0:00

Let's talk a little pituitary anatomy physiology.

0:03

It's kind of my thing.

0:05

Here's a Coronal T2 fast spin echo image,

0:08

high resolution. Here's a coronal T1.

0:10

Contrast is on board.

0:11

There's a pituitary tuft and stalk.

0:13

And here's the sagittal T1 weighted non-contrast

0:18

image as a reference so you can see where you are.

0:20

If I click over here, you can see you're right about

0:23

in the middle of the anterior pituitary gland.

0:27

Now, the anterior pituitary gland secretes a

0:29

lot of stuff. It secretes growth hormone,

0:32

thyroid stimulating hormone (TSH), follicle stimulating

0:36

hormone (FSH), luteinizing hormone (LH),

0:39

adrenocorticotrophic stimulating hormone or ACTH

0:43

and melanin stimulating hormone (MSH).

0:47

So that's the anterior gland.

0:49

In the posterior gland, you're going to have secretion of

0:51

antidiuretic hormone and oxytocin which control breast

0:57

milk secretion, hyponatremia or serum sodium, and other

1:02

factors that are a little bit beyond

1:04

the scope of this discussion now.

1:06

But let's look at the anatomic position of structures in

1:10

the pars distalis or anterior portion of the

1:13

pituitary gland known as the pars distalis.

1:16

Here's the tuft. And right next to it,

1:17

these little dark areas known as the mucoid ridge.

1:21

Found here are ACTH and TSH secreting microadenomas.

1:27

Now, this is important because surgical indication for

1:30

microadenomas is much stronger when you have ACTH

1:34

secretors or in the lateral wedge where you find growth

1:38

hormone secretors that produce either gigantism in the

1:42

adult or acromegaly in the younger individual.

1:44

What else is found out here in the lateral wedge?

1:48

The common prolactin-secreting microadenomas.

1:51

So prolactin and GH secretors out here,

1:55

ACTH and TSH secretors in here in the mucoid wedge.

1:59

And then finally, FSH and LH secretors,

2:03

quite uncommon,

2:04

can occur anywhere in the gland because

2:06

they're scattered throughout the gland.

2:08

We'll turn our attention to gland size

2:11

and shape in a separate vignette.