- [Voiceover] It's time to start moving
into the actual glands and going gland by gland
through the body.
We'll start with the hypothalamus.
The hypothalamus is up in the bottom part of the brain.
It's really the homeostatic control center of the brain.
It helps to coordinate the brain's activity,
helps to process information entering and exiting,
helps to coordinate all the hormone control
of pituitary glands.
So it's linking the nervous system and endocrine system.
It actually makes two of its own hormones.
It makes antidiuretic and it makes oxytocin.
So by producing these two hormones, it's playing the part
of endocrine but it's also playing the part of nervous
because it's making these hormones with nervous tissue.
Now the hypothalamus is going to control the secretions
of the pituitary gland.
Controlling because it sends down stimulatory
or inhibitory signals to the pituitary gland.
Ha ha, that pituitary gland.
Lot of times you can hear it
referred to as the master gland.
Now, master gland, maybe, maybe not.
Can think that the hypothalamus controls it,
but a lot of times you'll think of it as master gland.
Secretes eight different hormones
that control other endocrine organs.
And that's why it's a lot of times
referred to as the master gland.
It has a front and back, anterior, front, posterior, back.
So the anterior and posterior pituitary
both make up the overall pituitary gland.
The posterior pituitary is connected to the hypothalamus
and that means it can receive the two hormones
the hypothalamus produces.
The hypothalamus produces antidiuretic hormone
and oxytocin.
So it's produced in the hypothalamus
and then transported to the posterior pituitary.
The posterior pituitary will store
and then secrete those two hormones.
So antidiuretic we already said is being stored
in the posterior pituitary,
but it's meant to conserve water.
Helps to balance the water in your bodies.
The more antidiuretic hormone you have,
the more water is being conserved.
The more water is being kept in your body.
Oxytocin.
Oxytocin is going to interact
with uterine contractions during labor.
It deals with milk ejection
as the infant is starting to feed.
So oxytocin and antidiuretic hormone.
Both produced by the hypothalamus,
but stored and secreted through the posterior pituitary.
So here's a look at that posterior pituitary.
All of it is at the back half of the pituitary gland.
Now the posterior pituitary could have a nursing infant,
the stimulus is received, travels up the spinal cord
to the hypothalamus.
It causes the cells in the hypothalamus
to release more oxytocin.
Oxytocin is transported down to the mammary glands.
So it's a feedback cycle.
The stimulation of the nursing infant
causes more milk production and more milk ejection.
But it's all helped by the hormone oxytocin.
Now to go to the front side of the pituitary,
go to the anterior pituitary.
We still are controlled by the hypothalamus.
But in this case, the hypothalamus is not producing hormones
that are stored by the anterior pituitary.
Instead, the hypothalamus is producing, releasing,
inhibiting hormones.
So if our releasing hormone comes down,
the anterior pituitary releases that hormone.
But if an inhibiting hormone comes down,
the anterior pituitary will not
release that particular hormone.
So here we have ACTH, and abbreviations are perfectly fine.
ACTH stimulates the adrenal gland.
Makes the stuff called cortisol.
TSH, thyroid stimulating hormone.
Well, thyroid stimulating, it stimulates the thyroid.
Causes the thyroid to be functional.
FSH and LH, so follicle-stimulating hormone
and lutenizing hormone.
Both will help stimulate growth, development,
and functionality of the gonads.
So the ovaries and testes.
But these two hormones are typically not produced
until puberty is reached.
They happen to appear at the age of 10-13,
well, that varies, sometimes a little bit earlier,
sometimes a bit later, everyone goes through puberty
at their own rate.
But once an individual is producing FSH and LH,
they'll start to initiate sexual maturation.
It'll help with the development and process of puberty.
Prolactin helps with milk production.
Growth hormone.
Well, really, growth hormone does a lot.
It makes things grow, which makes sense.
So it has major effects on the bones and the muscles.
And most of its action is during childhood
and early adolescence,
when the largest amount of growth is occurring in the body.
Alright, we start with the hypothalamus.
It can either give a releasing or inhibiting hormone,
goes down to the pituitary,
and the pituitary can produce these six major hormones.
ACTH goes to the adrenal cortex,
TSH goes to thyroid,
FSH and LH head down to the ovaries and testes,
and yes, both males and females have both FSH and LH.
Prolactin, mammary glands.
Growth hormones, mainly the skeletal,
but muscles, and bones.
So here are the basic six hormones produced,
stored, and secreted from the anterior pituitary.
Well, just like any other system,
there are disorders, there's problems.
We have the term hypersecretion and hyposecretion.
Well, hypersecretion is when you have too much.
Hyposecretion is when you have too little.
In the case of diabetes insipidus,
you have hyposecretion of antidiuretic hormone.
That means that there's not enough antidiuretic hormone.
Well, if there's not enough antidiuretic,
that means the body's not conserving water properly,
which can lead to dehydration.
So diabetes insipidus.
Gigantism: hypersecretion of growth hormone in children.
That means there's too much growth hormone in a child.
They are growing faster than the average child.
Acromegaly.
Acromegaly is still extra growth hormone,
but it's extra growth hormone in adults.
So that means really, gigantism and acromegaly
have the same problem: too much growth hormone.
Difference is, in gigantism, the individual
becomes very tall, but everything's in proportion.
Arms, legs, hands, feet, everything looks normal, just big.
While in acromegaly, now things are not in proportion.
The hands, the feet, the face will be overgrown
compared to the rest of the body.
They get larger, more fit.
Pituitary dwarfism.
Well, we have hyposecretion, so not enough, growth hormone.
In this case, the individual ends up with short stature.
If a person's identified to have pituitary dwarfism
during childhood, they can be treated
by actually being given extra growth hormone.
Extra growth hormone during childhood
can potentially help to increase the rate of growth.
This is gonna show you the idea of pituitary gigantism
and pituitary dwarifsm.
I'm willing to bet you could probably guess
which one is the gigantism and which one is the dwarfism.
Actually, that little guy in the hand, dwarfism.
The big guy holding him, gigantism.
Here is acromegaly.
These pictures are all of the same individual
throughout their life.
The top left, young girl, looks totally normal.
Top right, you get a young female.
You might say the face is a little bit larger
at this point, but not much yet.
Bottom left.
Look at how the forehead, the nose, the jawline
has increased in size.
Bottom right, you can see how the facial features
are much larger and much coarser.
The progression of acromegaly.
The hypersecretion, or too much growth hormone
after typical growth has ended.