SGU Pathology: Endocrine Set 1
Terms in this set (102)
What are the general functions of the endocrine system?
metabolic functions: chemical reactions
transport of substances through cell membranes
cellular metabolism: growth, secretion
Alopecia is associated with which endocrine diseases?
Bone fracture is associated with which endocrine disease?
What diagnostic tests can be done to assess the endocrine system?
specific hormone assays
What are the different types of hormones?
polypeptide (water soluble)
steroid (lipid soluble)
Where do polypeptide hormones come from?
RER synthesis; stored in cytoplasm as secretory granules
Where do steroid hormones come from?
SER synthesis from cholesterol
Which type of hormone has continuous biosynthesis?
What happens when steroid hormones penetrate the plasma membrane and bind to target cell cytosolic receptors?
move to nucleus to increase mRNA transcription which increases protein synthesis
Catecholamines and iodothyronine hormones are derived from _____
Catecholamines act like which other type of hormone?
What are examples of catecholamines?
Iodothyronines act like which other type of hormone?
How do endocrine diseases most importantly present?
What are possible outcomes of prolonged hyperstimulation by trophic hormones or metabolic signals?
hyperfunction and physical enlargement of the peripheral endocrine glands
Hypofunction of endocrine glands is usually attributable to the destruction of ______
What are examples of primary hyperfunction?
What causes primary hyperfunction?
autonomous hypersecretion due to tumor or hyperplasia of the gland
What happens in secondary hyperfunction?
lesion in one organ secretes excess trophic hormone leading to long-term stimulation and hypersecretion by the target organ
What are some potential diseases caused by decreased degradation of hormones?
hyperestrogenism/feminization in men with cirrhotic liver
hypercalcemia in chronic renal dz dogs
Long-term xenobiotics could cause _______ degradation of hormone
Is thyroid neoplasia a result of increased or decreased degradation of thyroxine?
Long-term exogenous corticosteroids can lead to what disease?
iatrogenic Cushing's disease
What is the consequence of excess progestogens in dogs?
What are some causes of primary hypofunction?
destruction of secretory cells
failure of development of endocrine gland
genetic/biochemical defect in biosynthesis
What are examples of secondary hypofunction?
destructive lesion interfering with secretion of trophic hormone
hypofunction of target gland
Lack of adenylate cyclase in the cell membrane can cause what disease?
nephrogenic diabetes insipidus
What are consequences of failure of the fetal endocrine system?
hypoplasia of endocrine target organs
cessation of fetal growth
What embryonic structure does the pituitary gland (hypophysis) come from?
dorsal evagination of the oropharyngeal ectoderm
= Rathke's pouch
What are the parts of the adenohypophsis (anterior lobe)?
What types of cells come from the adenohypophysis?
Pituitary hormones are involved in what processes?
fluid and electrolyte balance
What are the acidophilic hormones that come from the adenohypophysis?
What are the basophilic hormones that come from the adenohypophysis?
gonadotrophs: LH, FSH
What hormones come from the neurohypophysis?
What diseases can results from adenohypophyseal hyperfunction?
Cushings disease (ACTH)
What diseases are associated with adenohypophyseal hypofunction?
addison's disease (ACTH)
ovarian follicular cysts (LH)
Diabetes insipidus is a result of hypofunction of which part of the pituitary gland?
What are the categories of disorders of the adenohypophysis?
What are consequences of ewes eating veratrum californicum in early pregnancy?
cranial malformation --> cyclops
aplasia/hypoplasia of fetal pituitary
What disorder of the adenohypophysis results in prolonged gestation?
What lesions are associated with pituitary dwarfism?
large, multiloculated cyst in sella turcica
absence of adenohypophysis
What are functional neoplasms of the pituitary gland?
neoplasms that produce trophic hormones that stimulate target organs
What diseases are associated with nonfunctional pituitary neoplasms?
What type of pituitary neoplasm is more common in adults? younger animals?
adults: adenoma and carcinomma
How can you differentiate adenoma from nodular hyperplasia?
adenoma is bigger and has a capsule
What species are you most likely to see adenoma of the pars intermedia?
most common in horses
*second most common in dogs
What diseases are associated with adenoma of the pars intermedia?
if functionally inactive: hypopituitarism and diabetes insipidus
if functionally active: cushing's disease
In dogs, syndromes of cortisol excess is related what type of cell?
type B cell
In horses, POMC is associated with adenoma of _____
In horses, hirsutism is assocaited with adenoma of ______
Inactive chromophobe adenoma may be seen in what species?
How do animals with chromophobe adenomas present clinically?
incoordination, weakness and collapse after exercise
What are the consequences of craniopharyngioma?
CNS/cranial nerve disorders
subnormal secretion of GH and other trophic hormones
Pituitary gland carcinomas may be found in what species?
older dogs and cows
Pituitary gland carcinoma are functionally inactive but may lead to what diseases?
What are some causes of pituitary abscesses?
baceteria: arcanobacterium pyogenes
Pituitary abscesses are sporadic in what species?
What are the clinical signs of pituitary abscesses?
neurological signs due to associated meningitis or encephalitis
What are the 2 forms of diabetes insipidus?
hypophyseal form: reduced secretion of ADH
nephrogenic form: kidneys fail to concentrate urine; adequate amount of ADH
What are causes of hypophyseal form of diabetes insipidus?
lesions interfering with ADH synthesis or secretion
compression/destruction of pars nervosa, infundibular stalk or supraoptic nucleus
What are causes of nephrogenic diabetes insipidus?
lack of adenylate cyclase in plasma membrane of epithelial cells in distal tubules and collecting ducts
cells fail to respond to ADH
What are the clinical signs of diabetes insipidus?
urine with low osmolality even with water deprivation
How can you tell the difference between the hypophyseal and nephrogenic forms of diabetes insipidus?
administration of exogenous ADH will lead to rapid increase in urine osmolality above that of plasma in hypophyseal form only
What embryologic structures are the arenal medulla and cortex derived from?
adrenal medulla: neuroectoderm
adrenal cortex: mesoderm
Which zone of the adrenal cortex produces mineralcoritcoids (aldosterone)?
What controls the production of mineralcorticoids in the zona glomerulosa?
What zone of the adrenal cortex produces glucocorticoids (cortisol and corticosterone)?
What controls the production of glucocorticoids from the zona fasciculata?
What is the general effect of cortisol and corticosterone?
affects glucose homeostasis by acting on metabolism of carbs, proteins and lipids
What are the effects of glucocorticoids?
increase glucose production
inhibit action of insulin
suppress inflammation, healing and immune response
What type of hormone does zona reticularis produce?
sex hormones: androgens
What are the effects of aldosterone in the kidney?
increase resorption of sodium
increase resorption of water
increase excretion of potassium
What happens with excessive glucocorticoid levels?
inhibition of bone formation
suppression of calcium absorption
delayed wound healing
What is the effect of stress on blood levels of cortisol?
Adrenal cortex hypoplasia is associated with what disorders?
Capsular sclerosis is a senile change seen in what species?
What are some degenerative/inflammatory lesions of the adrenal cortex?
calcification of the adrenal glands
Calcification of the adrenal glands is common in what species?
adult cats and monkeys
Amyloid usually involves what zone of the adrenal cortex?
What are some causes of adrenalitis?
bacteria: gram negatives
parasites: toxoplasma gondi
Nodular hyperplasia of the adrenal cortex may be seen in what species?
What are signs of nodular hyperplasia of the zona reticularis?
greater muscle mass
hypertrophy of clitoris
involution of mammary gland
Are cortical adenomas usually functional or non-functional?
Are cortical adenomas unilateral or bilateral?
How can you differentiate nodular hyperplasia from adenoma of adrenal cortex?
adenomas are larger, unilateral and encapsulated
What are some sequelae of cortical carcinomas?
compression of adjacent organs
What are clinical signs of functional proliferative lesions in ferrets?
bilaterally symmetrical alopecia
palpable mass at cranial pole of kidney
Congenital adrenal hyperplasia could be caused by deficiency in which enzyme?
What hormones are affected by congenital adrenal hyperplasia?
reduced cortisol levels
excessive androgen production
Where might you find ectopic ACTH syndrome tumors?
small cell lung cancer
pancreatic islet cell tumor
medullary carcinoma of thyroid
What causes the pot-bellied appearance in animals with excess cortisol?
What effect does excess cortisol have on bone?
decreases calcium absorption from GI
increases calcium excretion by kidneys
**skeletal mass decreases; bones become weaker
What effect does excess cortisol have on skin?
atrophy of hair follicles and sebaceous glands --> alopecia
What effect does excess cortisol have on the vascular system?
thinning of walls vessel walls, rupture --> hematoma
increase number of circulating RBC
Calcinosis cutis is associated with what disease?
cushing's disease (= hypercortisolism)
True/False: mineralcorticoids are not affected in Addison's disease
**no electrolyte imbalance!
What is the hallmark of Addison's disease?
hypokaluria and hyperkalemia
True/False: adrenal medulla is essential for life
What lesions are associated with adrenal medullary hyperplasia?
diffuse or nodular
non-encapsulated proliferation of chromaffin cells
What is the most common neoplasm of the adrenal medulla?
Pheochromocytoma mostly occurs in what species?
dogs and cattle