Epinephrine
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Endocrine & Hormones
- Leptin
- Ghrelin
- Protein Hormones
- Steroid Hormones
- Insulin
- Diabetes
- Glucagon
- Epinephrine
- Cortisol
- Thyroid Hormones
- Calcitonin
- Parathyroid Hormone (PTH)
- Anterior Pituitary
- Prolactin
- Luteinizing Hormone (LH)
- Follicle-Stimulating Hormone (FSH)
- Growth Hormone (GH)
- Posterior Pituitary
Summary
Epinephrine is a hormone that is produced by the adrenal medulla. Epinephrine is a tyrosine-derivative that is hydrophilic, and can therefore easily dissolve in water and blood to move throughout the body. Once epinephrine reaches a target cell, it relies on external receptors outside of the cell to trigger a second messenger cascade inside the cell, in order to cause epinephrine’s downstream effects. Epinephrine is produced when we are stressed, and stimulates the fight-or-flight response. During this response, epinephrine increases blood flow to skeletal muscles and reduces blood flow to digestive organs or other organs not necessary for survival.
Key Points
- Epinephrine
- Norepinephrine has the same endocrine function as Epinephrine
- Origin: Adrenal Medulla
- Type: Tyrosine derivative
- Water-soluble (hydrophilic)
- Cannot diffuse across cell membrane
- Uses GPCR pathway
- Uses a secondary messenger system because Epinephrine acts like a hydrophilic protein hormone
- Water-soluble (hydrophilic)
- Trigger: Stress
- Effects:
- Increases blood flow to skeletal muscles
- Constricts blood vessels/reduces blood flow to most organs
- Promotes glycogenolysis in liver
- All actions by epinephrine are designed to promote the fight or flight response