1. Production: Hormones are produced by specialized glands within the body, such as the pituitary gland, thyroid gland, adrenal glands, and pancreas.
2. Secretion: Once produced, hormones are secreted into the surrounding interstitial fluid, a fluid that surrounds cells.
3. Entry into Bloodstream: From the interstitial fluid, hormones diffuse into nearby capillaries, which are tiny blood vessels.
4. Circulation: The bloodstream carries hormones throughout the body, reaching target cells and organs.
5. Target Cells: Hormones bind to specific receptors on target cells, like a key fitting into a lock. This binding triggers a chain of events within the cell, leading to a specific response.
Types of Hormones and Transport:
* Water-soluble hormones: These hormones, like insulin and epinephrine, dissolve in the bloodstream and travel freely.
* Lipid-soluble hormones: These hormones, like testosterone and estrogen, need a carrier protein to travel in the bloodstream. The carrier protein shields the hormone from being broken down by the body's enzymes.
Key Points:
* The bloodstream acts as the transportation system for hormones, ensuring they reach their intended destinations.
* The specific type of hormone dictates how it travels in the blood (free or bound to a carrier protein).
* The binding of hormones to receptors on target cells initiates specific cellular responses, allowing for the regulation of various bodily functions.
