One of the following is called emergency hormone in man.

Analyze the question: The question asks which hormone is known as the "emergency hormone." This refers to the hormone released when the body faces stress, danger, or excitement.

Explain the concept: Adrenalin (also called epinephrine) is secreted by the adrenal medulla, which sits on top of the kidneys. It prepares the body for "fight, flight, or fright" situations. Its effects include:

• Increased heart rate and blood pressure
• Faster breathing
• Conversion of glycogen to glucose in the liver, which raises blood sugar for quick energy
• Dilation of the pupils
• Diversion of blood from the skin and digestive system to the muscles
• Erect body hairs and pale skin (due to constricted skin blood vessels)

Check each option:

• A. Adrenalin: Released during emergencies such as fear, anger, or danger. Correct.
• B. Prolactin: Secreted by the pituitary gland and stimulates milk production in nursing mothers.
• C. Testosterone: The male sex hormone, secreted by the testes. It controls male secondary sexual characteristics and sperm production.
• D. Thyroxine: Secreted by the thyroid gland and regulates metabolic rate, growth, and development.

Answer: The emergency hormone is Adrenalin, so the correct option is A.

Exam tip: Remember the "3 Fs": Fight, Flight, Fright = Adrenalin. Whenever you see "emergency hormone," think of the adrenal glands. Also, a lack of iodine affects thyroxine (causing goitre), and prolactin relates to lactation, so those names tie to their own functions.