Endocrine System Summary

Endocrine System Overview

  • Endocrine Glands: Ductless, secrete hormones directly into the bloodstream.

  • Exocrine Glands: Secrete products into ducts, not part of endocrine system.

Endo- Stay

Exo- Exit

Types of Hormones

  • Nonsteroid Hormones: First messengers that bind to cell membrane receptors.

  • Steroid Hormones: Bind to receptors in target cell nucleus affecting DNA.

Hormone Secretion Regulation

  • Negative Feedback: Reverses physiological changes.

  • Positive Feedback: Amplifies physiological changes (uncommon).

Endocrine Disease Mechanisms

  • Hypersecretion: Excess hormone, Hyposecretion: Insufficient hormone.

  • Polyendocrine Disorders: Issues with multiple hormones.

Prostaglandins

  • Local hormones acting on tissues where produced, influencing functions like respiration and blood pressure, the GI tract, and reproduction.

Pituitary Gland

  • Anterior Pituitary Hormones: adeno=gland

  • Thyroid- stimulating hormone (TSH),

  • Adrenocorticotropic hormone (ACTH),

  • Follicle-stimulating hormone (FSH)

  • Luteinizing hormone (LH),

  • Growth hormone (GH),

  • Prolactin (lactogenic hormone) (PRL).

  • Posterior Pituitary Hormones: nuero=nervous

  • Antidiuretic hormone (ADH),

  • Oxytocin (OT).

Thyroid Gland

  • Hormones: T4 20%, T3 80%, Calcitonin.

  • Function: Regulates metabolic rate, decreases blood calcium.

Parathyroid Glands

  • Hormone: PTH, increases blood calcium concentration.

  • Calcitonin- Regulates calcium levels

  • Posterior to the thyroid gland.

Adrenal Glands

  • Cortex Hormones: Outer area.

  • Cortisol =(glucocorticoids) increases blood glucose, and aldosterone (mineralocorticoids) regulates blood pressure.

  • Medulla Hormones: Inner area. Adrenalin/nonadrenline Epinephrine, norepinephrine.

Pancreas

  • Hormones: Insulin (lowers glucose) & glucagon (raises glucose).

  • Considered a endocrine and exocrine glands.

Sex Glands

  • Ovaries: Estrogen - effects on female development, fallopian tubes, and ovaries.

  • Testes: Testosterone - effects on male characteristics. produces male characteristics

Anterior pituitary glans.

  • Thymus: Thymosin, important for immune function. Posterior to the heart.

  • Placenta: HCG, estrogens, progesterone for pregnancy maintenance.

  • Pineal Gland: Secretes melatonin, regulates sleep and seasonal changes.

  • Other Organs: Produce hormones affecting appetite and sodium regulation (e.g., ghrelin, ANH, leptin).