Endocrinology Flashcards
(149 cards)
1
Q
granulomatous inflammation of tender thyroid what disease?
A
Subacute (de Quervain’s) granulomatous thyroiditis
2
Q
bone path 2ary to hyperPTH?
A
osteitis fibrosa cystica -resporption of bone leading to fibrosis and cystic spaces
3
Q
3 disease associated with phaeochromocytoma
A
- MEN 2A/B
- VHL disease
- NF type 1
4
Q
what boney cell type does PTH activate?
A
osteoblasts - which then themselves activate osteoclasts and secrete Alk Phos
5
Q
head trauma precipitating central DI
what is the difference in lesion to hypothalamus and posterior pituitary?
A
hypothalamus - permanent loss of ADHergic neurons, permanent disease
posterior pit - ADHergic neruons will regenerate after some time and disease will remit
6
Q
what is the receptor implicated in familial hypocalciuric hypercalaemia?
A
GPCR - calcium-sensing receptor (CaSR)
Ca binding CaSR inhibits PTH release
7
Q
‘scalloping’ of colloid suggests what?
A
graves disease
8
Q
what is the treatment for post-thyroidectomy hypoPTH?
A
calcitriol
not calcidiol because it requires conversion under control of PTH
9
Q
what arrhythmia occurs with hyperT4?
A
atrial fib esp in elderly
10
Q
epidemiology of Reidel fibrosing thyroiditis
A
young female
11
Q
Rx graves disease
A
- beta-blockers 2. thioamide 3. radioiodine ablation
12
Q
how does cortisol affect the immune system?
A
inhibits phospholipase A2
inhibits IL-2
inhibits mast cell degranulation
13
Q
what thyroid neoplasm?
A
Follicular adenoma
benign proliferation of follicles surrounded by fibrous capsule
14
Q
in CAH with 17 hydroxylase deficiency, what hormones are not made?
A
cortisol and sex steroids
15
Q
natural history of de Quervain thyroiditis?
A
self-limiting rarely (15%) progress to hypothyroidism
16
Q
metabolic effects of hyperT4?
A
hypocholesterolaemia hyperglycaemia
17
Q
what is the mechanism and side effects of biguanides?
A
metformin
binds to AMPK to decrease glucose production and insulin resistance
lactic acidosis - so contraindicated in renal insufficiency
18
Q
chronic inflammation and extensive fibrosis of the thyroid on biopsy what disease?
A
Reidel fibrosing thyroiditis
19
Q
what is sevelamer?
A
phosphate-binding polymer that reduces absorption of phosphate in the GI tract
used for hyperphosphataemia in CKD
20
Q
anterior neck mass of thyroid origin?
A
thyroglossal duct cyst
21
Q
symptoms of phaeochromocytoma? (5)
A
headaches, episodic HTN, palpitations, tachycardia and diaphoresis
22
Q
phaeochromocytoma rule of 10 (4)
A
- 10% extramedullary
- 10% malignant
- 10% familial
- 10% bilateral
23
Q
what is the major side effect of GLP-1 analogues?
A
pancreatitis
modest weight loss :)
24
Q
follicular adeoma malignant or benign?
A
benign
25
common metformin toxicity?
lactic acidosis
26
what is the mechanism for fibrate drugs?
fenofibrate, gemfibrozil
activating PPAR-alpha, increases lipoprotein lipase
27
Rx cushing syndrome
surgical resection if tumour
*medical* - ketokonazole or metyrapone
28
how does cortisol impact blood pressure?
cortisol increases expression of alpha1-adrenoceptors, which are vasoconstrictive
29
in CAH with 11 hydroxylase deficiency, what hormones are not made?
*strong mineralocorticoids* and cortisol
so you get clitoral enlargement/precocious puberty but HTN with hypokalaemia.
low renin and aldosterone (b/c pregnenolone being shunted to **DHEA** and **DOC**)
30
'hard as wood', nontender thyroid suggests what disease?
Reidel fibrosing thyroiditis
31
thyroid biopsy shows chronic inflammation with formation of germinal centres
hashimoto thyroiditis
32
MEN1 neoplasms
pancreatic endocrine tumour
parathyroid hyperplasia
pituitary adenoma
33
which thyroid CA?
anaplastic CA
very undifferentiated tumour not really making any structures
34
1 common and 2 uncommon causes of primary hyperPTH
parathyroid adenoma
sporadic parathyroid hyperplasia and parathyroid carcinoma
35
decreased glucose
increased insulin
increased c-peptide
what pathology?
insulinoma
always check for MEN1!
36
two aetiologies of nephrogenic DI
inherited mutations drugs - lithium, demeclocycline (antibiotic)
37
arrhythmia, hyperthermia, vomiting and hypovolaemic shock ... diagnosis?
thyroid storm
38
symptoms of cholinergic crisis?
* salivation
* lacrimation
* urination
* defactation
(SLUD)
39
what is Winter formula?
when is it used?
PaCO2 = (1.5 \* HCO3-) + 8 +/- 2
expected compensatory range for PaCO2 in metabolic acidosis
in DKA is PaCO2 is above the range this indicates a degree of respiratory failure (pulmonary oedema, respiratoy fatigue or decreased GCS)
40
perioral tingling, muscle spasm, Trousseu and Chvostek signs ... eventually seizures.
lab findings?
causes? (4)
1. hypocalcaemia
causes - damage to parathyroids (iatrogenic/autoimmune), tumour lysis syndrome, severe vitamin D deficiency, sepsis
41
mental retardation, short stature, coarse facial features, umbilical hernia, enlarged tongue diagnosis?
cretinism
42
what is the side effect of PTU?
agranulocytosis
43
how to tell the difference between ACTH from pit adenoma or paraneoplastic ACTH?
dex suppression test - will reduce ACTH from pit adenoma but not from paraneoplastic source
44
three layers of adrenal cortex
glomerulosa, fasiculata, reticularis
45
watery diarrhoea
hypokalaemia
achlorhydria
what pathology?
VIPoma
46
what are the classes of antihyperlipidaemic drugs and how do they work?
1. _statins_ - HMG-CoA reducase inhibitor. stop hepatic synthesis of cholesterol
2. _ezetemibe_ - block intestinal absorption through NPC1L1 transporter, increase hepatic cholesterol production, decease serum LDL
3. _Niacin, fish oil, fibrates_ - block hepatic production of triglycerides and conversion of VLDL to LDL
4. _PCSK1 inhibitor_ - block internalisation of LDL receptor, increasing hepatic clearance of LDL
5. _bile acid-binding resins_ - induce bile acid wasting, increase hepatic comsuption of cholesterol in regeneration of bile acids, decrease serum LDL
47
what is cinacalcet? indication?
'calcimimetic' - activates Ca-sensing receptor in parathyroids, decreasing PTH
indicated in 2ary hypercalcaemia (CKD)
48
walk through - CRF leading to secondary hyperPTH and renal osteodystrophy
renal failure, unable to excrete phosphate
increase serum Pi binds free Ca2+
decrease Ca++ stimulates PTH (all four glands)
PTH stimulates boney resorption
Lab findings: **++** PTH, **-** Ca2+, **++** Alk Phos, **++** Pi
49
what thyroid neoplasm with ionizing radiation during childhood?
papillary carcinoma
50
prognosis of papillary CA?
excellent
51
serum glucose definition in HONC?
why are ketones absent?
\>500 mg/dL
small amount of circulating insulin prevents ketogenesis
52
what changes in FBC when starting steroids?
neutrophilia
neutrophil demargination from lung vasculature
53
increased urine cAMP suggests what pathology?
hyperPTH
54
what thyroid CA? what feature helps distinguish this?
medullary CA
local deposition of amyloid (malignant cells in amyloid stroma)
55
what muscle and nerve can be damaged in thyroidectomy (caudal end)
muscles - intrinsic muscles of the larynx, except cricothyroid
nerve - recurrent laryngeal
*R laryngeal* runs in close proximity to *inferior thyroid artery*, which must be ligated in total thyroidectomy
56
what drugs can lead to SIADH (3)?
carbamazepine
cyclophosphamide
SSRIs
57
Rx SIADH?
water restriction demeclocycline (blocks effect of ADH)
58
four thyroid neoplasms?
1. papillary
2. anaplastic
3. medullary
4. follicular
59
decrease 131-I uptake suggests...
adenoma or carcinoma warrants FNA biopsy
60
association with long standing hashimoto's & enlarged glad
marginal zone B cell lymphoma
61
somatostatin secreted from what cells in the pancreas?
delta cells
inhibit the release of GH, secretin, CCK, glucagon (**-**),
insulin (**----**) and gastrin
--\> more likely hyperglycaemia
62
what are the different adrenoceptors found on pancreatic beta cells and what are their actions?
alpha 2 - inhibits insulin secretion
beta 2 - promotes insulin secretion
overall, adrenaline physiologically will act more on alpha2 and cause supression of insulin release
63
alchlorhydria
cholelithiasis and streatorrhoea
what pathology?
somatostatinoma
64
roughly what should be the steady state maximum urine osmolality achieved during a water deprivation test?
500 - 520 mOsm/L
65
what is the main side effect fo DPP4 inhibitors?
DPP4 = enzyme that breaks down endogenous GLP-1
nasopharyngitis
66
catecholamines, glucagon and glucocorticoids induce insulin resistance by what mechanism?
serine and threonine phosphorylation of both IR and IRS-1
67
what is the role of neurophysin?
produced in the hypothalamus to facilitate transport of ADH and oxytocin to the neurohypophysis
68
overall action of aldosterone on the collecting ducts
what is the electrolyte imbalance in hyperaldosteronism? resulting symptoms?
to resorb Na+ in exchange for K+ and H+
hypokalaemic alkalosis
hypertension, parasthesia and muscle weakness
69
features of Kallman syndrome (3)
pathogenesis
associated mutation (2)
delayed puberty (central hypogonadism), anosmia, clef lip/palate
failure of GnRH-stimulating neurons to migrate from origin in olfactory placode
KAL-1 or FGFR-1
70
diagnosis of GH adenoma?
elevated GH and IGF-1 lack of GH supression with OGTT
71
considerations of methimazole (carbimazole) in hyperthyroidism (3)
1. teratogenic
2. cholestasis
3. agranulocytosis (neutrophils \<500 cells/microL)
72
most common thyroid **carcinoma**
papillary (80%)
73
what CA goes to adrenals?
lung CA
74
Rx central DI
recombinant AVP
75
craniopharygnioma is a tumour arising from what?
who gets them?
remnant of the Rathke pouch
children (presents between 5 - 10 years old)
76
RET oncogene suggests what disease?
presence indicates what management?
MEN2A or MEN2B
prophylactic thyroidectomy
77
what must be monitored in SGLT-2 therapy?
kidney function (BUN and creatinine)
78
TSH-independent hyperthyroidism suggests what?
multinodular goitre ('toxic') from secondary iodine deficiency, though usually euthyroid
79
how are these sulfonylureas different?
glipizide, glyburide, glimepiride
glimepiride & glyburide are longer acting (more hypo's)
glipizide = shorter acting with fewer hypo's
80
which anti-androgen supresses testosterone secretion from Leydig cells?
ketoconazole
81
what is eflornothine? what is it used for and how dose it work?
ornithine decarboxylase inhibitor
facial hair removal
ornithine decarboxylase functions as a DNA mismatch repair enzyme. inhibition = decreased cell growth and increase apoptosis. topical application kills hair follicles
82
elevated calcitonin suggests what CA?
what lab finding will you have?
medullary thyroid CA
hypocalcaemia
83
Rx for phaeochromocytoma?
surgical excision
**but must include medical management**
1. phenoxybenzamine (irreversible alpha-blocker)
* followed by*
2. beta-blocker
84
associated HLA types with diabetes mellitus type 1
HLA-DR3
HLA-DR4
85
what is the mechanism of sulfonylureas and meglitinides?
glipizide, glyburide, glimepirilide
nateglinide, repaglinide
side effects?
insulin secretogogues - inihibits beta cell K+ channels, resulting in insulin secretion
hypoglyaemia and weight gain
86
**low** Ca with **high** PTH suggests what pathology?
pseudohypoparathyroidism
PTH is being appropriately secreted in the absence of Ca++ but there is an autocomal dominant mutation in the PTH-R (a Gs GPCR).
87
what is the major endocrine side effects of amiodarone?
amIODarone is 40% iodine by weight
so both hypo-/hyper-thyroidism
check serum TSH for preexisting thyroid disease
88
antimicrosomal antibodies suggest what disease?
hashimoto thyroiditis
89
pathogenesis of sheehan syndrome?
pituitary doubles in size during pregnancy but the blood supply does not change. if woman loses blood intrapartum will infarct the pituitary gland
90
treatment of GH adenoma?
ocreotide (somatostatin analog) GH receptor antagonist surgical removal
91
pathogenesis of sheehan syndrome?
pituitary doubles in size during pregnancy but the blood supply does not change. if woman loses blood intrapartum will infarct the pituitary gland
92
what is the boney structure that holds the pituitary gland?
sella turcica
93
what is ezetemibe?
inhibitor of Niemann-Pick C1-like 1 transporter protein (NPC1L1)
inhibits transport of dietary cholesterol from the GI lumen into intestinal enterocytes
lower dietary choesterol to liver reduces intrahepatocyte concentration, so LDL receptor is upregulated in order to pull cholesterol out of circulation.
94
hypopituitarism - causes (4)?
1. pit adenoma (adults) 2. craniopharyngioma (children) 3. sheenhan syndrome 4. empty sella syndrome (1ary - herniation of arachnoid & CSF into sella , 2ary to trauma)
95
what is the effect of oestrogen on thyroid hormones?
oestrogen (pregnancy, OCP, menopause Rx) increases the circulating levels of thyroxine-binding globulin (TBG)
normal HPT axis increases total T3/4 levels to saturate increasing TBG
free T3/4 remains normal (euthyroid) but **total** levels increase
96
what is the most common cause of male hypogonadism?
Klinefelter syndrome (47 XXY)
sertoli and leydig cell dysfunction. low testosterone and low inhibit. high gonadotrophs (LH & FHS). subsequently high aromatase, so high oestrogen
gynaecomastia, testicular atrophy, infertility, intelectual disability.
97
hypotension, hyperpigmentation, low Na+, high K+, N&V...
what disease? aetiologies (4)?
adrenal insufficiency
can be acute (WF syndrome) or chronic (autoimmune, TB, metastatic spread)
98
how does hyperthyroidism increase sympathetic nervous system activity?
increases beta1-adrenoceptor expression
99
acne, elevated haematocrit, testicular atrophy, aggressivity, gynaecomastia
suggests what?
androgen steroid abuse
100
how are newborns screened for CAH?
serum 17-hydroyxprogesterone
101
central diabetes insipidus - diagnosis
water deprivation test urine osmolality does not increase
102
how to tell the difference between anaplastic thyroid CA and Reidel fibrosing thyroiditis if they both involve the airways?
epidemiology anaplastic thyroid CA for old people and Reidel for young women
103
how does hyperthyroidism increase basal metabolic rate?
global upregulation of Na+-K+ ATPase
104
what enzyme mediates lens damage in hyperglycaemia?
aldose reductase
converts glucose to sorbitol
105
association of growth hormone adenoma?
secondary diabetes GH stimulates gluconeogenesis and decreases glucose uptake into cells
106
MEN2A neoplasms
medullary carcinoma
pheochromocytoma
parathyroid adenoma
107
cell signalling of glucagon in the liver
activate Gs, AC, cAMP, PKA --\> gluconeogeneis (pyruvate carboxylase, PEP carboxykinase) and glycolysis (glycogen phosphorylase), inhibit glycolysis (decreasing fructose 2,6-bisphosphate)
108
enlarged tongue and deepening of the voice... what's happening?
myxedema of the soft tissue classic in hypothyroidism of older children and adults
109
galactorrhoea, amennorhoea
prolactinoma
...woman breast feeding
110
what is the mechanism of aciton of canagliflozin/dapagliflozin?
main side effects and considerations?
inhibit tubular reabsorption of glucose
glucosuria, UTIs - volume depletion and hypotension
must monitor renal function before and during drug treatment
111
4 causes of cushing syndrome
1. iatrogenic (bilateral atrophy)
2. primary adrenal adenoma, hyperplasia, carcinoma (cushing disease, unilateral)
3. ACTH-secreting pit adenoma (bilateral hyperplasia)
4. paraneoplastic ACTH (bilateral hyperplasia)
112
in CAH with 21 hydroxylase, what hormones are not made?
any mineralocorticoids and cortisol
113
sheenhan syndrome presentation?
1. poor lactation 2. loss of pubic hair (dependent on androgens, dependent on LH) 3. fatigue
114
what is the mechanism of action of TZDs/glitazones?
piloglitazone/rosiglitazone
mechanism = binds PPAR-gamma to increase insulin sensitivity
s/e = weight gain, oedema, heart failure, increase # risk
115
brown tumour of adrenal?
pheochromocytoma
116
what cells secrete PTH?
chief cells of parathyroid gland
117
SIADH serum Na+ and serum osmolality?
Na+ - low osmolality - low
118
MEN2B neoplasms
medullary carcinoma
pheochromocytoma
ganglioneuroma of oral mucosa
*Marfanoid habitus*
119
headache and episodic hypertension associated with urination...
what pathology?
phaeochromocytoma found in the bladder wall rather than adrenal medulla
120
what class of drugs are cholestyramine, colestipol and colesevelam?
mechanism
side effects
bile acid-binding resins
**bind bile** in intestine, inhibit enterohepatic circulation --\> **bile acid wasting**
intrahepatic cholesterol needed to synthesis new bile acid, **increase LDL receptor** recycling, **decrease serum LDL**
s/e's: GI upset, malabsroption, **hypertriglycerideamia**
121
symptoms of male prolactinoma?
decreased libido and headache
122
route of metastatic spread for follicular thyroid carcinoma?
haematogenous
Four Carcinoma Route Haematogenously
(follicular, choriocarcinoma, RCC, HCC)
123
what muscle and nerve can be damaged during thyroidectomy (cranial end)
muscle - cricothyroid (increases voice pitch)
nerve - external superior largyngeal
124
differentials for low bone density (5)
vitamin D deficiency
primary hyperPTH
prolactinoma
cushing syndrome
hyperthyroidism
125
monozygtic twin concordance studies show genetic correlation between T1DM and T2DM to be what percentages?
50% and 80% respectively
126
symptoms on non-functioning pit adenoma
1. bilateral hemianopsia
2. headache
3. hypopituitarism
127
diabetes diagnosis
fasting blood sugar
random blood glucose
GTT (2 hours after load)
fasting \>126 mg/dL
random \>200 mg/dL
glucose tolerance test \>200 mg/dL
128
antithyrogolbulin antibodies suggest what disease?
hashimoto thyroiditis
129
nephrolithiasis in hypercalcaemia - what stone?
calcium oxalate
130
what thyroid neoplasm?
2x pathoG findings here?
papillary CA
1. psammoma body (concentric layers of calcification)
2. orphan annie eye nuclei
131
considerations of PTU therapy in hyperthyroidism (3)
1. hepatotoxic
2. ANCA-vasculitis
3. agranulocytosis (neutrophils \<500 cells/microL
132
hypotension, adrenal hyperplasia, salt wasting (hyperkalaemia, hyponatraemia)
precocious puberty, clitoral enlargement
what disease?
CAH - 21-hydroxylase deficiency
133
mechanism of action for PTU
inhibits thyroid peroxidase
134
base of tongue mass of thyroid origin called?
lingual thyroid
135
which thyroid CA has poorest outcome
anaplastic - extensive local invasion leading to dysphagia and resp distress
136
HLA subtype associated with hashimoto thyroidis
HLA-DR5
137
pathology?
type 2 diabetes mellitus
deposition of amyloid (hyalinisation) of islets
138
what is the difference between follicular adenoma and carcinoma?
invasion of the follicles through the fibrous capsule.
139
central DI serum Na+ serum osmolality urine osmolality
serum Na+ - high serum osmolality - high urine osmolality - low
140
eosinophilic metaplasia of cells that line the follicles on thyroid biopsy suggests what disease? what are these cells called?
hashimoto thyroiditis Hurthle cells
141
how does metyrapone work in Cushing's?
inhibition of 11beta-hydroxylase, blocking production of cortisol from 11-deoxycortisol
142
4 aetiology of SIADH
1. paraneoplasitc (Small cell lung CA) 2. head trauma 3. pulmonary infection 4. drugs
143
what is the mechaism of action of acarbose or miglitol?
class of drug? main side effects?
inihibits intestinal absorbtion of disaccherides
alpha-glucosidase inhibitors
diarrhoea and flatulence
144
causes of cretinism? (4)
1. maternal hypothyroidism in early pregnancy 2. thyroid agenesis 3. thyroid peroxidase deficiency 4. iodine deficiency
145
what cell type is proliferating in medullary thyroid carcinoma?
parafollicular C cells
146
Rx thyroid storm
beta-blockers, steroids, propylthiouracil
147
examples of dopamine agonist?
bromocriptine, cabergoline suppress prolactinoma
148
coalescing painful erythematous plaques, GI symptoms, diabetes.
what pathology?
glucagonoma
149
what medications activate PPAR-gamma?
what are the main side effects?
TZDs/glitazones
rosiglitazone, piloglitazone
weight gain and oedema; HF; increased risk of fractures
