Adrenal gland Flashcards
1
Q
What are the three major classes of steroids produced by the adrenal cortex
A
glucocorticoids mineralocorticoids and adrenal androgens
2
Q
What do glucocorticoids regulate
A
metabolism and immune responses
3
Q
What do mineralocorticoids regulate
A
blood pressure vascular volume and electrolytes
4
Q
What do adrenal androgens influence in females
A
secondary sexual characteristics
5
Q
Which zone of the adrenal cortex produces mineralocorticoids
A
the glomerulosa
6
Q
Which hormone is the primary mineralocorticoid
A
aldosterone
7
Q
Which zone of the adrenal cortex produces glucocorticoids
A
the fasciculata
8
Q
Which hormone is the primary glucocorticoid
A
cortisol
9
Q
Which zone of the adrenal cortex produces adrenal androgens
A
the reticularis
10
Q
What is the primary adrenal androgen
A
dehydroepiandrosterone (DHEA)
11
Q
What is the substrate for adrenal steroid biosynthesis
A
cholesterol
12
Q
How is cholesterol taken up by the adrenal cortex
A
through the LDL receptor
13
Q
What increases LDL receptor numbers in the adrenal cortex
A
long-term ACTH stimulation
14
Q
What does excess cortisol cause
A
Cushing’s syndrome
15
Q
What does excess aldosterone cause
A
aldosteronism
16
Q
What does excess adrenal androgens cause
A
adrenal virilism
17
Q
What are the two main causes of Cushing’s syndrome
A
exogenous glucocorticoids or endogenous adrenal activation
18
Q
What percentage of Cushing’s syndrome cases are ACTH dependent
A
80%
19
Q
What are the two main causes of ACTH-independent Cushing’s syndrome
A
adrenal adenoma and adrenal carcinoma
20
Q
What are the two main causes of ACTH-dependent Cushing’s syndrome
A
corticotrope adenoma and ectopic ACTH secretion
21
Q
What is the typical body habitus in Cushing’s syndrome
A
centripetal obesity
22
Q
What blood pressure reading is commonly seen in Cushing’s syndrome
A
greater than 150/90
23
Q
What skin finding is characteristic of Cushing’s syndrome
A
broad violaceous striae
24
Q
What psychiatric symptoms can occur in Cushing’s syndrome
A
personality changes
25
What urinary test is a good screening tool for Cushing’s syndrome
24-hour urine free cortisol excretion
26
What can cause pseudo-Cushing states
psychiatric disorders chronic pain severe exercise alcoholism diabetes and obesity
27
What test detects loss of diurnal cortisol variation
midnight salivary cortisol level
28
What is the most effective treatment for Cushing’s syndrome
surgical resection of the ACTH or cortisol-producing lesion
29
What is an alternative treatment if surgery fails in ACTH-dependent Cushing’s syndrome
bilateral adrenalectomy
30
What is the best surgical treatment for Cushing’s disease
transsphenoidal resection of a microadenoma
31
What is a non-surgical treatment option for Cushing’s disease
pituitary radiation therapy with adjunctive medical therapy
32
What test is done after an abnormal urine free cortisol result
plasma ACTH and high-dose suppression test
33
What does undetectable ACTH and no suppression indicate
adrenal tumor
34
What does high ACTH and no suppression indicate
ectopic ACTH secretion
35
What does high ACTH and partial suppression indicate
pituitary adenoma
36
What are common symptoms of mineralocorticoid excess
fatigue muscle weakness and cramps
37
What condition is often suspected in mineralocorticoid excess
hypertension
38
What electrolyte abnormality is associated with mineralocorticoid excess
hypokalemia
39
What are the two main causes of mineralocorticoid excess
primary adrenal disease and nonadrenal causes
40
What happens to renin levels in primary adrenal mineralocorticoid excess
they are low
41
What happens to renin levels in nonadrenal causes of mineralocorticoid excess
they are high
42
What are three nonadrenal causes of mineralocorticoid excess
congestive heart failure cirrhosis and decreased renal blood flow
43
What is the most common cause of primary hyperaldosteronism
aldosterone-producing adenoma
44
What is a rare adrenal tumor that can cause primary hyperaldosteronism
aldosterone-producing adrenal carcinoma
45
What are three causes of secondary hyperaldosteronism
renovascular hypertension diuretics and renin-secreting tumors
46
What common food can cause apparent mineralocorticoid excess
licorice
47
What enzyme does licorice inhibit
renal 11β-hydroxysteroid dehydrogenase type 2
48
What ion is reabsorbed in excess in primary hyperaldosteronism
sodium
49
What ion is excessively lost in primary hyperaldosteronism
potassium
50
What is a common blood pressure finding in mineralocorticoid excess
severe diastolic hypertension
51
What is the main test used to screen for primary aldosteronism
morning plasma aldosterone to renin ratio
52
What aldosterone to renin ratio suggests primary hyperaldosteronism
greater than 20 to 1
53
What are the four confirmatory tests for primary hyperaldosteronism
oral sodium loading saline infusion fludrocortisone suppression and captopril challenge
54
What imaging is done after a positive confirmatory test for primary hyperaldosteronism
adrenal CT
55
What is the surgical treatment for unilateral primary hyperaldosteronism
laparoscopic adrenalectomy
56
What is the medical treatment for bilateral adrenal hyperplasia
mineralocorticoid receptor antagonist
57
What medication is used to treat primary hyperaldosteronism if surgery is not possible
spironolactone or amiloride
58
What are the two main categories of adrenal insufficiency
primary adrenal failure and secondary ACTH deficiency
59
What is lost in primary adrenal insufficiency
both glucocorticoid and mineralocorticoid activity
60
What hormone is deficient in secondary adrenal insufficiency
cortisol
61
What is the main symptom of Addison’s disease
asthenia
(abnormal physical weakness or lack of energy)
62
What causes hyperpigmentation in Addison’s disease
excess ACTH
63
Where is hyperpigmentation most commonly seen
elbows hand creases areolae and mucous membranes
64
What is a common cardiovascular finding in Addison’s disease
arterial hypotension
65
What are common gastrointestinal symptoms in Addison’s disease
nausea vomiting diarrhea and abdominal pain
66
What is the presentation of acute adrenal insufficiency
hypotension confusion circulatory collapse and fever
67
What can trigger an adrenal crisis
hemorrhage metastasis or acute infection
68
What is a key laboratory finding in adrenal insufficiency
subnormal cortisol response to ACTH stimulation
69
What electrolyte abnormalities are seen in adrenal insufficiency
hyponatremia and hyperkalemia
70
Why does hyponatremia occur in adrenal insufficiency
sodium loss due to aldosterone deficiency
71
Why does hyperkalemia occur in adrenal insufficiency
aldosterone deficiency and acidosis
72
What is the screening test for adrenal insufficiency
plasma cortisol 30-60 min after cosyntropin
73
What indicates possible adrenal insufficiency on screening
subnormal cortisol response
74
What distinguishes primary from secondary adrenal insufficiency
ACTH and aldosterone response to cosyntropin
75
What ACTH level is seen in primary adrenal insufficiency
high
76
What ACTH level is seen in secondary adrenal insufficiency
low or normal
77
What is the emergency treatment for adrenal crisis
IV hydrocortisone and saline with dextrose
78
Why is dexamethasone used before confirming adrenal insufficiency
it does not interfere with cortisol measurement
79
What is the maintenance therapy for adrenal insufficiency
prednisone and fludrocortisone
80
How is prednisone dosed for maintenance
5 mg PO every morning
81
What is given in primary adrenal insufficiency for mineralocorticoid replacement
fludrocortisone
82
How should steroid doses be adjusted during illness or surgery
increased with IV hydrocortisone tapering after recovery
83
What are catecholamine-secreting tumors called when they arise in the adrenal medulla
pheochromocytomas
84
What are extra-adrenal catecholamine-secreting tumors called
paragangliomas
85
What is a common psychological symptom of pheochromocytoma
anxiety and fear of impending death
86
What are common cardiovascular symptoms of pheochromocytoma
palpitations hypertension and chest pain
87
What are common gastrointestinal symptoms of pheochromocytoma
nausea vomiting and epigastric pain
88
What are common neurological symptoms of pheochromocytoma
headache tremor and diaphoresis
89
How can pheochromocytoma-related hypertension present
sustained paroxysmal or normal
90
What are common signs of a pheochromocytoma spell
forceful heartbeat pallor tremor headache and diaphoresis
91
What can trigger a pheochromocytoma spell
postural change anxiety medications exercise or increased intra-abdominal pressure
92
How long do pheochromocytoma spells typically last
15 to 20 minutes
93
What is the most reliable biochemical test for pheochromocytoma
24-hour urine metanephrines and catecholamines
94
What laboratory finding confirms pheochromocytoma
increased plasma or urine fractionated catecholamines and metanephrines
95
What medications can falsely elevate catecholamine levels
tricyclic antidepressants levodopa amphetamines decongestants ethanol and clonidine withdrawal
96
When should imaging be performed for pheochromocytoma
only after biochemical confirmation
97
What is the first-line imaging test for pheochromocytoma
MRI or CT of the adrenal glands and abdomen
98
What is the primary treatment for pheochromocytoma
complete surgical resection
99
Why is preoperative medical therapy required in pheochromocytoma
to control blood pressure and prevent intraoperative crises
100
What is the recommended sequence for adrenergic blockade in pheochromocytoma
α-adrenergic blockade first then β-adrenergic blockade
101
How long before surgery should α-adrenergic blockade be started
7 to 10 days
102
Why must α-blockade be initiated before β-blockade
to prevent unopposed α-adrenergic stimulation and worsening hypertension
103
What is the preferred drug for preoperative blood pressure control
phenoxybenzamine
104
What are the three zones of the adrenal cortex and their secretions
zona glomerulosa aldosterone zona fasciculata cortisol zona reticularis androgens
105
What hormone controls cortisol and androgen secretion
ACTH
106
When is cortisol highest and lowest
highest at 8 AM lowest at 8 PM
107
What controls aldosterone secretion
serum sodium and renin-angiotensin system
108
What is the main cause of Cushing syndrome
ACTH-producing pituitary adenoma
109
What are common symptoms of Cushing syndrome
truncal obesity moon face hypertension muscle weakness and osteoporosis
110
What is the most sensitive test for early Cushing syndrome
24-hour urine free cortisol
111
How is Cushing syndrome differentiated from stress-induced cortisol elevation
dexamethasone suppression test
112
What does the short dexamethasone test show in Cushing syndrome
no suppression and cortisol >10 ug/dL
113
What ACTH level is seen in adrenal tumors
low
114
What ACTH level is seen in ectopic ACTH production
very high often >300 pg/mL
115
What does the high-dose dexamethasone test show in Cushing disease
cortisol suppression
116
What metabolic abnormalities are found in Cushing syndrome
hyperglycemia hypokalemia metabolic alkalosis
117
What is the main cause of Addison disease
autoimmune adrenal destruction
118
What are key symptoms of Addison disease
weakness vomiting diarrhea hyperpigmentation hypotension and fasting hypoglycemia
119
Why does Addison disease cause hyperpigmentation
increased ACTH precursor stimulates MSH
120
What laboratory test is diagnostic for Addison disease
low morning plasma cortisol
121
What test confirms adrenal insufficiency
synacthen (cosyntropin) stimulation test
122
How is secondary hypoadrenalism differentiated from Addison disease
low ACTH without hyperpigmentation
123
What test differentiates pituitary and hypothalamic causes of adrenal insufficiency
CRH stimulation test
124
What electrolyte abnormalities are seen in Addison disease
hyponatremia hyperkalemia metabolic acidosis
125
What is Conn’s syndrome
primary hyperaldosteronism due to excess aldosterone
126
What is the most common cause of Conn’s syndrome
bilateral adrenal hyperplasia
127
What is the main cause of secondary hyperaldosteronism
excessive renin-angiotensin activation
128
What is the most common symptom of hyperaldosteronism
resistant hypertension
129
What is the key laboratory finding in primary hyperaldosteronism
hypokalemia
130
What happens to plasma renin in primary hyperaldosteronism
decreased
131
What happens to plasma renin in secondary hyperaldosteronism
increased
132
What test confirms primary hyperaldosteronism
PAC/PRA ratio >25-30
133
What is the purpose of the saline suppression test
to confirm primary hyperaldosteronism
134
What is the effect of captopril in normal subjects
decreases aldosterone to <15 ng/dL
135
Congenital Adrenal Hyperplasia (CAH)
is caused by mutations in genes encoding enzymes involved in glucocorticoid synthesis
136
CAH presents a mixed picture of cortisol deficiency and adrenal androgen overproduction
cortisol deficiency stimulates CRH and ACTH leading to hyperplasia and excess androgen production
137
CAH is inherited as an autosomal recessive trait
95% of cases are due to 21α-hydroxylase deficiency while most others are due to 11β-hydroxylase deficiency
138
Salt-wasting form of 21α-hydroxylase deficiency
appears in infancy with hypotension and high mortality due to inadequate cortisol and aldosterone synthesis
139
Laboratory features of salt-wasting 21α-hydroxylase deficiency
include hyponatremia
140
Simple virilizing form of 21α-hydroxylase deficiency
presents in neonatal or early childhood with androgen excess and no salt loss due to nearly normal mineralocorticoid production
141
Non-classical 21α-hydroxylase deficiency
presents in adolescence or early adulthood with androgen excess while cortisol and aldosterone production are preserved
142
Marked elevation of 17-hydroxyprogesterone (17-OHP)
is the key diagnostic feature of classical 21α-hydroxylase deficiency
143
ACTH stimulation test
is useful in non-classical CAH where ACTH injection results in a significant increase in 17-OHP
144
Laboratory findings in classical CAH
include increased androgens (DHEA and DHEAS)
145
11β-hydroxylase deficiency
leads to cortisol deficiency
146
Accumulation of deoxycorticosterone (DOC) in 11β-hydroxylase deficiency
results in sodium retention
147
Elevated 11-deoxycortisol
is the best biochemical marker for diagnosing 11β-hydroxylase deficiency
148
Pheochromocytomas
are catecholamine-secreting tumors arising from chromaffin cells in the adrenal medulla
149
Common symptoms of pheochromocytoma
include severe headaches
150
Catecholamines
include epinephrine and norepinephrine
151
Best initial biochemical test for pheochromocytoma
is plasma or urinary metanephrines due to their high sensitivity
152
Plasma metanephrines testing
should be done in the supine position after 20-30 minutes of rest to avoid false positives
153
Catecholamines are less sensitive for pheochromocytoma diagnosis
because they are secreted intermittently and have a short plasma half-life
154
Urinary vanillylmandelic acid (VMA)
has poor sensitivity and is not commonly used for pheochromocytoma diagnosis
155
Clonidine suppression test
is used when metanephrine levels are mildly elevated to differentiate true pheochromocytoma from stress-related increases
156
Failure of normetanephrine suppression after clonidine
indicates pheochromocytoma since tumor catecholamine secretion is independent of sympathetic control
157
Other laboratory findings in pheochromocytoma
include hyperglycemia and diabetes mellitus
