Quiz 40: Antibacterial Agents
The pituitary hormone of our body consists of two lobes: anterior and posterior. The posterior lobe of the pituitary doesn't synthesize hormones. The hormones produced by the hypothalamus get stored in the posterior lobe of the pituitary gland. This is because the posterior lobe acts as an extension of the nerve tissue of the hypothalamus. The hormone oxytocin gets synthesized in the Para ventricular nuclei while the hormone Anti-diuretic (ADH) gets synthesized in the supra-optic nuclei. Both oxytocin and ADH are polypeptides and the only difference among the two is in the place of two amino acids in the structure. The hormones secreted by the posterior pituitary get controlled by the nerve reflexes.
a. The medical condition Diabetes Insipidus (DI) develops when there is a deficiency or lack of development of Anti-diuretic hormone (ADH). In that case there occurs loss of water from the body in the form of urine in large quantity. The other signs and symptoms of diabetes mellitus are: urge of urination at frequent intervals, weight loss due to unknown reason, extreme hunger and changes in vision. b. The treatment of the rare medical condition Diabetes Insipidus (DI) might involve replacement therapy by the use of synthetic vasopressin. The vasopressin injection is available in the trade name of Pitressin Synthetic and Desmopressin is available in acetate form in an abbreviated name DDAVP. c. The most frequent side effects of the use of vasopressin in the treatment of Diabetes Insipidus (DI) are nausea, diarrhoea and cramping in the gastrointestinal tract. The other side effects to be noted are shortness of breath, congestion in nasal and irritation in the nasal cavity. The patient should be warned of possible drug interactions that might take with the vasopressin. Therefore it is important that the patient take necessary precautions like following diet plan, doing exercise for at least 30 minutes, drinking lots of water especially 30 minutes before the food intake so that the stomach gets full.
A small pea-sized gland located in a bony hollow behind the nose and attached to the base of the brain by a stalk is the pituitary gland. It helps in maintaining important body functions. It controls other endocrine glands so it is called the master gland. Hormones are secreted from the front part and back part of the gland. Hypothalamus is located above the pituitary gland. It controls the pituitary gland by sending signals. The extension of the neurons of the paraventricular and supraoptic nuclei of the hypothalamus is known as the posterior pituitary. Insulin is a hormone produced in the pancreas. The pancreas consists of exocrine and endocrine cells, is situated behind the stomach. The endocrine cells are in clusters in the pancreas and are known as Islets of Langerhans. Alpha cells, beta cells, delta cells are the 3 types of endocrine cells. Beta cells secrete insulin. When there is a rise in glucose level in the blood, insulin is released from the beta cells in the pancreas. Hence option (A) is wrong. Thyroxine is a hormone secreted into the blood by the thyroid gland. The Thyrotropin-Releasing Hormone (TRH) secreted by the hypothalamus stimulates the pituitary gland to produce Thyroid Stimulating Hormone (TSH). The production of thyroid hormones( thyroxine, triiodothyronine) by thyroid glands is stimulated by Thyroid Stimulating Hormone(TSH). Hence option (B) is wrong. Cortisol also called stress hormone is one of the steroid hormones. It is produced in adrenal glands and is released from it. The Corticotropin-Releasing Hormone (CRH) from the hypothalamus stimulates the Adrenocorticotrophic hormone from anterior pituitary which stimulates adrenal glands to produce cortisol. Hence option (C) is wrong. Mifepristone is a synthetic (human-made) steroid. It is a progesterone antagonist. It terminates pregnancies. Hence option (E) is wrong. Oxytocin is a peptide-derived hormone that stimulates smooth muscles of the uterus at the time of pregnancy and also stimulates lacteals in the breast. Oxytocin is synthesized by neurons in the hypothalamus and is stored and released by the posterior pituitary gland. The posterior pituitary gland does not synthesize hormones. Hence option is correct from the given options.