Module 7 endocrine dysfunction Flashcards
hyposecretion
endocrine gland released inadequate amount of hormone
secondary: when secretion of tropic hormone (TSH, ACTH) is inadeuqate to cause target gland to secrete adequetly.
primary hyposecretion
example thyroid
serum thyroid low but TSH high. thyroid not secreting adequately
secondary hyposecretion
example thyroid
Both TH and TSH low, anterior pituitary not secreting adequately
hypersecretion
primary: gland secretes abnormally high amount of hormone: tropic hormone low
secondary: related to elevated tropic hormone
hyporesponsive
hormone resistant
- s/s same as hyposecretion
- lack of or deficiency in receptors
- loss common: secondary. messenger dysfunction
- plasma level hormones normal or high r/t lack of negative feedback
tumors/cancer
pituitary tumors can cause
- excessive hormone production
- local effects of tumor
- inadequate hormone production by the remaining pituitary gland
defective receptor or enzyme/genetic disease
receptor associated disorders -decreased number of receptors - impaired function of receptor antibodies against specific receptors antibodies that mimic hormone action unusual expression of receptor function
hypopituitarism
decrease in production of hormones
panhypopituitarism
all hormones decreased or absent
aging and endocrine system
cellular processes slow with age: decline in GH and TH -> atrophy and dec. metabolism
regulatory and feedback mechanisms decline
binding affinities and receptor density decrease
tissues less responsive
hormones and aging endocrine system
decrease:
- aldosterone
- GH
- calcitonin
- renin
- T3 and T4
unchanged or slightly decrease:
- cortisol
- epinephrine
- insuline
increase
- FSH
- LH
- norepinephrine
- PTH
Diabetes insipidus s/s
excessive thirst large amounts of diluted urine nocturia hypernatremia (r/t H2O deficit) - dry mucous membranes - dec. sweat and saliva - disoriented - lethargy - seizures
causes of diabetes insipidus
neurogenic: too little ADH
nephrogenic: normal ADH
psychogenic: normal ADH, too much water
neurogenic DI
too little ADH: synthesis, transport, or release pituitary tumors brain tumors infections immunologic problems thrombotic problems
nephrogenic DI
normal ADH acquired, permanent or reversible renal tubule is insensitive to ADH - levels of ADH normal but the tubules no longer respond causes - pyelonephritis - amyloidosis - destructive uropathies - polycystic kidney disease - anesthetic drug use - lithium carbonate
psychogenic DI
compulsive water drinking by individuals with psych disorders.
periodic polyuria, high urine volumes, and plasma osmolarity low
DI tx
replacement of ADH daily
DDAVP (vasopressin): synthetic analog of ADH
syndrome of inappropriate ADH (SIADH)
excessive release of ADH from the posterior pituitary gland or another source
- hypervolemia
- dilutional hyponatremia
- increase in total body fluid
causes: - tumors
- non malignant lung disorders (TB)
- primary lung malignancies
- drug induced
- carbamazapine, morphine, barbituates
SIADH s/s
due to hypotonicity of body fluids
- hyponatremia
- confusion, seizures, comea
- fatigue
- anorexia
- increased urine specific gravity
- weakness
- muscle cramps
- N/V
- postural BP changes
- lethargy
SIADH tx
water restriction IV saline (Na) combined with diuretic lithium: block ADH
GH function
increase cell size and mitosis
increase differentiation of cells
increased metabolism
bone and cartilage growth
GH deficiency categories
decreased GH secretion
defective GH action (abnormal GH or defective receptor)
defective IGF-1
dwarfism
insufficient GH resulting in stunted or halted growth
puberty may be delayed of not occur
dwarfism s/s
infants: normal birth wt and ht, hypoglycemia
children:
- below 3% in growth
- dental eruption delayed, permanent teeth irregular
- thin hair
- poor nail growth
- delayed bone formation
- delayed puberty
dwarfism tx
hormone replacement
GH excess
nearly always because of uncontrolled production of GH by a somatotropic tumor in pituitary gland
giantism
GH excess prior to epiphyseal plate closure, before puberty
giantism s/s
95% growth percentile
up to 8 ft tall
cardiomegaly and heart failure
acromegaly
excess GH after epiphyseal plate closure at puberty
acromegaly s/s
increased ring and shoe size enlarged frontal sinuses: prominent brow progressive underbite coarsening of facial features, skin tags internal organs increase in size - goiter - cardiomegaly deep voice large tongue: sleep apnea
GH excess tx
surgical removal of tumor
counter effects of excess GH
octreotide: synthetic somatostatin
GH receptor antagonist
hypothyroidism
congenital
- thyroid dysgenesis
- abnormal receptors
- defective synthesis
acquired
- lymphocitic thyroiditis (hashimoto, autoimmune)
– large thyroid caused by lymphocytic invasion
hashimoto
thyroid specific CD4 helper T cells induce both the cellular (CD8 cytotoxic cells) and humoral (B cells) of the autoimmune response
- T cells: parenchymal destruction
- B cells: secrete inhibitory anti-TSH receptor and other antibodies
hypothyroidism s/s infant untreated
- dull appearance
- thick, protuberant tongue
- thick lips, feeding difficulty
- prolonged jaundice
- poor muscle tone
- bradycardia
- mottled extremity
- umbilical hernia
- hoarse cry
- intellectual disability
hypothyroidism s/s adult
loss of hair coarse brittle hair periorbital edema puffy face normal or small thyroid bradycardia constipation cold intolerance muscle weakness edema of extremities
hypothyroidism tx
TH replacement
hyperthyroidism
follicular cell hyperfunction- increased synthesis and secretion of T3 and T4
excessive ingestion of Thyroid hormone
- graves disease
- hyperfunctioning adenoma (toxic goiter)
- TSH cell adenoma
- iatrogenic
thyroid storm
life threatening thryotoxicosis - excessive TH acutely released
- increased temp
- tachycardia
- dysrhythmia
- CHF
- extreme restlessness
- agitation
- psychosis
hyperthyroidism s/s
thin hair exophthalmos enlarged thyroid heart failure wt loss diarrhea warm skin, sweaty palms hyperreflexia pre-tibial edema
hyperthyroidism tx
betablockers: acute symptoms
drugs to inhibit thyroid production
radioactive iodine to destroy part of thyroid gland
surgical removal of thyroid
- tumors
- could result in removal of parathyroid gland: hypocalcemia
adrenocortical insufficiency
hyposecretion of adrenocortical hormones results from - disease of adrenal cortex -- primary adrenocortical insufficiency -- addisons disease inadequate secretion of ACTH lack of CRH from hypothalamus congenital adrenal hyperplasia - adrenal insufficiency in peds
addison’s (primary insufficiency)
destruction of adrenal cortex through idiopathic or autoimmune mechanisms, TB, trauma/hemorrhage, fungal disease, neoplasia
- due to high functional reserve, s/s may not be noticed till 90% of cortical tissue is destroyed
addisonian crisis/ acute adrenal insufficiency
true medical emergency inadequate gluocorticoids/mineralcorticoids in circulation dec. vascular tone dec. cardiac output inadequate blood volume -> vascular collapes hypotension tachycardia shock s/s
hypothalamic-pituitary dysfunction (secondary adrenal insufficiency)
iatrogenic: corticosteroid therapy for chronic illness
- prolonged exposure suppresses CRH and ACTH stimulation through negative feedback
- lack of ACTH results in atrophy of cortex
adrenocortical insufficiency s/s
weakness hypotension hypoglycemia hyperpigmentation hyperkalemia wt loss
adrenocortical insufficiency tx
replacing hormones: 2/3 in am 1/3 in pm
adrenal crisis
- glucocorticoids IV until s/s resolve then titrated
volume replacement
congenital adrenal hyperplasia (adrenogential syndrome)
enzyme needed for cortisol production lacking, due to gene defect
- autosomal recessive
decreased cortisol -> increased ACTH secretion -> adrenal hypertrophy and overproduction of steroid precursors -> shunted to androgens
congential adrenal hyperplasia (adrenogential syndrome) s/s
infants: virilization of female genitalia
– enlarged clitoris
– fused labia
-males: enlarged penis and hyperpigmented scrotum
adulte female
- beard
- deep voice
- baldness
- masculine distribution of pubic hair
- growth of clitoris to resemble penis
- masculine characteristics
congenital adrenal hyperplasia tx
glucocorticoids
hypercortisolism
hyperfunction of adrenal cortex
- primary: disease (adrenal adenoma)
- secondary: hyperfunction of the anterior pituitary: increased ACTH (cushing disease)
- tertiary: hypothalamic dysfunction or injury
hypercortisolism/ cushing s/s
truncal obesity moon face dorsocervical fat pad hirsutism (women with hair growth like men) muscle wasting striae petchiae glucose intolerance hypertension hypokalemia
hypercortisolism tx
result of exogenous glucocorticoid therapy
- reduce doses slowly
pituitary disease
- transspenoidal hypophysectomy or laser ablation of anterior pituitary
adrenal tumor
- unilateral adrenalectomy
hyperaldosteronism
primary: conn syndrome
secondary: poor kidney perfusion
conn syndrome
usually a result of aldosterone secreting tumors
- aldosterone not under pituitary control
- pt have decreased potassium and increased Na
secondary hyperaldosteronism
conditions that stimulate the renin-angiotensin-aldosterone cascade
- HF
- decreased kidney perfusion
- liver cirrhosis
hyperaldosteronism tx
spironolactone: aldosterone antagonist
Na restriction
K replacement
pheochromocytoma
tumor of chromaffin tissue that results in the excessive production and release of catechomamines
adrenal medula excretes 2 hormones
- epi and norepi
– bind to adrenergic receptors in heart, smooth muscle, glands
– sympathetic response
pheochromocytoma s/s
HTN classic triad - headache - tachycardia - diaphoresis tremor nervous emotional pallor fatigue GI complaints orthro hypotension
pheochromocytoma tx
surgical removal of tumore
sympathetic blocking medications
hyperparathyroidism
primary: increased PTH
single parathyroid adenoma
hyperplasia
bone reabsorption and formation increases
Ca serum level does not rise uncontrollably
hyperparathryroidism s/s
hypercalcemia
hyperparathyrroidism tx
surgical removal of abnormal gland
hypoparathyroidism
most frequently result of parathyroid or thyroid surgery or radiation
congenital: lack of parathyroid tissue and idopathic
autoimmune
hypoparathyroidism s/s
hypocalcemia
hypoparathyroidism tx
IV Ca
calcitriol: activated vitamin D
oral Ca supplement
