Question

What is a hormone? How a hormone works in our body?

please type the answers

thanks

Answer 1

Answer

Hormone is a chemical messenger released from an endocrine gland directly into blood stream that binds to receptors on a target cell.

• Endocrine system consist of endocrine glands and their secretions (hormones).
• Hormones function to regulate biological processes such as metabolism and cellular functions.

Working of hormones :

• Usually hormones are secreted triggered by a hormonal or neural stimulus.
• Regulating hormones (secreted by hypothalamus) triggers released of tropic hormones (from anterior pituitary) that binds to target endocrine glands and stimulate release of hormone from target glands.
  Example : Corticotropin releasing hormone stimulates release of adrenocorticotropic hormone which in turn stimulates cortisol release.
• Hormone secretions are mostly regulated by negative feedback mechanism in order to main homeostasis.
• There are some direct acting hormones that binds to target cells and stimulate desired physiological response.
  Example : Oxytocin stimulate uterine contractions.

There are two types of hormones :

1) Peptide hormones : They contain receptors on the cell membrane. They require a second messenger to initiate cellular response.

2) Steroid hormones : They can cross plasma membrane and bind to receptors in cell nucleus to inititate gene trasncription.