The hormones derived from an amino acid and secreted by the adrenal medulla are epinephrine (adrenaline) and norepinephrine (noradrenaline).
These hormones, also known as catecholamines, play a crucial role in the body's "fight or flight" response. Here's a more detailed explanation:
Adrenal Medulla and Hormone Secretion
The adrenal medulla is the inner part of the adrenal gland. It's primarily responsible for producing and secreting catecholamines, specifically:
- Epinephrine (Adrenaline): Released in response to stress, it increases heart rate, blood pressure, and blood sugar levels, preparing the body for action.
- Norepinephrine (Noradrenaline): Similar to epinephrine, it also raises heart rate and blood pressure. It is heavily involved in attention and response actions in the brain. It also contracts blood vessels, increasing blood pressure.
Amino Acid Derivation
Both epinephrine and norepinephrine are derived from the amino acid tyrosine. The synthesis pathway involves a series of enzymatic reactions that modify tyrosine into these active hormones.
Physiological Effects
These hormones have a wide range of effects on the body, including:
- Cardiovascular System: Increased heart rate and blood pressure.
- Respiratory System: Relaxation of bronchial muscles, allowing for increased oxygen intake.
- Metabolic System: Increased glucose production and release of energy stores.
- Nervous System: Increased alertness and focus.
Summary
Epinephrine and norepinephrine are crucial hormones produced by the adrenal medulla. Derived from the amino acid tyrosine, they mediate the body's response to stress and prepare it for "fight or flight."
