Endocrine System Functions and Common Health Issues

Endocrine System Overview

Key glands involved in the endocrine system include:

• Hypothalamus
• Pituitary gland
• Thyroid and Parathyroid glands
• Adrenal glands
• Pancreas
• Testes (in males)
• Ovaries (in females)

Hormone Types and Examples

Steroid Hormones

Produced by:

• Testes and Ovaries (e.g., testosterone, estrogen)
• Adrenal Cortex (e.g., cortisol)

Polypeptide Hormones

Produced by:

• Pituitary Gland (e.g., Human Growth Hormone - HGH, Luteinizing Hormone - LH)
• Pancreas (e.g., insulin)
• Hypothalamus (e.g., Growth Hormone-Releasing Hormone - GHRH)

Amino Acid-Derived Hormones

Produced by:

• Adrenal Medulla (e.g., epinephrine)
• Thyroid Gland (e.g., thyroxine)

Diabetes Mellitus

Type 1 Diabetes

Cause: The pancreas fails to produce insulin, leading to high blood glucose levels.

Signs & Symptoms (S&S):

• Polydipsia (excessive thirst)
• Polyphagia (excessive hunger)
• Polyuria (frequent urination)
• Weight loss

Treatment (Rx):

• Daily exercise
• Insulin injections or insulin pump

Complications: Can result in hypoglycemia or hyperglycemia.

Hypoglycemia (Low Blood Sugar)

Causes: Often related to medications, nutrition, and exercise interactions. Taking too much insulin relative to food intake or exercise can deplete blood glucose as glycogen stores are filled.

• Insulin injection without a meal
• Incorrectly high dose of insulin
• Too few carbohydrates consumed
• Strenuous or prolonged exercise

Treatment (Rx):

• Stop physical activity immediately.
• Ingest 15-20 grams of fast-acting carbohydrates.

Risk: Can lead to insulin shock if untreated.

Hyperglycemia (High Blood Sugar)

Causes:

• Missed or insufficient insulin dose (e.g., eating a meal without injection)
• Consuming too many calories/carbohydrates
• Illness or stress

Risks: Can lead to diabetic ketoacidosis (DKA) and diabetic coma. A characteristic sign can be fruity-smelling breath.

Treatment (Rx): Administer insulin as prescribed, adjust diet, monitor glucose levels.

Diabetic Ketoacidosis (DKA)

Mechanism: Occurs when glucose is unavailable for cells due to lack of insulin. The body starts burning fat for energy, producing metabolic byproducts called ketones, which are toxic at high levels.

Type 2 Diabetes

Mechanism: Characterized by normal to high insulin levels initially, but the body's cells have low sensitivity to insulin receptors. This leads to impaired glucose uptake and elevated blood glucose.

Prevalence: Traditionally considered an adult disease, but increasingly diagnosed in younger people.

Predictors: Strong links to family history and obesity.

Signs & Symptoms (S&S): Often includes polydipsia and polyuria, but onset can be gradual.

Treatment (Rx):

• Exercise
• Diet modification
• Oral medications or sometimes insulin

Exercise Considerations for Diabetics

Benefits: Helps manage blood glucose levels, improves insulin sensitivity, aids weight control.

Key Principles:

• Balance insulin injections and meals around exercise timing.
• Exercise plans should be individualized.

Guidelines:

• Stay hydrated.
• Monitor blood glucose before, during (if needed), and after exercise.
• Wear appropriate footwear.
• Carry diabetic identification.
• Be aware of the timing of exercise relative to meals and insulin.

Thyroid Disorders

Hypothyroidism (Underactive Thyroid)

Description: A common condition characterized by low thyroid hormone production, leading to a slowed metabolism.

Treatment (Rx): Thyroid hormone replacement, typically with levothyroxine (e.g., Levothroid).

Hyperthyroidism (Overactive Thyroid)

Description: Characterized by excessive thyroid hormone production, leading to a high metabolism. A common side effect can be exophthalmos (bulging eyes).

Common Cause: Graves' disease is the most frequent cause.

Adrenal Gland Disorders

Addison's Disease (Adrenal Insufficiency)

Description: The adrenal glands produce too little cortisol and often aldosterone. A characteristic sign can be hyperpigmentation (bronze skin).

Treatment (Rx): Lifelong corticosteroid replacement therapy. Proper hydration is important.

Cushing's Syndrome (Excess Cortisol)

Description: Caused by prolonged exposure to high levels of cortisol, either from external sources or excessive production by the adrenal glands. Often results in characteristic features like a 'moon face' (round face).

Treatment (Rx): Depends on the cause; may include surgery, radiation, or medication to reduce cortisol production or block its effects.

Other Related Conditions

Obesity

Hormonal imbalances can contribute to the development or persistence of obesity.

Gout

Cause: Caused by a defect in the metabolic breakdown of purines (a type of amino acid), leading to an accumulation of uric acid in the blood. Uric acid crystals (salts) can build up in joints, often in distal appendages like the toes/feet, causing inflammation and pain.

Treatment (Rx): Medications to lower uric acid levels or treat inflammation, dietary changes (e.g., limiting purine-rich foods).

Osteoporosis

Mechanism: A condition where bone resorption by osteoclasts outweighs bone formation by osteoblasts, leading to weakened, brittle bones. Can be caused or exacerbated by hormonal disturbances (e.g., estrogen loss after menopause) and nutritional deficiencies.

Paget's Disease of Bone

Description: An abnormality of bone remodeling, marked by disorganized phases of excessive bone resorption followed by excessive, structurally unsound bone formation.