Anatomy of pituitary gland

Pituitary gland Anatomy

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: Hypopituitarism Hyperpituitarism Hyperprolactinemia 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.

12. GIGANTISM ACROMEGALY DWARFISM

13. PROLACTIN T he 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 ) R elaxin 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) T hyroid gland

19. Which of the two hormones are released from the neurohypophysis ? a) Oxytocin and Antidiuretic hormones b) V asopression and L utenizing hormones c) Growth hormone and Prolactin d) Anteriordiuretic and Anteriorcorticotropic hormones

20. THANK YOU