Endocrinology Study Notes

Location: Base of the brain, below the hypothalamus.
Function: Often referred to as the "master gland" due to its regulatory role in other endocrine glands.
Hormones Produced:
- Anterior Pituitary:
  - Growth Hormone (GH)
  - Prolactin (PRL)
  - Thyroid-Stimulating Hormone (TSH)
  - Adrenocorticotropic Hormone (ACTH)
  - Follicle-Stimulating Hormone (FSH)
  - Luteinizing Hormone (LH)
- Posterior Pituitary:
  - Antidiuretic Hormone (ADH)
  - Oxytocin
Regulation: Controlled by hypothalamic hormones—releasing and inhibiting hormones.

Adrenal Glands: Located on top of each kidney, divided into cortex and medulla.
Common Disorders:
- Cushing's Syndrome: Overproduction of cortisol; symptoms include weight gain, hypertension, and mood changes.
- Addison's Disease: Underproduction of cortisol and aldosterone; symptoms include fatigue, weight loss, and low blood pressure.
- Primary Hyperaldosteronism (Conn's Syndrome): Excess aldosterone leads to hypertension and low potassium levels.
Diagnosis: Blood tests, urine tests, imaging (CT/MRI), suppression testing.

Thyroid Gland: Located in the neck, regulates metabolism through hormone production.
Common Disorders:
- Hypothyroidism: Low hormone production; symptoms include fatigue, weight gain, and cold intolerance.
- Hyperthyroidism: Excess hormone production; symptoms include weight loss, rapid heartbeat, and heat intolerance.
- Hashimoto’s Thyroiditis: Autoimmune disorder leading to hypothyroidism.
- Graves’ Disease: Autoimmune disorder causing hyperthyroidism.
Diagnosis: Blood tests for TSH, T3, T4 levels, and thyroid antibodies.

Types of Diabetes:
- Type 1 Diabetes: Autoimmune destruction of insulin-producing beta cells in the pancreas.
- Type 2 Diabetes: Insulin resistance and eventual pancreatic beta-cell dysfunction.
Management Strategies:
- Type 1: Insulin therapy (injections or pump); continuous glucose monitoring.
- Type 2: Lifestyle modification (diet, exercise), oral medications (metformin, sulfonylureas), insulin therapy if needed.
Complications: Neuropathy, retinopathy, nephropathy, cardiovascular disease.
Monitoring: Regular blood glucose checks, HbA1c tests quarterly or biannually.

Mechanisms:
- Feedback Loops: Negative feedback maintains homeostasis, e.g., the hypothalamic-pituitary-adrenal axis.
- Hormonal Interactions: Synergistic, antagonistic, and permissive actions among hormones.
Factors Affecting Regulation:
- Circadian Rhythms: Hormones like cortisol have diurnal variations.
- Physiological Conditions: Stress, illness, and age can impact hormone levels.
Disruption: Can lead to hormonal imbalances, resulting in various medical conditions.

Located at the base of the brain, below the hypothalamus.
Often called the "master gland" due to its role in controlling other endocrine glands.
Produces hormones that regulate growth, metabolism, reproduction, and stress response.
Anterior pituitary hormones include: growth hormone (GH), prolactin (PRL), thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), follicle-stimulating hormone (FSH), and luteinizing hormone (LH).
Posterior pituitary hormones include: antidiuretic hormone (ADH) and oxytocin.
Regulation of pituitary hormone release is controlled by hypothalamic hormones, including releasing and inhibiting hormones.

Adrenal glands are located on top of each kidney and divided into cortex and medulla.
Common disorders include Cushing's syndrome, Addison's disease, and primary hyperaldosteronism (Conn's syndrome).
Cushing's syndrome is characterized by excess cortisol production, resulting in symptoms like weight gain, hypertension, and mood changes.
Addison's disease is caused by underproduction of cortisol and aldosterone, leading to fatigue, weight loss, and low blood pressure.
Primary hyperaldosteronism is due to excessive aldosterone secretion, causing hypertension and low potassium levels.
Diagnosis of adrenal disorders often involves blood tests, urine tests, and imaging studies like CT or MRI.

The thyroid gland is located in the neck and regulates metabolism through hormone production.
Common thyroid disorders include hypothyroidism, hyperthyroidism, Hashimoto's thyroiditis, and Graves' disease.
Hypothyroidism occurs when the thyroid produces insufficient hormones, causing symptoms like fatigue, weight gain, and cold intolerance.
Hyperthyroidism is characterized by excessive thyroid hormone production, leading to weight loss, rapid heartbeat, and heat intolerance.
Hashimoto's thyroiditis is an autoimmune disorder that destroys thyroid tissue, leading to hypothyroidism.
Graves' disease is another autoimmune disorder that stimulates excessive thyroid hormone production, causing hyperthyroidism.
Diagnosis of thyroid disorders involves blood tests to measure TSH, T3, and T4 levels, along with thyroid antibody testing.

Diabetes mellitus is a metabolic disorder characterized by hyperglycemia due to impaired insulin production or action.
Types of diabetes include type 1 diabetes, type 2 diabetes, and gestational diabetes.
Type 1 diabetes results from autoimmune destruction of insulin-producing beta cells in the pancreas.
Type 2 diabetes is characterized by insulin resistance and eventual pancreatic beta-cell dysfunction.
Management of type 1 diabetes typically involves insulin therapy (injections or pump) and continuous glucose monitoring.
Type 2 diabetes management focuses on lifestyle modifications (diet, exercise), oral medications, and insulin therapy if needed.
Complications of diabetes include neuropathy, retinopathy, nephropathy, and cardiovascular disease.
Regular blood glucose monitoring and HbA1c tests are crucial for diabetes management.

Hormone regulation depends on feedback loops and interactions among hormones.
Negative feedback loops maintain homeostasis by regulating hormone production and release.
Examples include the hypothalamic-pituitary-adrenal (HPA) axis.
Hormones can interact synergistically (amplifying each other), antagonistically (opposing each other), and permissively (allowing other hormones to exert their effects).
Factors affecting hormone regulation include circadian rhythms, physiological conditions, and disruptions.
Disruptions in hormone regulation can lead to hormonal imbalances, causing various medical conditions.