U-World: Other Flashcards
What are the characteristics of a melanoma (remember ABCDE)?
Asymmetry
Border irregularities
Color variation (brown/ tan/ black/ red)
Diameter > 6mm
Evolving (lesion changing in size/ shape/ color, or new lesion)
Why might a person with melanoma get seizures?
Melanoma can metastasize to the brain.
Melanocytes come from what embryologic origin?
Neural Crest Cells (NCCs)
What cells are derived from neural crest cells (NCC’s)?
“MOTEL PASSES” Melanocytes Odontoblasts (tooth cell) Tracheal lining Enterochromaffin cells (produce catecholamines in the adrenal medulla) Leptomeninges (arachnoid, pia) PNS ganglia (cranial, dorsal root, autonomic) Adrenal medulla Schwann cells Spiral membrane (aorticopulmonary septum) Endocardial cushions Skull bones
What embryo cells are melanocytes derived from?
NCCs (neural crest cells)
What embryo cells are odontoblasts (tooth cells) derived from?
NCCs (neural crest cells)
What embryo cells is the tracheal lining derived from?
NCCs (neural crest cells)
What embryo cells are enterochromaffin cells derived from?
NCCs (neural crest cells)
What embryo cells are leptomeninges (arachnoid, pia) derived from?
NCCs (neural crest cells)
What embryo cells are PNS ganglia (cranial, dorsal root, autonomic) derived from?
NCCs (neural crest cells)
What embryo cells is the adrenal medulla derived from?
NCCs (neural crest cells)
What embryo cells are Schwann cells derived from?
NCCs (neural crest cells)
What embryo cells is the spiral membrance (aorticopulmonary septum) derived from?
NCCs (neural crest cells)
What embryo cells are endocardial cushions derived from?
NCCs (neural crest cells)
What embryo cells are skull bones derived from?
NCCs (neural crest cells)
What is pleiotropy?
When multiple phenotypes (lots of random symptoms) result from a single genetic mutation
What’s the difference between endothelial and epithelial cells?
Endothelial cells- cells lining blood vessels
Epithelial cells- cells lining other tissues
What cellular organelle is found both in the cytoplasm and bound to the ER?
Ribosomes
Where is mRNA made in a cell? Where is rRNA (ribosomal RNA) made in a cell?
mRNA—> in the nucleus
rRNA—> in the nucleolus
What is the inheritance pattern of PKU?
Autosomal recessive
Eczemia rash, weird gate, intellectual disability, and musty body odor. What is it?
PKU
What do hypohidrosis and hyperhidrosis mean?
hypohidrosis- diminished sweating
hyperhidrosis- excessive sweating
What is acetoacetate?
a ketone body
How long do you have to fast/ be starving for your body to begin producing ketone bodies?
kids–> 8-10 hours
adults–> 1-2 days
What pathway leads to formation of ketone bodies?
beta-oxidation (break down fatty acids to make ketone bodies)
What hormone can be given to treat Turner syndrome patients?
growth hormone
growth hormone receptors are what kind of receptors?
JAK-STAT
If you suspect hyper or hypothyroidism, what test are you going to order?
serum TSH
what is hypotonia?
floppy baby syndrome
How does hypothyroid myopathy present?
Myalgias (muscle pains), proximal muscle weakness, elevated creatine kinase, and delayed relaxation of deep tendon reflexes.
(*other causes of myopathy with elevated creatine kinase include inflammatory myopathies, muscular dystrophies, and HMG-CoA reductase inhibitors)
Patient has bitemporal hemianopsia (loss of peripheral vision) and irregular menses. What is likely to be the problem?
Pituitary adenoma compressing the optic chiasm- most likely PROLACTINOMA (since the tumor is secreting prolactin, that inhibits GnRH and can stop a woman from having her period)
What are somatotrophs?
cells in the anterior pituitary that secrete GH (growth hormone)
What are lactotrophs?
cells in the anterior pituitary that secrete prolactin
What do the following anterior pituitary cells secrete? Gonadotrophs Corticotrophes Thyrotrophes Lactotrophes Somatotrophes
Gonadotrophs--> FSH, LH Corticotrophes--> ACTH Thyrotrophes-->TSH Lactotrophes--> Prolactin Somatotrophes--> GH
Obese woman with hirsutism and bad periods. what should you think of?
PCOS
Most common cause of hirsutism (male-like hair growth) in a woman is what?
PCOS
How can oral contraceptive pills treat hirsutism in a woman?
By suppressing pituitary LH secretion–> decreased androgen production by the ovaries
What part of the adrenal steroid synthesis pathway does Metyrapone inhibit? Explain the Metyrapone stimulation test.
Metyrapone inhibits the last step to make cortisol (11 beta-hydroxylase) from 17-OH.
Metyrapone stimulation test: give Metyrapone. Since that stops production of cortisol, the body will accumulate 17-OH and you pee out more 17-OH. Also, the body will inc ACTH in an attempt to inc Cortisol. If you see increase in ACTH, 11-OH, and urinary 17-OH that means the patient’s hypothalamic-pituitary adrenal axis is intact/ working.
Where is pre-pro-insulin made in pancreatic beta cells? How about pre-insulin? Where is insulin and c-peptide released from?
pre-pro-insulin is made in the RER (rough ER).
pro-insulin in the secretory granules.
pro-insulin gets cleaved–> insulin + C-peptides in the secretory granules and it gets released from there by exocytosis.
What hormone regulates the zona fasciculata and reticularis of the adrenal gland? What regulates the zona glomerulosa?
ACTH regulates the zona fasciculata (makes cortisol) and zona reticularis (makes androgens) of the adrenal gland. Angiotensin II (from RAAS) regulates zona glomerulosa (makes aldosterone) of the adrenal gland.
What effects will increased ACTH have on the adrenal gland?
Excess production of cortisol (from zona fasciculata) and androgens (from zona glomerulosa). This can present as Cushing’s symptoms + irregular periods and hirsutism in women.
*Does not lead to production of excess aldosterone (zona glomerulosa) bc that’s under the regulation of ATII (from RAAS).
Most common cause of hyperthyroidism
Grave’s disease
Most common cause of hypOthyroidism
Hashimoto’s thyroiditis
What are thyrotropin receptor antibodies (TRAb)?
TSH stimulating antibodies seen in Grave’s disease
What does pretibial myxedema mean? How about Graves ophthalmopathy?
pretibial myxedema= non pitting edema in the shins. Graves ophthalmopathy= bulging eyes. Both findings specific to Graves disease (most common hyperthyroidism) are due to TSH stimulating antibodies. The shins and eyes have TSH receptors–> increased production of GAGs (connective tissue fluid)–> non-pitting edema in shins and thickening of eye muscles the pushes eyes out of sockets
epinephrine stimulates release of what other hormone?
glucagon
(remember, glucagon is all about breaking stuff down for energy in a fasting state, and epi is all about this too bc you want fast energy in a short-term stress situation like running from a bear)
How does renal reabsorption of glucose change in response to insulin?
It doesn’t! The kidney PCT reabsorbs nearly all glucose no matter what, independent of insulin. (the only exception to this is T2DM where you have so much excess glucose that it overwhelms the kidney tubules and some goes out into your pee)
In T1DM (insulin deficiency), you have an excess of counter-regulatory hormones. What are these?
glucagon, cortisol, and growth hormone
(these 3 hormones usually oppose insulin- they pretty much do the opposite things- so without insulin in the mix, they are unopposed and have a greater effect)
How does 21-OH deficiency (type of congenital adrenal hyperplasia) present?
salt wasting (usually in a baby) and virilization in females (you can't make aldosterone or cortisol from the adrenal glands--> shunting to making more androgens. Lack of aldosterone leads to salt wasting)
What is thyroxine?
thyroid hormone
Increased pituitary gonadotropin release in a kid would result in what?
precocious puberty (gonadotropins include FSH and LH)
What is Waterhouse-Friederichsen syndrome?
kid gets Neisseria meningitidis–> sepsis and DIC–> hemorrhagic necrosis of the adrenal glands (bleeding out into the tissue and that destroys the adrenal glands)
kid presents with nuccal rigidity (neck stiffness), fever, vomiting, altered mental status. Has hypotension, Na+ wasting, hyperkalemia, low platelet count. He rapidly develops cardiovascular failure and bleeding from venipuncture sites and passes away. What happened?
Waterhouse-Friederichsen syndrome. This means: Neisseria meningitidis (neck stiffness, fever, vomiting, altered mental status)–> sepsis and DIC (bleeding out all over, low platelet count)–> hemorrhagic necrosis of the adrenal glands (bledding out into the tissue and that destroys the adrenal glands) (adrenal glands fail–> no aldosterone–> hypotension, salt wasting, and hyperkalemia).
Patient presents with nodule on left thyroid gland and increased calcitonin levels. What cancer is most likely and what gene mutation goes along with this?
Medullary carcinoma (the thyroid cancer where your parafollicular, not follicular cells are affected–> inc calcitonin and dec calcium in the blood). Associated with RET gene mutation.
What 2 endocrine conditions are associated with RET mutations?
Medullary thyroid cancer (medullary carcinoma) and pheochromocytoma (tumor of adrenal medulla choffamin cells that produce catecholamines). So MEN 2a and 2b (since these multiple endocrine neoplasias include both these).
What’s the difference between primary and secondary amenorrhea?
primary amenorrhea–> you’ve never had a period
secondary amenorrhea–> you had periods but now they’ve stopped (*can be due to hypothalamus, pituitary, ovarian, uterine, or other endocrine disorders)
What transport mechanism does glucose use to get into cells from the blood?
facilitated diffusion (does not require ATP, but does require the help of transport proteins, which are the GLUT proteins)
Where is GLUT 4 found?
skeletal and adipose cells (muscle and fat)
this is insulin-dependent channels for glucose uptake into cells
Histo of which thyroid cancer can be described as follows? nuclei with cleared centers and calcified bodies.
Papillary carcinoma (orphan Annie eye nuclei and psammoma bodies)
Histo of which thyroid cancer can be described as follows? Nests of polygonal cells with Congo red-positive deposits.
Medullary carcinoma (Congo-red deposits is referring to amyloid deposits from calcitonin, since this is cancer of the calcitonin-secreting parafollicular cells of the thyroid)
Histo of which thyroid cancer can be described as follows? pleomorphic giant cell nests with occasional multinucleated cells
Anaplastic carcinoma (malignant cells don’t look anything like normal thyroid cells)
What should you suspect in a patient taking carbamazepine or cyclophosphamide with low Na+, confusion, and seizures?
SIADH
These drugs inc risk for SIADH. Inc ADH–> retain excess water–> dec [Na+] and neuronal swelling, cerebral edema–> mental status changes and seizures
How can a prolactinoma affect the bones?
excess prolactin–> more inhibition onto GnRH–> decreased estrogen–> amenorrhea (no periods), vaginal dryness, and inc risk for OSTEOPOROSIS with inc risk of fractures (why? because estrogen dec osteoclast activity, so with less of the protective estrogen, you have more osteoclast activity which means more breaking down of bones)
What are the criteria for diabetes? include fasting glucose, random glucose, and A1c.
fasting glucose > 126
random glucose > 200
A1c > 6.5%
(*or oral glucose tolerance test- screening for gestational DM and cystic fibrosis related DM)
How might CKD (chronic kidney disease) affect A1c?
CDK–> decreased erythropoietin (since the kidneys make EPO)–> decreased RBCs–> falsely elevated A1c (less RBCs to hold hemoglobin A1c, so those RBCs that are around carrying it will have more glucose bound to it)
How might beta-thalassemia affect A1c?
beta thal–> HbA2 gets elevated–> resulting RBCs are prone to hemolysis (so more turnover)–> falsely low A1c
SIADH patients have euvolemic hyponatremia. Explain.
SIADH= too much ADH release= too much retention of water. This excess water dec [Na+]= hyponatremia. But, ANP and BNP kick in to
smoker presents with confusion and low [Na+]. What should you think of?
SIADH secondary to small cell carcinoma (paraneoplastic syndrome)
Craniopharyngiomas are tumors arising from what embryologic structure?
Rathke’s pouch
The anterior pituitary forms from what in embryology?
out-pouching of the pharyngeal roof called Rathke’s pouch
What is a craniopharygioma and how might it present?
Childhood tumor arising from Rathke’s pouch (out-pouching of the pharyngeal roof that forms the anterior pituitary gland). Present with mass effect and visual defects.
Patient has history of SLE. Presents with HTN, obesity, muscluar weakness, ecchymoses, and hyperglycemia. What is the most likely diagnosis?
Cushing’s syndrome (inc Cortisol) probably due to glucocorticoid therapy to treat her lupus
(*note: hyperglycemia is due to the fact that cortisol opposes insulin–> prevents glucose from coming into cells, so more glucose remains in the blood)
Why do we taper patients off steroids (glucocorticoids) rather than just have them stop cold turkey?
Sudden discontinuation of steroids can cause adrenal crisis. (Giving exogenous steroids causes the body to produce less endogenous steroids. If we stop them all fast, your body cannot adapt and you are still making less steroids without getting any more from meds.)
Why might a lupus patient develop bilateral cortical atrophy to her adrenal glands?
Taking endogenous steroids to treat lupus–> body starts producing less and less endogenous steroids (negative feedback since you’re getting steroids from the meds)–> leads to atrophy over time because the organs are not stimulated as much (you don’t use it you lose it–organs shrink when they aren’t used as much)
Why might MEN 2B patients experience headaches?
MEN 2B= multiple endocrine neoplasia consisting of medullary thyroid carcinoma, pheochromocytoma (tumor of the adrenal medulla–> excess catecholamines), and mucosal neuromas (papules on lips and tongue). The excess catecholamines cause increases BP and as a result, headaches from the extra pressure within.
Why can a prolactinoma cause decreased testosterone production and decreased libido in men?
excess prolactin–> inhibits GnRH–> less LH–> less testosterone
Will a patient with DKA have increased or decreased K+ within cells? Outside of cells?
In cells–> decreased K+
Outside of cells–> increased K+
why? Insulin increases K+ going into cells (due to activation of the Na/K pump). DKA patients do not have insulin, so the opposite is true. Another way to think of it: DKA patients are in a metabolic acidosis, so there’s increased H+ acid outside cells that will come into cells. As a result, more K+ will be brought outside of cells to balance charges (normal- high K+, so possibly hypERkalemia)
What does insulin do to K+ levels?
Insulin drives K+ into cells (by stimulating the Na/K pump). That means less K+ is outside of cells in the blood= hypOkalemia.
What weight changes are you most likely to see in a patient with Cushing’s syndrome as a result of ectopic ACTH production from small cell carcinoma?
weight loss.
Don’t get fooled…in Cushing’s (excess cortisol) we often see re-distribution of fat–> central fat obesity with striae. However, if the Cushing’s is secondary to cancer, it is more likely that the patient is losing weight from the cancer increasing metabolic demand.
Will you see increased, normal, or decreased levels of the following in a primary hypOthyroid patient? TSH, T4, T3.
TSH will be HIGH due to negative feedback.
T4 will be LOW due to the hypothyroidism (underactive thyroid gland).
T4–> T3, so you’d expect T3 to be low too, but not a lot of it is made (you only need a little active TH at once) so even though there’s less T4, there’s plenty of T4 ingredients to make the amount of T3 you need. So oftentimes, T3 levels are NORMAL in hypOthyroid patients.
What is a secretagogue?
A substance (like a drug) that causes another substance to be secreted.
If you see elevated insulin but low C-peptide, what does that suggest?
exogenous insulin secretion (insulin made in the body by pancreatic beta cells gets released with c-peptide, so if insulin is high, c-peptide would be high too–unless the patient is injecting themselves with insulin)
If you see elevated insulin and C-peptide–> hypoglycemia, what does that suggest?
The body is making too much insulin due to an insulin-secreting pancreatic tumor (insulinoma) or an insulin secretagogue (medication that stimulates pancreatic beta cells to secrete insulin, like Sulfonylurea).
What is a VIPoma?
A non-beta cell panreatic islet cell tumor that secretes too much VIP (vasoactive intestinal polypeptide). This can lead to watery diarrhea, hypokalemia, and impaired gastric acid secretion.
What’s the most common type of congenital adrenal hyperplasia?
21-OH deficiency
A deficiency in the enzyme that catalyzes the following reaction is called what? Progesterone–> 11-deoxycorticosterone.
21-OH deficiency (the most common cause of congenital adrenal hyperplasia).