What is the primary class of hormones produced by the Zona Glomerulosa?
Mineralocorticoids
What is the primary class of hormones produced by the Zona Fasciculata?
What stain type are the cells here?
Glucocorticoids
Basophilic
What is the primary class of hormones produced by the Zona Reticularis?
Androgens
What is the primary class of hormones produced by the adrenal medulla?
What is the stain type of the cells?
Catecholamines
Basophilic
What is the stimulant for the medulla to secrete Catecholamines?
Sympathetic preganglionic nerve terminals
What is an easy way to remember the hormones produced by the adrenal cortex zones?
G = Salt
F = Sugar
R = Sex
Aldosterone is under the influence of what?
Angiotensin II
What is the rate limiting step for adrenal steroid biosynthesis in the adrenal cortex?
What is the single starting compound that gives rise to all three classes of steroid hormones?
Rate limiting step = Cholesterol to Pregenolone
Starting compound = cholesterol!
TEST: What hormone is responsible for the conversion of Cholesterol to Pregnenolone?
ACTH
Adrenal pathology can be divided into what two basic categories?
1) Non-neoplastic
2) Neoplastic
Non-neoplastic adrenal lesions include what two kinds of pathology?
HYPER-functioning and
HYPO-functioning
TEST: Neoplastic adrenal lesions include what two kinds of pathology?
Between the two, which one is more RARE and why?
Functional (Secreting)
Non-functional
FUNCTIONAL is more rare because neoplastic processes "tend not to have more mature cells
,"
Stuck in evolutionary phases...?necessary machinery to secrete something in excess
Overproduction of the hormones in the Zona Glomerulosa results in what endocrinopathy?
Hyperaldosteronism
Overproduction of the hormones in the Zona Fasciculata results in what endocrinopathy?
Cushing's Syndrome (hypercortisolism)
Overproduction of the hormones in the Zona Reticularis results in what endocrinopathy?
Virilizing Syndrome (adrenogenital)
TRUE or FALSE: Most cases of hypercortisolism is exogenous and is mostly from iatrogenic causes
TRUE
What are two DEPENDENT causes of hypercortisolism?
1) Pituitary ACTH tumor
2) Ectopic ACTH tumor (small cell carcinoma of lung)
What are two INDEPENDENT causes of hypercortisolism?
1) Cortical neoplasm (adrenal adenoma or carcinoma in the Zona Fasciculata)
2) Primary cortical hyperplasia (rare)
TEST: List some of the physical features of Cushing's syndrome (10)
Central obesity
Buffalo humps (redirection of fat)
Moon facies
Weakness/muscle wasting
Hirsuitism (from INDIRECT increase in androgens)
HTN (from INDIRECT increase in aldosterone)
Diabetes
Osteoporosis
Striae (violaceous)
Easy bruising
TEST: Primary Hyperaldosteronism causes too much ____ retention, ___ excretion, and ultimately _______
Na+ retention
K excretion
HTN
What is the most common cause of PRIMARY hyperaldosteronism?
Cortical hyperplasia
(overproliferation of the cortex, specifically the cells in the Zona Glomerulosa)
When the Primary hyperaldosteronism is due to a neoplasm (most often an adenoma) in the cortex, what is this syndrome called?
Conn's Syndrome
Which syndrome MIMICS Primary Hyperaldosteronism?
Liddle Syndrome
What are some causes of secondary hyperaldosteronism?
Decreased renal perfusion (increase in renin)
Hypovolemia and edema
PREGNANCY (causes increase in renin)
TEST: When you have a cortical neoplasm causing too much (cortisol/aldosterone/androgens), it is more likely a __________ than an ________ (one of the exceptions)
Cortical neoplasm causing too much ANDROGENS is more likely a
CARCINOMA than an ADENOMA
****TEST: What is the most common cause of congenital adrenal hyperplasia? (think enzyme deficiency)
21-Hydroxylase deficiency (causes 95% of cases)
TEST: List the effect of 21-hydroxylase deficiency on the levels of:
- Cortisol
- Aldosterone
- Androgens
Cortisol DECREASES
Aldosterone DECREASES
Androgens INCREASES
TEST: What color would you expect the adrenal cortex to be?
YELLOW (all adrenal cortex hormones are derived from cholesterol, which essentially is fat and fat is yellow)
Primary chronic adrenal insufficiency is also known as what?
Addison's disease
Secondary adrenal insufficiency is primarily caused by what?
Too low ACTH levels (and
ACTH is required to make all of the adrenal cortical hormones as it is used to convert cholesterol to pregenolone)
What are some causes of primary ACUTE adrenal insufficiency?
Rapid withdrawal of steroids
Massive adrenal hemorrhage (Waterhouse-Friderichsen Syndrome)
Newborns with DIFFICULT DELIVERIES
Anticoagulant treatments
Post-surgical DIC patients
A rapid removal of steroids can be considered both ___ ___ and ___
Primary acute and Secondary depending on the text.
Waterhouse-Friderichsen Syndrome is usually due to what bacteria?
Neisseria Meningitides caused hemorrhagic necrosis
AGAIN: The most common cause of Addison's disease is what?
AUTOIMMUNE adrenalitis
What are some common causes of primary chronic adrenal insufficiency?
Infections
Metastasis (adrenal glands are a favorite site for early lung metastasis)
Genetic disorders (enzyme deficiencies)
TEST: One of the main differences between primary and secondary chronic adrenal insufficiency is what?
Why?
Secondary has a LACK of hyperpigmentation because ACTH levels are already too low, which probably means MSH levels are too low as well (vs primary, where ACTH levels are high from lack of feedback inhibition)
(Adenomas/carcinomas) are USUALLY more common forms of cortical neoplasms, with the exception being ________ producing cortical neoplasms
ADENOMAS
Except ANDROGEN-producing cortical neoplasms
If you see Spironolactone bodies on a histological section, what endocrinopathy does that indicate?
Hyperaldosteronism!
Which is why they were treating the HTN with Spironolactone
What is the primary tumor that arises from the adrenal medulla?
Pheochromocytoma
BOARDS: What is the 10% rule of pheochromocytomas?
10% arise in MEN
10% are EXTRA-adrenal
10% are bilateral
10% are malignant
10% are in childhood
What is the hallmark of malignancy?
Metastasis!