Endocrine Path Flashcards
Satiety hormone. Produced by adipose tissue. Decreases during starvation. Mutation in ** gene leads to congenital obesity. Sleep deprivation leads to decreased ** production.
Leptin–> LeptIN keeps you thIN!
Stimulate cortical reward centers –> increasing desire for high-fat foods.
Endocannabinoids –> The munchies!
Stimulates hunger (orexigenic effect) and GH release (via GH secretagog receptor). Produced by stomach. Increases with sleep loss and Prader-Willi syndrome.
Ghrelin–> Ghrelin makes you hunGHRE!
Physical fx: large anterior fontanel, persistence of a posterior fontanel, an umbilical hernia, and a large tongue (macroglossia). What disease is at hand?
Congenital hypothyroidism
What is a neuroblastoma? What is hallmark? What is the normal age for its findings?
Most common tumor of the adrenal medulla; arises from neural crest cells. –> Hallmark: Homer-Wright Rosettes. Usually found in children less than 4 years old.
What is a pheochromocytoma? Why does it have the rule of 10s?
Most common tumor of the adrenal medulla in adults. Derived from chromaffin cells (arise from neural crest). 10%-malignant -bilateral -extra-adrenal -calcify -kids
What is Zollinger-Ellison syndrome?
Gastrin-secreting tumor (gastrinoma) of pancreas or duodenum. May be assoc. w/MEN 1.
Multiple Endocrine Neoplasias: MEN 1: which pathologies are associated?
Pituitary tumors (prolactin or GH), parathyroid adenomas, and pancreatic endocrine tumors (ZE SD, insulinomas, VIPomas, glucagonomas-rare).
(Pituitary, parathyroid, and pancreas)
Multiple Endocrine Neoplasias: MEN 2a: what pathologies are associated?
Parathyroid hyperplasia, Pheochromocytoma, and Medullary thyroid cancer.
Multiple Endocrine Neoplasias: MEN 2B; what pathologies are associated?
Neuromas (oral/intestinal), Medullary thyroid cancer, and Pheochromocytomas.
This hormone is secreted in response to decr. blood volume (via ATII), and incr. plasma (K+); causes incr. Na+ reabsorption, incr. K+ secretion, incr. H+ secretion.
Aldosterone
This hormone is secreted in response to incr. plasma osmolarity and decr. blood volume. Binds to receptors on principal cells, causing incr. number of aquaporins and incr. H2O reabsorption.
Anti diuretic hormone (ADH) - aka Vasopressin.
This hormone is secreted in response to decr. plasma [Ca2+], incr. plasma [PO4-3] or decr. Plasma 1-25-(OH)2 D3. Causes incr. [Ca2+] reabsorption (DCT), decr. [PO4-3] reabsorption (PCT), and 1-25-(OH)2 D3 production (incr. Ca2+ and PO4-3 absorption from gut via vitamin D).
Parathyroid Hormone (PTH)
This hormone causes efferent arteriole constriction leading to incr. GFR and incr. FF but with compensatory Na+ reabsorption in proximal and distal nephron. Net effect: preservation of renal function (incr. FF) in low-volume state with simultaneous Na+ reabsorption (both proximal and distal) to maintain circulating volume.
Angiotensin II (AT II)
This hormone is secreted in response to incr. atrial pressure. Causes incr. GFR and Na+ filtration with no compensatory Na+ reabsorption in distal nephron. Net effect: Na+ loss and volume loss.
Atrial Natriuretic Peptide
What causes a Multiple Endocrine Neoplasias? What is the genetic inheritance?
Autosomal dominant in all 3 cases. Pheochromocytoma associated with RET defect, parathyroid adenomas due to menin, a tumor suppressor found on Chromosome 11.
Most common type of thyroid cancer- accounts for about 80% in adults. What is the 2nd and 3rd MC types?
Papillary thyroid cancer is MC
Follicular is 2nd MC with about 15%
Medullary is 3rd with about 4%
Defective G-coupled Ca+2 sensing receptors in multiple tissues (eg parathyroids in kidneys). Higher than normal Ca2+ levels required to suppress PTH. Excessive renal Ca2+ reuptake —> mild hypercalcemia and hypocalciuria with normal to increased PTH levels.
Familial Hypocalciuric hypercalcemia
Enlargement of existing ACTH secreting pituitary adenoma after bilateral adrenalectomy for refractory Cushing disease (due to removal of cortisol feedback mechanism). Presents with hyperpigmentation, headaches, and bitemporal hemianopsia. Treatment: pituitary irradiation or surgical resection. What pathology is at hand?
Nelson Syndrome
Defective GH receptors—> decreased linear growth. Increased GH, decreased IGF-1. CF: short stature, small head circumference, characteristic facies with saddle nose and prominent forehead, delayed skeletal maturation, small genitalia. What pathology is at hand?
Laron Syndrome (dwarfism)
Neuroemdocrine cells in rosettes - metastatic small bowel tumors that secrete high levels of 5-HT, causing recurrent diarrhea, niacin deficiency (pellagra) associated with Neuroendocrine markers Chromogranin A and synaptophysin. Hard to find in imaging studies if only confined to GI tract.
Rule of 3= 1/3 metastasize 1/3=present with secondary malignancy, and 1/3 = are multiple.
Carcinoid Syndrome
*most common malignancy in small intestine
What is the insulin-dependent glucose transporter for adipose tissue, striated muscle?
GLUT4
***exercise can also increase glut4 expression
What is the insulin-dependent glucose transporter for RBCs, brain, cornea, and the placenta?
GLUT1
What is the insulin-dependent glucose transporter for Beta islet cells, liver, kidney, and the small intestine.
GLUT2
What is the insulin-dependent glucose transporter for brain and the placenta?
GLUT3
What is the insulin-dependent glucose transporter for spermatocytes and GI tract?
GLUT5 (fructose)
What is the insulin-dependent glucose transporter for kidney and the small intestine?
SGLT1/SGLT2 - Sodium-glucose cotransporters
What organs or cells undergo insulin-independent glucose uptake?
BRICK LIPS
Brain, RBCs, intestine, cornea, kidney, liver, islet (beta) cells, placenta, and spermatocytes.
What is the rule of 3 in carcinoid syndrome?
Rule of 3= 1/3 metastasize 1/3=present with secondary malignancy, and 1/3 = are multiple.
**most common malignancy in the small intestine
Px presents the filling features: large tongue, increased spacing of the teeth, deep voice, large hands and feet, coarse facial features, and impaired glucose tolerance. What pathology is at hand?
Acromegaly
What is the most common pituitary adenoma? What are the most common clinical features?
Prolactinoma - CF: low libido, galactorrhea, amenorrhea, infertility, and bilateral hemianopsia.
What is the diagnostic criteria for gigantism or acromegaly?
IGF-1 and it’s measured via an oral glucose tolerance test, because glucose suppresses GH.
A patient presents with Thyrotoxicosis after being with iodine deficiency for some time. The patient presents with an autonomous nodule, that produces an excess of thyroid hormone after being replete. What pathology is at hand?
Jod-Basedow phenomenon
What bone disorder results from excess PTH?
Osteitis fibrosa cystica (von Recklinghausen Disease of the bone)
What is being described:
Protective auto regulation; sudden exposure to excess iodine temporarily turns off thyroid peroxidase (decreases T3/T4 production).
Wolff-Chaikoff effect
What are incretins and what is their role in endocrine function?
They are called glucagon-like peptide 1 (GLP-1)s, where they increase beta 1 sensitivity to glucose and are released after meals, and this increase satiety (desired for weight loss).
Their effects are decreased by alpha-2 and beta-2 stimulation.
