What are the four functions of the endocrine system?
Use and store fuel
Electrolyte homeostasis/ balance
Growth and development
Reproduction
What are the anatomic borders (anterior, superior and posterior) of hypothalamus?
Anterior: optic chiasm
Superior: hypothalamic sulcus
Posterior: mammillary bodies
Direct preganglionic motor fibers from the hypothalamus causes _____ to secrete _____
Adrenal medulla
Epinephrine and norepinephrine
Where did the hypothalamus derive from embryologically?
Prosencephalon which develops into diencephalon
T/F: adenohypophysis is not neural tissue, did not develop from the neural system itself but from the gut/oral ectoderm instead
True
Which part of the pituitary is the rathke’s pouch associated with?
Anterior pituitary from the ectodermal tissue that is moving upwards to meet with the downward moving neurohypophysis. The region that closes up is the rathke’s pouch
Where can craniopharyngioma form?
In rathke’s pouch, usually tumor of childhood
In H&E staining of anterior pituitary, acidophils stain _____________, basophils stain ________
Basophils- stain blue to purple: FSH, LH, ACTH, TSH (think B-FLAT)
What can amino acid pool do for you?
Protein turnover- make cell walls and build muscle
Gluconeogenesis- amino acid be used to make glucose when glucose is limited
Energy production by converting amino acid into pyruvate
Fat cells- converting amino acids to fatty acids and store as triglyceride
Amino acid from the amino acid pool undergoes ______ to become glucose/ ketone or enter kreb cycle
Catabolism
Full blown lipolysis and gluconeogenesis occurs after _____ hours of starvation
24 hours
Glycogenolysis predominates right after meal, while lipolysis and gluconeogenesis slowly rise up. By the 24th hour of starvation, glycogenolysis ceases and the other two take over as energy production
By which time period of starvation would CNS start using ketones as fuel instead of glucose?
When in the protein conservation phase about 10 days of starvation
This is when protein catabolism decreases to a minimum (gluconeogenesis decreases)
T/F: Insulin dominates during fasting state
False; glucagon dominates during fasted stated: increase in glycogenolysis, gluconeogenesis and ketongensis
In fasted state: glycogenolysis _____, gluconeogenesis ____ and ketogenesis ___
Increase
Increase
Increase
Central molecule in metabolism is ____
Acetyl CoA
T/F: ACTH stimulates secretion of the adrenal medulla
False; literally in the name, adrenoCORTICOtroupic hormone, therefore it stimulates the adrenal cortex. Adrenal medulla is under direct control of the hypothalamus preganglionic motor fiber to secrete epinephrine/ norepinephrine
The strongest vasoconstrictor known to man is _____, aka ______ and it basically makes pee _____ concentrated, and you pee ____ (Frequency)
ADH
Vasopressin
More
Less
Hiking in Arizona over the summer would cause ___ secretion of ADH due to _____
Increased
Dehydration
T/F: ADH inserts water channels in the kidney tubule in order to excrete out more water out of the body
False; it inserts water channel in the kidney tubule in order to reabsorb water back in the system. (Think pee less, and more fluid back in system to raise bp)
Renin controls Na+ by increase Na+ _______. What happens with water and K+?
Reabsorption of sodium from urine back to blood.
This would also bring water back in the blood, and actually pee out more K+
T/F: Tyrosine based hormones are peptide based hormones, these include thyroxin, catecholamine and melanin
False; tyrosine based hormones are amine hormones, thyroxin, catecholamine and melanin are tyrosine hormones
Which group of hormones require further processing in order activate?
Peptide hormones are first synthesized as prohormones which requiring further cleavage
Steroid hormones are synthesized from ______; amino acid derivative hormones are synthesized from _____
Cholesterol
Tyrosine
T/F: Thyroid hormone is a tyrosine derivative hormone, however, unlike other tyrosine hormones, thyroid hormones bind directly on nuclear receptors instead of cell membrane receptors
True; thyroid hormone, along with steroid hormones, both bind directly to intracellular receptors as opposed to cell membrane receptors like peptide hormones and adrenaline (other type of tyrosine derived hormone)
What are the hydrophobic hormones?
Adrenal steroids and sex steroids
Rest are hydrophilic
____ is in charge of sex hormone productions, ie testosterone, estrogen; while _____ is in charge of egg/sperm production
LH
FSH
Sella turcica is the bony cavity in the _____ bone of the skull
Sphenoid
T/F: Pineal gland secretes MSH
False; pineal gland secretes melatonin. MSH is secreted in the pars intermedia region of the anterior pituitary
“Releasing” hormones are secreted from _______, and sent to the ______ and stimulates the ____ cells to secrete the pituitary hormones
Hypothalamus
Pituitary gland
“trope”
SIADH, symptom of inappropriate ADH, is _____function of the _____ pituitary
Hyperfunction
Posterior
Hyperfunction of the anterior pituitary results in these conditions:
Prolactinoma
Gigantism/ acromegaly
Cushing disease
Hypofunction of the posterior pituitary results in this condition _____
Diabetes insipidus
Hypofunction of the anterior pituitary results in these conditions:
Sheehan syndrome
Empty sella syndrome
T/F: excess of FSH/LH could result in infertility
True
What happens when there is excess oxytocin?
We don’t know yet!
Cushing’s disease is a(n) ____ of ___ hormone
Excess
ACTH
Which examination finding is suggestive of a pituitary tumor?
Bitemporal hemianopsia
Patients presenting with bitemporal hemianopsia or unexplained visual field defects or visual loss should be considered to have a _______
Pituitary disorder
Imagining showing irregular speckled calcification and a mass in the sella turcica, indicative of:
Craniopharyngioma
How to remove craniopharyngioma?
Surgery- endonasally penetrate the sphenoidal sinus and go to the base of the pituitary
T/F: pituitary adenoma and craniopharyngioma are different names for the same thing
False; pituitary adenoma is without calcification whereas craniopharyngioma has calcifications present
Craniopharyngioma mass effects?
Cranial nerve deficits
Epilepsy
Anosmia – loss of ability to smell
Positional vertigo (CN VIII affected)
T/F: Craniopharyngioma leads to hyperpituitarism requiring lifelong treatment
False; hypopituitarism
T/F: hypothalamic dysfunction, as a result of craniopharyngioma, often leads to hyperphagia and obesity
True
Compression of the pituitary stalk by craniopharyngioma leads to what effect of prolactin secretion?
Hyperprolactinemia- because the inhibition by dopamine is removed due to the mass effect
Prolactinomas symptoms?
Amenorrhea (no menstruation)
Galactorrhea (spontaneous milk secretion)
Infertility
T/F: hyperprolactinemia inhibits the surge in LH so no ovulation occurs, leading to infertility
True
What are some causes of panhypopituitarism?
Congenital malformations of septo-optic dysplasia (HESX1)
Pituitary tumors
Sheehan syndrome – associated with pregnancy
Apoplexy- infarct from adenomas, radiation damage, traumatic brain injury
Empty sella syndrome
Infiltrative disease like fungal, TB, Langerhans cell histiocytosis, DI, hemochromatosis
Atrophy or compression of pituitary is _____ syndrome
Empty sella
Sudden hemorrhage of pituitary gland, often in the presence of an existing pituitary adenoma is _____
Pituitary apoplexy
Ischemic infarct of pituitary following postpartum bleeding is ____ syndrome
Sheehan
What is the most common pituitary adenoma?
Prolactinoma
Macroadenoma is _____ mm, microadenoma is _____ mm
Over 10mm is macroadenoma
Less than 10 mm is microadenoma
When does cortisol peak?
In the morning
Lowest level at night
(whereas growth hormone/ IGF-1 peaks at night!)
What is the difference between cushing’s disease and cushing’s syndrome?
Cushing’s disease = tumor
Cushing’s syndrome = increased cortisol
Pituitary adenomas ____ pituitary secretion
Increase =Hormone excess
T/F: In panhypopituitarism, all the anterior pituitary hormones are low
False; prolactin could be elevated, because the release of prolactin is no longer inhibited by dopamine
Low urine specific gravity and very pale urine indicates ____
Diabetes insipidus, which is hypofunction of the posterior pituitary
Urine osmole lower than _____ mOsm/kg suggests diabetes insipidus, along with ____ Na+
Less than 300 urine osmole
And high serum sodium and plasma osmole, >145 serum Na+
(do water deprivation test to confirm)
T/F: diabetes insipidus results in hypernatremia, and large quantities of dilute urine
True
If untreated, diabetes insipidus can lead to ______
Hypotension and hypovolemic shock
When serum osmolality is high and/or decrease blood volume, ____ is released from the ___ pituitary
ADH
Posterior
What is the receptor that vasopressin (ADH) binds to in the kidney?
Type 2 vasopressin receptor (V2R), a G-protein receptor that would increase blood volume by bringing water back to body
What happens when vasopressin binds V2R in the kidney?
Increases osmotic water transport through the regulation of the aquaporin-2
Water channel localized in the kidney collecting ducts
Vasopressin is a _____ (type) hormone, that is secreted when _____
Nonapeptide (9 amino acid residues)
Dehydration
The only chemical that leads to decrease in prolactin is ____. All other chemical and even sleep lead to increased prolactin
Dopamine
When does prolactin level peak?
High in day time, dip during the day and rise up again at night
T/P: baby suckling leads to increase prolactin secretion from the posterior pituitary
False; baby suckle causes increase in oxytocin, which is released from the posterior pituitary, and this leads increased in prolactin from the anterior pituitary
Hypothyroidism would have what effect on prolactin production?
Increase prolactin
Hypothyroidism is increased TRH (releasing hormone from the hypothalamus)
T/F: Prolactin binds two G-protein receptor in order to activate signaling
False; prolactin does need to bind 2 receptors, but these are two JAK-STAT (cytokine receptors)
What are neurogenic causes of increased prolactin production?
Chest-wall injury,
Breast stimulation
Breast feeding
Increase in estrogen would have what effect on prolactin production?
Increase
T/F: prolactinoma is the only tumor that can be shrunk by taking a pill
True; dopamine agonist drugs such as Bromocriptine
Dopamine antagonist antipsychotic drugs would ____ prolactin production
Increase! Because taking away the dopamine inhibitory effects on prolactin release
Prolactinoma causes ____ in females, ____ in males and _____ in both sexes
Menstrual dysfunction, infertility in female
Erectile dysfunction, gynecomastia in male
Nipple dc, libido dysfunction, visual fields defect, headache, growth failure in both
T/F: Higher prolactin level would likely have a bigger tumor in prolactinoma cases
True
T/F: Endonasal surgery is the primary option in treating prolactinoma, dopamine agonist use is supplemental
False; dopamine agonist is first go-to option, if tumor does not reduce in size with therapeutic drug, surgery is the next option; unless the tumor is large, then do the surgery first
Prolactinoma surgery is indicated when:
Resistance/ intolerance to dopamine agonist drug
Or CSF leakage, chiasm herniation apoplexy- neuro damage is evident
T/F: surgical intervention is initial treatment of choice for large prolactinoma tumors and other hyper functional tumors
True
T/F: most hyperprolactinemia is drug related issue, as opposed to prolactinoma
True. Though prolactinoma is the most common pituitary adenoma when there is a mass
All anterior pituitary hormones are produced by _____ week of gestation
12
Sheehan syndrome, empty sella, pituitary apoplexy are all _____ conditions
Hypopituitiary
Hyperglycemia _____ growth hormone, and hypoglycemia ____ Growth hormone level
Decrease/ suppresses (because too much glucose already in blood)
Increases
ACTH deficiency can result in these conditions:
Central/ secondary adrenal insufficiency
Adult GH deficiency
Best imaging method for evaluating pituitary adenoma is____
MRI with and without contrast
Adult with growth hormone deficiency can develop _____
Central adiposity aka visceral full of fat
Osteoporosis
T/F: Whenever ACTH is made, so is MSH
True, they are both on the POMC gene thing
Primary adrenal insufficiency has ______ ACTH, Central (secondary) AI has ____ ACTH
High in primary
Low in central
Primary adrenal insufficiency has ____ skin pigmentation while central (Secondary) AI has ____ skin pigmentation
Dark (because there is high ACTH, and therefore high MSH)
Pale
Aldosterone level is decrease in _____ adrenal insufficiency
Primary
Normal aldosterone in central adrenal insufficiency
T/F: Primary adrenal insufficiency is associated with autoimmune disease
True
“feeling like a medical student” is what condition:
Adult Growth hormone deficiency. Low cortisol
Small cell cancer of the lung can form when there is ______ amount of vasopressin
Increased (too much ADH (vasopressin) d/t ectopic ADH secretion)
Salt diabetes, resulting in dry, pruny appearance and polydipsia, and polyuria is due to _____ vasopressin
