Endocrine System Flashcards
What are the 2 ways that hormones can achieve effect?
- single hormone can affect multiple tissues
- estradiol – matures and maintains reproductive system, cause maturation and release of egg during menstruation, and thickens uterus lining
- single function regulated by multiple hormones
- lipolysis controlled by many hormones
- epinephrine
- norepinephrine
- thoralidor
- growth hormone
- cortisol
- lipolysis controlled by many hormones
What are the 2 mechanisms of action for hormones?
- surface cell receptors – surface receptors receive hormone, effect achieved by second messenger
- nuclear receptor – hormone enters cell nucleus and alters cell function
What part of the brain is the coordinating center of the endocrine system?
hypothalamus
What is the purpose of the pituitary gland in the endocrine system?
- AKA master gland
- secretion of hormones that control functions of cells through negative feedback
What do the anterior and posterior pituitary control?
– anterior pituitary:
- growth
- metabolic activity
- sexual development
- secretes tropic hormones
– posterior pituitary:
- secretes vasopressin (ADH)
- secrete oxytocin (sexual reproduction, bonding hormone)
Where are the adrenal glands located?
on top of each kidney
What are the 2 hormones that the adrenal glands secrete?
- mineralocorticoids – controls body’s potassium and sodium content
- ex: aldosterone
- glucocorticoids
- metabolism of carbs, proteins, fat
- stress response
- emotional stability
- immune function
- ex: cortisol
What hormone does the adrenal medulla secrete?
catecholamines (stimulates fight/flight response)
How would you assess the endocrine system?
- obtain a nutrition history
- changes in food and fluid intake
- dietary deficiencies
- changes in energy level
- may be due to thyroid or adrenal disorder
- elimination patterns
- sexual and reproductive function
- greatly affected
- physical appearance changes
- hair texture/distribution
- facial
- voice quality
- proportion
- may be difficult to assess due to a variety of signs and symptoms
- may be gender related
What kind of diagnostic tests could confirm endocrine disorders?
- blood assays
- test hormone levels
- urine tests – usually 24 hour collection
- stimulation and suppression tests
- admin stimulating or suppressing agents and measure response
- glucose tests
- tests pancreas function
- imaging – MRI or radioactive scanning
What are 2 disorders of the anterior pituitary gland?
- hypopituitarism
- hyperpituitarism
What is hypopituitarism?
deficiency of one or more hormones (like gonadotropins or growth hormone)
What results in a gonadotropin hormone deficiency?
changes in sexual function
What results in a growth hormone deficiency?
- in children – short stature
- in adults – increased rate of bone destruction
How does a gonadotropin deficiency present differently in males and females?
- males – facial body hair loss, impotence
- females – amenorrhea, dyspareunia (painful intercourse), decreased libido
What are some causes of hypopituitarism?
- tumors (benign or malignant)
- anorexia nervosa
- shock
- severe hypotension
- head trauma
- infection
- pituitary adenoma
What are some assessment characteristics for hypopituitarism?
- secondary sex characteristics
- changes in visual acuity
- vision
- peripheral vision
- diplopia
- limited eye movement
- headaches
What is the primary intervention for hypopituitarism?
replacement of deficient hormones
What is hyperpituitarism?
oversecretion of one or more hormones
What is acromegaly? Why is early detection and treatment important for acromegaly?
– acromegaly: an oversecretion of growth hormone after puberty
– early detection and treatment prevent irreversible damage
What is gigantism?
oversecretion of growth hormone before puberty
What is the most common cause of hyperpituitarism?
pituitary adenoma – abnormal growth of tissue surrounding pituitary gland (pituitary tumor that compresses the optic chiasm and arteries in the brain)
What are some assessment characteristics for hyperpituitarism?
- impotence
- amenorrhea
- libido changes
- fatigue
- changes in visual acuity
- headache
- visual disturbance
- weight changes – could indicate tumor
What are some treatment interventions for hyperpituitarism?
- drug therapy
- parlodel – reduces amount of GH produced
- sandostatin – reduces amount of circulating GH
- permax
- dostinex
- somavert
- radiation
- gamma knife procedure – emits radition to make pituitary gland/tumor smaller
- hypophysectomy – removal of pituitary gland/tumor
- operation
- endoscopic transnasal
- transsphenoidal approach
- craniotomy
What are some important postoperative care interventions for hyperpituitarism?
- monitor neuro response
- assess for post-nasal drip or nasal drainage
- could be CSF
- elevate HOB
- decreases chance of increased intracranial pressure
- avoid coughing or straining (constipation)
- avoid brushing teeth
- assess for meningitis
- avoid bending
- educate on hormone replacement treatment
- assess for numbness in incision area
- assess for decreased sense of smell
- administer vasopressin (ADH)
- ADH production will be decreased with removal of pituitary
What are 2 disorders of the posterior pituitary?
- diabetes insipidus
- syndrome of inappropriate antidiuretic hormone (SIADH)
What is diabetes insipidus?
a deficiency in ADH – the body does not naturally produce ADH
What are some signs and symptoms of diabetes insipidus?
- loss of large volumes of dilute urine
- more than 4L in 24 hours
- excessive thirst
- hypotension
- tachycardia
- high hemoglobin and hematocrit
- high BUN
- dry, cracked mucus membranes
How is diabetes insipidus diagnosed?
- 24 hour intake and output measurement
- MRI of head
- urinalysis
What are some interventions for diabetes insipidus?
- encourage fluids
- monitor I&Os
- daily weights
- medications
- Diabinese (chlorpropamide) – diabetes medication that stimulates pancreas to produce insulin and decrease blood sugar
- desmopressin – synthetic form of ADH
What is syndrome of inappropriate antidiuretic hormone (SIADH)?
when ADH is secreted even when plasma osmolarity is low or normal
What are some signs and symptoms of SIADH?
- hyponatremia
- fluid overload
- lethargy
- headaches
- changes in LOC
- tachycardia
- hypothermia
How is SIADH diagnosed?
- labs
- serum electrolytes
- BUN
- creatinine
- urinalysis
What are some interventions for SIADH?
- fluid restriction
- measure I&Os
- daily weights
- hypertonic saline – when serum saline is very low
- medications
- vasopressin antagonists – promote water excretion without sodium loss
- Samsca (tolvaptan)
- Vaprisol (conivaptan)
- diuretics – when sodium is normal and HF is present
- vasopressin antagonists – promote water excretion without sodium loss
What are 2 disorders of the adrenal gland?
- adrenal gland hypofunction (acute adrenal insufficiency)
- adrenal gland hyperfunction
How does adrenal gland hypofunction (acute adrenal insufficiency) result?
- destruction of adrenal glands (primary form AKA Addisons)
- nonspecific autoimmune response
- infection
- trauma
Discuss the pathophysiology of Addison’s disease.
– cortisol and aldosterone levels are low
– hypothalamus and anterior pituitary secrete:
- CRH (corticotropin releasing hormone) – stimulates adrenal glands
- ACTH (adrenocorticotrophic hormone) – stimulates secretion of cortisol (glucocorticoids) and aldosterone (mineralcorticoids)
What are some signs and symptoms of Addison’s disease?
- lethargy
- fatigue
- anemia
- low BP
- hyponatremia
- hyperkalemia
- hypercalcemia
- bronze skin pigmentation – from increased secretion of ACTH which affects melanocyte stimulating hormone
- thinning body hair
- hypoglycemia
How is Addison’s disease diagnosed?
- ACTH stimulation study – most definitive
- blood studies
- decreased cortisol
- decreased fasting blood glucose
- decreased sodium
- high potassium
- high BUN
- imaging – skull X-rays, CT
- CT will determine pituitary or adrenal gland issue
What are some interventions for Addison’s disease?
- measure I&Os
- daily weights
- assess for hypoglycemia
- assess vitals and heart rhythm
- medications
- cortisol replacement – prednisone
- mineralocorticoid hormone – fludrocortisone (Florinef)
What is adrenal gland hyperfunction?
oversecretion of one or many adrenal hormones
What is an example of a disease that results from adrenal gland hyperfunction? What demographic more commonly gets this disease?
– Cushing’s disease – hypercortisolism
– more common in women
What are some signs and symptoms of Cushing’s disease?
- increased total body fat
- trunk obesity
- buffalo hump
- moon face
- hypertension
- muscle atrophy
- osteoporosis
- striae
- thinning skin
What are some interventions for Cushing’s disease?
- restore fluid balance
- drug therapy – decrease cortisol production
- nutrition
- restrict fluids
- restrict sodium
- adrenalectomy
- prevent skin injury
- prevent infection
- prevent acute adrenal insufficiency by regular administration of corticosteroids
What is hyperthyroidism?
excessive secretion of thyroid hormone
What is Graves’ disease? What are some signs and symptoms?
– Graves’ disease: autoimmune disorder where antibodies attach to TSH receptor sites, increasing thyroid gland size and increasing thyroid hormone production
- most common manifestation of hyperthyroidism
– signs and symptoms:
- goiter
- exophthalmos (bulging eyeballs)
- pretibial myxedema
What are 2 other manifestations of hyperthyroidism?
- toxic multinodular goiter – hyperthyroidism caused by multiple thyroid nodules
- exogenous hyperthyroidism – excessive use of thyroid replacement hormones
What are some signs and symptoms of hyperthyroidism?
- heat intolerance – hallmark sign
- weight loss
- increased daily BMs
- exophthalmos
- photophobia (sensitivity to light)
- goiter
- mood swings
How is hyperthyroidism diagnosed?
- labs
- serum T3
- serum T4
- free T4
- TSH
- TSH-RAb – high titers indicate Graves’ disease
- thyroid scan – evaluates size and position of thyroid
- increased uptake in iodine = hyperthyroidism
- ultasonography – evaluate masses or nodules
- EKG – assess tachycardia
What are some interventions for hyperthyroidism?
- monitor temperature
- provide quiet environment
- reduce room temp
- encourage fluids
- encourage cool showers
- medication
- antithyroid drugs (PTU) – decrease iodine uptake
- iodine preparations
- beta-adrenergic blocking drugs
- radioactive iodine therapy (RAI)
- thyroid picks up RAI
- thyroid cells become destroyed by radiation
- thyroid hormone replacements needed for life
- thyroidectomy
What are some etiologies of hypothyroidism?
- thyroidectomy
- RAI therapy
- low iodine intake
Describe the difference in incidence between hyperthyroidism and hypothyroidism.
– hyperthyroidism – more common in women 20 - 40 years old
– hypothyroidism – more common in women 30 - 60 years old
What is hypothyroidism? What are 2 tell-tale signs of hypothyroidism?
– hypothyroidism: decreased metabolism from low levels of thyroid hormones
– 2 tell-tale signs:
- myxedema: mucousy, nonpitting edema
-
myxedema coma: decreased metabolism of hypothyroidism causes reduced cardiac output and decreased perfusion to the brain and other organs
- life-threatening
- high mortality rate
- rare
What is Hashimoto’s disease?
an autoimmune disease of the thyroid, causing hypothyroidism
What are some signs and symptoms of hypothyroidism?
- increased time sleeping and lethargy
- cold intolerance
- facial edema
- bradycardia
- weight gain
- goiter
- depression
How is hypothyroidism diagnosed?
- labs
- decreased T3
- decreased T4
- variable TSH
What is thyroiditis? What are the 3 types?
– thyroiditis: inflammation of thyroid gland
– 3 types:
- acute – bacterial
- subacute – viral
- chronic – autoimmune (bacterial or viral)
- Hashimoto’s disease – most common type
- affects women more than men
- Hashimoto’s disease – most common type
What are the 4 types of thyroid cancers? Which is most common? How do you treat each type?
– 4 types of thyroid cancers:
- papillary: slow growing; affects younger women
- follicular: invades blood vessels; adheres to trachea, neck, great vessels; affects older pts
- medullary: occurs as part of multiple endocrine neoplasia; affects pts 50+
- anaplastic: rapidly growing, aggressive tumor
– papillary is most common
– anaplastic is treated with radiation; papillary, follicular, and medullary are treated with surgery
What is the function of the parathyroid glands?
maintain calcium and phosphate balance
What is hyperparathyroidism? What is the result of hyperparathyroidism?
– hyperparathyroidism
- causes increased production of parathyroid hormone (PTH)
- this results in increased kidney absorption of calcium and increased excretion of phosphorus – hypercalcemia and hypophosphatemia
– result:
- decreased bone density – PTH breaks down bone to increase serum calcium
- increased calcium deposits in soft tissues
- increased renal calculi
What are some interventions for hyperparathyroidism?
- monitor cardiac
- monitor for tingling and numbness in muscles
- prevent bone fractures and injury
- medication
- diuretics and hydration therapies – Lasix
- oral phosphates
- calcitonin
- parathyroidectomy – ensure calcium levels are normal prior to removal
What is an important assessment to make after hyperparathyroidectomy?
assess for hypocalcemia – Trousseau’s and Chvosteks sign
What is hypoparathyroidism? What are the 3 types?
– hypoparathryoidism: decreased function of parathyroid gland resulting in a lack of PTH
- rare
– 3 types:
-
iatrogenic hypoparathyroidism: results from removal of parathyroid gland
- most common form
- idiopathic hypoparathyroidism: unknown cause
- hypomagnesemia: caused by ETOH, malabsorption syndromes, and chronic renal failure
What are some interventions for hypoparathyroidism?
- correct hypocalcemia
- correct vitamin D deficiency
- correct hypomagnesemia
