Animal Biology: Adrenalines and Thyroxine

Adrenaline:

This is a hormone produced by the adrenal glands situated above the kidneys.
It is also known as the “fight or flight” hormone.
Production increases during stressful situations to ‘prepare’ the body for potential danger.
It increases heart rate which pumps blood quickly and ensures high oxygen supply to muscles.
Adrenaline also triggers the liver to convert stored glycogen into glucose which is then released into the bloodstream for increased energy.

Thyroxine:

This hormone is produced and released by the thyroid gland found in the neck.
Thyroxine is responsible for regulating basal metabolic rate (BMR), which is the speed of chemical reactions happening in cells when the body is at rest.
It also aids in growth and development in the body.
The production of thyroxine is affected by the negative feedback mechanism to maintain a balanced concentration of the hormone in the body.
For example, if thyroxine levels are too high or too low, the hypothalamus and pituitary gland will increase or decrease the release of TSH (thyroid-stimulating hormone) which regulates thyroxine production.
Disorders can occur due to improper thyroxine levels. Hypothyroidism is when less thyroxine is produced, leading to a decrease in metabolic rate. Hyperthyroidism is when excessive thyroxine is produced, leading to increased metabolic rate, nervousness, and rapid heartbeat.