Endocrine Pathology Flashcards
what are the functions of the endocrine system
- maintain metabolic equilibrium (homeostasis)
- secrete chemical messengers (hormones)
- regulate activity of various organs
- process of feedback inhibition
what does the process of feedback inhibition do
-increased activity of target tissue
- typically down regulates activity of gland secereting stimulating hormone
what are the types of endocrine diseases
- disease of under/over production of hormones
- diseases associated with development of mass lesions
what are functional tumors
tumors that secrete the hormone native to the gland
what organs are affected by endocrinopathies
-anterior pituitary
- posterior pituitary
- thyroid
- parathyroid
- pancreas
-adrenal
where is the pituitary gland
- base of brain sella turcica
- connected to the hypothalamus via a stalk composed of axons
what is the central role of the pituitary gland
regulation of other endocrine glands
what are the two components of the pituitary gland
- anterior lobe/ adenohypophysis
- posterior lobe/ neurohypophysis
how big is the pituitary gland
1 cm
what are the cells types in the anterior pituitary and what hormones do they produce
- somatotrophs: GH
- lactotrophs: prolactin
-corticotrophs: ACTH - thyrotrophs: TSH
- gonadotrophs: FSH and LH
what are the cell types in the posterior pituitary and what hormones do they produce
- ADH/vasopressin
- oxytocin
what are the diseases of the anterior pituitary
- decreased/increased secretion of trophic hormones
- hypopituitarism/hyperpituitarism
describe hypopituitarism
-destructive lesions- ischemia, radiaiton, inflammation and neoplasms
what is hyperpituitarism
- functional adenoma within anterior lobe
- local mass effects- enlargement of sella turcica, visual field abnormalities, increased intracranial pressure
what are the causes of hypopituitarism
- pituitary adenomas
- radiation treatment
- neurosurgery
- sheehan syndrome
what is sheehan syndrome
ischemic necorsis of pituitary gland
what are the clinical manifestation of hypopituitarism
- pituitary dwarfism
- amenorrhea and infertility
- decreased libido and impotence
- postpartum lactation failure
- hypothyroidism
- hypoadrenalism
what are the causes of hyperpituitarism
- pituitary adenomas
- pituitary hyperplasia
- pituitary carcinomas
- hypothalamic disorders
what are the clinical manifestations of hyperpituitarism
- gigantism
- acromegaly
- cushing disease
describe hyperpituitarism
-primary tumor
- excess GH
-adenoma of anterior pituitary
-2nd most common
- affects all growing tissues
when does gigantism occur
when excesss GH is secreted before epiphyseal plates close
describe gigantism
- generalized overgrowth more than 3 standard deviations
- headaches
- chronic fatigue
- arthritis, osteoporosis
- muscle weakness
- hypertension
- CHF
describe acromegaly
- late diagnosis
- poor vision: photophobia
- enlarges skull, hands, feet and ribs
-soft tissue and viscera enlarged - enlarged maxilla, mandible, nasal, frontal bones and maxillary sinus
what are the intraoral manifestations of acromegaly
- diastemas
- malocclusion
- macroglossia
- enlarged lips
- sleep apnea
what are the diseases of the posterior pituitary
- diabetes insipidus (Central)
- secretions of inappropriately high levels of ADH (SIADH)
what are the manifesations of diabetes insipidus in posterior pituitary pathology
- polyuria, dilute urine
- polydipsia
what are the manifesations of SIADH in posterior pituiary pathology
- hyponatremia
- cerebral edema
- neurologic dysfunction
- increase in total body water: blood volume normal and no peripheral edema
where is iodide stored and what is it bound to
in the thyroid gland bound by thyroglobulin
what is the difference between T3 and T4
one iodide
T4 is exclusively produced by:
the thyroid
majority of T3 is result of:
T4 conversion
what is the activator for the synthesis of TSH
TRH
what is the activator for T3 and T4 production
TSH
what 3 glands are responsible for the thyroid function
- hypothalamus
- pituitary
- thyroid
how do T3 and T4 circulate
- mostly bound to thyroxine
- some are free in circulation
which form of T3 and T4 are metabolically active
free hormones, not bound
what is primary hypothyroidism
- intrinsic abnormality in the thyroid
- surgery
- radiotherapy
- autoimmune
what is secondary hypothyroidism
pituitary failure
what are the 2 manifestations of hypothyroidism
- myxedema
- cretinism
describe myexedma
- in adults
- generalized fatigue
- apathy
- mental slugishness
- listless
- cold intolerance
- overweight
describe cretinism
- childhood
- impaired skeletal development
- severe mental retardation
- short stature
- course facial features
- delayed tooth eruption
what are symptoms of hypothyroidism
- cold intolerance
- fatigue, lethargy
- weight gain
- constipation
- bradycardia
what are the levels of TSH, T3 and T4 in primary hypothyroidism
- high TSH
- low T4
- low T3
what are the levels of TSH, T3 and T4 in secondary hypothyroidism
- low TSH
- low T4
- low T3
what is the treatment for hypothyroidism
supplements
describe hashimoto thyroiditis
- autoimmune
- painless enlargement- systemic and diffuse
- risk of B cell non hodgkins lymphoma
what are the clinical signs and symptoms of hyperthyroidism
- goiter (small)
- exopthalmus (frequent)
- heat intolerance
- weight loss
- malabsorption and diarrhea
- tachycardia
- irritability and anxiety
what are the most common causes of hyperthryoidism
autoimmune-graves disease
what are the lab values for hyperthyroidism
- T4 and free T4 elevatde
- T3 and free T3 elevated
- TSH and TRH supressed
what are the symptoms of hyperthyroidism
- weight loss
- nervousness
- rapid pulse
-goiter - muscle wasting
- tachycardia
- increased appetite
- exopthalmos
- intolerance to heat
what is the mechanism of hyperthyroidism
autoantibodies stimulate the thyroid hormone production
what is the treatment for hyperthyroidism
ablation
what is the significance of hyperthyroidism
- thyroid storm
- caused by infection, stress, trauma
- elevated body temp
- tachycardia
- 20-40% mortality
what is diffuse and multinodular goiter
- thyroid enlargement
- impaired synthesis of thyroid hormone
- iodine deficiency
- hyperplasia of follicle from pituitary stimulation
- maintenance of minimal function: euthyroid
- diffuse early on then nodular
what is the sequence of events in endemic goiter
- diet deficient in iodine
- decreasd output of T3 and T4 by thyroid
- pituitary responds by secreting TSH
- thyroid hyperplasia
what are the thyroid neoplasms
- adenoma
- papillary carcinoma
- follicular carcinoma
- medullary carcinoma
describe thyroid adenomas
- solitary
- males
- younger
- warm/ cold nodules
describe thyroid papillary carcinomas
- 75-85%
- all ages
- radiation
- 10 year = 95%
- worse in elderly