section 1.1 | Primary vs Secondary Endocrine Function

Heart (secondary)

• Hormone: Atrial natriuretic peptide (ANP)

• Function: Helps lower blood pressure by causing the kidneys to remove excess salt and water

• Adipose Tissue

(secondary)

• Hormone: Leptin

• Function: Signals the brain to reduce hunger when enough fat is stored in the body.

• Kidneys

(secondary)

• Hormone: Erythropoietin (EPO)

• Function: Stimulates the production of red blood cells when oxygen levels are low.

Liver (secondary)

• Hormones: Thrombopoietin, Angiotensinogen

  • Functions: 

    • Thrombopoietin: Stimulates platelet production in the bone marrow

    • Angiotensinogen: Precursor to angiotensin II, which helps regulate blood pressure and fluid balance

  • Special Fact: The liver is the largest exocrine gland in the body, weighing about 3 pounds in an average adult.

how many primary endocrine organs

10

1. Hypothalamus

1. Infundibulum

1. Pituitary Gland (also called the hypophysis)

1. Anterior Pituitary Gland (also called the adenohypophysis)

2. Posterior Pituitary Gland (also called the neurohypophysis)

1. Pineal Gland

no structure

1. Thyroid Gland

no structure

1. Parathyroid Glands

no structure

1. Thymus Gland

no structure

1. Adrenal Glands

1. Adrenal Cortex

   1. Zona Glomerulosa

   2. Zona Fasciculata

   3. Zona Reticularis

2. Adrenal Medulla

1. Pancreas

1. Pancreatic Islets

   1. Alpha Cells (do not abbreviate as α)

   2. Beta Cells (do not abbreviate as β)

2. Pancreatic Acini (also called acinar cells)

1. Ovaries

no structure

1. Testes

no structure