An overlay on the profile of a man's head and shoulders
shows the pituitary gland just below the brain ahead of the brain stem.
The pituitary gland lies deep inside the head. It's often called the "master gland"
because it controls many of the things other glands do.
A box contains an enlarged view of the pituitary and hypothalamus.
The pituitary looks like two bulbs hanging below the hypothalamus,
a rectangular structure
Just above the pituitary is the hypothalamus.
It sends hormonal or electrical signals to the pituitary.
These determine which hormones the pituitary will release.
For example, the hypothalamus might send a hormone called GHRH,
or growth hormone releasing hormone.
Another box appears next to the one showing the pituitary.
It contains the cutaway image of a man's head and shoulders.
One half of the image shows the man's muscles, the other the skeleton.
Arcs streaming from the pituitary show the release of hormone.
That would trigger the pituitary's release of growth hormone,
which affects the size of both muscle and bone.
How important is this?
The box on the right is replaced by a full frontal image of a man with a fig leaf over his genitals.
Not getting enough during childhood can cause pituitary dwarfism.
The man's image shrinks.
Getting too much can cause the opposite condition called gigantism.
The man's image grows significantly larger than the original image.
Then the image is replaced by a box showing
a man's head with hardened and dry looking features.
In a body that has already matured, too much growth hormone can cause acromegaly.
With this condition, facial features become rough and course;
the voice becomes deeper; and hand, foot, and skull size expand.
A new image in the box shows a close up a man's neck with an overlay of the thyroid gland.
The gland in the middle of the neck resembles a pair of lobed wings.
A different hormonal command from the hypothalamus might trigger the
release of thyroid stimulating hormone or TSH.
TSH causes the thyroid to release two hormones called T3 and T4
that stimulate metabolism in other cells throughout the body.
The box is now replaced by a frontal image of a man with an overlay
of the skeleton showing the kidneys on either side of the lower spine.
The pituitary can also release a hormone called antidiuretic hormone, or ADH.
It's produced in the hypothalamus and stored in the pituitary.
A box showing one kidney and ureter replaces the skeletal image.
ADH affects the production of urine. When it's released,
the kidneys absorb more of the fluid that passes through them.
That means less urine is produced.
Alcohol inhibits the release of ADH,
so drinking alcoholic beverages results in more urine production.
A pulsing change in the ureter's color shows urine passing through it.
The screen changes to show a frontal image of a woman.
Her breasts and genitals are covered by fig leaves.
An overlay shows the adrenal glands below her breasts
on either side of the abdomen and also shows the ovaries.
The pituitary gland produces other hormones that control
other bodily functions and processes.
For instance, follicle stimulating hormone, or FSH, and luteinizing hormone, or LH,
are hormones that affect the ovaries and egg production in women.
In men, they affect the testes and sperm production.
Prolactin is a hormone that affects breast tissue in nursing mothers.
ACTH or adrenocorticotrophic hormone causes the adrenal glands
to produce important substances similar to steroids.
The screen changes again. The frontal image of the man is on the left.
On the right is a box with a close up of the man's head.
As the narrator talks, the images change.
Growth,
The full figure grows larger on screen.
puberty,
The facial image grows a beard.
baldness,
The facial image has lost its hair.
even sensations like hunger and thirst,
are just a few of the processes that are influenced by the endocrine system.