Anterior Pituitary

Question 1

Where is the anterior pituitary located?

Answer 1

Depression of sphenoid bone connected to hypothalamus by stalk

Question 2

Where is the anterior pituitary’s capillary plexus located?

Answer 2

Top of infundibulum

Question 3

Why is the blood brain barrier compromised in the hypothalamus/pituitary?

Answer 3

Due to fenestrated capillaries - more sensitive and no dilution

Question 4

What are the 5 anterior pituitary endocrine cell types?

Answer 4

Corticotrophs
Gonadotrophs
Thyrotrophs
Lactotrophs
Somatotrophs

Question 5

What cells are the acidophils?

Answer 5

Somatotrophs (GH)
Lactotrophs (Prolactin)

Question 6

What cells are the basophils?

Answer 6

Thyrotrophs (TSH)
Gonadotrophs (FSH and LH)
Corticotrophs (ACTH)

Question 7

What does a recessive PROP1 mutation cause?

Answer 7

decreased prolactin, GH, TSH, LH and FSH
Sub-/infetrtile
increased longevity

Question 8

What does a recessive PIT1 mutation cause?

Answer 8

Decreased prolactin and GH/TSH
Small and impaired fertility
Increased longevity

Question 9

What type of hormones are all anterior pituitary hormones?

Answer 9

Trophic and peptide hormones bar prolactin

Question 10

What process is anterior pituitary hormone release?

Answer 10

Receptor mediated process

Question 11

What is the endocrine axis for HPG?

Answer 11

GnRH -> FSH and LH -> gonads

Question 12

What is the endocrine axis for growth hormone IGF-I axis?

Answer 12

GHRH -> Growth hormone -> Liver, other cells, many organs and tissues

Question 13

What is the endocrine axis for HPT?

Answer 13

TRH -> TSH -> Thyroid

Question 14

What is the endocrine axis for HPA?

Answer 14

CRH -> ACTH -> Adrenal cortex

Question 15

What is the inhibitor for growth hormone?

Answer 15

SS

Question 16

Which 3 hormones belong to the melanocortins?

Answer 16

Adrenocorticotropic
Lipotropin
Melanocyte-stimulating hormone

Question 17

Which 2 hormones belong to the Somatomammotropins?

Answer 17

growth hormone
prolactin

Question 18

Which 3 hormones belong to the glycoprotein hormones?

Answer 18

Luteinizing hormone
Follicle-stimulating hormone
Thyroid-stimulating hormone

Question 19

Where are melanotrophs more abundant?

Answer 19

Loaded pituitaries

Question 20

How is prolactin regulated?

Answer 20

Increase in estrogen/progesterone increases prolactin (during pregnancy)

Question 21

What is prolactin release inhibited by?

Answer 21

Dopamine

Question 22

What are 5 physiological roles associated with prolactin?

Answer 22

Lactation - development of glandular tissue and milk production
Immune tolerance - suppresses maternal immune system
Nurturing instinct
Broodiness

Question 23

What is mammogensis?

Answer 23

Development of functional breast

Question 24

When does mammogenesis start and end?

Answer 24

In puberty and is completed in the third trimester in response to sustained levels of progesterone and estrogen

Question 25

What 2 things does prolactin specifically promote?

Answer 25

Lobuloalveolar proliferation and development Milk production pre and postpartum

Question 26

What cells does prolactin act on?

Answer 26

Lactocytes in alveoli

Question 27

What is hyperprolactinemia?

Answer 27

prolactin inhibits GnRH -> normal LH and FSH cycles resume when breast feeding stops

Question 28

What are 40% of hyperprolactinemia cases due to?

Answer 28

benign pituitary adenomas

Question 29

What is Galactorrhea?

Answer 29

Inappropriate expression of breast milk

Question 30

What is secondary amenorrhea?

Answer 30

Absence of normal uterine cycling outside of factors affecting ovaries due to hyperprolactinemia

Question 31

What does secondary amenorrhea cause?

Answer 31

Inhibiting GnRH production -> inhibits LH and FSH and then estrogen Infertility and loss of libido