Pituitary Gland Study Guide

What is the pituitary gland?

The pituitary gland is a small, pea-sized gland located at the base of the brain, below the hypothalamus. It is divided into two parts: the anterior lobe (adenohypophysis) and the posterior lobe (neurohypophysis).

Functions of the Pituitary Gland

The pituitary gland is responsible for secreting several important hormones that control various bodily functions, including:

• Growth hormone (GH): regulates growth, metabolism, and body composition.
• Adrenocorticotropic hormone (ACTH): stimulates the adrenal glands to produce cortisol, which helps the body respond to stress.
• Thyroid-stimulating hormone (TSH): stimulates the thyroid gland to produce thyroid hormones that regulate metabolism.
• Prolactin: stimulates milk production in the mammary glands.
• Follicle-stimulating hormone (FSH) and luteinizing hormone (LH): regulate the reproductive system and the production of sex hormones.
• Antidiuretic hormone (ADH) and oxytocin: produced in the hypothalamus but stored and released from the posterior pituitary, these hormones regulate water balance and uterine contractions during childbirth.

Regulation of Pituitary Hormones

The pituitary gland is under the control of the hypothalamus, which secretes releasing and inhibiting hormones that regulate the secretion of pituitary hormones. These hypothalamic hormones are transported to the pituitary gland via a network of blood vessels known as the hypothalamic-pituitary portal system.

Disorders of the Pituitary Gland

Imbalances in pituitary hormone levels can lead to various disorders, such as gigantism (excess growth hormone in children), acromegaly (excess growth hormone in adults), Cushing's syndrome (excess ACTH), and diabetes insipidus (deficiency of ADH).

Summary

The pituitary gland is a vital component of the endocrine system, regulating hormone production and maintaining homeostasis in the body. Its intricate relationship with the hypothalamus ensures the precise control of hormone secretion and overall bodily functions.