Pituitary Gland & Hormones

• The endocrine system includes all ductless glands in the body.
• Ductless glands include, pituitary, thyroid, parathyroid and adrenal glands, Islets of Langerhans of pancreas and the endocrinal parts of the ovary and testes.

Pituitary Gland

• The pituitary gland is also referred to as hypophysis cerebri and the master gland.
• This gland sits at the base of the brain, in the sella turcica of the sphenoid bone.
• It is covered by a fold of dura mater.
• The pituitary gland weighs about 0.5 grams and is 1 cm in diameter.
• Pituitary Gland connects to the hypothalamus, by the infundibulum.
• It is divided into two parts anterior and posterior lobe

Hormones released by the anterior lobe

• Growth hormone = GH
• Prolactin
• Lutenizing hormone = LH
• Follicle stimulating hormone = FSH

Hormones released by the posterior lobe

• Oxytocin
• Vasopressin (anti-diuretic hormone) = ADH

Clinical anatomy of the Pituitary Gland

• Pituitary adenoma may cause ballooning of sella turcica.

Thyroid Gland

• The thyroid gland weighs 30 grams
• It sits in the lower part of the front of the neck, just below the larynx.
• It is a butterfly or H-shape
• The thyroid gland consists of two lobes, right and left, connected by an isthmus.
• The thyroid glands secretes thyroxine
• Enlarged thyroid gland, is referred to as goitre

Parathyroid Glands

• Four small rounded glands embedded in the posterior surface of the Thyroid gland
• Secretes the parathyroid hormone (PTH)

Islets of Langerhans of Pancreas

• The pancreas gland is a mixed gland (both endocrine and exocrine functions)
• The exocrine portion of the pancreas secretes digestive juice into the pancreatic duct
• The endocrine portion secretes its hormones directly into the blood
• The Islets of Langerhans of Pancreas secretes hormones
• Insulin is secreted by beta cells
• Glucagon is secreted by alpha cells

Adrenal Glands

• Also referred to as the suprarenal gland
• Sits on the upper pole of the kidney
• Each gland weighs 12 grams and is 2.5 cm in length
• Formed of an outer layer called the cortex and an inner core called the medulla

Testes

• The endocrine parts of the testis are its interstitial cells of Leydig
• Leydig cells sit in connective tissue spaces between the semineferous tubules
• It secretes testosterone.

Ovaries

• The endocrine parts are the cells forming the Graffian follicles
• These cells secrete estrogen and progesterone hormones.

Overview of the pituitary gland and its function as a master gland. Hormones released by the anterior lobe include Growth Hormone, Prolactin, Lutenizing Hormone, and Follicle Stimulating Hormone. The posterior lobe releases Oxytocin, and Vasopressin.