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Flashcards in Pituitary 1 Deck (32)
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1
Q

What are the 6 hormones released by the anterior pituitary gland?

A

GH, TSH, ACTH, PRL, FSH, LH

2
Q

What are the regulating hormones for stimulating or inhibiting release of the hormones of the anterior pituitary gland?

A

GHRH, GHIH (somatostatin), GnRH, CRH, PIF/Dopamine, TRH

3
Q

How does the hypothalamus communicate with the anterior pituitary gland?

A

Via the vascular portal system

4
Q

What embryological structure becomes the anterior pituitary gland?

A

Rathkes pouch

5
Q

Mammosomatotrophs, somatotrophs, and lactotrophs are derived from stem cells that express which transcription factor?

A

PIT 1

6
Q

Gonadotrophs are derived from stem cells that express which two transcription factors?

A

SF1 and GATA 2

7
Q

Talk about the anatomy of the posterior pituitary gland, its relationship with the hypothalamus, the 2 hormones secreted, their target functions, and what triggers their release.

A

The hypothalamus and the posterior lobe is connected via the pituitary stalk. They communicate via axons. So oxytocin and ADH are produced in the hypothalamus and stored in the terminals of the axons in the posterior lobe. Oxytocin is released upon cervix dilation for uterine contraction for labor and upon nipple stimulation for lactation. ADH is triggers by several different stimuli including increased osmolarity to conserve water.

8
Q

What are the three most common causes of hyperpituitarism and which is most common?

A
  1. Adenoma
  2. Hyperplasia
  3. Carcinomas of the anterior pituitary
9
Q

What age is peak incidence for a pituitary adenoma?

A

35-60

10
Q

What do non functional adenomas usually present with?

A

Mass effect

11
Q

What are the three most common symptoms of mass effect due to a non functional adenoma?

A

Headache, bilateral temporal hemianopsia due to compression of optic chiasm, hypopituitarism because of compression of normal anterior lobe tissue.

12
Q

What size of pituitary adenoma corresponds with microadenoma, macro adenoma, and giant adenoma?

A

Less than 1 cm, 1-4 cm, and greater than 4

13
Q

What are the most common mutations in pituitary adenomas?

A

G protein mutations

14
Q

Roughly half of somatotroph cell adenomas have what mutation?

A

GNAS

15
Q

What structure do we always need to keep in mind as a buzz word for a pituitary adenoma?

A

Sella turcica

16
Q

What is typical behavior of atypical pituitary adenomas and what mutation are we dealing with?

A

Very aggressive/invasive

TP53 mutations

17
Q

What are the specific cell types secreting the anterior pituitary hormones?

A

Lacotrophs, somatotrophs, corticotrophs, gonadotrophs, and thyrotrophs

18
Q

What is the most common functioning pituitary adenoma and the prevalence?

A

Lactotroph adenoma at 30%

19
Q

2 main clinical signs of lactotroph adenoma in females?

A

Amenorrhea and galactorrhea

20
Q

Which gender and age is most commonly diagnosed with lactotroph adenoma early and why?

A

Women 20-40 because their period is messed up

21
Q

2 most common clinical symptoms in men with a lactotroph adenoma?

A

Decreased sex drive and headache due to mass effect

22
Q

Histologically, what are the two classifications of lactotroph adenomas and which one is more common and which one is rare?

A

Sparsely granulated is most common

Densely granulated is rare

23
Q

2 ways to treat lactotroph adenomas?

A

Surgery or more commonly give a dopamine agonist like bromocriptine or cabergoline

24
Q

In the abasence of a lactotroph adenoma, what 6 situations can increase prolactin in the body?

A

Pregnancy, lactation, loss of dopamine, mass, renal failure, hypothyroidism

25
Q

What is the second most common type of functioning pituitary adenoma and what do these adenomas cause in kids and adults?

A

Somatotroph adenoma.

Gigantism in kids and acromegaly in adults

26
Q

3 most common clinical signs of acromegaly in adults?

A

Enlarged bones of hands, feet and jaw
Enlarged visceral organs leading to problems like heart failure
Enlarged tongue

27
Q

What is the most common clinical sign of gigantism in kids?

A

Long bone growth in arms and legs

28
Q

What condition presents secondary to somatotroph adenoma and why?

A

Diabetes because GH induces liver gluconeogensis

29
Q

The diagnoses of growth hormone adenoma relies heavily on what two things being elevated in the serum?

A

GH and IGF1

30
Q

What is the most sensitive test for diagnosis acromegaly?

A

Failure to suppress GH production in response to an oral load of glucose

31
Q

Three ways to treat somatotroph adenoma?

A

Surgery, somatostatin agonist, or GH receptor antagonist

32
Q

What is unique about a somatotroph that is unlike the other pituitary adenomas?

A

It can be mixed with prolactin secreting cells, which created a pituitary adenoma called a mammosomatotroph adenoma