What is the hormone produced by adipose tissue which signals satiety?

Correct Answer: B

Rationale: Leptin is the correct answer because it is a hormone produced by adipose tissue that signals satiety to the brain, helping regulate energy balance and food intake. Melatonin is a hormone that regulates sleep-wake cycles, not hunger. Thymosins are involved in immune function. Glucagon is a hormone that increases blood sugar levels, not related to satiety.

Correct Answer: C

Rationale: In the context of the endocrine system and its role in maintaining fluid balance in the body, the correct answer to the question is C) Aldosterone. Aldosterone is a hormone produced by the adrenal glands that plays a crucial role in regulating the body's water and electrolyte balance. Aldosterone acts on the kidneys to increase the reabsorption of sodium and water back into the bloodstream, while promoting the excretion of potassium in the urine. This mechanism helps to conserve water in the body during dehydration by increasing blood volume and maintaining blood pressure within normal range. Now, let's examine why the other options are incorrect: A) Atrial natriuretic peptide (ANP) is a hormone that promotes the excretion of sodium and water by the kidneys, thereby reducing blood volume and blood pressure. This action is opposite to what is needed during dehydration. B) Oxytocin is a hormone primarily involved in uterine contractions during childbirth and milk ejection during breastfeeding. It does not play a direct role in water conservation. D) Thyroxine is a hormone produced by the thyroid gland that regulates metabolism, growth, and development. It is not directly involved in water conservation mechanisms. In an educational context, understanding the functions of different hormones in the endocrine system is essential for comprehending how the body maintains homeostasis. Knowing the specific roles of hormones like aldosterone in fluid balance helps healthcare professionals diagnose and manage conditions related to fluid and electrolyte imbalances effectively. This knowledge is crucial in fields such as endocrinology, nephrology, and critical care medicine.

Correct Answer: A

Rationale: The correct answer is A because blood vessels in the gut are not innervated by the enteric nervous system. The enteric nervous system primarily regulates gut motility, secretion, and blood flow, but it does not innervate blood vessels. The myenteric plexus lies between the longitudinal and circular muscle layers, making choice B correct. Parasympathetic supply to the gut comes from the vagus nerve and sacral nerves, supporting choice C. Sympathetic supply is often inhibitory on cholinergic postganglionic fibers, making choice D accurate. Therefore, A is incorrect as the enteric nervous system does not innervate blood vessels in the gut.

Correct Answer: B

Rationale: The correct answer is B: B12. B12 is a water-soluble vitamin because it dissolves in water and can be easily excreted through urine if taken in excess. It plays a crucial role in red blood cell formation and neurological function. Vitamins D, A, and K are fat-soluble vitamins, meaning they require fat for absorption and are stored in the body's fat tissues, making it harder to excrete excess amounts. This is why B12 is the only water-soluble vitamin among the choices.

Correct Answer: C

Rationale: The correct answer is C: peristaltic rushes. Peristaltic rushes are abnormal and excessive contractions that can result in diarrhea or bowel urgency. In normal health, peristalsis (A) is the coordinated contraction and relaxation of intestinal smooth muscles that moves contents along the digestive tract. Weak antiperistalsis (B) refers to reverse contractions that are weaker than normal peristalsis. Tonic contractions (D) are sustained contractions that help maintain muscle tone and control flow. Therefore, peristaltic rushes are the only option that does not occur in normal health due to their abnormal and disruptive nature.