What is the purpose of the adrenal glands?
Produce hormones that enable patients to cope with changing environments
Where are the adrenal glands located?
A pair of small glands that rest on the superior pole of each kidney
What is the collective name for the hormones that they adrenal glands produce?
Corticosteroids
What are corticoids that effect sodium and potassium
Mineralocorticoids
What are corticoids that regulate carbohydrate metabolism?
Glucocorticoids
These are sex hormone precursors?
Gonadocorticoids
This hormone is produced by the anterior pituitary and regulates glucocorticoid and gonadocorticoid synthesis
ACTH (adrenocorticotroptic hormone)
What controls ACTH?
CRH (corticotropic releasing hormone) from the hypothalamus
What regulates the minerocorticoid pathway
Angiotensin 2
What is secreted by nephrons in response to blood pressure and to sodium levels in the nephron’s tubules.
Renin
What is the plasma substrate from which renin produces angiotensin I.
Angiotensinogen
What converts angiotensin 1 into angiotensin 2?
Pulmonary converting enzyme
What stimulates aldosterone secretion and sodium and water retention
The conversion of angiotensin 1 to angiotensin 2
This disease is the result of excess glucocorticoids
Cushings Syndrome/Disease
What causes high levels of glucocorticoids?
- Prolonged ACTH stimulation
- Glucocorticoid therapy for other treatments
- Adrenal Tumors
What is primary disease?
Effects the organ itself
What is secondary disease?
Involves an organ or cause elsewhere
This is a way to describe any condition that produces an elevation in glucocorticoid levels.
Cushings syndrome
This is when the disorder is caused by a pituitary lesion. It is named after the neurosurgeon who first published the description of the disease
Cushings disease
Characteristics of Cushing’s Disease
- Moon face
- Muscle weakness
- Hypertension
- Fat deposition in abdomen and base of neck
What can cause the production of accessive ACTH?
Pituitary tumor
What are causes of secondary cushing syndrome?
- Hypothalamus tumor
- Non-endocrine tumor
- Brochogenic carcinoma
This is hypersecretion of the aldosterone secreting cells of the adrenal cortex
Primary Hyperaldosteronism
What is another name for primary hyperaldosteronism?
Conn’s syndrome
What can cause Conns Syndrome/ Primary Hyperaldosteronism
-Cortical adenoma
What can Conns syndrome result in?
-Systemic hypertension due to sodium and water retention of the kidney
What is the basic idea behind secondary hyperaldosteronism?
-Aldosterone is released in response to activation of the RAA system
What are examples of things that cause secondary hyperaldosteronism?
- CHF
- Pregnancy
- Decreased renal perfusion
- Hypoalbuminemia
What are causes of adrenocortical hyposecretion?
- Destruction of the adrenal cortex
- Suppression of ACTH by high therapeutic doses of glucocorticoids
- Infection
- Tumor
- Adrenal infarction
What is the most common cause of Adrenocortical hyposecretion?
Addisons disease
Autoimmune disease in which destruction of the adrenal gland occurs causing inability to secrete adequate amounts of corticosteroids.
Addisons disease- Primary Adrenocortical insufficiency
What are symptoms of Addisons disease- Primary Adrenocortical insufficiency
- Weakness
- Fatigue
- Anorexia
- Hyperpigmentation of skin
Any disorder of the hypothalamus and pituitary such as metastatic cancer, infection, infarction or irradiation that reduces the output of ACTH.
Secondary adrenocortical insufficiency
What are symptoms of Secondary adrenocortical insufficiency
- Weakness
- Fatigue
- Anorexia
- NO Hyperpigmentation of skin
These 2 levels can be measured but are difficult to interpret sometimes due to the effects of stress and sleep cycle variations
- Cortisol
- ACTH
T/F- tests that evaluate cortisol and ACTH response to physiologic factors may be more reliable.
True
Almost all cortisol is bound to…?
Cortisol binding globulin
When is plasma cortisol the highest? Lowest?
- 8 am is highest
- 11 am is lowest
This measures the degree to which plasma cortisol exceeds protein binding capacity
Urine free cortisol
What are precursors of cortisol that can be measured when trying to establish a diagnosis of congenital adrenal hyperplasia?
- 17-Hydroxysteriods
- 17-Ketosteroids
This is the major androgen produced by the adrenal gland and can be measured in the plasma or the urine
DHEA-S
During this test… patient is given a dose of dexamethasone (synthetic steroid) which should suppress ACTH production and therefore decrease cortisol.
Dexamethasone Suppression Test
This test… uses synthetic bioactive ACTH to test adrenal cortisol producing ability
Cortrosyn Stimulation Test
Laboratory Findings with Cushings disease (ACTH, urine free cortisol, d-suppression test)
- Elevated ACTH levels
- Elevated Urine Free Cortisol levels
- Dexamethasone Suppression Test reveals failure to suppress cortisol levels
Laboratory Findings with Cushing’s Syndrome (urine free cortisol, ACTH)
- Elevated Urine Free Cortisol levels
- ACTH will typically be elevated but will be depressed if adrenal tumor secreting increased cortisol.
Laboratory findings with adrenal insufficiency
- Addison’s disease will show an elevated ACTH and low plasma and urine cortisol levels.
- Cortrosyn Stimulation test will reveal no increase in cortisol levels.
- Secondary cases of insufficiency will show a depressed ACTH and cortisol level.