Anatomy of pituitary gland
- 1. ANATOMY OF PITUITARY GLAND DR TANYA RASHID ANATOMY DEPT
- 2. THE PITUITARY GLAND ◦ Small and oval shaped attached to the undersurface of brain by the infundibulum. ◦ Its main function is to secrete hormones. ◦ The gland is sometimes called as the “master gland” because it is involved in many processes and is vital for life.
- 3. LOCATION ◦ It is situated in the hypophysial fossa, a depression in the sella turcica of body of sphenoid. Hypophysial fossa
- 4. The pituitary gland is divided into: ◦ Anterior lobe OR adenohypophysis ◦ Posterior lobe OR neurohypophysis.
- 5. THE ANTERIOR LOBE (ADENOHYPOPHYSIS) IS FURTHER SUBDIVIDED INTO: ◦ Pars distalis (largest part responsible for hormone secretion) ◦ Pars intermedia (between anterior and posterior lobes) ◦ Pars tuberalis (an upwards extension of pars anterior that surrounds the anterolateral aspect of infundibulum) THE POSTERIOR LOBE (NEUROHYPOPHYSIS) IS DIVIDED INTO: ◦ Median eminence ◦ Infundibulum ◦ Pars nervosa (responsible for hormone secretion)
- 6. ANATOMIC RELATIONS ◦ ANTERIORLY: the sphenoid sinus. ◦ POSTERIORLY: the dorsum sellae, the basilar artery and the pons. ◦ SUPERIORLY: the diaphragma sellae, which has a central aperture that allows the passage of the infundibulum. ◦ INFERIORLY: The body of the sphenoid, with its sphenoid air sinuses. ◦ LATERLLAY: the cavernous sinus and its contents.
- 7. HORMONES OF THE PITUITARY GLAND ANTERIOR LOBE HORMONES ◦ Anteriorcorticotropic hormone (ACTH) ◦ Follicle stimulating hormone (FSH) ◦ Growth hormone (GH) ◦ Lutenizing hormone (LH) ◦ Thyroid stimulating hormone (TSH) ◦ Prolactin POSTERIOR LOBE HORMONES ◦ Antidiuretic/vasopressin hormone ◦ Oxytocin
- 8. BLOOD SUPPLY ◦ ARTERIAL SUPPLY: from the superior and inferior hypophyseal artery (branches of the internal carotid) ◦ VENOUS DRAINAGE: into the cavernous sinus.
- 9. PITUITARY GLAND CONDITIONS ◦ Several conditions can affect your pituitary gland. ◦ Disorders occur most often in the anterior pituitary. ◦ Most are caused by the tumor in or around the pituitary gland. ◦ EXAMPLES OF PITUITARY GLAND DISORDERS INCLUDE: 1) Hypopituitarism 2) Hyperpituitarism 3) Hyperprolactinemia 4) Cushing’s disease
- 10. HYPOPITUITARISM ◦ The pituitary insufficiency, is a condition in which the pituitary gland does not make enough of certain hormones. EXAMPLE: decreased growth hormone, DWARFISM ◦ Dwarfism is the result of insufficient GH. The most common complications related with dwarfism are: ◦ Bowed legs ◦ Arthritis ◦ Hunching of back ◦ Sleeping disorders ◦ Weight gain that can place more strain on spine and joints.
- 11. HYPERPITUITARISM ◦ Results in the excess production or secretion of one or more hormones. ◦ Prolactin and Growth hormones are most commonly over produced. EXAMPLES: ◦ Gigantism is the result of hypersecretion of GH in children. ◦ Abnormally tall but body proportions are normal. ◦ Acromegaly is the over secretion of GH in adulthood. ◦ Continued growth of bony, connective tissue leads to disproportionate enlargement of tissue.
- 13. PROLACTIN ◦ The hormone that tells the body to make breast milk when a female is pregnant or breast-feeding. ◦ Production of prolactin takes place in the pituitary gland. ◦ For males and those who are not pregnant or breast-feeding, there are only low levels of prolactin in the body.
- 14. HYPERPROLACTINEMIA ◦ Overproduction of prolactin from a pituitary tumor (prolactinoma) can cause a decrease in other hormones like estrogen in women and testosterone in men. ◦ Excessive prolactin in the blood affects men and women differently. ◦ In women, prolactinoma might cause: Irregular menstrual periods
- 15. CUSHING’S DISEASE It is caused by hypersecretion of ACTH which causes the production of too much cortisol, (Hypercortisolism) SYMPTOMS: ◦ Moon face ◦ Weight gain ◦ Thin skin ◦ Hirsuitism ◦ Buffalo hump ◦ Loss of memory ◦ Abdominal striae
- 16. MULTIPLE CHOICE QUESTIONS WHICH OF THE FOLLOWING HORMONE IS PRODUCED BY PITUITARY GLAND IN BOTH MALES AND FEMALES BUT FUNCTIONAL ONLY IN FEMALES? ◦ a) Relaxin ◦ b) Prolactin ◦ c) Vasopressin ◦ d) Somatotrophic hormones
- 17. GIGANTISM AND ACROMEGALY ARE DUE TO: ◦ a) Hyperthyroidism ◦ b) Hypothyroidism ◦ c) Hyperpituitarism ◦ d) Hypopituitarism
- 18. Which of the following gland is regarded as the “MASTER GLAND” ? ◦ a) Adrenal gland ◦ b) Hypothalamus ◦ c) Pituitary gland ◦ d) Thyroid gland
- 19. ◦ Which of the two hormones are released from the neurohypophysis ? ◦ a) Oxytocin and Antidiuretic hormones ◦ b) Vasopression and Lutenizing hormones ◦ c) Growth hormone and Prolactin ◦ d) Anteriordiuretic and Anteriorcorticotropic hormones