Chemical Coordination MCQs for MDCAT

Correct answer: A. Secretin

Secretin, released by the duodenum in response to acidic chyme, stimulates the pancreas to secrete bicarbonate-rich pancreatic juice.

Correct answer: B. Aldosterone

Aldosterone, secreted by the adrenal cortex, controls the concentration of sodium ions in body fluids by promoting renal sodium reabsorption.

Correct answer: C. Progesterone

The corpus luteum, formed from the ruptured follicle after ovulation, secretes progesterone to maintain the uterine lining.

Correct answer: A. Glycogen to Glucose

Glucagon promotes the breakdown of stored glycogen into glucose, raising blood glucose levels.

Correct answer: D. Tropic or trophic hormones

Tropic (trophic) hormones, secreted by the anterior pituitary, regulate the secretion of hormones from other endocrine glands.

Correct answer: B. Follicle Stimulating Hormone, Luteinizing Hormone, Prolactin

The gonadotrophic hormones secreted by the anterior pituitary are follicle-stimulating hormone (FSH), luteinizing hormone (LH) and prolactin.

Correct answer: B. Insulin

Beta cells of the islets of Langerhans produce insulin, which lowers blood glucose by promoting its uptake into cells.

Correct answer: A. Insulin

B-cells of the pancreas secrete insulin, a hormone essential for regulating blood sugar levels by facilitating the uptake of glucose by cells. Insulin also plays a key role in promoting the storage of glucose as glycogen in the liver and muscles, thus helping to lower blood sugar levels after meals. Dysfunction of insulin secretion or action can lead to diabetes mellitus.

Correct answer: C. Ovulation stage

The ovulation stage is when the mature egg is released from the ovary. Leutinizing hormone (LH) levels surge dramatically just before ovulation. This surge in LH triggers the reslease of the egg from the ovary, allowing it to travel through the fallopian tube for potential fertilization. Thus, the level of LH is maximum during the ovulation stage.

Correct answer: B. Myometrium

The labor pains to expel the fetus are due to the action of oxytocin on Myometrium Oxytocin is a hormone that is released by the pituitary gland during labor. It acts on the smooth muscle layer of the uterus, known as the myometrium, causing it to contract. These uterine contractions are responsible for pushing the fetus down the birth canal during childbirth. Oxytocin also plays a role in stimulating milk ejection during breastfeeding.

Correct answer: C. Sertoli

Option C is correct.FSH (Follicle stimulating hormones) stimulates spermatogenesis by stimulating Sertoli cells to complete the development of sperms. Sertoli cells are supporting cells that are found in the seminiferous tubules of the testes. They play a vital role in spermatogenesis, the process by which sperm cells are produced. FSH stimulates Sertoli cells to produce a number of factors that are essential for spermatogenesis, including: Androgen binding protein (ABP), which binds to testosterone and makes it available to developing sperm cells Growth factors, which promote the growth and development of sperm cells Inhibitin, which inhibits the production of FSH.Leydig cells are another type of cell that is found in the testes. They are responsible for producing testosterone, the male sex hormone. Testosterone is also essential for spermatogenesis, but it is produced in response to LH (luteinizing hormone), not FSH.Inhibin is a hormone that is produced by Sertoli cells. It inhibits the production of FSH and LH. This helps to ensure that the production of sperm cells is regulated.TSH (thyroid stimulating hormone) is a hormone that is produced by the pituitary gland. It stimulates the thyroid gland to produce thyroid hormones. Thyroid hormones are not involved in spermatogenesis.

Correct answer: A. Prolactin

Prolactin is a hormone produced by the pituitary gland that plays a crucial role in lactation and breastfeeding. During pregnancy and breastfeeding, prolactin levels increase significantly, stimulating the growth of milk-producing cells in the breast and initiating milk production. In breastfeeding mothers, prolactin levels remain elevated to maintain milk production and support lactation. Frequent suckling by the baby stimulates the release of prolactin, ensuring a continuous supply of milk.