Histology-Pituitary & Pineal

Question 1

Identify the structures indicated below:

Answer 1

1) Pars anterior 2) Pars nervosa 3) Pars intermedia 4) Pars tuberalis wrapping around infundibulum

Question 2

What makes up the bulk of the pars nervosa?

Answer 2

Axons extending from neurons in the supraoptic and paraventricular nuclei in the hypothalamus

Question 3

Identify the structures indicated below:

Answer 3

1) Anterior pituitary 2) Pars nervosa 3) Pars intermedia 4a) Pars tuberalis 4b) Infundibulum

Question 4

Identify the structures indicated in this slice from the anterior pituitary:

Answer 4

1) Basophils 2) Acidophils 3) Colloid mass 4) Erythrocytes in fenestrated capillaries

Question 5

What products are secreted by acidophils from the anterior pituitary?

Answer 5

Lactotrophs secrete prolactin. Somatotrophs secrete growth hormone.

Question 6

What products are secreted by basophils from the anterior pituitary?

Answer 6

Gonadotrophs secrete FSH and LH. Corticotrophs secrete ACTH, beta-endorphin and beta-lipotropin. Thyrotrophs secrete TSH.

Question 7

Identify the structures indicated in this slice from the anterior pituitary:

Answer 7

1) Acidophil 2) Basophil

Question 8

Identify the structure shown below:

Answer 8

Colloid mass

Question 9

What are the precursor cells to the cells indicated below? Degranulated cells? Follicular cells?

Answer 9

The cells shown are chromophobes.

Question 10

What structure is indicated below?

Answer 10

Junction between the pars distal is and pars nervosa.

Question 11

Identify the structures indicated below:

Answer 11

Large colloid follicles in the pars intermediate

Question 12

Identify the structures indicated below:

Answer 12

Herring bodies, these are grayish bodies found in the sea of axons of the pars nervosa. Note that larger Herring bodies have granules inside of them.

Question 13

What should be covering this structure?

Answer 13

This is the pineal body and it should be covered by pia mater. Note the brain sand (black spots), highly vascularized tissue and high density of pinealocytes.

Question 14

What structures are indicated below?

Answer 14

Note the corpora arenacea (brain sand) indicating that we are in the pineal gland. 1) secretory pinealocytes (rounded nuclei) 2) glial cells (elongated nuclei)

Question 15

What structures are indicated below?

Answer 15

1) secretory pinealocytes (rounded nuclei) 2) glial cells (elongated nuclei)

Question 16

What is the origin of the structure indicated below?

Answer 16

This is a colloid-containing cyst in the pars intermedia. These are remnants of Rathke’s pouch (hypophyseal diverticulum from the oral cavity)

Question 17

What part of the pituitary gland are you looking at and what is secreted from this region?

Answer 17

This is the pars nervosa, full of axons that descend from the supraoptic and paraventricular nuclei of the hypothalamus. ADH and oxytocin are secreted from the pars nervosa.

Question 18

What structures are indicated below?

Answer 18

A pituicyte and Herring body (storage area containing neurosecretory granules in axonal swellings along the length of the axon)

Question 19

What type of capillaries are found in this sample from the pituitary gland?

Answer 19

Note the acidophils, basophils and RBCs stained with MSB. The pars anterior has fenestrated capillaries to allow secretory products from the endocrine cells access to the blood.

Question 20

The stain below was specific for basophils. What hormones are synthesized by basophils?

Answer 20

FSH, LH, Thyrotrophin and Adrenal Corticotropin

Question 21

What is this section taken from?

Answer 21

Pineal gland. Note the lobules with striations that extend into the trabeculae. Note that the lobules are full of melatonin-secreting pinealocytes.