Disorders of the Hypothalamus and Pituitary Gland

Question 1

The pituitary gland is located at …..?

Answer 1

Base of the skull in a saddle-shaped cavity of the sphenoid bone called the sella turcica

Question 2

The pituitary gland is composed of …..?

Answer 2

An anterior (adenohypophysis) and a posterior (neurohypophysis) lobe.

The anterior lobe constitutes approximately 80% of the gland.

Question 3

EMBRYOLOGY of anterior pituitary ..?

Answer 3

The anterior pituitary gland originates from the Rathke pouch as an invagination of the oral ectoderm.

Question 4

What are craniopharyngiomas ….?

Answer 4

Persistent remnants of the original connection between the Rathke pouch and the oral cavity can develop into craniopharyngiomas, the most common type of tumor in this area.

Question 5

How many cells in anterior pituitary …?

Answer 5

Five cell types in the anterior pituitary produce 6 peptide hormones.

• Somatotropes produce growth hormone (GH),
• lactotropes produce prolactin (PRL),
• thyrotropes make thyroidstimulating hormone (TSH),
• corticotropes express proopiomelanocortin (POMC), the precursor of adrenocorticotropic hormone (ACTH), and
• gonadotropes express luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

Question 6

What are The biologic effects of GH ….?

Answer 6

It include increases in linear growth, bone thickness, soft tissue growth, protein synthesis, fatty acid release from adipose tissue, insulin resistance, and blood glucose

Question 7

The mitogenic actions of GH are mediated through …?

Answer 7

Insulin-like growth factor 1 (IGF-1), formerly named somatomedin C

Question 8

Conditions increase the release of prolactin ..?

Answer 8

Dopamine antagonists,
states of primary hypothyroidism,
administration of thyrotropin-releasing hormone (TRH), and
pituitary tumors result in increased serum levels of PRL

Question 9

Factors which decreases the release of prolactin ..?

Answer 9

Dopamine agonists and

processes causing destruction of the pituitary

Question 10

T he primary physiologic role for PRL …?

Answer 10

Initiation and maintenance of lactation.

Question 11

The posterior lobe of the pituitary contains ?

Answer 11

neurons of the supraoptic and paraventricular nuclei of the hypothalamus

Question 12

What are the 2 hormones produced by neurosecretion in the hypothalamic nuclei and released from the posterior pituitary. ?

Answer 12

Arginine vasopressin (antidiuretic hormone [ADH]) and oxytocin