Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Step 1 > Endocrinology > Flashcards

Endocrinology Flashcards

1
Q

Anterior midline neck mass that moves with swallowing or tongue protrusion

A

THYROGLOSSAL DUCT CYST

Compare to branchial cleft cyst (lateral neck) from persistent cervical sinus which is not mobile

Note - Most common ectopic thyroid tissue site is the tongue (lingual thyroid - at base of tongue)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Thyroid embryologic origin

A

Endoderm - Thyroid tissue

Neural crest - Parafollicular (C) cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Adrenal gland embryologic origin

A

Mesoderm - Cortex

Neural crest - Medulla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Layers and function of the adrenal cortex and medulla

“GFR”

A

Zona Glomerulosa - Aldosterone
Zona Fasciculata - Cortisol
Zona Reticularis - Sex hormones

Medulla/Chromaffin cells - Catecholamines

Note - Aldosterone, Cortisol, and Sex hormones all derived from cholesterol (e.g. SER)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Embryologic origin of Anterior pituitary (Adenohypophysis) and Posterior pituitary (Neurohypophysis)

A

Anterior - Oral ectoderm (Rathke’s pouch)
Posterior - Neuroectoderm (Hypothalamus)

Note - Craniopharyngiomas (solid, cystic, calcification) are tumors arising from remnants of Rathke’s pouch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Acidophil anterior pituitary hormones

A

GH
PRL

Note - All the rest (FSH, LH, ACTH, TSH) are basophils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Pituitary hormones sharing an a-subunit

A

TSH, LH, FSH share with hCG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Mechanism of posterior pituitary release of Vasopressin/ADH and Oxytocin

A

Produced in supraoptic and paraventricular nuclei of the hypothalamus, respectively

Transported to posterior pituitary via neurophysins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Orientation and function of pancreatic alpha, beta, and delta islets of Langerhans

A

alpha - Glucagon peripherally
beta - Insulin centrally (near capillaries)
delta - Somatostatin interspersed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Mechanism of insulin production

A

Cleavage of presignal from Preproinsulin (RER)
Proinsulin stored in secretory granules
Cleavage of proinsulin
Exocytosis of insulin (disulfide bonds) and C-peptide

Note - Both Insulin and C-peptide are increased in insulinomas and Sulfonylurea abuse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Insulin effect on kidneys

A

Increased Na retention

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Insulin-independent tissues and their transporters

A

GLUT1 - Brain, Placenta, RBCs, Cornea
GLUT3 - Brain, Placenta
GLUT2 - Liver, Pancreas, Kidney, Basolateral intestines

Note - GLUT2 is bidirectional and has a high Km (sensing), while GLUT1/3 have a low km (basal)

Note - GLUT5 also insulin independent, but only used by Spermatocytes and Intestines (apical) for Fructose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Insulin-dependent tissues and their transporter

A

GLUT4 - Adipose, Striated muscle

Insulin binds Tyrosine Kinase Receptor (TKR)
Induces RAS/MAP pathway (cellular growth)
Also induces Phosphoinositide-3 kinase (PI3K) pathway
Increased GLUT4 and glycogen/lipid/protein synthesis

Note - GLUT4 increased during exercise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Mechanism of insulin secretion by beta cells

A 
Glucose enters beta cells with GLUT2
Glycolysis increases ATP
Closes ATP-sensitive K channels
Cell membrane depolarization
Voltage-gated Ca channels open
Ca-mediated stimulation of insulin exocytosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q 
Function of hypothalamic hormones...
CRH
Dopamine
TRH
GHRH
Somatostatin
GnRH (pulsatile)
A 
CRH - Increased ACTH, MSH, b-endorphin
Dopamine - Decreased PRL, TSH
TRH - Increased TSH, PRL
GHRH - Increased GH
Somatostatin - Decreased GH, TSH
GnRH - Increased FSH, LH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Amenorrhea
Osteoporosis
Hypogonadism
Galactorrhea

A

PITUITARY PROLACTINOMA

Prolactin suppresses GnRH (FSH, LH)

Treat with Bromocriptine (dopamine agonist)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Function and feedback mechanism of Prolactin release from anterior pituitary

A

Inhibits GnRH (FSH/LH) and stimulates milk production

Negative - Tonically by Dopamine, also Prolactin inhibits itself by promoting Dopamine release

Positive - Elevated TRH in hypothyroidism, and Estrogen (OCP, pregnancy)

Note - Renal failure causes hyperprolactinemia by decreasing elimination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Function and feedback mechanism of GH (somatotropin) release from anterior pituitary

A

Stimulates linear growth and muscle mass via IGF-1 secretion by the liver, also increases insulin resistance (diabetogenic)

Negative - Glucose, Somatostatin, feedback by IGF-1

Positive - Exercise, Sleep, Puberty, Hypoglycemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Hormonal regulation of hunger and satiety

A

Hunger - Ghrelin from stomach
Satiety - Leptin from adipose tissue

Note - Also increased hunger via endocannabinoid stimulation of Hypothalamic/Nucleus accumbens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

ADH levels in central and nephrogenic DI

A

Central - Decreased
Nephrogenic - Increased due to V2 resistance

Note - Posterior pituitary damage causes transient central DI, while hypothalamic damage causes permanent central DI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Mechanism of…
Bilateral adrenal hyperplasia
Hypertension
Hypokalemia
Lack of secondary sexual characteristics (XX)
Ambiguous genitalia and undescended testes (XY)

Increased Mineralocorticoids (Corticosterone), Pregnenolone
Decreased Cortisol, Androstenedione

Note - Decreased RAAS

A

17A-HYDROXYLASE DEFICIENCY (CAH)

Decreased conversion of…
Pregnenolone to 17-Hydroxypregnenolone

Low cortisol sensed by the hypothalamus - Treat with Corticosteroids to decrease ACTH and thus shunting to mineralocorticoids

Note - Androstenedione is converted to Testosterone mainly in the periphery not the adrenals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q 
Mechanism of...
Bilateral adrenal hyperplasia
Hypotension
Hyperkalemia
Virilization (XX)
Salt wasting in infancy, or precocious puberty (XY)

Increased Sex hormones, 17-Hydroxyprogesterone
Decreased Cortisol, Aldosterone

Note - Increased RAAS

A

21-HYDROXYLASE DEFICIENCY (CAH)

Decreased conversion of…
Progesterone to 11-Deoxycorticosterone

Low cortisol sensed by the hypothalamus - Treat with Corticosteroids to decrease ACTH and thus sex hormone production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q 
Mechanism of...
Bilateral adrenal hyperplasia
Hypertension
Hypokalemia
Virilization (XX)

Increased Sex hormones, 11-Deoxycorticosterone
Decreased Cortisol, Corticosterone, Aldosterone

Note - Decreased RAAS

A

11B-HYDROXYLASE DEFICIENCY (CAH)

Decreased conversion of…
11-Deoxycorticosterone to Corticosterone - Combination of increased sex hormones and increased mineralocorticoids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Mechanism of cortisol action on blood pressure

A

Upregulates a1 receptors on arterioles
Binds Aldosterone receptors

Note - May cause steroid-psychosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Metabolic cortisol action (hyperglycemia)
Increases insulin resistance (diabetogenic) Increases peripheral catabolism Hypogonadism Note - Paradoxically causes glycogenesis in the liver
26
MSK cortisol action
Decreases fibroblast activity (thinning, striae) Decreases bone formation (osteoblast inhibition) Note - Normal PTH
27
Inflammatory and immune cortisol action
``` Blocks IL-2 (T cells) Blocks NF-kB induced IL-1, TNF-a (Neutrophilia) Blocks Phospholipase A2 (GI bleeding) Blocks Histamine release from Mast cells Reduces Eosinophils/Basophils ```
28
``` Mechanism of acidosis induced... Cramps Pain Paresthesia Carpopedal spasm ```
Increased pH Increased affinity of Albumin for Ca Decreased ionized Ca - hypocalcemia
29
Function and feedback mechanism of Vit D activation (skin/intestine to liver to kidney)
As Calcitriol... Increases Ca and PO4 absorption in the gut Increases bone mineralization Negative - Calcitriol, Hypercalcemia Positive - PTH, Hypocalcemia, Hypophosphatemia
30
Function of PTH from chief cells of parathyroid
Increased bone resorption of Ca and PO4 Increased kidney (DCT) resorption of Ca Decreased kidney (PCT) reabsorption of PO4 Increased 1a-hydroxylase (PCT) for Calcitriol production
31
Mechanism of bone resorption by PTH
Increased RANK-L and M-CSF by osteoblasts Binds RANK on osteoclasts Activates NF-kB and JTK Note - Estrogen increases OPG expression by osteoblasts which acts as a decoy receptor for RANK
32
Feedback mechanism of PTH
Negative - Extreme hypomagnesemia, Hypercalcemia Positive - Hypocalcemia (ionized), Hypomagnesemia, decreased 1,25-Vit D, Hyperphosphatemia Note - Causes of hypomagnesemia include diarrhea, diuretics, alcohol abuse, and Aminoglycosides
33
Function and feedback mechanism of Calcitonin release from Parafollicular (C) cells
Decrease bone resorption of Ca Positive - Hypercalcemia
34
Effects of T3 on bone, brain, heart, and metabolism
Bone growth with GH Brain maturation Increased b1 receptors in heart Potentiates sympathetic activity (e.g. b3) Increased metabolism via increased N/K-ATPase Increased catabolism
35
Mechanism of T3 production
Tyrosine is turned into Thyroglobulin Thyroglobulin released into follicular lumen Combined with I2 (organification) and renters cell Coupling makes T3 (DIT/MIT) or T4 (DIT/DIT) T3 and T4 (Thyroxine) released into circulation T4 converted to T3/rT3 in tissue by Deiodinase Note - All enzymatic reactions by Thyroid peroxidase
36
Wolff-Chaikoff effect
Excess iodine temporarily inhibits thyroid peroxidase decreasing T3/T4 production Note - Iodine enters follicle from blood via Na/I symporter and is oxidized to Iodine by Thyroid peroxidase
37
TBG binds most T3/T4 in blood and only free hormone is active - TBG is increased/decreased by... Hepatic failure Estrogen (Pregnancy, OCP) Steroids
Increased - Estrogen | Decreased - Hepatic failure, Steroids
38
Signaling pathway for vasodilators... BNP ANP NO EDRF
Guanylyl cyclase - cGMP/PKG
39
Signaling pathway for growth factors... ``` Insulin IGF-1 FGF PDGF EGF ```
TKR - RAS/MAP and PI3K/Akt/mTOR Note - PI3K activity inhibited by PTEN
40
Signaling pathway for acidophiles and cytokines... ``` PRL GH G-CSF Erythropoietin Thrombopoietin Immunomodulators (e.g. IL, IFN) ```
Non-receptor tyrosine kinase (JAK-STAT) Note - No autophosphorylation
41
Signaling pathway for steroid hormones... ``` Progesterone Estrogen Testosterone Cortisol Aldosterone T3/T4 Vit D ```
Intracellular receptors - DNA binding Zinc-finger domains
42
Signaling pathway for the following hormones... ``` ADH (V1) Oxytocin GnRH TRH Angiotensin II Gastrin ```
Gq/PLC - IP3/Ca and DAG/PKC
43
Signaling pathway for the following hormones... ``` ADH (V2) Glucagon FSH/LH GHRH CRH/ACTH TSH PTH/Calcitonin hCG MSH ```
Gs/Adenylate cyclase - cAMP/PKA Note - Like all G-proteins requires replacement of GDP with GTP to dissociate a subunit
44
Screening algorithm for Cushing syndrome
Increased 24-hr urine free cortisol No suppression with overnight low-dose dexamethasone Measure ACTH Decreased ACTH (ACTH-independent): 1) Discontinue exogenous glucocorticoids - bilateral adrenal atrophy 2) MRI for adrenal adenoma - hyperplasia of involved gland with atrophy of uninvolved gland Normal or Elevated ACTH (ACTH-dependent) - bilateral adrenal hyperplasia: High-dose dexamethasone suppression test and CRH stimulation test 1) MRI for Cushing Disease/Pituitary Adenoma - suppression and stimulation 2) Chest CT for Ectopic ACTH (e.g. SCLC) - no suppression and no stimulation
45
``` Diagnosis algorithm for... Weakness Fatigue GI disturbance Weight loss Sugar and salt cravings Orthostatic hypotension Hyponatremia ```
ADRENAL INSUFFICIENCY Random serum ACTH and cortisol: Primary - Low cortisol, High ACTH Secondary (pituitary) - Low cortisol, Low ACTH Tertiary (hypothalamic) - Low cortisol, Low ACTH Note - Follow with response to ACTH test to confirm
46
Metyrapone stimulation test algorithm
Metyrapone blocks 11-deoxycortisol to Cortisol: Normal - Low Cortisol, High ACTH/11-deoxycortisol Primary - Low Cortisol/11-deoxycortisol, High ACTH Secondary/Tertiary - Low Cortisol, 11-deoxycortisol, ACTH
47
Difference in presentation between primary and secondary/tertiary adrenal insufficiency Note - Tertiary (hypothalamic) most often due to withdrawal from exogenous steroid use
Primary presents with mucosal hyperpigmentation, hyperkalemia, and hyperchloremic (non-anion gap) metabolic acidosis Secondary/tertiary present with only hyponatremia secondary to hypotension induced ADH release - Aldosterone release is via RAAS
48
Two most common causes of chronic adrenal insufficiency (Addison's)
Autoimmune TB Note - Acute (shock, adrenal crisis) often due to Waterhouse-Friderichsen syndrome (N. meningitidis)
49
Hypertension Hypokalemia Metabolic alkalosis
HYPERALDOSTERONISM Primary due to adrenal adenoma (Conn syndrome) with low Renin Secondary due to renovascular HTN or a JGA tumor with high Renin No edema or hypernatremia due to aldosterone escape mechanism (ANP)
50
Embryologic origin of neuroendocrine tumors
ENTEROCHROMAFFIN-LIKE CELLS Contain amine precursor uptake decarboxylase
51
``` Toddler with... Abdominal distention Firm, irregular mass crossing midline Opsoclonus-myoclonus Elevated HVA and VMA (catecholamine metabolites) ```
NEUROBLASTOMA Adrenal medulla tumor - Originates from neural crest cells and may occur anywhere along the sympathetic chain Note - Compare to unilateral, smooth Wilms tumor (nephroblastoma)
52
``` Gene associated with... Small blue round cells Homer-Wright rosettes Bombesin+ NSE+ ```
NEUROBLASTOMA N-myc oncogene
53
Treatment of elevated urine catecholamines and metanephrines Associated with... VHL MEN2 (RET) NF1 Note - Often presents with orthostatic hypertension
PHEOCHROMOCYTOMA Originates from Chromaffin cells (neuroendocrine - neural crest) or extra-adrenal sympathetic chain Irreversible a-antagonist (Phenoxybenzamine) followed by b-blocker prior to tumor resection to prevent hypertensive crisis. Phenoxybenzamine is an irreversible long acting alpha adrenergic blocker that prevents peripheral vasoconstriction. DO NOT give beta blockers alone because unopposed vasoconstriction Note - Rule of '10s"
54
Difference between hypothyroid and hyperthyroid myopathy
Hypothyroid - Proximal weakness with high CK Hyperthyroid - Proximal weakness with normal CK Note - Hypothyroidism myopathy also presents with myoedema
55
Cholesterol levels in hypothyroid and hyperthyroid
Hypothyroid - Hypercholesterolemia (low LDLR) | Hyperthyroid - Hypocholesterolemia (high LDLR)
56
Smooth and diffuse goiter
Graves disease Hashimoto thyroiditis Iodine deficiency TSH-secreting pituitary adenoma
57
Nodular goiter
Toxic multinodular goiter Thyroid adenoma Thyroid cancer Thyroid cyst
58
Hurthle cell (pink cytoplasm) Lymphoid aggregates with germinal centers Moderately enlarged, nontender thyroid Elevated TSH Decreased T4 Normal/Decreased T3 Note - T3 has a short half life and may be normal due to increased conversion of T4 to T3
HASHIMOTO THYROIDITIS Antithyroid peroxidase (antimicrosomal) and antithyroglobulin antibodies - associated with HLA-DR5 May initially present as hyperthyroid due to thyrotoxicosis from follicular rupture Note - Associated with non-Hodgkin's lymphoma (enlarging goiter)
59
``` Infant with... Intellectual disability Pot-bellied Pale Puffy-faced Protruding umbilicus Protuberant tongue ```
CONGENITAL HYPOTHYROIDISM (CRETINISM) Due to maternal hypothyroidism, thyroid agenesis/dysgenesis, or iodine deficiency
60
Viral infection followed by hyperthyroidism and then hypothyroidism Elevated ESR Jaw pain Very tender thyroid Decreased radioiodine uptake
SUBACUTE GRANULOMATOUS THYROIDITIS (DE QUERVAIN) Mixed cellular infiltrate with granulomatous inflammation
61
Fixed, hard painless goiter Autoimmune pancreatitis Retroperitoneal fibrosis Noninfectious aortitis
RIEDEL THYROIDITIS (HYPOTHYROIDISM) Thyroid replaced by fibrous tissue with inflammatory infiltrate - fibrosis may extend to surrounding structures like anaplastic carcinoma Note - Systemic manifestations due to IgG4
62
Tall crowded follicular epithelial cells Scalloped colloid Diffuse goiter
GRAVES DISEASE TSI IgG leads to Type II hypersensitivity that stimulates TSH receptors (goiter)
63
Mechanism of pretibial myxedema and exophthalmos Note - Especially common during radioactive iodine therapy, and specific for Graves disease
Autoimmune reaction against TSHRs Infiltrating Th1 cells release cytokines Stimulated pretibial and retroorbital fibroblasts Increased fibroblast secretion of hydrophilic GAGs Increased osmotic swelling, inflammation, and adipocytes Note - Treat with glucocorticoids
64
Focal patches of hyperfunctioning follicular cells
TOXIC MULTINODULAR GOITER TSH receptor mutation makes hot nodules work independently of TSH Note - Rarely malignant
65
Jod-Basedow phenomenon
Thyrotoxicosis if a patient with iron deficiency or hot nodule is repleted with iodine
66
Treatment of thyroid storm | 'Four Ps"
Propranolol Propylthiouracil Prednisolone Potassium Iodide (Lugol iodine)
67
Diagnosis algorithm of thyroid adenoma/carcinoma
Decreased radioactive iodine uptake | Proceed to FNA
68
Fibrous capsule | Colloid containing microfollices
THYROID (FOLLICULAR) ADENOMA Invasion of capsule means follicular carcinoma - spreads hematogenously Note - Surgical resection needed for diagnosis
69
Hoarseness from thyroid surgery occurs during ligation of which arteries near which nerves
Inferior thyroid artery damages recurrent laryngeal nerve - all intrinsic laryngeal muscles (arytenoids) except cricothyroid Superior thyroid artery damages external superior laryngeal nerve - cricothyroid. Internal branch supplies sensation to the supraglottic area Note - L recurrent loops under aortic arch and R recurrent loops under bifurcation of brachiocephalic trunk
70
Empty appearing nuclei with central clearing - "orphan annie eyes" Branching papillary structures with Psammoma bodies Nuclear grooves Note - Tall cell variant also has elongated epithelial cells
PAPILLARY CARCINOMA Childhood irradiation - spreads to cervical nodes
71
``` Mutations associated with... Papillary carcinoma Follicular carcinoma Medullary carcinoma Anaplastic carcinoma ```
RET/BRAF RAS RET p53
72
Sheet of spindle cells in amyloid stroma - stains with Congo red
MEDULLARY CARCINOMA Tumor arising from parafollicular "C" cells
73
``` Shortened 4th/5th digits Short stature Hypocalcemia Hyperphosphatemia Elevated PTH ```
ALBRIGHT OSTEODYSTROPHY Pseudohypoparathyroidism 1A - Autosomal dominant mutation in Gs causing end-organ resistance to PTH Note - Maternal inheritance only due to imprinting
74
Shortened 4th/5th digits Short stature Normal Ca, PO4, PTH
PSEUDOPSEUDOHYPOPARATHYROIDISM Occurs when mutation in Gs is inherited from father
75
Mechanism of familial hypocalciuric hypercalcemia
Mutation in G-protein coupled receptor (CaSR) in parathyroid and kidneys means higher than normal Ca levels required to suppress PTH Note - PTH levels may be normal or elevated
76
Hypercalcemia with low PTH
PTH-INDEPENDENT HYPERCALCEMIA Excess Ca intake Thiazide diuretics Malignancy
77
``` Hypercalcemia Hypercalciuria Hypophosphatemia Elevated PTH Elevated ALP Elevated cAMP (urine) ```
PRIMARY HYPERPARATHYROIDISM Parathyroid adenoma or hyperplasia
78
Skeletal manifestations (3) of hyperparathyroidism
OSTEITIS FIBROSA CYSTICA Subperiosteal thinning Cystic spaces filled with brown fibrous tissue - osteoclasts and deposited hemosiderin Salt-and-pepper skull
79
Hypocalcemia Hyper or hypophosphatemia Elevated PTH Elevated ALP
SECONDARY HYPERPARATHYROIDISM Hyperplasia due to decreased Ca absorption Hyperphosphatemia in CKD, hypophosphatemia in other causes Note - Causes renal osteodystrophy (osteoid matrix accumulation in bone lesions)
80
Hypercalcemia | Markedly elevated PTH
TERTIARY HYPERPARATHYROIDISM Refractory hyperparathyroidism resulting from CKD
81
Hyperpigmentation Headaches Bitemporal hemianopia
NELSON SYNDROME Enlargement of exciting ACTH-secreting pituitary adenoma after bilateral adrenalectomy for refractory Cushing disease - removal of cortisol feedback mechanism Treat with pituitary irradiation or removal
82
Increased serum IGF-1 (somatomedin C) with failure to suppress serum GH following oral glucose tolerance test Note - Increased risk of CRC
ACROMEGALY GH-secreting pituitary adenoma in adults - Increased IGF-1 leads to increased proliferation of chondrocytes in growth plate Treat with resection or Octreotide (Somatostatin) Note - Same adenoma in children causes increased linear bone growth instead (gigantism), and eventually HF
83
``` Short height Small head circumference Saddle nose Prominent forehead Small genitalia Decreased IGF-1 Increased GH ```
LARON SYNDROME (DWARFISM) Defective GH receptor leads to decreased linear growth
84
Lab findings in DI... ADH Urine specific gravity Serum osmolality
Decreased (central) or normal (nephrogenic) < 1.006 > 290 mOsm/kg Note - In central urine osmolality increases by 50% with exogenous ADH, in nephrogenic there is minimal response
85
Treatment of nephrogenic DI
Hydrochlorothiazide - increases Na excretion Stop offending agents (e.g. Lithium)
86
Mechanism of euvolemic hyponatremia
SIADH Water retention leads to decreased aldosterone and increased ANP/BNP Urinary Na secretion with normalization of ECF
87
Treatment of SIADH
Fluid restriction Salt tablets Demeclocycline (ADH antagonist) Note - Correcting hyponatremia too quickly may result in osmotic demyelination syndrome (central pontine myelinolysis)
88
Failure to lactate Absent menstruation COld intolerance
SHEEHAN SYNDROME
89
Sudden onset severe headache Bitemporal hemianopsia Diplopia (CN III palsy)
PITUITARY APOPLEXY Sudden hemorrhage - often of an already existing adenoma Treat with glucocorticoids to prevent hypotension
90
Embryologic origin and location of branchial cleft cyst
Second branchial cleft (pharyngeal groove) - Anterior to sternocleidomastoid Note - First branchial cleft forms external auditory meatus
91
Interaction between insulin resistance and FFA
Chronically elevated FFAs contribute to insulin resistance by impairing insulin-dependent glucose uptake and increasing hepatic gluconeogenesis
92
Most common cause of hereditary hypothalamic DI
Mutation in neurophysin carrier molecule
93
``` Hyperglycemia Weight loss Necrolytic migratory erythema DVT Depression ```
GLUCAGONOMA Treat with Octreotide
94
Mechanism of cataract formation and peripheral neuropathy in hyperglycemia
POLYOL PATHWAY Aldose reductase converts Glucose to Sorbitol Sorbitol dehydrogenase converts Sorbitol to Fructose Hyperglycemia saturates Sorbitol dehydrogenase Sorbitol builds up inside the lens and Schwann cells Increased osmotic pressure pulls water into the lens Note - Seminal vesicles use this pathway the most as sperm relies on fructose for energy
95
Mechanism of insulin resistance by TNF-a, Catecholamines, Glucocorticoids/Cortisol, and Glucagon
Activation of Serine proteases leads to phosphorylation of Serine and Threonine residues on Insulin Receptor and Insulin Receptor Substrate
96
Weight gain Hypertension Hyperglycemia Proximal muscle weakness (normal CK)
CUSHING SYNDROME ``` Will also see... Skin hyperpigmentation (ACTH excess) Skin atrophy Purple striae Central obesity ```
97
Mechanism of microangiopathy (nephropathy, retinopathy, neuropathy) in hyperglycemia
Excess non-enzymatic glycosylation Crosslinking with collagen in vessel walls and interstitium Note - Also facilitates inflammatory cell infiltration and LDL deposition leading to atherosclerosis
98
Most effective all-cause mortality preventative measure in diabetics
Smoking cessation Note - Tight glycemic control reduces microvascular complications but has no effect on macrovascular complications (e.g. MI, stroke)
99
XY with feminized genitalia Normal blood pressure Normal testosterone Enzyme deficiency resulting
5A-REDUCTASE TYPE 2 DEFICIENCY Decreased conversion of Testosterone to DHT results in male pseudohermaphroditism Note - During puberty type 1 in the skin becomes activated and external genitalia masculinize
100
Diabetes Gallstones Hypochlorhydria Steatorrhea
SOMATOSTATINOMA (D CELL TUMOR) Hyperglycemia from insulin inhibition Gallstones from CCK inhibition Hypochlorhydria from Gastrin inhibition Steatorrhea from Secretin inhibition and decreased motility
101
Mechanism of functional hypothalamic amenorrhea in low BMI patients
Decreased Leptin as a result of low adipose stores decreases pulsatile GnRH release, inhibiting pituitary LH/FSH release and thus estrogen Note - Increases risk of osteoporosis
102
Pituitary and hypothalamic causes of hypopituitarism
``` Pituitary: Infiltration (lymphocytic hypophysitis) Hemorrhage Ischemia Mass lesion ``` Hypothalamic: Sarcoidosis Radiation Infection Note - Hypothalamic causes will paradoxically elevate Prolactin due to reduced Dopamine production
103
Competitive agonist for I/Na symporter - pretreatment reduces radioiodine effectiveness
Perchlorate
104
Large pleomorphic giant cells in a thyroid nodule
ANAPLASTIC CARCINOMA
105
Glutamic acid decarboxylase antibodies - HLA-DR3/4
T1DM Note - Genetic predisposition of T2DM is actually higher Note - Insulin sensitivity is actually high in T1DM rather the disease is due to direct beta cell destruction
106
Histology of T2DM
Islet amyloid polypeptide (IAPP) deposits
107
``` Recurrent... Diarrhea Flushing Wheezing Right-sided endocardial fibrous plaques Tricuspid regurgitation Elevated urinary 5-HIAA ``` Prominent rosettes on histology
CARCINOID SYNDROME Small intestine neuroendocrine tumor - Become symptomatic only after metastasis due to high first pass metabolism of Serotonin
108
Common mutations and tumors in... MEN1 MEN2A MEN2B Note - All are autosomal dominant
MEN1 (Menin) - Pituitary adenoma, Pancreatic endocrine (e.g. Gastrinoma, Insulinoma), Parathyroid hyperplasia MEN2A (RET) - Medullary thyroid cancer, Pheochromocytoma, Parathyroid hyperplasia MEN2B (RET) - Medullary thyroid cancer, Pheochromocytoma, Mucosal neuroma and Marfanoid habitus Note - MEN2A all derived from neural crest
109
Criteria for diagnosis of diabetes
Fasting > 126 Random > 200 A1C > 6.5 Note - OGT mostly used for gestational diabetes
110
Fetal effects of diabetes
Increased placental glucose transfer... Macrosomia b-cell hyperplasia Hypoglycemia after delivery Note - Also associated with hypertrophic cardiomyopathy, placental vasculopathy, and malformations
111
Drugs causing osteoporosis by... ``` Increasing Vit D catabolism Decreasing Estrogen Decreasing Testosterone and Estrogen Decreasing Ca absorption Decreasing bone formation ```
Phenobarbital, Phenytoin, Carbamazepine (CYP-450) Aromatase inhibitors, Medroxyprogesterone GnRH agonists PPIs Steroids, Unfractionated Heparin, Thiazolidinediones
112
absence of GnRH secretory neurons in hypothalamus defective migration fromt he olfactory placode
kallman syndrome central hypogonadism anosmia delayed puberty impaired sense of smell
113
DKA labs
hyperkalemia hyponatremia and hypovolemia hyperglycemia

Step 1 (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions