Endocrine System

Question 1

Function of endocrine system

Answer 1

-maintenance of homeostasis-> mediated by hormones
-Regulated by feedback systems

Question 2

Increased function endocrine system

Answer 2

-Primary: increased hormone by abnormal gland
-Secondary: increased hormone by normal gland that is excessively stimulated

Question 3

Decreased function of endocrine system

Answer 3

-Primary: decreased hormone by abnormal gland
-Secondary: decreased hormone by normal gland that is inadequately stimulated

Question 4

Pituitary gland structure

Answer 4

-Anterior lobe (adenohypophysis)
Pars intermedia
Pars tuberalis
-Posterior lobe (neurohypophysis)
pars nervosa
Infundibular stalk

Question 5

Function of Adenohypophysis

Answer 5

-Growth hormone (somatotrophin)
-Luteotropic hormone (stimulate progesterone)
-Luteinizing hormone (stimulate estrogen)
-Follicle stimulating hormone (Follicle growth and spermatogenesis)
-TSH
-ACTH
-Melanocyte stimulating hormone

Question 6

Function of neurohypophysis

Answer 6

-ADH
-Oxytocin

Question 7

Acidophils

Answer 7

Somatotrophs and gonadotrophs

Question 8

Basophils

Answer 8

Gonadotrophs and thyrotropes

Question 9

Chromophobes

Answer 9

Corticotropes and melanotrophs

Question 10

Pituitary increased hormone activity

Answer 10

Functional neoplasia
Increased stimulation by hypothalamus
Antehormone like substance

Question 11

Dicreased pituitary hormone activity

Answer 11

Destructive lesions
Non responsive tissue targets

Question 12

Decreased pituitary hormone activity

Answer 12

Destructive lesions
Non responsive tissue targets

Question 13

Chromophobe adenoma

Answer 13

Functional adenoma
Chromophopes are unregulated and produce too much ACTH (Cushings) can cause diffuse hyperplasia of the adeoma, most likely to be microademona and be function less likely to be macroademoa which is more of a space occupying mass

Question 14

Pars intermedia adenoma

Answer 14

Chromophobe adenoma in dogs, Can be functional or compressive. More common in horses could be from age related oxidative injury of dopaminergic neurons

Question 15

Pituitary pars intermedia dysfunction in horses

Answer 15

Decrease dopamine results in increased activity of melanotrophs->POMC-> ACTH and other products
Can be from hyperplasia to micro/macroadenoma and cause hypothalamic compression
Adrenal glands normal

Question 16

Signs of PPID

Answer 16

Increased hair growth
Increased adipose tissue deposition
Weight loss

Question 17

Somatotroph adenoma

Answer 17

Mainly cats, dogs, sheep
Functional adenoma-> increase insulin like growth factor (acromegaly, diabetes mellitus)
Non functional adenoma-> panhypopituritism and hypothalamic compression

Question 18

Pituitary cysts

Answer 18

Abnormal development in or around the pituitary gland. Can compress or damage surrounding structures

Question 19

Craniopharyngeal duct cyst

Answer 19

Diabetes insipidus
Pituitary hypofunction

Question 20

Pharyngeal hypophyseal cyst

Answer 20

Respiratory distress

Question 21

Oropharyngeal ectoderm cyst

Answer 21

Panhypopituitarism
Juvenile hypopituitarism in German shepherds

Question 22

Pituatary dwarfism

Answer 22

Failure of Rathkes pouch to differentiate adenohypophysis
Decreased growth hormone (insulin-like growth factor 1)
Retention of puppy hair progressing to alopecia

Question 23

Craniopharyngioma

Answer 23

Neoplastic remnants of Rathkes pouch oropharyngeal ectoderm. See hypothalamic destruction and decreased hypothalamic trophic hormones. young dogs, rare

Question 24

Non functionadenoma

Answer 24

Not secreting hormones, see issues because of pressure on hypothalamic areas

Question 25

Pituitary abscesses

Answer 25

In cattle and secondary to nasal septal infections Space occupying lesions. See blindness, depression, drooling, tongue prolapse, similar to rabies

Question 26

Pituitary DIabetes insipidus

Answer 26

Destruction of neurohypophysis or Supraoptic nuclei of the hypothalamus. Decreased ADH

Question 27

Hyperfunction of adrenal gland

Answer 27

Primary or secondary adrenal involvement

Question 28

Hypofunction of adrenal gland

Answer 28

May be primary or secondary adrenal involvement

Question 29

Adrenal cortical adenoma or carcinoma

Answer 29

Most arise from zona fasciculata. Less common glomerulosa in cats of reticularis in ferrets. Adenomas more common than carcinoma

Question 30

Diffuse Adrenal hyperplasia

Answer 30

Occurs secondary to functional chromophobe adenoma of the pituitary (excess ACTH) See hyperadrenocorticism

Question 31

Nodular adrenal hyperplasia

Answer 31

Age related change in dogs, cats, horses, Some are functional and some non functional

Question 32

Pheochromocytoma

Answer 32

Arise in chromaffin cells of the medulla. Most non function . Can get functional neoplasia resulting in hypertension due to NE. Can be benign or malignant

Question 33

Adrenal hypoplasia or agenesis

Answer 33

Rare condition of dogs. Agenesis is fatal. See hypoadrenocarticism

Question 34

Diffuse adrenal cortical atrophy

Answer 34

Common in dogs on long term glucocorticoid therapy resulting in inhibition of adrenal cortical function and subsequent atrophy. Uncommonly idiopathic or immune mediated

Question 35

Injury to the adrenal galnd

Answer 35

Due to high vascularity -Thrombosis due to DIC -Adrenalitis due to infectious emboli -Metastatic neoplasia