Adrenal Flashcards
1. When given a diagram of the adrenal gland, identify the layers of the cortex (glomerulosa, fasiculata, reticulate) and medulla, and identify and summarize the functions of the hormones synthesized in each anatomical region. 2. Compare and contrast the following diseases/disorders of the adrenal glands: • Addison’s disease and Cushing’s disease • Aldosteronism • Hirsutism & virilization • Pheochromocytoma 3. Discuss the difference between Cushing’s disease and Cushing’s syndrome. 4.
Where are the adrenal glands located?
Superior to the kidneys. Little hats on the kidneys
What the two regions of the Adrenal Gland?
- Cortex
- Medulla
What are the three components of the Cortex?
- Zona Glomerulosa
- Zona Fasciculata
- Zona Reticularis
The cortex takes up _____% of the adrenal gland?
80-90%
The Medulla takes up ______% of the adrenal gland?
10-20%
What molecules/hormones/etc come out of the Adrenal Gland?
- Aldosterone
- Cortisol
- Androgens
- Catecholamines
Aldosterone is a __________.
Mineralocorticoid
Cortisol is a __________.
Glucocorticoid
The Zona Glomerulosa is the most ______ layer of the cortex.
Superior
The Zona Fasciculata is the ______ layer of the cortex.
Middle/Intermediate
The Zona Reticularis is the most ______ layer of the cortex.
Inferior
The Zona Glomerulosa produces ________.
Mineralocorticoids (Aldosterone)
The Zona Fasciculata produces _________.
Glucocorticoids (Cortisol)
The Zona Reticularis produces __________.
Androgens (Androdtenedione, DHEA, and DHEA-S)
The Medulla produces ________.
- Catecholamines
- Metanephrines
- Normetanephrines
- Vanillylmandelic Acid
What are the two most common Catecholamines?
- Epinepherine
- Norepinephrine
If these products are overproduced, what effect will this have on the patient?
Make them sick!!!
Overproduction of Aldosterone will cause what disease/condition?
Hypertension
Aldosterone is secreted from the ________ and its site of action is on the ______________________.
Zona glomerulosa of the Adrenal Cortex;
Distal Nephrons of the Kidneys
What is the function of Aldosterone?
- Reabsorb Sodium and Chloride (which means water will follow)
- Secrete Potassium and Hydrogen
- Water Homeostasis
What initiates the Renin-Angiotensin-Aldosterone?
The system can be activated when there is a loss of blood volume or a drop in blood pressure (such as in hemorrhage or dehydration). This loss of pressure is interpreted by baroreceptors in the carotid sinus. In alternative fashion, a decrease in the filtrate NaCl concentration and/or decreased filtrate flow rate will stimulate the macula densa to signal the juxtaglomerular cells to release renin.
Release of cortisol from the ______ is stimulated by _______.
Zona Fasciculata; ACTH
Release of Androgens from the ______ is stimulated by _______.
Zona Reticularis; ACTH
T/F: The effect of ACTH is slow, taking hours to instigate an effect.
False, it is rapid and occurs within minutes.
The release of ACTH occurs _______ during the 24 hour cycle. Sometimes referred to as a ________ Pattern.
Episodically; Circadian
***Note: If ACTH is released episodically, then Androgens and Cortisol are also released episodically.
***Fun Fact: ACTH spikes in the morning. #MorningSex
When is ACTH secretion increased?
- Stress (Trauma, Sx, Anxiety, Emotional Disturbance)
- Low circulating levels of cortisol
When is ACTH inhibited?
- High circulating levels of cortisol
- Presence of synthetic glucocorticoids
Cortisol can inhibit ACTH secretion at two sites?
- Hypothalamus (Corticotropin Releasing Factor)
- Adenohypophysis (Corticotrophin)
When patients are taking exogenous Cortisol, this will inhibit the secretion of the endogenous pathway at the two ACTH secretion sites. Because of this, when the patient is being taken OFF of exogenous Cortisol, what should we do?
TAPER the exogenous cortisol off because the body needs to begin slowly making the glucocorticoids on its own again.
Physiologic Effects of Glucocorticoids
- Stimulate Gluconeogenesis
- Induce insulin resistance
- Increase release of AA and FA
- Elevate RBC and platelet levels
- Maintain normal vascular response to vasoconstrictors
- Stimulation of PMN leukocytosis
- Depletion of circulating eosinophils and lymphocytes
- Decrease macrophage adherence to endothelium
Elevated levels of aldosterone is a condition called _____________.
Hyperaldosteronism (Conn’s Syndrome)
Hyperaldosteronism can cause what conditions?
- Hypertension
- Hypokalemia
Causes of Hyperaldosteronism?
- Aldosterone producing Adenoma (60-70%)
- Bilateral Adrenal Hyperplasia (~34%)
- Unilateral Adrenal Hyperplasia (<1%)
- Familial Hyperaldosteronism
- Ectopic Hyperaldosteronism (very rare)
How do you screen for Hyperaldosteronism?
Measure 8 am plasma aldosterone (PA) and plasma renin activity (PRA) levels. Obtain PA/PRA ratio.
– Ratio of 4-10 is NORMAL
– Ratio of > 20 is Primary Aldosteronism
**Some drugs can alter hormone levels. i.e. Spironolactone will falsely increase PRA. ACE Inhibitors need to be stopped too.