The Pituitary Gland and the Hypothalamus

Question 1

what is the name given to the depression in the skull where the pituitary gland sits?

Answer 1

sella turcica

Question 2

in the body of which cranial bone does the pituitary gland sit?

Answer 2

sphenoid bone

Question 3

identify structures 1-5

Answer 3

1. hypothalamus
2. pituitary gland
3. optic chiasma
4. thalamus
5. sphenoid air sinus

Question 4

Clinical: Enlargement of the pituitary gland in disease often impinges on the crossing fibres of the optic chiasm.
Which fibres from the optic nerve, nasal or temporal, cross over to the opposite side at the chiasm?

Answer 4

nasal fibres

Question 5

What therefore would the resultant visual field defect be due to pituitary gland enlargement?

Answer 5

bitemporal hemianopia

Question 6

what is the anterior pituitary gland also called?

Answer 6

pars anterior/adenohypophysis

Question 7

what is the posterior pituitary gland also called?

Answer 7

pars nervosa/neurohypophysis

Question 8

1. identify which is anterior and which part is posterior
2. label the pituitary stalk, anterior and posterior lobes

Answer 8

Question 9

which is the larger of the two pituitary lobes?

Answer 9

anterior pituitary

Question 10

which of the two pituitary lobes is glandular and manufactures numerous hormones?

Answer 10

anterior pituitary

Question 11

what is the function of the posterior pituitary?

Answer 11

stores hormones coming from hypothalamus in synaptic terminals and releases them when required

Question 12

label the anterior and posterior pituitary

Answer 12

Question 13

Now look at the image below showing anterior pituitary under high power. Identify three types of cells: acidophilic (which stain pink), basophilic (which stain light purple) and chromophobic (which do not take up much stain and therefore appear pale). Can you see capillaries?

Answer 13

Question 14

The posterior pituitary looks very different to the anterior pituitary (see image below). It contains non-myelinated axons which are the neurosecretory cells. The cell bodies of these cells are located in the hypothalamus.
What hormone(s) do these cells secrete?

Answer 14

• ADH/vasopressin
• oxytocin

Question 15

what are the two types of acidophils found in the anterior pituitary called and what do they secrete?

Answer 15

• somatotrophs > secrete GH
• mammotrophs > secrete prolactin

Question 16

what are the three types of basophils found in the anterior pituitary and what do they secrete?

Answer 16

• corticotrophs > ACTH, MSH
• thyrotrophs > TSH
• gonadotrophs > FSH, LH

Question 17

what is the arterial blood supply of the hypothalamus and pituitary?

Answer 17

• from branches of the internal carotid artery > the superior hypophysial artery and the inferior hypophysial artery.
• superior hypophysial > hypothalamus and anterior pituitary
• inferior hypophysial > posterior pituitary

Question 18

how does the hypothalamus communicate with the anterior pituitary?

Answer 18

hypothalamic-hypophyseal portal system

Question 19

how does the hypothalamus communicate with the posterior pituitary?

Answer 19

hypothalamic axons and nerve terminals

Question 20

venous drainage of hypothalamus and pituitary?

Answer 20

through hypophysial veins into the cavernous sinus