Endocrinology Flashcards
(126 cards)
1
Q
NAD+ regeneration under anaerobic conditions.
regeneration under aerobic conditions
A
NADH transfers protons to pyruvate to form lactate (via lactate dehydrogenase) and regenerate NAD+
NAD+ is converted to NADH in TCA cycle, NADH is converted to NAD+ in electron transport chain when making ATP
2
Q
NAD+ is required in which reaction?
A
convert glyceraldehyde-3-phosphate to 1-3-bisphosphoglycerate (via glyceraldehyde-3-phosphate dehydrogenase)
3
Q
glycogen phosphorylase- pathway, action, activation
A
glycolytic pathway, breaks down glycogen for energy in during muscle contraction (cleaves glucose-1-P until 4remain before a branch point). activated by phosphorylation once cAMP becomes activated by epinepherine
4
Q
carnitine-def, function, vit needed for synthesis
A
amino acid responsible for transport of fatty acids into mitochondria for beta-oxidation. need vit C for synthesis
5
Q
amt of pyruvate in cells. synthesized how?
A
large amt usually not limiting factor for glycolysis. formed from PEP (phsophoenolpyruvate) via pyruvate dehydrogenase in glycolysis
6
Q
citrate- pathway, formation, inhibits
A
TCA cycle, condensation of acetyl-CoA with oxaloacetate (via citrate synthase)
7
Q
chronic renal failure leads to what levels of Ca2+ , phosphorous and PTH? why?
A
elevated PTH and low serum Ca2+ due to 2nd hyperparathyroidism. also causes high phosphorus levels. low 1,25 Vit D b/c 1-alpha hydroxylase (in kidneys) is low. also kidney is responsible for excreting phosphorus
8
Q
low Ca2+ -high PTH (2) -low PTH (2) high Ca2+ -high PTH (3) -low PTH (2)
A
low Ca2+
-not eating enough, chronic renal failure (2nd parathyroidism)
-hypoparathyroidism (surgical removal, autoimmune, Di George)
high Ca2+
-because of high PTH, hyperplasia, adenoma, carcinoma (1ary parathyroidism)
-eating too much, cancer (PTH-independent hypercalcemia)
9
Q
neurophysins. mutations cause? made where? and released into circulation where?
A
carrier proteins for oxytocin and vasopressin (ADH) from production in paraventricular (oxytocin) and supratoptic (ADH) nuclei to release in axons of posterior pituitary. point mutation in neurophysin II leads to diabetes insipidus (too little ADH)
- made in neuronal cell bodies of paravent and supraoptic neclei
- releeased into circulation form axon terminals in posterior pituitary gland
10
Q
principle source of blood glucose after 24 hrs
12-18 hrs
A
gluconeogenesis-glucose is formed from lactate glycerol and glucogenic amino acids
glycogenolysis-breakdown of glycogen
11
Q
In glycolysis which enzymes are unidirectional? what enzymes in gluconeogensis are used to bypass them?
A
1-hexokinase (glucose to glucose-6-phosphate), 2-phosphofructokinase (fructose-6-phosphate to fructose 1,6 bisphosphate), and 3-pyruvate kinase (PEP to pyruvate)
3-pyruvate carboxylase- converts pyruvate to oxaloacetate (in mitochondria)- require B7 cofactor
*oxaloacetate is shunted to cytosol via malate shuttle
-phophoenolpyruvate carboxykinase (PEPCK) (converts oxaloacetate to phosphoenolpyruvate)-in cytosol
2-fructose1,6-bisphosphatase (converts fructose 1,6 bisphosphate to fructose-6-phsophate)-in cytosol
1-glucose-6-phosphatase (converts glucose-6-phosphate to glucose)- in ER
12
Q
major steps in glycogenolysis
A
glycogen to glucose-1-phosphate
glucose-1-phosphate to glucose-6-P
13
Q
first fatty acid made by acetyl CoA during lipogenesis in the fed state
A
palmitate acid- pg 115 FA
14
Q
chemical name for HMG CoA
A
3-hydroxy-3methylglutaryl-coenzyme A
15
Q
most common cause of hypothyroidism in US
A
Hashimoto disease (autoimmune destroys thyroid)
16
Q
forms of thyroid hormone most active form inactive form Thyroid hormone that regulates feedback of TSH secretion (it's affect on other form levels) enzyme that converts one to the other
A
T3, T4, and T3r T4 (produced the most) T3r T3 (decreased TSH, T4, and T3r) type II deiodinase (within hypothalamus and pituitary gland) comverts T4-T3 for feedback inhibition. other enzymes convert T4 to T3 or T4 to T3r but not T3 to T3r.
17
Q
common endocrine cause of elevated CK levels
other causes?
A
hypothyroidism-(leads to muscle wasting)
HMG-CoA inhbitors,
autoimmune disease (polymyositis/dermatomyositis)
muscular dystrophies (Duchenne or Beckers)
18
Q
why is an increased risk of osteoporosis (loss of bone density) with a prolactin secreting pituitary adenoma?
A
prolactin inhbits GnRH which leads to hypogonadism which can lead to decrease esterogen (esp in women) leading to accelerated bone loss
19
Q
genetic triad of gastric ulcers with pitutary adenoma, and parathyroidism
A
MEN type I disease 3Ps (parathyroidism, peptic ulcer (usually from gastrin secreting cancer in pancreas) and pituitary adenoma
20
Q
mechanism of insulin resistance in overweight pts (type II D)
marker for insulin deficiency in Type I D
A
- increased levels of FFA and serum TG- can lead to Diabetes type II
- increased beta-hydroxybutyrate levels
21
Q
homocystinemia role of in vascular disease
A
can cause atherosclerosis
22
Q
symptoms in pheochromocytoma vs carcinoid syndrome
A
- catecholamine release-HTN, tachycardia, HA, diaphoresis, and tremors
- produces 5-hydroxyindoleacetic acid (HIAA); Hypotension, facial flushing, bronchospasm, diarrhea
23
Q
treatment for mothers with gestational diabetes
A
diet and light exercise or if that doesn’t work
insulin, avoid oral hypoglycemic meds b/c of risk of fetal hyperinsulinemia and hypogycemia
24
Q
shape of coccicioides immitis vs cryptocococcus neoformans
A
- spherules (round structures with endospores)-causes fungal lung disease and disseminated mycosis
- narrow budding yeast with round or oval encapsulated cells
25
glucagon effects which organ in type 1 diabetes. not pancreas b/c
- causes increase production of glucose from liver
- beta cells in pancreas are absent. or else glucagon would stimulate insulin release. note glucagon is released from alpha cells in pancreas
26
21-hydroxylase deficiency-male vs female presentation, hormone levels, ion levels, presentation
- males have normal genitalia and females have ambiguous genitalia
- low cortisol and aldosterone, increased androgens and ACTH
- increased renin, 17-hydroxyprogesterone
- hyperkalemia, hyponatremia
- hypotension, vomiting
27
pt with delayed puberty plus anosmia- problem which secretion of which hormone?
Kallmann syndrome.
| GnRH-secreting neurons fail to migrate from olfactory placode to hypothalamus
28
Name 1 high yield preventative intervention in almost every UMSLE pt?
smoking cessation!!!!!
29
histological description of
- zona glomerulosa
- zona fasciculata
- zona reticularis
- medulla
- cells are rounded or arched clusters
- foamy appearing cells in columns
- basophilic cells in anastomosing cords
- shape interface between cortex and medulla-chromaffin cells with deeply basophilic cytoplasm
30
neurons that innervate sweat glands and chromaffin cells release? a part of which autonomic nervous system?
acetylcholine, sympathetic
| note* all other preganglonic neurons in sympathetic nervous secrete Ach.
31
most postganglionic cells in sympa secret? two exceptions?
NE
- sweat glands-ACh
- chromaffin cells- catecholamines (80% epi and 20% NE)
32
reduction of which hormone can biliary stones? why not secretin?
- cholecystokinin-reduced gallbladder contractility
| - causes steatorrhea and decreased GI mobility
33
describe vitamin D production
- a 2 step process with sunlight UV (ring opening) and heat (isometization) converts 7-dehydrocholestreol (aka provitmain D3) to cholecalciferaol (vitamin D3)
- form here vitamin D3 or plant D2 undergoes two hydroxlyation steps to form active vitamin D
- the first hydroxylation step occurs in liver with cytochrome P450 enzyme 25-hydroxlyase (vitamin D to 25-hydroxy vitamin D aka calcidiol)
- kidney enzyme 1-alpha hydroxylase converts calcidiol to calcitrol (1,25 dihydroxy vitamin D)
34
how can kidney compensate for increased amounts of 1,25 dihydroxy vitamin D?
kideny has enzyme 24-hydroylase that can convert calcidiol (25-hydroxy vitamin D) to 24,25 dihydroxy vitamin D an inactive substance
35
GH causes release of what hormone from where? disease is called (in children? adults?)
defective growth hormone receptors leads to what syndrome? associated hormone levels?
- causes linear growth by inducing release of IGF-1 from liver
- gigantism in children and acromegaly in adults
- Laron dwafism=high serum growth hormone and low IGF-1
36
total body iron is regulated by which acute phase reactant? mech? how does it enter circulation? how is iron transported in body?
through hepcidin.
- prevent release of iron bound by ferritin in intestinal epithelial cells and by macrophages.
- enters circulation through ferroportin (basolateral iron transporter)
- travels in bloodstream on transferrin (delivers to bone marrow for heme production)
37
inactivating mutations in which enzyme results in mild hyperglycemia that can be exacerbated by pregnancy
glucokinase
38
McArdle's syndrome-aka, pathway problem, enzyme missing, presentation
type 5 glycogen storage disease
- glycogenolysis
- myophosphorylase an isoenzyme of glycogen phosphorylase (glycogen to glucose -1 phosphate)
- exercise intolerance, myoglobinuria, and muscle pain with physical activity
39
name serious complication of antithyroid medications. name 2 examples of such medication
- agranulocytosis (watch for pts who presents with fever)
| - methimazole or PTU
40
lung mass and hyponatremia suggests? urine concentration? body fluid volume?
- small cell lung carcinoma causing SIADH
- over concentration of urine and increased Na+ excretion
- normal body fluid volume
41
when is GTP synthesized in TCA cycle? when is GTP used in gluconeogenesis?
- by succinyl-CoA synthetase (succinyl CoA to succinate)
- hydrolysis of GTP is required for phosphorylation and decarboxylation of oxaloacetate to PEP by phophoenolpyruvate carboxykinase
42
FSH stimulates release of what from where?
| LH stimulates release of what from where?
- inhibin B form Sertoli cells
| - testosterone from Leydig cells
43
central DI
| partial vs complete
- more than 10% increase in urine osmolality following administration of vasopression during a water deprivation test suggest partial central DI
- if response is more than 50% increase than it's complete central DI
44
pt has excessive thirst and increased urine production: 2 possible outcomes if water deprivation test is normal
- normal test (two consecutive urine samples show >30mOsm/kg change)
- primary polydipsia-excessive consumption of water (usually female pt with overt mental illness)
- postobstructive polyuria- increased urinary output. pt with recent surgical (Foley catheter) relief from some sort of urinary obstruction
45
visceral obesity- def and prognosis factor for?
- waist to hip ratio (visceral fat to subcutaneous fat)
| - determinant of insulin resistance
46
hyperactive jaw jerk reflex-def, vairant of which sign, indicative of which ion imbalance
- tap on jaw elicits masseter muscle spams
- variant of Chovstek's sign(tap on facial nerve anterior to ear causes facial muscle contraction)
- low serum Ca2+ level <7.0mg/dL
47
role of phosphodiesterase
termination of effects of hormones that act by cAMP or cGMP GPCR messenger systems
48
which drug can be used to treat BPH and androgenetic alopecia? mech?
Finasteride
| -suppress peripheral conversion of testosterone to dihydrotestosterone
49
- drug that decreases Leydig stimulation by LH
- drug that decreases Leydig androgen synthesis
- drug that decreases peripheral androgen aromatization
- drugs the impairs androgen receptor interaction
- GnRH agonists used in a continuous fashion (leuprolide)
- ketoconazole (weak anti-androgen) also used to inhibit steroid production by adrenals
- aromatase inhbitor (anastrozole/exemestane) used in postmenopausal women with breast cancer
- flutamide, used to treat prostate cancer but not BPH
50
17 alpha hydroxlyase deficiency vs 5 alpha reductase deficiency
- impairs synthesis of androgens (males appear female and females have normal genitalia), hypogonadism, HTN, and hypokalemia
- defective conversion of testosterone to dihydrotestosterone (males have ambiguous genitalia) but develop 2ndary sexual characteristics. no problems with HTN, or K+ levels.
51
biotin is needed for which enzymatic rxns? give 2 important examples? ingestion of what can lead to biotin deficiency?
- acts at CO2 carrier in carboxylase enzyme conversion
- pyruvate carboxylase (pyruvate to oxalotate- biotin def can lead to increased pyruvate levels. it gets converted to lactic acid=metabolic acidosis)
- propionyl CoA carboxylase (synthesize succinyl CoA form amino acids like valine, biotin def can lead to incereased propionyl CoA and increased odd chain fatty acids
- avidin (found in egg whites)
52
treatment of infertility due to anovulation:
- drug that acts like FH
- drug that acts like LH
menotropin (human menopausal gonadotrophin); leads to formation of dominant ovarian follicle
-hCG, stimulates ovulation by minicking LH surge
53
receptor tyrosine kinase
| vs tyrosine kinase associated receptor- structure, signaling pathways, examples
- cytosolic domain is enzyme vs cytosolic domain lacks enzymatic activity
- MAP-kinase (receptor autophosphorylates and triggers phosphorylation of RAS protein) vs JAK/STAT (receptor activates Janus kinases which phosphorylase STATs)
- Growth factor receptors ( EGF, PDGF, FGF) vs receptors for cytokines, growth hormone, prolactin, IL-2
54
main side effect of anti-diabetic drugs:
- glitazone/thiazolidinediones (pioglitazone, rosiglitazone)
- sufonylureas/insulin
- sulfonlyurea
- insulin
- metformin
- GLP-1 analogs (exenatide and liraglutide)
- weight gain and edema
- hypoglycemia
- agranulocytosis
- postural hypotension
- lactic acidosis
- pancreatitis
55
mechanism of thiazolidinediones-receptor it binds to and family of that receptor
binds to peroxisome proliferator-activated receptor gamma (PPAR-gamma)
-this receptor belongs to steroid and thyroid superfamily of nuclear receptors
56
symptoms of adrenal crisis, treatment, not vassopressors (dopamine) or epi because
- vomiting, abdominal pain, weight loss, and hyperpigmentation
- corticosteroids
- response to vasopressors is limited
- not epi b/c it's no a potent vasoconstricotr (has both alpha and beta receptors) used for anaphylaxis, severe asthma, and cardiac arrest
57
what can cause hypoglycemia in a diabetic pt
vigorous exercise due to increased glucose uptake by muscles as rapid subcutaneous insulin absorption when the injection occurs in a limb that is subsequently exercised
58
name two ways that beta blockers help to treat thyrotoxicosis
- decrease sympathetic outflow and it's effect on target organs (thyroid hormone acts on beta 1)
- decrease rate of peripheral conversion of T4 to T3
59
thyroid drug mechanisms:
- anion inhibitors (2 examples)
- thionamindes (2 examples)
- iodide salts
- block iodide absorption by thyroid gland via competitive inhibition (perchlorate, pertchnetate)
- decrease formation of thyroid hormone by inhibiting thyroid peroxidase (methimazole, propylthiouracil)
- inhibit synthesis and release of thyroid hormones
60
LH, FSH, and estradiol levels in pt with anorexic nervosa, presentation of disease
- all three decreased
| - distorted body image, inadequate diet, regular exercise, dry skin, lanugo hair, female teenager.
61
what should be added to flutamide to treat prostate cancer?
GnRH in a continuous manner
62
hormone levels of calcitonin in chronic renal failure
levels of calcitonin are high despite relative hypocalcemia because excretion of calcitonin is impaired
63
nucleous appearance in light microscopy and electron microscopy
-dark intranuclear body
64
- actions of insulin on glucagon
- actions of glucagon
- metabolic actions of insulin
- inhibitory
- glycogenolysis, gluconeogenesis, lipolysis, and ketone body production
- increases glucose, a.a and potassium uptake by cells, inhibits ketoacid formation and inhibits lypolysis
65
17 alpha hydroxlyase vs 11 beta hydroxylase
both have HTN
- increased aldo vs increased 11-deoxycorticosterone
- decreased sex vs increased sex hormones (XY ambiguitiy an XX lack secondary sex characteristics vs XX virulization)
66
permanent vs transient central DI
- damage to hypothalamic nuclei or pituitary stalk
| - damage to posterior pituitary gland
67
cortisol receptors are located where? action of cortisol-receptor complex?
- intracellularly
| - binds to hormone responsive elements causing an alteration in the transcription of target genes
68
two mechanisms leading to lactic acidosis
- tissue hypoxia
| - hepatic hypoperfusion (liver can't clear lactate)
69
predisposing factors for aspiration pneumonia not reduced intercostal muscle strength or immobility because
- altered consciousness (impairing cough reflex and glottic closure), dysphagia, GERD, nasogastric and endotracheal tubes, protracted vomiting, large volume tube feeding in recumbent position
- these can cause atelectasis
70
drugs used to treat hirtuism
- spironolactone
| - antiandrogens (flutamide, and finasteride)
71
important genes effected by action of PPAR gamma
```
-nuclear receptor that alter transcription of gene responsible for glucose and lipid metabolism
increases:
-adiponectin gene
-fatty acid transport protein
-insulin receptor substrate
-GLUT-4
```
72
- causes transient increase and then a decrease in both testosterone and DHT levels
- decreases only DHT levels
- leupromide
| - finasteride (5 alpha reductase in inhibitors)
73
MEN type 1 vs MEN type 2
| -genetic defect of MEN 1
gastrinomas vs no gastrinomas
| -MENIN gene on chromosome 11
74
MEN 1
MEN 2a
MEN 2b
3Ps (pituitary (prolactin and ACTH), pancreatic tumor, parathyroid turmor)
- MPP medullary carcinoma of thyroid, pheo, parathyroid
- MPM medullary carcinoma of thryroid, pheo, marfanoid habitus/mucosal neuromas (oral/intestinal ganglioneuromatosis)
75
-bilateral vs unilateral atrophy of adrenal gland
- exogenous glucortiocoids
| - adrenocorticol adenoma (atrophy of opposite adrenal gland due to negative feedback from cortisol release)
76
when do protons dissociate from amino acids?
when pH exceeds the pKa associated with each given proton
77
how to treat loss of consciousness due to hypoglycemia in non medical vs medical setting
- non medical: intramuscular glucagon b/c intramuscular glucose at high dose would cause damage to muscle
- medical setting: intravenous dextrose, given as a slow push
78
role of aldose reductase, next step in pathway.
- most active where?
- cells that have low amts of second hormone can become damaged in hyperglycemia
- (converts sugars into corresponding sugar alcohols) converts glucose to sorbitol (also convers glactose to galactitol)
- sorbitol is converted to fructose with sorbitol dehydrogenase.
- seminal vesicles
- lens, retina, renal papilla, and Schwann cells.
79
give example of long acting insulin (2), medium (1), short (3)
- glargine and detemir (once a day)
- NPH (18 hrs twice a day)
- lispro, aspart, and glulisine (3 times a day with meals)
80
- excessive unmineralized osteoid and widened osteoid seams (aka osteoid matrix accumlation around trabeculae)
- trabecular thinning with fewer interconnections
- mosaic pattern of lamellar bone with irregular sections of lamellar bone, linked by cement lines
- primary unmineralized spongiosa in medullary canals with no mature trabeculae
- subperiosteal thinning with cystic degeneration.
- vitamin D deficiency
- osteoporosis
- Paget's disease
- Osteopetrosis "marble bone disease"
- hyperparathyroidism
81
subperiosteal thinning in medial sides of second and third phalanges of the hand and granular "salt and pepper" appearance of the calvarium
hyperparathyroidism
82
what 2 things can lead to increase insulin, C-peptide, and pro-insulin levels? how to differentiate between them?
- drugs (sulfonylurea* and meglitinide*) and insulinoma
| - screening urine or blood for hypoglycemic agents
83
phosphorylation of which amino acids can lead to insulin resistance? which drugs are responsible for this?
- serine and threonine by serine kinase
| - THF-alpha, catacolamines, glucocorticoids, and glucagon activate these serine kinases
84
non catabolic action of glucocorticoids
cause proteolysis in other organs, but can increase protein synthesis (esp proteins involved in gluconeogensis and glycogenesis) in LIVER via gluconeogenesis effects
85
- follicular hyperplasia with tall cells forming intrafollicular projections
- branching structures with interspersed calcified bodies
- sheets of uniform cells forming small follicles
- nests of polygonal cells with Congo red positive deposits
- pleomorphic giant cell nests with occasional multi nucleated cells
- variant of papillary thyroid cancer typically found in older individuals more invasive than typical papillary thyroid cancer
- well-differentiated papillary thyroid cancer (calcified bodies=psammoma bodies)
- follicular adenoma
- medullary carcinoma of thyroid gland
- anaplastic thyroid carcinoma (poor prognosis)
86
using standard free energy to determine substrate vs product concentration
if standard free energy delta G is negative then rxn favors products
- if delta G is positive then rxn favors substrate formation
- if zero then there is no net change in concentration
87
- mononuclear, parecnchymal infiltration with well-developed germinal centers
- mixed cellular infiltration with occasional multinucleate giant cells
- extensive fibrosis extending beyond thyroid capsule
- chronic lymphocytic throiditis aka Hashimoto's thyroiditis
- subacute granulomatous thyroiditis (Quervain's thyroiditis)
- Riedel's thyroiditis
88
Hashimoto vs Quervain's
- normal ESR, hypothyroididsm, non tender thyroid with rubbery texture, high titier of anti-thyroid peroxidase autoantibody
- increased ESR, reduced radioactive iodine uptake (b/c thyroid hormone is released but production is not increased), pt with recent illness, tenderness, can lead to thyrotoxicosis (release of stored thyroid hormone due to inflammation)
89
effect of thyroid binding globulin on total T4 and T3 levels? substances that increase TBG?
- increase total T4 and T3 but not free T4 and T3 levels
| - pregnancy, OCPs, hormone replacement therapy (estrogens)
90
neonatal complicaitons of diabetes during pregancy
- premature delivery
- fetal macrosomia
- neural tube defects
- hypoglycemia (b/c increased levels of fetal insulin still persist after birth)
- hypocalcemia
- polycythemia
- respiratory distress
- transient hypertrophic cardiomyopathy
91
name enzyme responsible for synthesis of epinephrine? how is it control? where does it occur?
phenylethanolamine-N-methyltransferase (PMNT)
- occurs mainly in adrenal medulla
- cortisol from adrenal cortex causes increased transcription of PNMT
92
conversion of tyrosine to epinepherine
tyrosine to DOPA (via tyrosine hydrosylase)
DOPA to Dopamine (via dopa decarboxylase)
dopamine to NE (vis dopamine beta-hydroxylase)
NE to EPI (via phenylethanolamine-N-methyltransferase PNMT)
93
somatomedin C aka and effect on bone vs sex steroids
IGF-1, causes gigantism b/c unlike excessive sex steroids IGF-1 does not lead to premature closure of epiphysis.
94
two major side effects of thiazolidinediones (pioglitazone, troglitazone, and rosiglitazone)
- fluid retention which can exacerbate heart failure
| - hepatotoxicity, periodic liver function tests are required.
95
familial hypocalciuric hypercalcemia vs hyperparathyroidism
- both have high PTH and calcium
| - use calcium urine (low in FHH b/c defective receptor doesn't allow PTH to be suppressed by increase in Ca2+
96
name drug used to treat HTN that cause hypercalcemia
hydrochlorothiazide
97
name diabetic drug that targets:
- membrane ion channels
- surface tyrosine kinase-coupled receptor
- surface adenylate cyclase-coupled receptor
- intracellular nuclear receptor
- surface membrane bound enzymes
- intracellular microsomal enzymes
- sulfonylureas
- insulin
- GLP-1 analogs
- TZDs
- alpha-glucosidase inhbitors
- metformin
98
name three categories of volume contraction and expansion and examples of each
- isoomostic vol contraction=free water and electrolyte loss are equal from ECF compartment only (acute GI hemorrhage or diarrhea)
- hyperosmotic vol contraction=free water loss is greater than electrolyte loss from both ICF and ECF; (diabetes insipidus and sweating)
- hypertonic vol expansion=electrolyte gain is more than free water gain in ECF only. water shifts from ICF to ECF (hypertonic saline infusion)
- hypoosmotic vol expansion=free water gain is greater than electrolyte gain in both ECF and ICF (psychogenic polydipsia and SIADH)
- hypoosmotic vol contraction=electrolyte loss is greater than water loss from ECF only. water shifts into ICF.
99
signaling pathway for TRH, TSH and T3/T4
- cAMP
- IP3
- nuclear receptor
100
how can a pt with testicular tumor present with hyperthyroidism?
- hCG is structurally similar to TSH. (also similar to FSH and LH, all share alpha subunit)
- testicular tumors (teratomas, seminomas) can secrete hCG and in high concentrations can stimulate TSH causing hyperthyroidism
101
metryapone testing. effects on ACTH and cortisol levels
- enzyme that inhibits cortisol synthesis by blocking (11 beta hydroxlyase)
- lowers cortsol, increased ACTH and cortisol intermediates (11-deoxycortisol) and breakdown products (17 hydroxy-corticosteroids)
102
how is inorganic iodide transported in to thyroid follicular cell. name substances that can compete with this process.
- NIS (sodium iodide transport)
- perchlorate, pertechnetate, and radioactive iodine ("radioactive material with heavy isotopes"), postassium iodide, thyocinate
103
large oxyphilic cells with granular cytoplasm
Hurthle cells in Hashimoto's disease
104
GLUT receptors have a higher preference for which type of glucose. uptake is facilitated and not endocytosis b/c
D-glucose.
| -endocytosis is how cholesterol enters cells
105
when are thyroid function tests required?
lithium and amiodarone
106
when is metformin contradicted?
in any case when lactic acidosis can be dangerous. primarily renal failure but also liver dsyfunction, congestive heart failure, alcoholism and sepsis
107
which should be measured to confirm menopause? LH or FSH not estrogen because?
- although estrogen levels are decreased, it can be produced peripherally from adrenal gland so estrogen levels can be normal
- FSH is better measurement b/c decreased est causing lack of inhibition increasing it's levels. LH increased too but later in menopause and not as much as FSH
108
papillary carcinoma vs follicular carcinoma vs medullary
-most common, psammoma bodies and ground glass nuclei, no invasion vs second most common, capsular invasion vs uniform or spindle shaped cells that stain positive for congo red (amyloid) and calcitonin
109
name anti-diabetic drug that increases secretion of insulin. not TZDs because?
- TZDs work on increasing cell sensitivity to insulin
| - sulfonylureas close K+ channels in beta cell membrane leading to increased insulin secretion
110
why are pts with essential fructosuria clinically normal? what enzyme is lacking? and which enzyme takes over?
b/c hexokinase is able to convert fructose to Fructose 6 phosphate despite lack of fructokinase.
111
how is Grave's opthalmopathy controlled? why not by ustilizing beta blockers? why not conventional anti-thyroid therapy
- beta blockage helps some with therapeutic relief before reduction in thyroid hormones can be achieved. also use beta blockers if you have more symptoms (tachycardia and tremors).
- high-dose glucocorticoids such as prednisone should be used instead b/c conventional antithyroid drugs do not improve ophthalmopathy b/c it's due to an inflammatory process
112
how to treat congenital adrenal hyperplasia?
low dose exogenous corticosteroids to suppress excessive ACTH secretion and reduce stimulation of adrenal cortex
113
Na, K, and bicarbonate levels in primary hyperaldosteronism. why?
- K and H are low b/c of K+ and H wasting by principle cells and alpha intercalating cells in collecting duct
- Na would be high but aldosterone escape keeps it's level normal
- aldosterone escape is when increased volume causes production of ANP in heart which leads to diuresis of water and salt.
114
pituitary hemorrhage vs subarachnoid bleed?
- both have severe headache and double vision
| - bitemporal vision loss is seen only in pituitary hemorrhage
115
def symptoms of sheehan's syndrome?
- ischemic necrosis of pituitary
- postpartum pituitary bleed in women
- inodolent presentation with failure to lactate
116
drugs in breast cancer
- inhibitor of peripheral conversion of androgens to estrogens
- antifungal agent that decreases androgen synthesis by inhibiting multiple enzyme pathways
- inhibitor of epidermal growth facto and HER2/neu pathway
- receptor associated with activation of HER2/neu receptor
- anastrozole
- ketoconazole
- trastuzumab
- tyrosine kinase
117
symptoms of VIPoma
intractable diarrhea, metabolic acidosis and hypokalemia
118
presentation of type 1 diabetes. pt pop (race, age, history)
polyuria, polydipsia, and polyphagia, fatigue, and weight loss
-pt will usually have had a recent viral infection and will be a young Caucasian adult
119
tyrosine kinase leads to activation of what proteins within cells? not JAK b/c.
- protein phosphatase
| - JAK (Janus protein kinase) is part of second messenger system for peptide hormones in JAK-STAT pathway.
120
mech of anorexia-related ammenorrhea. BMI def of anorexia?
- loss of pulsatile secretion of gonadotropin-releasing hormone from hypothalamus
- not pituitary or ovary problem.
- BMI less than 17.5 kg/m2
121
permissive vs tachyphylaxis vs synergistic vs additive
- allow second drug to have it's effect (i.e cortisol is permissive for muscle reactivity to catecholamines*)
- decreased drug responsiveness with repeated administration
- combined effect exceeds sum of individual drug effects
- combined effect equals sum of individual effects
122
what type of insulin is used to treat DKA?
regular insulin
123
order to insulin drugs from fastest acting and shortest lasting to slowest and long lasting
- aspart, lispro, glulisine
- insulin
- NPH
- detemir
- glargine
124
presentation of glucagonoma
-diabetes mellitus, necrolytic erythema and anemia
125
2 used of DDVAP
- von Willebrand disease b/c it induces endothelial procoagulatory protein release (including vWF)
- treatment of enuresis, (ADH analog)
126
role of tamoxifen and raloxifene in bone, breast, and endometrium
- stimulatory in bone and endometrium (increase bone mineral density in osteoperosis pts and endometrial cancer risk)
- inhibitory in breast (used to treat breast cancer)
- can also increase incidence of thromboembolic disease
