Final: Ch 32 Disorders of Endocrine Control of Growth & Metabolism Flashcards
anterior pituitary produces which hormones
GH
TSH, FSH
ACTH
LH
prolactin
posterior pituitary produces what hormones
ADH
Oxytocin
definition of hypo function
decreased gland function for any reason
congenital absence of gland or lack of enzyme
destruction by low blood flow, infection, inflammation, autoimmune rxn
aging decreases function, hormone receptors down-regulated
definition of hyper function
increased hormone production for any reason
overstimulation or tumor
primary disorders
in the gland itself
secondary disorders
result from altered stimulation of a normal gland
tertiary disorders
result from destruction of the hypothalamus
pituitary tumors are mostly ______
adenomas
symptoms of pituitary tumors depend on…
hormone secreted
can produce headache, n/v, visual disturbance
carcinoma of pituitary
uncommon
may need surgical removal
hypo pituitarism
decreased secretion of pituitary hormones
seen when 3/4 of anterior pituitary destroyed
symptoms of hypo pituitarism
weakness, fatigue
low appetite, sexual function
cold intolerance
sequence of loss for hypo pituitarism
look for the ademona (GH, LH, FSH, TSH, ACTH)
ACTH loss most serious –> adrenal insufficiency
Dx, Rx of hypo pituitarism
test for pituitary hormone levels
treat cause
replace hormones
assessment of hypothalmic-pituitary function
blood tests: ACTH, cortisol, PL, TSH, T3/4, FSH, LH, GH,
plasma/urine osmolarity
MRI of hypothalamus/ant pit
growth hormone (somatotropin) release is controlled by
GHRH and GHIH (somatostatin)
growth hormone is stimulated by
low BS
high aa
stress
exercise
what does growth hormone stimulate
growth via IGF-1 by upping protein synthesis
cartilage growth
bone growth
endocrine organ growth
muscle growth
growth hormone has anti-____ effects
insulin
ups lipolysis
lowers glucose use
definition of short stature in children
hight less than 3rd percentile or slow linear growth
treatment of short stature in children
rule out endocrine causes
test GH, IGF-1 levels
use bone x-ray to assess bone age
MRI or CT of hypothalamus/pituitary
idiopathic short stature
genetic/familial
correct patent’s height for sex and average
are the kids normally proportioned?
constitutional short stature
common in boys > girls
growth delay
late development/puberty/growth spurt
GH deficiency in children is from?
from lack of GHRH or from pituitary lack of GH (give GH)
inability to produce GH receptors (give IGF-1)
GH deficiency in adults
can be present from childhood or develop in adulthood
increases central obesity and atherosclerosis risk
GH production ____ with age
falls
marketed as the fountain of youth
Dx Rx of GH deficiency in adults
Dx: stimulation test with insulin or L-dopa
Rx: GH replacement, higher lean body bass, bone density, GF
tall stature in children
constitutional tall stature: tall vs. peers
Marfan’s
XYY
excessive sex hormones or GH
GH excess in children causes
gigantism
high GH –> high IGF prior to closure of epiphyseal plates
causes of excessive GH in adults
GH secreting pituitary adenoma
symptoms of excessive GH in adults
acromegaly - soft tissue and flat bone growth
deep voice, and malocclusion
insulin resistance
headaches
visual disturbances
Rx of excessive GH in adults
correct metabolic abnormality
remove tumor
GH analogs stimulate neg feedback inhibition of GH
precocious puberty
early activation of hypothalmic-pituitary-gonad-axis
early development of secondary sex characteristics
idiopathic or from abnormality
treatment depends on cause
anatomy of thyroid
gland located inferior and anterior to larynx
contains colloid filled follicles
colloid contains thyroglobulin
in the thyroid, iodine is captured by
Na+/I- co-transporter
active process
stimulated by TSH
in the thyroid, iodine is moved into the colloid by ______
pendrin
active process
iodine is oxidized and added to ______
tyrosine –> T3, T4
uses thyroid peroxidase
T3/T4 added to __ and stored in _____
TG, colloid
what causes release of T3/T4
TSH
T4 = 90% of released hormone
travels in plasma bound to TBG/other proteins
control of thyroid hormone secretion
stress and cold trigger TRH release from hypothalamus
TRH triggers TSH release from ant. pit.
TSH triggers T3/T4 production and release from TG
negative feedback inhibition of TRH/TSH
effect of thyroid hormone on metabolic rate
increases for all tissues (glucose, fat, protein use increases)
normal levels of T3/T4 needed for protein synthesis
in hyperthyroidism, muscle breakdown _____
increases –> fatigue
fat mobilization and use increases
in hypothyroidism what happens to serum cholesterol
increases
effect of thyroid hormone on the cardiovascular system
CO, HR, contractility, blood volume, O2 use all increase
effect of thyroid hormone on GI
motility and secretion increase
diarrhea in hyperthyroidism
effect of thyroid hormone on neuromuscular system
increases muscle tone –> tremors in hyperthyroid
needed for infant brain development
more CNS activity –> nervousness in hyperthyroid
congenital hypothyroidism causes
lack of gland
lack of ability to synthesize T3/T4 or TSH
symptoms of congenital hypothyroidism
slow brain development/overall development
jaundice
respiratory/feeding difficulties from large tongue
sluggishness/lack of interest
umbilical hernia
Dx, Rx of congenital hypothyroidism
Dx: screening for T4 and TSH
Rx: hormone replacement begun by 6 wks of age = normal intelligence
acquired hypothyroidism (myxedema) in children or adults
usually primary - hashimoto’s
can be from surgery, iodine deficiency, or too much iodine
symptoms of acquired hypothyroidism
hypo-metabolic state
weight gain
fatigue
cold intolerance
fluid accumulation
low HR
Dx of acquired hypothyroidism
T3/T4, TSH testing
anti-thyroid Ab test (anti-TPO)
Rx of acquired hypothyroidism
synthetic T3/T4
myxedematous coma
potentially fatal complication of severe hypothyroidism
coma, hypothermia, hypoventilation, cardiac collapse, electrolyte imbalance
precipitating factors of myxedematous coma
cold
sedatives (low drug metabolism in hypothyroidism)
Rx of myxedematous coma
manage fluid and electrolyte imbalances
treat hypercapnea/hypoxia
don’t re-warm b/c cardiovascular collapse
2 causes of hyperthyroidism
Grave’s disease (autoimmune, most common)
adenoma
symptoms of hyperthyroidism
hyper-metabolic state
nervousness, irritability, tachycardia
weight loss
exopthalamus (eye bulge)
heat intolerance
Rx of hyperthyroidism
remove gland w/ surgery or radioactive iodine
anti-thyroid drugs block production of T3/T4 and T4 -> T3
beta-blockers reduce sympathetic symptoms
grave’s disease (hyperthyroid state)
most common in 20-40 yoa
autoimmune disease - Ab stimulate TSHr
cytokines activate fibroblasts behind orbit –> exophthalmos
thyroid storm
life threatening crisis of thyrotoxicosis (hyperthyroidism)
caused by disease stress (infection, ketoacidosis)
large spike in thyroid hormone
symptoms of thyroid storm
high fever
tachycardia
angina
HF
treatment of thyroid storm
cool down
fluids
beta-blockers
anti-thyroid drugs
steroids for stress
adrenal cortex secretes
steroids
aldosterone
cortisol
testosterone
adrenal medulla secretes
catecholamines
biosynthesis of cortical steroids
made from cholesterol using enzymes
cortisol and testosterone are secreted to ____
ACTH
aldosterone regulated by which system
RAA
adrenal sex hormones (T) has little to no impact on _____
males
body hair growth in females?
aldosterone does what
act on kidney to retain Na and excrete K
hypothalamus is stimulated by multiple ____ factors
stress
dimural variation peak at 6-8 am
metabolic effects of cortisol
gluconeogenesis
protein catabolism
lipid mobilization
higher blood sugar
psychological effects of cortisol (pharma dose)
psychosis
behavioral change
anti-inflammatory effects of cortisol pharma dose
inhibit prostaglandin synthesis
immune effect of cortisol pharma dose
lower cell and humoral immunity
adrenal suppression
long-term cortisol therapy suppresses adrenal function
recovery takes months
tests for adrenal function
cortisol
aldosterone
ACTH
congenital adrenal hyperplasia
recessive enzyme deficiency - low cortisol high ACTH and androgens
21alpha-hydroxylase most common, 11beta-hydroxylase rare
decreased aldosterone
females congenital adrenal hyperplasia
virilization of genitalia
Rx of congenital adrenal hyperplasia
replace missing hormones
surgical reconstruction of genitalia
primary adrenal cortical insufficiency (addison’s disease)
autoimmune destruction of entire adrenal cortex
can be from cancer or infection
causes hyperpigmentation and requires lifelong hormone replacement
secondary adrenal cortical insufficiency
caused by pit defect or cortical suppression by exogenous steroids
aldosterone normal
no increased ACTH so no hyperpigmentation
acute adrenal crisis
happens when a person w/ cortical insufficiency is stressed (infection or surgery)
replace salt, sugar, and steroids
support any failing functions
treat cause
glucocorticoid excess (cushing’s syndrome) 4 causes
overproduction of ACTH by pit tumor
adrenal tumor
non-pit tumor secreting ACTH
long-term cortisol therapy
symptoms of cushing’s
fat pads (buffalo hump)
muscle atrophy
Na retention –> HTN
K+ loss
diabetes
Dx of cushing’s
tert urine for 24 hr cortisol excretion
test blood for ACTH to determine cause
Rx of cushing’s
surgery
irradiation
medication
Addison’s produces low levels of _______ but high levels of ____
Cortisol, ACTH
Does Hashimoto’s (hypothyroidism) cause high trophic hormone levels?
Yes
Does grave’s (hyperthyroidism) cause lowered trophic hormone levels?
Yes
Does secondary adrenal cortex insufficiency cause lowered cortisol and ACTH?
Yes
Does acromegaly mean high GH and IGF-1?
Yes
Do defects in the 21 and 11 hydroxylase genes cause less cortisol and aldosterone, but high testosterone?
Yes