The Pancreas

• Located right under the stomach.
• Secretes two key hormones that regulate blood glucose levels:
  • Insulin (produced by pancreatic beta cells)
  • Glucagon (produced by pancreatic alpha cells)
• Function of Insulin and Glucagon:
  • Work oppositely to tighten regulation of blood glucose.
  • Maintain energy balance as glucose is essential for cellular activity.

Roles of Insulin

1. Recognized as an anabolic hormone (as it promotes protein synthesis, cellular growth, maintenance, as well as healing).
2. Promotes uptake of glucose, amino acids, and lipids by cells.
3. Supports the formation of proteins and cell maintenance.
4. Helps in storage and utilization of nutrients.
   • Critical to prevent problems associated with low or high levels of insulin.

Pineal Gland

• Located in the brain.
• Secretes melatonin.
• Function:
  • Regulates sleep-wake cycle (circadian rhythm).
  • Helps control sleep patterns.

Heart: Atrial Natriuretic Peptide (ANP)

• ANP hormones are secreted from the heart.
• Work oppositely to ADH (antidiuretic hormone) and aldosterone.
• Function:
  • Maintain water-salt balance in the blood.
  • Promote excretion of salt and water in urine when blood volume or pressure is high.

The Thymus

• Located in the neck region.
• Produces thymosin hormones which are
  • Essential for maturation of T lymphocytes.
    • T lymphocytes are crucial for adaptive immunity.
• The thymus atrophies during adulthood, which may contribute to weakened immune response in aging.

Adipose Tissue

• Produces the hormone leptin.
• Function:
  • Suppresses appetite.
  • Sends signals to tell the brain when you are full.
  • Regulates fat storage in adipose tissue.
• Adipose tissue stores fat for energy between meals and is also used in regions such as joints as padding to allow for compression of tissues during movement.  Adipose also provides insulation.

Digestive Tract Hormones

• Produces several hormones involved in digestion:
  • Gastrin: increases gastric motility and gastric juice secretion.
  • Cholecystokinin (CCK): increases gall bladder contraction (and opens hepatopancreatic sphincter releasing bile into duodenum) and increases production of digestive enzymes by the pancreas.
  • Secretin: increases production of bile by the liver and bicarbonate buffer by the pancreas
  • Vasoactive Intestinal Peptide (VIP): induces vasodilation of intestinal blood vessels
  • Gastric Inhibitory Peptide (GIP): inhibits gastric motility and gastric juice production
  • Enterocrinin: increases secretion of intestinal alkaline mucus
• These hormones stimulate gastrointestinal secretions (enzymes, acids, mucus, buffers).
• Also regulate motility (movement of material) along the GI tract.

Kidneys and Endocrine Function

• Secrete Erythropoietin (EPO):
  • EPO:  Stimulates red blood cell production.
• Produces calcitriol hormone.
  • Initially produced in the skin as vitamin D (precursor to calcitriol)
  • Vitamin D can also be ingested in dairy products supplemented with vitamin D.
  • Vitamin D is converted to an intermediary product by the liver, which is then sent to kidneys for conversion into calcitriol.
  • Function of Calcitriol:
    • Promotes calcium absorption in the intestines.
    • Essential for bone health.

Summary

• The endocrine system involves a complex interaction of hormones from multiple organs.
• These hormones regulate metabolism, growth, immune function, water balance, reproduction, and digestion.
• Proper function of each component is vital for overall health and homeostasis.

Summary – My Table Version: