Ch. 32 Disorders of Endocrine Control of Growth and Metabolism Flashcards
Functions of the endocrine systems
- controls growth/development
- regulates energy metabolism
- muscle/adipose tissue distribution
- sexual development
- fluid and electrolyte balance
- inflammation and immune response
hormones
substances/chemical mediators that are released from endocrine tissues —> blood system—->target tissues to generate a response
are the adrenal glands affected with renal failure?
no
hypofunction
- absence or impaired development
- absence of enzymes
- gland destruction
- decline in function
Causes:
- blood clots/impeded blood flow
- septic/infection
- inflammation
- autoimmune
- neoplastic growth
- age
- atrophy(side effect of medication)
hyperfunction
- excessive hormone production
- excessive stimulation
- hormone producing tumor (tumor forms originally on gland)
primary defect
target organ defective
secondary defect
organ that produces stimulating hormones defective
tertiary defect
hypothalamic dysfunction(both primary and secondary)
Hormones produced by the pituitary gland
ACTH (adrenal cortex tropic hormone) TSH (thyroid stimulating hormone) GH (growth hormone) FSH (follicle stimulating hormone) LH (luteinizing hormone) PL (prolactin)
How many lobes does the pituitary gland have?
2: anterior and posterior
pituitary tumor
- could be primary or secondary
- functional or non functional
- small to large in size (large tumors will see increased intracranial pressure and experience vertigo, nausea, headache, vomiting)
hypopituitarism
- decreased secretion
- congenital or acquired(tumor/medication)
- gradual/acute onset
- many physical manifestations (fatigue, loss of appetite, impaired sexual frustration, cold dysfunction, increased morbidity/mortality)
what is the order that the pituitary hormones stop producing in?
1st- GH
LH
FSH
last- ACTH
Where is growth hormone produced
in the anterior pituitary gland
function of growth hormone
- necessary for linear bone growth
- abnormalities are not limited to just the skeleton… (englarged heart, metablolic disorders like fat and carbohydrate, impaired glucose tolerance)
- released during REM sleep, majority during childhood before puberty
Causes of decreased GH in Children
- idiopathic
- short stature
- no cause- etiology unknown
- psychosocial
- hypopituitarism
- emotionally deprived (will manifest with potbelly and poor nutrition)
excess GH in children
- Marfan’s syndrome (XXY) - arms are extremely long
- can be treated with hormones to close epiphyseal plate
- can result in gigantism
gigantism
too much GH before puberty
both gigantism and acromegaly can result in….
diabetes. because both are associated with increased glucose levels
decreased GH in adults
GH naturally decreases with age, but is still released during REM sleep
can result in many systemic complications…
- cardiac
- increased lipids/hyperlipidemia
- decreased bone mineral density
- decrease in lean muscle body mass
- increase in fat mass
- reduced exercise capacity
acromegaly
too much GH after puberty
-pronounced enlargement of face and nose (fingers too)
excess GH in adults
-most commonly caused by benign adenomas - excessive GH made
hypothyroidism
very common-5% of US population has
- Hair loss
- intolerance to cold
- receding hairline
- dark skin
- anorexia
- facial/eyelid edema
- thick tongue
treated with a synthetic hormone pill (synthroid)
congenital hypothyroidism
-treatable if found at birth (at birth baby will appear normal b/c they still have thyroid hormones from the mother. But then urine output will decrease and they wont gain weight) by checking TSH and T4 levels
acquired hypothyroidism
- slow, destruction/dysfunction
- could be primary, secondary, tertiary
- could be caused by iodine deficiency (result in goiter)
Hashimoto Thyroiditis
- autoimmune thyroiditis-etiology unknown, thyroid just stops working
- # 1 most common type of hypothyroidism
- more common in women
S/S
-tired, gain weight, eat less, cold intolerance, jaundice (affects liver), constipation
if hypothyroidism isn’t treated is could lead to…
myxedema
- hard, non pitting edema
- puffy eyes
- tongue enlarged
- coma/death
- hypothermia
- cardiovascular collapse
- hypoventilation
- hypernatremia
- hypoglycemia
- hypoxia
hyperthyroidism (thyrotoxicosis)
high levels of circulating thyroid hormone
Treatment:
- radioactive iodine
- surgical removal of all or part of thyroid
S/S
-irritable (don’t sleep), tachycardic, weight loss, heat intolerance, restless, fine motor tremors, exopthalmos
what do you worry about in patients hypothyroidism?
hyperthyroidism due to over medicating
Graves Disease
- most common cause of hyperthyroidism
- women ages 20-40 yrs old
- women are five times more likely to have than men
- autoimmune- etiology unknown
- abnormal TSH stimulation- TSH levels elevated
- often associated with other autoimmune diseases(myasthenia Gravis, pernicious anemia)
- diarrhea is seen because the metabolism is increased which means the GI tract is moving too fast
thyroid storm
crisis-life threatening
- could be overdose of synthroid
- precipitated by stress
manifests by:
- very high fever
- tachycardia
- CNS effects
- mortality is high
treated with a drug that blocks the hormones
What medicine should not be used during a thyroid storm?
aspirin
Addison’s disease
Primary adrenal cortical insufficiency
- lack of adrenal cortical hormones (steroids)
- most common cause of Addison’s disease today is autoimmune
- most common cause of Addison’s disease before the 1950s was TB
- requires lifetime hormone replacement
- adrenal cortex 90% destroyed before symptoms show
Addison’s patients…
require regular meals and exercise
they respond poorly to stressors (cold, heat)
acute adrenal crisis/Addisonian’s crisis is treated with fluids and steroids
Secondary Adrenal Cortical Insufficiency
- damaged pituitary gland or removal of pituitary gland
- could also be due to patients not tapering off steroid medications. if so they will give patient a higher dose of steroids and taper them off in hopes of resetting the adrenal gland
acute adrenal crisis
Addison’s disease + stress or illness = nausea, vomiting, weakness, hypotension, dehydration, vascular collapse
Glucocorticoid Excess
opposite of Addison’s disease- think adrenal gland
Cushing Syndrome
- glucocorticoid excess
- Cushing disease if caused by pituitary tumor
- adrenal form : benign/malignant adrenal tumor
- ectopic : non-pituitary tumor that secretes ACTH
- iatrogenic (physician induced) : cushing’s syndrome caused by long term steroid use
Cushing Syndrome manifestations
- thin arms and legs
- large waist
- diabetes
- buffalo hump
- Na+ and water retention
- hypertension
- cardiac hypertrophy
- moon face
- muscle wasting and fat accumulation
