Endocrine Exam #2 Flashcards
Hormones of the hypothalamus
- Corticotropin releasing hormone (CRH)
- Thyrotropin releasing hormone (TRH)
- Growth hormone releasing factor/somatotropin releasing hormone
- Gonadotropin releasing hormone (GnRH)
- Prolactin releasing hormone (PRH)
- Somatostatin (inhibits growth hormone release)
- Prolactin inhibiting hormone
- melanocyte hormone
Pituitary Gland (hypophysis)
- master gland of endocrine system
- excretes hormones that have a regulatory effect over the endocrine glands
All activities of the pituitary are controlled by….
Hypothalamus
Anterior Pituitary
(Adenohypophysis) gland composed of cells that secrete protein hormones
-secretes 6 hormones
Posterior pituitary
(Neurohypophysis) “storage shed” for hypothalamus
- directly connected to hypothalamus by nerve tract and composed of nerve tissue
- secretes ADH
Rate of production
mediated positive and negative feedback circuits
Rate of delivery
high blood flow to target organ/cells deliver more hormone than low blood flow
Rate of degradation and elimination
hormones metabolized & excreted thru several routes dependent on biologic half life
Growth Hormone
(liver, adipose tissue)
-promotes growth indirectly. Control of protein, lipid, and carb metabolism.
(growth and metabolism) (growth and tissue repair)
-increases glucose therefore giving people diabetes
Thyroid stimulating hormone
(thyroid gland)
- stimulates secretion of thyroid hormones –thyroid to secrete t3 and t4
- secreted from cells thyrotrophs
- helps control body metabolism and influence physical and mental growth
Adrenocorticotropic hormone (ACTH)
(adrenal gland, cortex)
-stimulates secretion of corticosteriods and glucocorticoid
-affects blood sugar, carb metab., influences sleep and protein breakdown.
controlled by CRH
-Prolactin
(mammary gland) (lactogenic hormone)
-milk production, lactogenic hormone
Gonadotropin hormones: FSH & LH
(ovary and testes)
-control reproduction function
B-lipotropin
(target organs)
-stimulate target organs to release hormones growth and development target organs
Growth Hormone (somatotropin)
- is a major participant in several physiologic processes including growth and metabolism
- pulsatile release pattern
Growth hormone effects on growth
increases protein synthesis, breakdown of fatty acids, breakdown glycogen to glucose liver, increase blood sugar/insulin antagonist
FSH: follicle stimulating hormone
- stimulates the epithelial cells of the testes to release testosterone
- —-male leydig cells are testicular cells that produce testosterone
LH: luteinizing hormone
- women-ovarian follicle works with estrogen to cause release of ova from ovaries
- ovary: release progesterone, development mammary glands fro milk secretion
Melanocyte-stimulating hormone
-stimulates production pigment cells in skin, eyes, and inside eyes
what is the first sign of a pituitary tumor?
infertility
Assessment of hypopituitarism
- hormone deficiencies involving anterior pituitary lead to end organ failure
- effects depend on specific hormone lacking
- deficient in ACTH & TSH cause tendency towards shock
Diagnosing hypopituitarism
- H&P
- MRI/CT– for presence of tumor
- lab values –direct/indirect measurement of hormone levels
Pituitary Dwarfism
- hyposecretion of GH in childhood
- normal body proportions and IQ
- excessive body fat & poor muscle development
- immature facial features, high pitch voice, slow nail growth, thin hair
- sexual maturation may not occur or delayed puberty –normal sexual function
- stunted growth – < 3rd percentile
1 Nursing goal for pituitary dwarfism
FIND & REFER
Nursing Management of pituitary dwarfism
- if tumor- remove (hypophysectomy)
- hormone replacement therapy - SQ GH injection
- teach lifelong replacement, psychologic support
Hyperpituitarism in children
Gigantism
Hyperpituitarism in adults
Acromegaly
Gigantism
- GH excess
- GH secreting adenoma –onset BEFORE closure of epiphyseal plate
- onset before closure of epiphyseal plate
- long bones still capable of longitudinal growth.
- caused by late ossification and hardening of bones
Signs and symptoms of Gigantism
- muscle weakness
- osteoporosis because of bones growing so fast and Calcium not being able to keep up
- arthritic changes and cardiac hypertrophy
Treatment of Gigantism
-GH WNL, surgery, radiation, meds
Acromegaly
- excessive GH secretion by overgrowth of bone and soft tissues
- develops AFTER closure of epiphyseal plate so bones grow in thickness and width
- relatively rare
- usually begins gradually….3-4 decades of life
- typically 7-9 years btwn onset of symptoms and diagnosis
Signs and symptoms of acromegaly
- skin thick, leathery, oily
- enlarged hands, feet, nose, sinuses, forehead prominent, and visceral organs.
- hypertrophy of lips and tongue. (trouble swallowing and speaking
- atherosclerosis–>cardiomegaly–>diabetes
Complications of cardiomegaly
- alters glucose metabolism, hyperglycemia, symptoms of polydipsia and polyuria (hormone antagonizes action insulin)
- alters fat, cho, protein and metabolism raising lipid levels leading to HTN and athersclerosis
Diagnosis of Acromegaly
GH levels > 50
BEDREST PRETEST
-oral glucose challenge response test is a definitive test
-CT, MRI, bone density
-H&P, c/o changes in dentures, hat, glove, ring, and shoe size
Surgery for acromegaly: hypophysectomy
-remove only tumor causing GH secretion (if complete pituitary removed will need hormone replacement thru-out life (decreased sensation of smell, taste, edema, bruising of eyes, nose, upper face)
Post-op care of transphenoidal adenectomy
- I&O FREQUENTLY & HOB ^ 30 DEGREES
- check for cerebrospinal fluid (question about nasal drip is constant swallowing or halo on gauze)
- IV antibiotics for CSF leakage
- avoid sneeze, cough, strain
Medications for acromegaly
- somatostatin analogs = decrease GH WNL
- dopamine agonists = suppresses GH secretion
- GH receptor antagonists = blocks secretion
- –most common: Octreotide (sandostatin)
Nursing care for Acromegaly
- evaluate changes in physical size, appearance– question changes in hat, glove and ring size
- good skin care
- high calcium diet
- pictures helpful bc changes occur slowly
- emotional support for appearance
Prolactinomas
- prolactin secreting adenoma accounts for 40-60% all hyperfunctioning tumors
- HAs, visual problems secondary to pressure optic chiasm
- galactorrhea, menstrual abnormalities, infertility, and hirsutism
- -drug therapy: first line Dopamine agonists,
- surgery depending on tumor size, radiation limited
Antidiuretic hormone (vasopressin) (ADH)
- **conservation of body water by reducing urine output
- *-channels transport solute-free water thru tubular cells back into blood leading to decreased plasma osmolarity & increased urine osmolarity
- ADH binds to receptors in distal or collecting tubules of kidneys and promotes resorption of water back into circulation
Plasma Osmolarity
- concentration solutes in blood
- **ADH secretion also stimulated by decreased BP and increase in osmolarity
Syndrome of inappropriate ADH (SIADH)
- ADH released despite normal or low plasma osmolarity
- results from abnormal production or sustained secretion ADH
Signs and Symptoms of SIADH
- fluid retention (you can’t pee)
- serum hypo-osmolality
- concentrated urine with normal or increased intravascular volume and normal renal function
- increased ADH renal absorption of H20 into circulation, ECF volume, decreased NA in urine
- NO EDEMA
Main signs and symptoms of SIADH
- decreased Na leading to muscle cramps, twitching, and HA.
- increased urine specific gravity
- brain cells swell leading to neuro sings and symptoms–> lethargy, seizures, personality changes, coma and death
SIADH diagnostics
- simultaneous measurement of urine and serum and osmolality
- **serum osmolality is less that urine osmolality because inappropriate excretion…concentrated urine and very diluted serum (DILUTE Na)
Nursing care for SIADH
- restore fluid volume and osmolality
- diuretics, increase Na diet, Na and K supplements
- **sometimes develop heart failure so may need lasix
- HOB 10 degrees
Diabetes Insipidus
(may be transient or lifelong)
- deficiency of ADH: kidney tubules fail to reabsorb H20
- excrete large amounts of dilute urine without glucose
- polydipsia, polyuria–> DI increased even more
Causes of DI
problems with hypothalamus or pituitary–brain tumor, injury, meds, infection
–decreased response to ADH, inadequate ADH,
Assessment Diabetes insipidus
- BP, SKIN TURGOR, I&O, DAILY WT
- urine is dilute, clear, colorless
- low specific gravity
- polydipsia-thirst mechanism stimulated and insatiable. Crave cold drinks
- combination of nocturia and polyuria
- wt loss, poor turgor, hypotension, tachycardia, shock
- hypernatremia
Diagnosis of diabetes insipidus
- **GOAL: maintain fluid and electrolyte balance
- water deprivation test: evaluates kidneys ability to produce urine with no PO water intake
- synthetic ADH hormone to determine is DI is caused by renal dysfunction
- low Na diet and thiazide diuretics
The adrenal gland
- small vascular glands located on upper portion of kidneys
- two parts: adrenal cortex and adrenal medulla
Adrenal Medulla
- extension of SNS
- secretes epi, norepi, and dopamine
- fight or flight response
- constriction of blood vessels and dilation of brinchioles
- increase HR, CO, pupil dilation
Adrenal Cortex
-secretes glucocorticoids, mineralcorticoids, androgens
Glucocorticoids
- **cortisol most abundant and potent
- necessary for life
- regulates blood glucose concentration- breaks down sugar for energy
- promote metab of carbs
- inhibit inflammation
Mineralcorticoids
- primarily aldosterone
- maintains extracellular fluid volume
- promotes reabsoprtion of Na and excretion of K
Adrenal Androgens
-stimulate pubic, axillary hair and sex drive in women
-converted to estrogens in peripheral tissue
-major control - negative feedback
hypothalamus secretes CRH–CRH stimulates ant. pituitary to secrete ACTH –ACTH stimulates adrenal cortex to secrete cortisol
Cushing Syndrome
- caused by excess of corticosteroids particularly glucocorticoids
- caused by adrenal tumors and ectopic ACTH production by tumors
Signs and Symptoms of Cushing’s Syndrome
- wt gain is most common
- buffalo hump
- sodium/water retention so monitor them.
- susceptibility to infection is a complication of long time hormone use
- hyperglycemia
- monitor skin
- purple striae on abdomen
- mineral corticoid excess may cause HTN secondary to fluid retention
Diagnosing Cushing’s syndrome
- 24 hr urine for free cortisol
- **plasma cortisol levels may be elevated with loss of diurnal variation
- CT/MRI for tumor location
- **hyperglycemia and POLYCYTHEMIA
Nursing Care for Cushing’s syndrome
- surgery adrenalectomy or hypophysectomy (pituitary adenoma) or meds to suppress
- Mitotane: suppresses cortisol production, alters metabolism of cortisol and decreases plasma and urine
- acceptance of appearance –meticulous skin care, observe Na & H20 retention
Adrenalectomy
- HTN and hyperglycemia must be controlled
- hypokalemia is corrected with supplements
- **may be hypotensive post-op until regulated by steroids
- **high doses of cortisone pre/post op
Post-op Adrenalectomy
- ** if decreased urinary output due to Na retention
- ** may be hypotensive until steroid therapy regulation
- high doses of corticosteroids are administered IV during and several days after surgery to ensure adequate response to surgery
- monitor I&O
- wear medic alert bracelet at all times
- avoid exposure to extreme temps, stress, and infection
Hyperfunction of adrenal cortex
- excessive aldosterone secretion which causes Na retention K & hydrogen ion excretion
- ** hallmark of disease is hypertension & hyperkalemic alkalosis
Signs and symptoms hyperfunctioning adrenal cortex
- Na retention leads to hypernatremia, htn, HA
- no edema
- potassium wasting leads to hypokalemia- cardiac arrhythmias, muscle weakness, may lead to tetany
Nursing care for hyperfunctioning adrenal cortex
- surgical removal if adrenal gland with adenoma
- pre-op: low Na diet, k sparing diuretics, k supplements, CCBs to control BP
Addison’s disease
- adrenocorticol insufficiency
- all 3 classes of adrenal corticosteroids are reduced -sugar, salt, sex
- autoimmune response destroying adrenal tissue
- insidious onset
- progressive weakness, fatigue, wt loss, anorexia are primary features
- Skin hyperpigmentation
Addison’s disease tri-ad
hypotension, hyponatremia, hyperkalemia
–hypotension, hyperpigmentation and weakness
Diagnosis and nursing care for Addison’s disease
- **protect against stress!!
- ** diet high in protein, high calorie, extra salt/sodium
- ** maintain fluid and electrolyte balance
- large amounts of NS and D5 are administered to reverse hypotension and electrolyte imbalance
- wear medic alert bracelet
- take corticosteroids early am to avoid GI distress
- *-wt gain, moon face, edema, behavior changes, increased urination and thirst- S/S infection
Pheochromocytoma
- adrenal medulla tumor that produces excessive catecholamines (epi and norepi
- severe hypertension
Triad of Pheochromocytoma
-pounding HA, tachycardia, profuse sweating
what is necessary for the synthesis of thyroid hormones?
Iodine
—iodized salt, fish, bread
Thyroid gland
highly vascular organ regulated by TRH from hypothalamus and TSH from anterior pituitary
- major function is production, storage, and release of 3 hormones that regulate metabolic processes
- –t3, t4, and calcitonin
T3 and T4 affect…
metabolic rate, caloric requirement, O2 consumption, growth and development, and carb and lipid metabolism
calcitonin
produced by C cells in response to high circulating levels
–inhibits bone resorption from bone, increases bone storage and renal excretion of Ca and phosphorus-lowers serum Ca
Radiologic studies for thyroid
- radiologic uptake thyroid scan- direct measurement activity, evaluation solitary nodules
- thyroid scan- evaluate nodules, benign= warm if malignant tumors= cold spots (bc doesn’t take up radioactive iodine)
- thyroid ultrasound
Simple negative feedback
hypothalamus–>TRH–>Ant. pituitary –> TSH –>T3 &T4
Hyperthyroidsim
- a sustained increase in synthesis and release of thyroid hormones by thyroid glands
- thyroiditis, nodular goiter, exogenous iodine excess, pituitary tumors, thyroid cancer
Most common form of Hyperthyroidism
Grave’s disease
Grave’s disease
- autoimmune disease of unknown etiology
- thyroid enlargement and excessive thyroid hormone secretion
- precipitating factors: insufficient iodine supply, infections, stress, genetic factors
Hyperthyroidism Tri-ad
1) increased tissue sensitivity to stimulation of SNS
2) Goiter
3) exopthalmus
Exopthalmos
-impaired drainage from orbit, increased fat and edema in retro-orbital tissues
Grave’s disease may have what effect on the CV system?
-give you palpitations!
rapid HR and
Signs and symptoms of Grave’s disease
^ HR, RR, appetite, thirst, wt loss
–nervousness, wt loss, appetite
Thyrotoxic Crisis (thyroid storm)
- increased thyroid hormone in blood
- ** hyperthermia increase in temp to 105 degrees
- tachycardia, HF, restless, agitation, seizures, abd. pain, N/V/D, coma
Treatment and Therapy for Thyrotoxicosis
- therapy aimed at reducing fever, fluid replacement and management of stressors
- labs to see if FT4 is high and TSH low
- Beta blockers for symptomatic relief and decrease HR
why is iodine useful is treating thyrotoxic crisis
- large doses of iodine inhibit T3 and T4 and block their release into circulation
- available SSKI (sat sol potassium) & Lugol’s solution
- decreases vascularity of thyroid making surgery safer and easier (bc thyroid very vascular)
- long term iodine therapy not effective
Anti-thyroid meds to treat thyrotoxic crisis
PTU and Tapazole inhibit the synthesis of thyroid hormones
Surgical therapy for hyperthyroidism
- subtotal thyroidectomy for those unresponsive to drug therapy with large goiters causing tracheal compression
- **Hemorrhage ASSESS by gently slipping hand behind neck to check for blood
- endoscopic thyroidectomy for small nodules
euthyroid
normal function
Nutrition for hyperthyroidism
- high caloric may be ordered for hunger and prevention of tissue break down
- avoid caffeine, highly seasoned foods, high fiber foods
- –major problem in inadequate diet
After thyroid surgery what is essential to keep at the bedside?
-suction equipment and tracheostomy tray
Tetany
numbness and tingling toes and fingers is possible post-op along with circumoral muscle twitch
Post-op of thyroid surgery
- stridor or numbness so may need IV calcium
- avoid goitrogens: rutabagas, turnips, and peanut skin
- avoid caloric intake
Thyroiditis
- inflammatory process in thyroid with several causes
- viral, fungal, and autoimmune
