Histology of the Endocrine System

Question 1

What are the two parts of the Hypophysis cerebri (pituitary gland)

Answer 1

Adenohypophysis (glandular part)

Neurohypophysis
(neural part)

Question 2

What are the 3 parts of the Adenohypophysis?

Answer 2

-Pars distalis
(anterior lobe)

• Pars intermedia
  (intermediate lobe)
• Pars tuberalis
  (tuberal lobe)

Question 3

What 3 types of cells occur in clusters in the pars distalis of the adenohypophysis?

Answer 3

Acidophils (Somatotrophs and Lactotrophs)

Basophils (Gonadotrophs, Thyrotrophs, Corticotrophs)

Chromophobes (post-secretory acidophils and basophils, follicular cells and stellate cells)

Question 4

What types of cells are found in the pars intermedia of the adenohypophysis?

Answer 4

• Melanotrophs
• Corticotrophs
• Follicular cells
• Stellate cells
• Cells lining the
  hypophysial cleft.

Question 5

What types of cells are found in the pars tuberalis of the adenohypophysis?

Answer 5

• Pars tuberalis cells
• Gonadotrophs
• Thyrotrophs

Question 6

What are the 3 parts of the neurohypophysis?

Answer 6

1. Median eminence.
2. Infundibulum
   (Infundibular stalk).
3. Pars nervosa (neural
   lobe).

Question 7

What cells are found in the neurohypophysis?

Answer 7

• Axons:
• Cells bodies are in the
  hypothalamus.
• Central gliocytes
  (pituicytes):
• These are supporting cells (neuroglial cells).

Question 8

What is the function of the pineal gland (Epiphysis cerebri)?

Answer 8

Melatonin secretion

Question 9

What cells are found in the pineal gland?

Answer 9

1. Pinealocytes
2. Central gliocytes

Question 10

What is brain sand?

Answer 10

Brain sand, also called Corpora arenacea, is normal. It consists of intercellular calcium deposits found in the pineal gland of old animals.

Question 11

How do thyroid follicular epithelial cells differ between resting and active states?

Answer 11

Resting - squamous/cuboidal

Active - Columnar

Question 12

How does the appearance of the chief cells of the parathyroid gland differ between active and inactive states?

Answer 12

Active = nucleus stains dark due to condensed chromatin. It also has dark acidophilic cytoplasm.

Inactive: Pale nucleus with light acidophilic cytoplasm.

Question 13

In the parathyroid gland of which species do oxyphil cells occur

Answer 13

Occur singly & in
clusters in horse &
ruminants. Rare in other species. Function unclear.

Question 14

What are the zones of the adrenal cortex?

Answer 14

• Outermost zone:
  Zona glomerulosa
  (ruminants)
• clusters

Zona arcuata (horses, pigs, carnivores)
- arches

• Zona intermedia
• Zona fasciculata
• Zona reticularis

Question 15

What cells are found in the adrenal medulla?

Answer 15

Monoamine-secreting/ chromaffin cells

Question 16

Name groups of endocrine cells within nonendocrine organs

Answer 16

• Pancreatic islets
• Theca interna
• Corpus luteum
• Testicular interstitial cells

Question 17

Name the types of cells found in the pancreatic islets as well as what hormones they secrete

Answer 17

• Alpha cells (A cells)
• glucagon
• Beta cells (B cells)
• insulin
• C cells (undiff. become other islet cells)
• Delta cells (D cells)
• somatostatin

Question 18

Where are single endocrine cells found?

Answer 18

• Glandular stomach
• Intestine
• Trachea

Question 19

What is the Diffuse neuroendocrine system?(DNES)

Answer 19

It consists of specialized cells scattered throughout the body that produce and release hormones in response to neurological or chemical signals.

Question 20

what are APUD cells?

Answer 20

• Some DNES cells are Amine Precursor Uptake
  and Decarboxylation (APUD) cells.
• APUD cells are able to take up &
  decarboxylate amines.

Question 21

Name the APUD cells

Answer 21

• Enteroendocrine cells (1% of cells lining GIT).
• Endocrine cells in mucosa of respiratory system.
• Juxtaglomerular cells in kidney.
• Pancreatic islet cells.
• Thyroid parafollicular cells.
• Corticotrophs & melanotrophs in
  adenohypophysis.