ENDORINE - part 2 Flashcards
also known as the butterfly shaped gland
thyroid gland
consist of two lobes located in the lower part of the neck, just below the voice box
thyroid gland
the 2 lobes of thyroid gland is connected by a narrow band called
isthmus
the fundamental structural unit of the thyroid gland
follicle
the site of the synthesis and storage of thyroid hormones
thyroid follicle
is a glycoprotein with a positive periodic acid schiff staining
thyroglobulin
it acts as a preformed matrix containing tyrosyl groups
thyroglobulin
types of cells in the thyroid gland
follicular cells (t3 and t4)
parafollicular or C cells (calcitonin)
is the neuroendocrine system that regulates the production and secretion of thyroid hormones
hypothalamic-pituitary-thyroid axis (HPTA)
by what week of gestation, which the gland begins to produce measurable amounts of thyroid hormones
11th week
TSH stimulates the synthesis of thyroid hormones through the cellular uptake of ___
dietary iodine
t4 is the prehormone of
t3
how t3 is produced as it says that its a prehormone of t4
in the cytoplasm from the removal of one iodine-outer ring of T4
the process of secretion into the circulation of T3 and T4 are all mediated by
TSH
is a biologically inactive metabolite of T4 and bound to TBG
reverse T3 (rT3)
if a mother has normal thyroid function, small amounts of maternal thyroid hormone crossing the placenta protect the fetus during development
what is the function of that small amount of thyroid hormone in fetus
critical in fetal NEUROLOGIC development
the actvity of thyroid hormones depends on the ____ of iodine atoms
location and number of iodine atoms
which type of thyroid hormone is metabolically active and which one is not
the metabolically active is the free thyroid hormone
the protein bound thyroid hormones are metabolically inactive
is the most important element in the biosynthesis of thyroid hormones
iodine
when iodide sources are diminished, ___ is produced in greater quantities, leading to increased T3 formation and release
MIT
iodine intake below _____ug/day is an indication of the deficiency of hormone secretion
50ug/day
it is a 32 amino acid monomeric peptide
thyrocalcitonin
is synthesized in the parafollicular cells from the cleavage and post translational modification of precalcitonin then procalcitonin
thyrocalcitonin
this maintains the balance of calcium and phosphorus in plasma
thyrocalcitonin
it is a protein that responds to systemic inflammatory conditions
procalcitonin
it is a marker for bacterial sepsis and part of the panel of test for covid 19
procalcitonin
discovered as a prohormone of calcitonin produced by C cells of the thyroid gland
procalcitonin
a 116 amino acid protein
procalcitonin
what organ is the major source of procalcitonin production, thus it may be considered as an acute phase protein
liver
functions of thyroid hormones
tissue growth
mental development
development of the central nervous system
heat production
control of oxygen consumption
influence carbohydrate and protein metabolism
energy conservation
major thyroid hormones
triiodothyronine T3/ 3,5,3’
tetraiodothyronine T4/ 3,5,3’5’
Free T3 and Free T4
it is the metabolically active form of thyroid hormones
triiodothyronine T3
t3’s principal application is in diagnosis of __
T3 thyrotoxicosis
this thyroid hormone is a better indicator of recovery from hyperthyroidism as well as the recognition of the recurrence of hyperthyroidism
triiodothyronine T3
it is helpful in confirming the diagnosus of hyperthyroidism especially in patients with no or minimally elevated T4
T3 - triiodothyronine
the first abnormality seen in cases of hyperthyroidism
elevated plasma level of T 3
ref range of T3
80-200 mg/dl
the principal secretory product of the thyroid gland
T4 tetraiodothyronin
it has the major fraction of organic iodine in the circulation/
tetraiodothyronine
it is completely synthesized in the thyroid gland
tetraiodothyronine
is a good indicator of the thyroid secretory rate
plasma concentration of t4
reference range of T4
5.5-12.5 ug/dl adult
11.8-22.6 ug/dl neonate
TBG or the thyroxine-binding globulin transports __
majority of T3
70% of total T4
binds rT3
thyroxine-binding albumin transports
20% of total T4
describe the affinity of T3 to thyroxne-binding globulin
lower affinity to TBG compared to T4
kahit most of t3 is transported by TBG, hindi pa rin sila ganon ka close
describe the affinity of the Thyroxine-binidng prealbumin to T 3
T3 has no affinity for prealbumin
albumin can transport what thyroid hormones
T3 and 10% of T4
are more specific indicators of thyroid function than the measurements of total hormone because the values are not affected by the TBG
free T3 and Free T4
is responsible for the metabolic activity of thyroid hormone
free T3
bets indicators of thyroid status
free t4 and TSH
diagnostic marker for hashimoto’s disease
thyroperoxidase autoantibody
detects grave’s disease
tsh receptor autoantibody
detects autoimmune thyroid disease in patients with a goiter
thyroglobulin autoantibody
detects hashimoto’s disease and grave’s disease
thyroglobulin autoantibody
signs and symptoms of hyperthyroidism
tachycardia, tremors, weight loss, heat intolerance, emotional lability, and menstrual changes
conditions under hyperthyroidism
grave’s disease
thyrotoxicosis
subacute granulomatous thyroiditis
subacute or silent lymphocytic thyroiditis
subclinical hyperthyroidism
most common cause of hyperthyroidism
graves’ disease (diffuse toxic goiter)
it is an autoimmune disease in which antibodies are produced activating the TSH receptor, goiter and hyperthyroidism are induced by thyroid-stimulating antibodies that resembles the action of TSH
graves’ disease
bale meron antibody na mukhang TSH tapos nagcacause ng production of thyroid hormone
this thyroid disease occurs 6x more commonly in women than in men, and commonly observed in younger age
grave’s disease
features of patient with grave’s disease
exophthalmos (bulging eyes)
and pritibial myxedema
applied to a group of syndromes caused by high levels of free thyroid hormones in the circulation
thyrotoxicosis
plummer disease is what type of thyrotoxicosis
T3 thyrotoxicosis
this thyroid disease is associated with neck pain, low-grade fever, and swings in thyroid function tests
subacute granulomatous thyroiditis/subacute nonsuppurative thyroiditis/De quervain thyroiditis (painful thyroiditis)
this thyroid disorder is possibly caused by viral infections
subacute granulomatous thyroiditis/subacute nonsuppurative thyroiditis/De quervain thyroiditis (painful thyroiditis)
this thyroid disease develops among women within 12 weeks after parturition
subacute or silent lymphocytic thyroiditis/ postpartum thyroiditis
it starts with symptoms of hyperthyroidism that progress to hypothyroidism
subacute or silent lymphocytic thyroiditis/ postpartum thyroiditis
hypothyroidism is treated with thyroid hormone replacement therapy, e.g. ____
levothyroxine
signs and symptoms of hypothyroidism
bradycardia, weight gain, coarsened skin, cold intolerance, and mental dullness
due to failure of the gland to secrete adequate thyroid hormones
primary hypothyroidism
mostly caused by ablation of the thyroid gland with radioactive iodine or thyroidectomy
primary hypothyroidism
most common cause of primary hypothyroidism
hashimoto’s disease
characterized by a thyroid replaced by a nest of lymphoid tissue - sensitized T lymphocyres/autoantibodies bind to cell membrane causing cytolysis and inflammatory reactions
hashimoto’s disease
is associated with enlargement of the thyroid gland (goiter )
hashimoto’s disease
is hashimoto’s disease painless?
yes
thyroid condition that is characterized as the peculiar nonpitting swelling of the skin
myxedema
this thyroid condition where the skin becomes infiltrated by mucopolysaccharide
myxedema
clinical feature of this thyroid condition is having
“puffy face”, weight gain, slow speech, eyebrows thinned, dry and yellow skin, and anemia
myxedema
a rare inflammatory disease of the thyroid gland, causing compression and fibrosis of adjacent tissue
riedel’s thyroiditis
distinct feature of the thyroid gland is having WOODY or STONY-Hard (irone hard) mass and usually with accompanying pain
Riedel’s thyroiditis
sometimes describes as an immunoglobulin-induced dysfunction of the thyroid
riedel’s thyroid
this thyroid disease is due to pituitary destruction or the presence of pituitary adenoma
secondary hypothyroiditis
a defect in the development or function of the thyroid gland since the beginning
congenital hypothyroidism/cretinism
symptoms of congenital hypothyroidism/cretinism
physical and mental development of the child are retarded
the most important thyroid function test- the best method for detecting clinically significant thyroid dysfunction
thyroid-stimulating hormone
it measures the relationship between the TRH and TSH secretions
thyrotropin releasing hormone
helpful in the detection of thyroid hormone resistance syndromes
thyrotrophin releasing hormone
it detects patients with euthyroid sick syndorme
reverse T3
it indirectlt assesses the level of free t4 in the blood
free thyroxine index
the smallest endocrine gland in the body
parathyroid gland
located on or near the thyroid capsule and sometimes within the thyroid gland
parathyroid gland
located posterior to the thyroid gland
parathyroid gland
most people have how many parathyroid gland
most have 4, some have 8, or 2
parathyroid hormone secretes what hormone
parathyroid hormone - a major hypercalcemic hormone
prime role of PTH
regulates plasma calcium concentration to prevent hypocalcemia
preserves calcium and phosphate ions within the reference limit
PTH
effect of PTH in bone
promotes resorption and releases calcium into the blood stream
effect of PTH in kidney
increases renal absorption of calcium
effect of PTH to vitamin D
stimulates conversion of inactive vitamin D to activated vitamin D3
most common cause of hypercalcemia
primary hyperparathyrpoidsism
due to the presence of a functioning parathyroid adenoma
primary hyperparathyroidism
effect of hyperparathyroidism in the phosphate presence in the urine
phosphaturia
kasi si pth nagpopromote ng exretion ng phosphate ions so may phosphaturia
the main cause of this hyperparathyroidism is the vitamin D deficiency and chronic renal failure
secondary hyperparathyroidism
nabuo dahil sa compensation in response to decrease serum calcium
this type of hyperparathyroidism is develops in response to decrease serum calcium
secondary hyperparathyroidism
hypoparathyroidism is due to what reason
due to accidental injury to the parathyroid glands (neck) during surgery
it develops due to genetic mutation resulting in ineffective PTH action in the presence of a functioning parathyroid gland
pseudohypoparathyroidism
normal gland abnormal hormone
how come that phosphate excretion is inhibited in renal disease in pseudohypoparathyroidism
due to non-responsiveness of the tubules to PTH - phosphate levels rise while calcium levels fall
the best method for PTH measurement involves the use of
antibodies that detect both the amino-terminal fragment and intact PTH
it is a pyramid-like shape (adult gland) gland located above the kidneys
adrenal gland
color of adrenal cortex and adrenal medulla
cortex - yellow
medulla - dark mahogany
the major site of steroid hormone production
adrenal cortex
hormones that adrenal cortex secretes
cortisol
aldosterone
weak androgens
the parent cell of all steroid hormones
cholesterol
the cortical hormones are synthesized from what lipoprotein
LDL
the secretion of adrenal glucocorticoids and androgens is regulated by
ACTH
the mineralocorticoid secretion is controlled by __
RAAS
3 layers of adrenal cortex
zona glomerulosa 10%
zona fasciculata 75%
zona reticularis 10%
this layer of adrenal cortex is the principal source of mineralocorticoid (regulated by RAAS)
ZONA GLOMERULOSA 10%
this layer of adrenal cortex is the site of glucocorticoid synthesis (regulated by ACTH)
zona fasciculata 75%
this layer of adrenal cortex is the site for synthesis of unsulfated DHEA
zona fasciculata 75%
this layer of adrenal cortex produces androstenedione and dehydroepiandrosterone weak androgens
zona reticularis
the principal glucocorticoid
cortisol
cortisol’s synthesis is regulated by
ACTH kasi glucocorticoid yan eh under ng fasciculata
cortisol is mostly bound to ____
transcortin or cortisol-binding globulin
free - 10%
effect of cortisol to insulin or glucose level
it stimulates gluconeogenesis in the liver, thus, resulting in hyperglycemia (with anti insulin effect )
the only adrenal hormone that inhibits the secretion of ACTH
cortisol - when plasma level is elevated
so if super dami na ni cortisol, kahit si ACTH pa ang nagreregulate sa niya, di na siya kakayanin
explain why cortisol is a valuable therapeutic agent for rheumatoid arthritis, SLE, and multiple sclerorsis
it has an anti inflammatory and immunosuppressive actions
cortisol follows circadian rhythm which means its highest concentration is at
daytime or morning 8:00 am to 10:00 am
this is the sensitive indicators of adrenal hyperfunction (endogenous corticolism )
24 hr urine free cortisol
a group of clinical and metabolic disorders characterized by adrenocortical hyperfunction
cushing’s syndrome
this hyperadrenalism that is caused primarily by excessive exposure to corticosteroids
cushing’s syndrome
due to chronic excessive production of cortisol by the adrenal cortex
cushing’s syndrome
cushing’s sydnrome is observed with low __ and ___
low plasma aldosterone and renin
clinical maniestattion of a patient with cushing’s syndrome
buffalo hump
hyperglycemia
thinning of the skin
poor would healing
purple striae
hypertension
hypercholesterolemia
cushing’s syndrome is bets diagnosed using blood samples collected at what time
at night kasi mababa to kapag gabi, so any elevation sa gabi means hyperproduction of cortisol
screening test of cushing’s syndrome
24 hr urine free cortisol - positive four fold increase
overnight dexamethasone suppression - positive when cortisol level is not suppressed
midnight salivary cortisol
confirmatory test for cushing’s syndrome
low dose dexamethasone suppression
midnight plasma cortisol
what beverage is best to avoid in UFC test
UFC - urinary free cortisol
alcohol- causes pseudocushing’s
causes of false positive UFC
high fluid intake and urine volume
for saliva, how many minutes of NPO are required for cortisol testing
15 mns before collection
how many days a patient must refrain from smoking for cortisol testing
1 day
sample of choice for SCREENING cortisol for pregnant women
urinary free cortisol
despite using urine for cortisol testing, how many percent of total adrenal secretion appears in the urine as cortisol
1% - despite being 1% this fraction provides valuable air in the diagnosis of adrenal disease
this test for cortisol may further be used to distinguished the possible cause of primary hyperadrenalism - that is if hyperplasia or adenoma or carcinoma
low-dose dexamethasone suppression
what preservative we can use for urine sample for the measurement of cortisol and aldosterone
10 grams of boric acid
the only cortisol that passes through renal filtration
urinary free cortisol
characterized by 90% destruction of the adrenal cortex with low or deficient cortisol in the presence of ACTH release
primary hypoadrenalism
example of hypocortisolism
addison’s disease (mostly caused by an autoimmune destruction of the adrenal cortex )
the gold standard test in the assessment of hypothalamus-pituitary axis
insulin tolerance tets
results from deficiency of enzymes necessary in the synthesis of cortisol
congenital adrenal hyperplasia
the most common form of Congenital adrenal hyperplasia
21-hydroxylase deficiency
this type of congenital adrenal hyperplasia leads to hirsutism in women and other symptoms caused by excess androgen levels such as virilization, infertility, and amenorrhea
21 hydroxylase deficiency
aside from the deficiency of enzyme to synthesized cortisol, what is the effect of congenital adrenal hyperplasia to androgen levels
can increase
kaya ung mga gurls nagkakaron ng male traits
the second most common form of CAH
11 b hydroxylase deficiency
it is characterized by pseudohermaphroditism in female infants, and incomplete masculinization in male infants
3 b hydroxysteroid dehydrogenase isomerase deficiency
the most severe form of CAH
congenital lipoid adrenal hyperplasia (Lipoid CAH )
secreted in the adrenal cortex and the most potent mineralocorticoid
aldosterone
it is a steroid hormone that helps regulate water, electrolytes, and blood pressure -
aldosterone
main determinant of renal excretion of potassium in the cortical collecting duct
aldosterone
aldosterone blood level at night
lower
enzyme needed for the synthesis of aldosterone
18 hydroxysteroid dehydrogenase
major stimuli of aldosterone secretion
angiotensin II and hyperkalemia
primary hyperaldosteronism is also called as
Conn’s disease
it is caused by aldosterone-secreting adrenal adenoma
conn’s disease
suggestive of primary hyperaldosteronism
> 30 ratio
diagnostic of primary hyperaldosteronism
> 50 ratio
confirmatory test for hyperaldosteronism
saline suppression
oral sodium loading
fludcortisone suppression
captopril challenge
it occurs as a result of excessive production of renin or overactivity of RAAS
secondary hyperaldosteronism
this type of hyperaldosteronism has elevated plasma levels of aldosterone and renin
both increase
secondary
kapag kasi sa primary, aldostestrone lang mataas
pseudohyperaldosteronism is also called as
liddle’s syndrome
it is a congenital disorder that is characterized by increase ENaC (epithelial sodium channel) actively in the renal collecting duct
liddle’s syndrome
it resembles primary hyperaldosteronism, clinically, but aldosterone and renin levels are low, with secondary hypertension
liddle’s syndrome
this is due to defective secretion of aldosterone and angiotensin
hypoaldosteronism
characterized by the inability of the renal tubules to respond to the action of aldosterone
pseudohypoaldosteronism
pseudohypoaldosteronism type 1 is also known as
salt losing nephritis
pseudohypoaldosteronism type II is also known as
gordon syndrome
pseudohypoaldosteronism type 1 has a defect in
not only potassium secretion but as well as sodium reabsorption that is why it’s called as salt losing nephritis
pseudohypoaldosteronism type II has a defect in
potassium secretion
high renin high aldosterone means
secondary hyperaldosteronism
low renin high aldosterone means
primary hyperaldosteronism - conn’s
high renin low aldosterone means
addison’s disease, heparin therapy, aldosterone biosynthetic defect
low renin low aldosterone
liddle’s syndrome
hyporeninemic hypoaldosteronism
11 hydroxylase deficiency
17 hydroxylase deficiency
drug induced mineralocorticoid excess
described the aldosterone in primary renin deficiency
aldosterone is always decreased (hyporeninemic hypoaldosteronism )
described the aldosterone in primary increase in PRA
increase PAC - secondary aldosteronism
adrenal insuffiency is very likely if the 8 am serum cortisol is ____ with high ___
if the cortisol is low with high ACTH
postural stimulation test is what kind of test
aldosterone test
are by products of cortisol synthesis that are regulated by ACTH
adrenal androgens
serves as the precursor for the production of more potent androgens and estrogens in tissues
adrenal androgens (weak androgens )
principal adrenal androgen
dehydroepiandrosterone (DHEA)
sulfated form of DHEA
DHEA- s
hormones produced from DHEA and DHEA s
estrogen, testosterone, androstenedione, 5 dihydrotestosterone
causes the sulfation of DHEA forming DHEA-S
sulfotransferase
males derive less than %%% of testosterone from adrenal secretion
less than 5 %
females depend on adrenals for %% to %%% of daily testosterone
40-65% wala kasi tayong itlog kaya ang mga gurls sa adrenal androgens magrerely for testosterone
it is composed primarily of chromaffin cells that secrete catecholamines
adrenal medulla
the precursor of the catecholamines such as norepinephrine, epinephrine, and dopamine
L-tyrosine
ratio in serum of norepinephrine to epinephrine
9:1
cathecholamines are %% protein bound
50%
this catecholamine is produced by the sympathetic ganglia
norepinephrine
the highest concentration of norepinephrine is found in
brain
this catecholamine acts as a neurotransmitter in both CNS and sympathetic nervous system
norepinephrine
this catecholamine is the most abundant medullary hormone secreted in the adrenal medulla
epinephrine
this catecholamine is produced from norepinephrine
epinephrine and comes only from adrenal gland
this catecholamine is called as the “flight or fight hormone”
epinephrine
why epinephrine is called a flight or fight hormone
it is released in response to physiologic (injuries) or psychological threats
this catecholamine increases glucose concentration by glycogenolysis
epniephrine
epinephrine
any form of stress that increases ___ levels stimulates its production
cortisol
epinephrine is best collected from what kind of sample
indwelling catheter since venipuncture may cause levels of catecholamines to rise
para madali, ganito nalang, since kapag veni nakakatakot, may iba na takot sa syringe, since it’s stress, tataas si catecholamine, false increase, gets? gets boomboompaw
is the major catecholamine metabolite in urine derived largely from norepinephrine
vanillylmandelic acid (VMA)
this catecholamine us produced in the body by the DOPA - decarboxylation of 3,4-dihydroxyphenylalanin
DOPAmine
dopamine is present in the highest concentration in the
regions of brain
this catecholamine is the major intact catecholamines present in urine
dopamine
major metabolite of dopamine
homovanillic acid
major metabolite of epinephrine and dopamine
epinephrine: vanillylmandelic acid (VMA)
dopamine: homovanillic acid (HVA)
a related disorder in which there’s a tumor of the adrenal medulla or sympathetic ganglia
pheochromocytoma
a related disorder in which there’s an overproduction of cathecholamines
pheochromocytoma
pheochromocytoma’s clinical manifestation
classic spells
hypertension
tachycardia
headache
tightness of chest
sweating
is a fatal malignant condition in children, resulting in excessive production of norepinephrine
neuroblastoma
