Final Flashcards
(235 cards)
What is the pathogenesis of pituitary cysts and pituitary dwarfism?
failure of oropharyngeal ectoderm of rathkes pouch to differentiate into cells of pars distalis, resulting in cysts and absence of adenohypophysis
What neoplasm causes compression and atrophy of adjacent portion of pituatary gland and can lead to lack of pituitary trophic hormones?
inactive chromophobe adenomas
What pituatary gland neoplasm destroys the pars distalis and neurohypophyseal system leading to panhypopituitarism and diabetes insipidus?
pituitary gland carcinoma
What are the 3 non-functional pituitary gland neoplasms?
inactive chromophone adenoma
pituitary gland carcinoma
craniopharyngioma
What functional pituitary neoplasm leads to hirsuitism in horses?
pars intermedia adenoma
What are the sequalae of a adrenocorticotroph hormone secreting ademona?
Secretes ACTH –>cushings dz
bilateral enlargement of adrenal glands (cortical hyperplasia)
What form of diabetes insipidus is due to inadequate ADH production due to compression of the pars nervosa, infundibular stalk, or supraoptic nucleus in the hypothalamus?
hypophyseal form
What form of diabetes insipidus is when the target cells in kedneys lack pathway to respond to ADH?
nephrogenic form
What are the 3 layers of adrenal gland cortex and what do they secrete?
Glomerulosa - aldosterone
Fasciculata - cortisol
Reticularis - progesterone, estrogens, androgens
What are immediate and later sequalae of reduced mineralcorticoids in addisons disease?
severe hyperkalemia, pronounced bradycardia
later –>hyponatremia and hypochloremia
What are the consequences of decreased glucocorticoids in addisons disease?
moderate hypoglycemia
hyperpigmentation of skin (lack of negative feedback to pituatary gland and increased ACTH)
What are the consequences of decreased glucocorticoids in addisons disease?
moderate hypoglycemia
hyperpigmentation of skin (lack of negative feedback to pituatary gland and increased ACTH)
What are the 3 causes of addisons disease?
adrenalitis (most common)
adrenocortical hemorrhage (waterhouse-friderichsen syndrome)
idiopathyic adrenocortical atrophy
What are causes of cushings disease?
functional corticotroph adenoma
functional adrenal gland neoplasm
iatrogenic
What are the 4 types of hyperplasia and neoplasia of the adrenal cortex?
Diffuse cortical hyperplasia (ACTH pituatary adenoma)
nodular hyperplasia (1ry)
adenomas of adrenal cortex
adrenal cortical carcinoma
Where do adrenal cortical carcinomas metastasize to?
liver
What is the sequalae of functional carcinomas and adenomas in the adrenal cortex?
severe atrophy of the contralateral adrenal cortex (negative feedback)
Where can pheochromocytomas invade? metastasize?
caudal vena cava
metastasize to liver, LN and lungs
What cells produce calcitonin?
Thyroid C cells (parafollicular)
What is the role of calcitonin?
antagonistic with PTH on bone resorption BUT synergistic in decreasing renal tubular reasborption of phosphorus
What are the 3 ways PTH respond to low calcium levels?
increasing osteoclasts
decreased reabsorption of P and increased Ca in kidneys
increase absorption of Ca and P in intestinces
What are the 3 causes of hypothyroidism?
lymphocytic thyroiditis
bilateral nonfunctional follicular cell neoplasm (and goiter)
long standing pituitary gland or hypothalamic lesions
What happenes to the skin in hypothyroidism?
hyperpigmentation, myxoedema, alopecia, hyperkeratosis
What happenes to the skin in hypothyroidism?
hyperpigmentation, myxoedema, alopecia, hyperkeratosis