Embryogenesis of Hypothalamus & Pituitary

Question 1

Anterior pituitary

Answer 1

originates from stomodeal ectoderm which is tissue in roof of embryonic mouth
-AKA adenohypophysis

Question 2

Stomodeal ectoderm

Answer 2

gives rise to a diverticulum (outpouching of flesh) called Rathke’s pouch

-as pouch forms, it breaks off from stomodeum and forms its own lobe

Question 3

Posterior pituitary

Answer 3

originates from the floor of the brain as a diverticulum called the infundibulum

-infundibulum differentiates into neurohypophysis (neural tissue)

Question 4

Sphenoid bone

Answer 4

forms a protective cavity around pituitary termed sella turcica

Question 5

Neural folds of ectoderm

Answer 5

will fold in on themselves and form neural tube (precursor to CNS)

Question 6

Non-neural ectoderm

Answer 6

forms peripheral nervous system

Question 7

Surge and Tonic centers

Answer 7

parts of hypothalamus that regulate reproductive hormones

-develop in absence of estradiol as it can’t cross the BBB

Question 8

Estradiol

Answer 8

Produced by female fetus, has high affinity for alpha-fetoprotein which cannot cross the blood brain barrier

Question 9

Development of male/female hypothalamus

Answer 9

Exposure to androgens during beginning of development begins to differentiate the hypothalamus