55) Alterations of Adrenal Hormones Flashcards
what are the adrenal hormones
The adrenal glands, located on top of the kidneys, produce several important hormones that play crucial roles in the body’s regulation of various physiological processes. Here are the key adrenal hormones:
1) Cortisol (Glucocorticoids):
Cortisol is a steroid hormone that influences the metabolism of carbohydrates, fats, and proteins. Its primary functions include:
Regulating Glucose: Cortisol helps maintain normal blood glucose levels by promoting glucose production in the liver and inhibiting glucose uptake in peripheral tissues.
Anti-inflammatory and Immunosuppressive Effects: Cortisol has potent anti-inflammatory properties and suppresses the immune response, helping to control inflammation and immune reactions.
Stress Response: Cortisol is often referred to as the “stress hormone” because it is released in response to stress. It helps the body adapt to stressors by increasing energy availability and suppressing non-essential functions.
2 )Aldosterone (Mineralocorticoids):
Aldosterone is a mineralocorticoid hormone that primarily regulates electrolyte and fluid balance in the body. Its main functions include:
Sodium and Potassium Regulation: Aldosterone acts on the kidneys, promoting the reabsorption of sodium and the excretion of potassium. This helps maintain proper sodium and potassium levels in the body, which are essential for normal cell function and fluid balance.
Water Balance: By controlling sodium levels, aldosterone indirectly regulates water balance in the body. Increased reabsorption of sodium leads to increased water reabsorption, which helps maintain blood pressure and overall fluid balance.
3 ) Epinephrine and Norepinephrine (Catecholamines):
Epinephrine (adrenaline) and norepinephrine (noradrenaline) are both catecholamine hormones released from the adrenal medulla. They are involved in the body’s immediate stress response, preparing the body for “fight-or-flight” situations. Their functions include:
Increased Heart Rate and Blood Pressure: Epinephrine and norepinephrine act on the heart and blood vessels, leading to increased heart rate, stronger contractions, and vasoconstriction. This promotes increased blood flow to essential organs and muscles during stress or danger.
Energy Mobilization: These hormones stimulate the breakdown of glycogen (stored glucose) into glucose in the liver, providing a quick source of energy for the body.
Bronchodilation: Epinephrine and norepinephrine relax the smooth muscles in the airways, leading to bronchodilation and increased oxygen intake during stress or physical exertion.
Pupil Dilation: Catecholamines cause the dilation of pupils, improving visual acuity and peripheral vision.
pathophysiology of each adrenal hormone:
Cortisol (Glucocorticoids):
Cortisol is primarily regulated by the hypothalamic-pituitary-adrenal (HPA) axis. The hypothalamus releases corticotropin-releasing hormone (CRH), which stimulates the pituitary gland to release adrenocorticotropic hormone (ACTH). ACTH then stimulates the adrenal glands to produce and release cortisol.
cortisol disorders:
Cushing’s Syndrome: Excessive production of cortisol can occur due to various causes such as adrenal tumors, pituitary tumors (Cushing’s disease), or prolonged use of glucocorticoid medications.
Excess cortisol leads to metabolic disturbances, such as increased blood glucose levels, redistribution of fat (resulting in central obesity and moon face), muscle wasting, thinning of the skin, easy bruising, and increased susceptibility to infections.
Adrenal Insufficiency (Addison’s Disease): Insufficient production of cortisol can result from autoimmune destruction of the adrenal glands, infections, or other causes. Low cortisol levels lead to fatigue, weight loss, low blood pressure, electrolyte imbalances, and impaired stress response.
Aldosterone (Mineralocorticoids):
Aldosterone production is primarily regulated by the renin-angiotensin-aldosterone system (RAAS). Renin, released by the kidneys in response to low blood pressure or low sodium levels, converts angiotensinogen into angiotensin I. Angiotensin-converting enzyme (ACE) then converts angiotensin I to angiotensin II, which stimulates the adrenal glands to release aldosterone.
Pathophysiology of aldosterone disorders:
Hyperaldosteronism: Excessive production of aldosterone can occur due to adrenal tumors (aldosterone-producing adenomas) or hyperplasia of the adrenal glands. This leads to increased sodium reabsorption and potassium excretion, resulting in hypertension, electrolyte imbalances (low potassium levels), and fluid retention.
Hypoaldosteronism: Insufficient production of aldosterone can be caused by autoimmune destruction, adrenal gland disorders, or medications. Low aldosterone levels lead to decreased sodium reabsorption and increased potassium retention, resulting in low blood pressure, electrolyte imbalances (high potassium levels), and dehydration.
