Write the name of two glands are the main secretary gland of brain

The brain is not only the central organ of the nervous system but also contains two major secretory glands that are directly involved in endocrine functions. These are:
  1. Pituitary gland (Hypophysis)
  2. Pineal gland (Epiphysis cerebri)
These glands are part of the neuroendocrine system, which links the brain and hormonal regulation. They help in maintaining homeostasis, regulating growth, metabolism, stress response, sleep cycle, reproduction and many other vital processes.

1. Pituitary Gland: The Master Gland

The pituitary gland is called the "master gland" because it controls the activity of almost all other endocrine glands in the body. It is located at the base of the brain, in a bony cavity called the sella turcica of the sphenoid bone. It is connected to the hypothalamus by a stalk called the infundibulum, which carries signals from the brain to control hormone secretion.

The pituitary gland has two main lobes:

i. Anterior Pituitary (Adenohypophysis)

This part develops from Rathke's pouch (ectodermal origin) and is the true glandular part. It synthesizes and secretes the following hormones:
  • GH (Growth Hormone) – Stimulates overall body growth, especially in bones and muscles.
  • TSH (Thyroid Stimulating Hormone) – Controls thyroid gland and its release of thyroxine.
  • ACTH (Adrenocorticotropic Hormone) – Stimulates adrenal cortex to release cortisol.
  • FSH (Follicle Stimulating Hormone) – Stimulates growth of ovarian follicles and spermatogenesis.
  • LH (Luteinizing Hormone) – Triggers ovulation in females and testosterone secretion in males.
  • Prolactin – Helps in milk production after childbirth.
All these hormones are under control of releasing or inhibiting hormones secreted by the hypothalamus.

ii) Posterior Pituitary (Neurohypophysis)

This part is formed from the neural ectoderm and does not produce hormones itself. It stores and releases two hormones made by hypothalamic neurons:
  • Oxytocin – Causes uterine contractions during labour and helps in milk ejection.
  • ADH (Antidiuretic Hormone or Vasopressin) – Promotes water reabsorption in kidneys and helps in regulating blood pressure.

2. Pineal Gland: The Biological Clock Regulator

The pineal gland is a small, cone-shaped gland located deep in the brain, between the two hemispheres in a groove near the thalamus. It is part of the epithalamus and is most known for regulating the circadian rhythm or biological clock of the body.

Its main hormone is:
  • Melatonin
    • This hormone is secreted during darkness and inhibited by light. It helps regulate sleep patterns and biological timing such as seasonal reproduction in animals.
    • Melatonin secretion is controlled by a pathway that involves the retina, suprachiasmatic nucleus (SCN) of the hypothalamus, and sympathetic nerves. Thus, light and dark cycles affect the pineal gland directly, allowing it to synchronise internal body functions with the environment.
The brain is not only the central organ of the nervous system but also contains two major secretory glands that are directly involved in endocrine functions. These are: Pituitary gland (Hypophysis) Pineal gland (Epiphysis cerebri) These glands are part of the neuroendocrine system, which links the brain and hormonal regulation. They help in maintaining homeostasis, regulating growth, metabolism, stress response, sleep cycle, reproduction and many other vital processes.





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