outside.
Adrenal medulla is the inside.
If we start with the cortex,
they have this grouping called the glucocorticoids.
Now coritsol is just one example,
but there's many different hormones in the glucocorticoids.
These glucocorticoids, they're helping maintin
blood glucose levels during long periods without food.
Most of these secretions are controlled
from the hypothalamus-pituitary control center.
We have mineralcorticoids.
Aldosterone is a main example here.
The mineralcorticoids, specifically aldosterone,
is going to help with sodium and water balance in your body.
By balancing sodium and potassium and water,
it helps make sure that your body's staying hydrated enough
and keeping everything in proper level.
Adrenal medulla.
Now the adrenal medulla is referred to
as a neuroendocrine gland.
The reason it's neuroendocrine
is because it will produce hormones,
but it's made up of nervous tissue.
Neuroendocrine, nervous and endocrine together.
So the adrenal medulla will actually triggered
by the sympathetic nervous system.
It's part of your nervous system
that helps control a lot of the
basic functionalities you have.
The hormones, epinephrine and norepinephrine.
Now this epinephrine and norepinephrine,
specifically the epinephrine,
gives rise to your fight or flight response.
Well your fight or flight is your put in a situation
it might be a life threaten situation,
either you fight the situation to try to survive,
or you run, flight, from the situation to survive.
So the fight or flight.
So your body pretty much goes on autopilot
and reacts automatically.
Alright we have our threats,
whether they're perceived or real it doesn't matter.
If your brain thinks it's a threat,
it's going to act as if it was a threat.
It activates the sympathetic nerves,
remember these are the ones that are involuntary.
The ones that just are controlling
your basic functionalities.
And surviving a threat is a basic functionality.
Sends the information down to the adrenal medulla,
the inside of the adrenal gland.
The norepinephrine, epinephrine are secreted.
They're secreted into the blood,
which travels to every cell in the body;
whichever ones are being targeted,
things like your eyes for eyesight;
your lungs for more respiration;
your muscles for more movement.
They'll reach those target cells
and cause 'em to kind of become agitated,
become excited and ready to move.