Block 3 Flashcards
often is referred to as the “master gland”
because, together with the hypothalamus, it orchestrates the complex
regulatory functions of many other endocrine glands.
anterior pituitary
The anterior
pituitary gland produces six major hormones:
(1) prolactin (PRL),
(2) growth hormone (GH),
(3) adrenocorticotropic hormone (ACTH),
(4) luteinizing hormone (LH),
(5) follicle-stimulating hormone (FSH),
and
(6) thyroid-stimulating hormone (TSH)
The pituitary gland weighs ?
~600 mg
The pituitary gland is located ?
within the sella turcica ventral to the diaphragma sella
The bony sella is contiguous
to vascular and neurologic structures, including the ?
cavernous sinuses, cranial nerves, and optic chiasm.
Hypothalamic neural cells synthesize specific releasing and inhibiting
hormones that are secreted to?
directly into the portal vessels of the
pituitary stalk.
Blood supply of the pituitary gland comes from the?
superior and inferior hypophyseal arteries
provides the major blood source for
the anterior pituitary, allowing reliable transmission of hypothalamic
peptide pulses without significant systemic dilution
The hypothalamic-
pituitary portal plexus
The posterior pituitary is supplied by the?
inferior hypophyseal arteries.
is directly innervated by hypothalamic neurons (supraopticohypophyseal and
tuberohypophyseal nerve tracts) via the pituitary stalk
posterior lobe
This transcription factor induces pituitary development of Pit-1-specific lineages as well as gonadotropes.
transcription factor Prop-1
This transcription factor determines
cell-specific expression of GH, PRL, and TSH in somatotropes, lactotropes,
and thyrotropes.
transcription factor Pit-1
Expression of high levels of estrogen receptors in cells that contain Pit-1 favors expression of what hormone?
PRL
thyrotrope embryonic factor (TEF) induces expression of what horrmone?
TSH
Gonadotrope cell development is further defined by the cell-specific expression of what nuclear receptors?
- steroidogenic factor (SF-1)
2. dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1 (DAX-1)
Development of corticotrope cells, which express the proopiomelanocortin
(POMC) gene, requires what transcription factor.
T-Pit transcription factor
Corticotrope cells express what gene?
proopiomelanocortin (POMC) gene
it is weakly homologous to GH and human placental lactogen (hPL)
PROLACTIN
PRL is synthesized in?
lactotropes
Marked lactotrope cell hyperplasia develops during ?
pregnancy and the first few months of
lactation.
Marked lactotrope cell hyperplasia which develops during pregnancy and the first few months of lactation is induced by?
estrogen
Normal adult serum PRL levels in men and women
10–25 μg/L in women and 10–20 μg/L in men
PRL secretion is pulsatile, with the highest secretory peaks occurring during ?
rapid eye movement sleep
Peak serum PRL levels (up to 30 μg/L) occur between what time?
4:00 and 6:00 a.m.
The circulating half-life of PRL is about ?
50 min.
the predominant central control mechanism of prolactin is ?
inhibitory
receptors that mediate inhibition of PRL synthesis and secretion.
Pituitary dopamine type 2 (D2)
receptors
a hypothalamic tripeptide that elicits PRL release within 15–30 min after intravenous injection
Thyrotropin-releasing hormone (TRH)
TRH primarily regulates what hormone?
TSH
also induces PRL release
Vasoactive intestinal peptide (VIP)
weakly suppress PRL secretion
glucocorticoids and thyroid hormone
Serum PRL levels rise transiently after what activities or situation?
Serum PRL levels rise transiently after exercise, meals, sexual intercourse, minor surgical procedures, general anesthesia, chest wall injury, acute myocardial infarction, and other forms of acute stress.
increase markedly (about tenfold) during pregnancy and decline rapidly within 2 weeks of parturition.
Prolactin
In the breast, the lobuloalveolar epithelium proliferates in response to ?
PRL, placental lactogens, estrogen, progesterone, and local paracrine growth factors, including insulin-like growth factor I (IGF-I).
PRL inhibits reproductive function by ?
- suppressing hypothalamic gonadotropin-releasing hormone (GnRH) and pituitary gonadotropin secretion
- and by impairing gonadal steroidogenesis in both women and men.
In the ovary, PRL ?
blocks folliculogenesis and inhibits granulosa cell aromatase activity, leading to hypoestrogenism and anovulation.
the most abundant anterior pituitary hormone
GROWTH HORMONE
a 44-amino-acid hypothalamic peptide that stimulates GH synthesis and release.
GH-releasing hormone (GHRH)
an octanoylated gastric-derived peptide, and synthetic agonists of the GHS-R induce GHRH and also directly stimulate GH release.
Ghrelin
is synthesized in the medial preoptic area of the hypothalamus and inhibits GH secretion.
Somatostatin (somatotropin-release inhibiting factor [SRIF])
_______, the peripheral target hormone for GH, feeds back to inhibit GH
IGF-I
Induces GH release
estrogen
Suppresses GH release
chronic glucocorticoid excess
preferentially suppress GH (and TSH) secretion
SST2 and SST5 subtypes
signals to suppress ACTH secretion
SST5
GH secretion is pulsatile, with highest peak levels occurring at?
at night
Elevated GH levels occur with what situations?
Elevated GH levels occur within an hour of deep sleep onset as well as after exercise, physical stress, and trauma and during sepsis.
Increased GH pulse frequency and peak amplitudes occur with ?
chronic malnutrition or prolonged fasting.
GH is stimulated by?
intravenous l-arginine, dopamine, and apomorphine (a dopamine receptor agonist), as well as by α-adrenergic pathways.
Effect of β-Adrenergic blockade to basal GH and GHRH- and insulin-evoked
GH release?
β-Adrenergic
blockade induces basal GH and enhances GHRH- and insulin-evoked
GH release.
express the greatest number of GH receptors
The liver and
cartilage
A GH receptor antagonist (pegvisomant) is approved for treatment of ?
acromegaly
the major source of circulating IGF-I
liver
These are the diseases that present hypertension except A. Pheochromocytoma B. Cushings C. Addisons D. Hyperaldosterolism
C. Addisons
Not a dermatologic manifestation of DM A. Acanthosis nigricans B. Granuloma annulare C. Abdominal stria D. Pigmented pre tibial papule
C. Abdominal stria
ophthalmic manifestation of DM
Answer: retinal neovascularization
With regards to body fat, which is not a clinical manifestation of Cushings A. Buffalo hump B. Central obesity C. Weight gain D. Lipoatrophy
D. Lipoatrophy
Torssueau and chvostiks sign is a clinical manifestation of what blood abnormality? a. Hypercalcemia b. Hypocalcemia c. Hyperkalemia d. Hypokalemia
b. Hypocalcemia
Acanthosis nigricans A. Exclusive DM B. Insulin resistance C. Dyslipidemia D. ALL OF THE ABOVE.
B. Insulin resistance
Joint manifestation in DM? A. Prayer sign B. Charcot sign C. Mallet toe D. AOTA
D. AOTA
eye presentation of DM
retinal vascularization
Breathing pattern in diabetic ketoacidosis A. Kussmal B. Cheyne - stokes C. Hyperventilation D. All of the above
D. All of the above
neuroglycopenic symptoms of hypoglycemia A. paresthesia B. shaking C. sweating D. confusion
D. confusion
Neurogenic symptom of hypoglycemia A. irritability B. nervousness C. seizure D. ataxia
C. seizure
Used to test for protective sensation for
diabetic patients
*Monofilament Test
Positive chovsteks sign A. Twitching of the palm B. Twitching of the forearm C. Pouting of the lips D. Twitching of the lips
D. Twitching of the lips
True of galactorrhea A. May be unilateral B. May be bloody C. May need nipple pressure to be demonstrated D. AOTA
D. AOTA
Best diagnostic tool for endocrine
abnormality-
Immunoassays
Epinephrine is produced in? A. Medulla B. Zona glomerulosa C. Zona Fasciculata D. Zona Reticularis
A. Medulla
Aldosterone produced in? A. Medulla B. Zona glomerulosa C. Zona Fasciculata D. Zona Reticularis
B. Zona glomerulosa
What produces androgen? A. Medulla B. Zona glomerulosa C. Zona Fasciculata D. Zona Reticularis
D. Zona Reticularis
Cortisol is found in what layer? A. Medulla B. Zona glomerulosa C. Zona Fasciculata D. Zona Reticularis
C. Zona Fasciculata
Indicative of grave's in 90% of the patient? A. Tachycardia B. Edema C. High Blood Pressure D. Exolpthamia
D. Exolpthamia
Most common cause of Cushing Disease-
ACTH-producing pituitary tumor
Efficacy in Cushing Syndrome except:
Steroid
It is a disease with a presence of increased catecholamines: A. Cushing's disease B. Addison's disease C. Pheochromocytoma D. Congenital Hyperplasia
C. Pheochromocytoma
Dexamethasone Suppression is a work up test for: a. Addison's b. Conn's c. Pheochromocytoma d. Cushing's
a. Addison’s
Most common cause of mineralocorticoid excess is: A. Bilateral multinodular adrenal hyperplasia B. Cushing's disease C. Congenital adrenal hyperplasia D. Adrenocortical adenoma
A. Bilateral multinodular adrenal hyperplasia
Treatment for adrenal insufficiency
a. steroids
b. mitotane
c. metyrapone
d. ketoconazole
a. steroids
The great masquerader A. Addison's B. Conn's C. Pheochromocytoma D. Cushing
C. Pheochromocytoma
