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Hyoscine is one of the most effective drugs for preventing motion sickness, but may cause photophobia or blurred vision. Which is the most similar prototype drug?
- A. A monoamine oxidase inhibitor
- B. Propranolol
- C. Atropine
- D. Bethanechol
Correct Answer: C
Rationale: Step 1: Hyoscine is an antimuscarinic drug used for motion sickness.
Step 2: Atropine is a similar prototype drug as it also belongs to the antimuscarinic class.
Step 3: Atropine, like hyoscine, can cause photophobia and blurred vision.
Step 4: Monoamine oxidase inhibitors (A) are not related to antimuscarinic drugs.
Step 5: Propranolol (B) is a beta-blocker and not an antimuscarinic drug.
Step 6: Bethanechol (D) is a muscarinic agonist, opposite in action to antimuscarinic drugs like hyoscine and atropine.
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State what the oesophagus connects to?
- A. Throat to lungs
- B. Duodenum to gall bladder
- C. Pancreas to duodenum
- D. Throat to stomach
Correct Answer: D
Rationale: The correct answer is D: Throat to stomach. The esophagus connects the throat (pharynx) to the stomach, allowing food to pass from the mouth to the stomach for digestion. Choice A is incorrect as the esophagus does not connect the throat to the lungs. Choices B and C are also incorrect as they mention connections that do not involve the esophagus. The esophagus specifically functions to transport food and liquids from the mouth to the stomach for further digestion.
What gland is located just superior to the kidneys?
- A. Pituitary
- B. Pancreas
- C. Ovaries
- D. Adrenal
Correct Answer: D
Rationale: The correct answer is D: Adrenal. The adrenal glands are located just superior to the kidneys. They are responsible for producing hormones such as cortisol, adrenaline, and aldosterone. The other choices are incorrect because the pituitary gland is located in the brain, the pancreas is located in the abdominal cavity, and the ovaries are located in the pelvic region. The adrenal glands are the only glands located just superior to the kidneys, making choice D the correct answer.
The anterior pituitary gland:
- A. is called the neurohypophysis.
- B. releases ADH and oxytocin.
- C. secretes releasing hormones.
- D. is connected to the hypothalamus by the portal capillaries.
Correct Answer: D
Rationale: Step-by-step rationale:
1. The anterior pituitary gland is connected to the hypothalamus by the portal capillaries.
2. This connection allows for the transport of releasing hormones from the hypothalamus to the anterior pituitary.
3. Releasing hormones stimulate the anterior pituitary to release specific hormones.
4. This communication pathway is essential for regulating hormone production and maintaining homeostasis.
Summary of other choices:
A: Incorrect. The neurohypophysis refers to the posterior pituitary, not the anterior pituitary.
B: Incorrect. ADH and oxytocin are released from the posterior pituitary, not the anterior pituitary.
C: Incorrect. Releasing hormones are produced by the hypothalamus, not the anterior pituitary.
A man has been told that he is not synthesizing enough follicle-stimulating hormone (FSH), and for this reason he may be unable to father a child. Choose the correct statement to explain this problem.
- A. FSH stimulates estrogen secretion by ovarian cells; therefore it is not synthesized by males.
- B. The physician is wronga hormone made in the adenohypophysis could not influence fertility.
- C. FSH stimulates sperm production in the testes.
- D. The man must be producing progesterone, which inhibits the synthesis of FSH.
Correct Answer: C
Rationale: Step 1: Follicle-stimulating hormone (FSH) is essential for sperm production in males.
Step 2: FSH is produced in the anterior pituitary gland.
Step 3: In males, FSH stimulates the Sertoli cells in the testes to support sperm production.
Step 4: Therefore, if a man is not synthesizing enough FSH, it can lead to reduced sperm production and fertility issues.
Summary:
A: Incorrect - FSH is synthesized by males in the anterior pituitary gland, not just females for estrogen secretion.
B: Incorrect - Hormones produced in the adenohypophysis, like FSH, play a crucial role in fertility.
D: Incorrect - Progesterone does not inhibit the synthesis of FSH; it is involved in the female reproductive system, not male fertility.
Each of the following parasympathomimetic drugs is correctly matched with an appropriate pharmacological action EXCEPT:
- A. Methacholine - vasodilation of peripheral blood vessels
- B. Neostigmine - stimulation of skeletal muscles
- C. Pilocarpine - increased sweat secretion
- D. Bethanechol - increased intraocular pressure
Correct Answer: D
Rationale: The correct answer is D. Bethanechol is a parasympathomimetic drug that primarily acts on muscarinic receptors in the bladder and gastrointestinal tract, causing increased smooth muscle contraction and promoting urination and improved GI motility. It does not affect intraocular pressure.
A, B, and C are incorrect:
A: Methacholine - acts as a muscarinic agonist causing bronchoconstriction, not vasodilation.
B: Neostigmine - inhibits acetylcholinesterase leading to increased acetylcholine levels, enhancing neuromuscular transmission, not directly stimulating skeletal muscles.
C: Pilocarpine - acts on muscarinic receptors in the eye, causing miosis and increased aqueous humor outflow, not increased sweat secretion.