Pituitary Endocrine

Question 1

Polypeptide & AA derived hormones

Answer 1

• Prominent RER and Golgi
• Secretory granules
• bind surface receptors
• Stain w/:
• -Synaptophysin
• -Chromogranin
• -PGP 9.5

Question 2

Steroid hormones

Answer 2

• Cytoplasmic lipid bodies
• SER
• mitochondria
• Continuous Sythesis
• Bind nuclear receptors
• Stain w/ Melan A

Question 3

Corticotroph adenoma (Hormone / Lesion / Clinical sign)

Answer 3

• ACTH –> cortisol secretion
• anterior pituitary neoplasia & Diffuse Bilateral Hyperplasia of adrenal cortex

-

Question 4

Somatotroph adenoma (Hormone / Lesion / Clinical sign)

Answer 4

• GH and Insulin-like hormone
• anterior pituitary neoplasia, acromegaly
• PU/PD (insulin resistant)

Question 5

Adrenocortical adenoma

Answer 5

–

Question 6

Thyroid follicular cell adenoma

Answer 6

–

Question 7

Thyroid C-cell adenoma

Answer 7

–

Question 8

Parathryroid adenoma

Answer 8

–

Question 9

Pancreatic islet cell adenoma

Answer 9

–

Question 10

What cells are in the pars distalis

Answer 10

• mixed cell type
  1. Acidophils
  - GH, PRL
  2. Chromophobes
  
  • ACTH
    
    3. Basophils
  • ACTH, TSH, FSH, LH
• little stroma
• highly vascular

Question 11

Pituitary disorders

Answer 11

1. non-functional pituitary –> mass effect on hypothalamus
2. Suprasellar neoplasms
3. Pituitary adenomas (intermedia/distalis)
4. Diabetes insipidus (neurohypophysis)

Question 12

Dz’s of Pituitary gland

Answer 12

1. Developmental disorders
2. Postnatal disturbances of growth most common
3. Degeneration /necrosis
4. Inflammation

Question 13

Developmental disorders

Answer 13

1. Aplasia
2. Failure of adenohypophyseal development (Cystic Rathke’s pouch)
3. Cyst

Question 14

Cystic Rathke’s Pouch

Answer 14

Oropharyngeal ECTOderm fails to differentiate to adenohypophysis

• -> fail to produce any trophic hormones
• -> Panhypopituitarism

-German shepherd dogs

Question 15

Postnatal disturbances of pituitary

Answer 15

1. Physiologic atrophy
2. Proliferation
   
   • hyperplasia
   • neoplasia
     - Microadenoma /Macroadenoma

Question 16

Adenomas associated with Pars distalis

Answer 16

1. Corticotroph adenoma –> ACTH

2. Somatotroph adenoma –> GH and Insulin-like hormone

Question 17

Adenomas associated with Pars intermedia

Answer 17

1. Corticotroph adenoma -DOGS

2. Melanotroph adeoma -HORSE

Question 18

Pituitary Pars intermedia dysfunction(PPID) in horse (Hormone / Lesion / Clinical sign)

Answer 18

• CLIP, MSH, Endorphines
• Enlarged pituitary gland (intermedia)-can cause damage to dopaminergic neurons of Pars nervosa

Clinical signs (due to mass effect)

• long, matted hair coat
• lack of temp regulation
• adipose deposits
• NORMAL adrenal gland

Question 19

Why is PPID, not a true cushing’s?

Answer 19

ACTH measures high in horses with PPID

• CLIP is structurally similar to ACTH, so it is detected by laboratory as ACTH
• However, adrenal glands are normal. Suggesting CLIP does not act like ACTH to secrete excess cortisol. –THEREFORE, it cannot be considered Cushings

Question 20

Define hirsutism –whats its significance

Answer 20

Excessive hairy-ness

-horses with PPID will present with this.

Question 21

2 suprasellar tumors

Answer 21

1. Craniopharyngioma

2. Germ cell tumor

Question 22

Main cause of Degeneration/ necrosis of pituitary

Answer 22

Compression via pituitary mass

-infarcts are rare

Question 23

Inflammation in pituitary

Answer 23

1. Immune mediated hypophysitis
2. Systemic infection–hematogenous
3. Adjacent inflammation

Question 24

What hormones are produced in the Pars Intermedia? and whats special about the dog?

Answer 24

MSH and CLIP

-Dogs: ACTH

Question 25

Disruption to HPA axis in fetus is assoc’ d w/….

Answer 25

prolonged gestation in ruminants