Nokea
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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How is hormone secretion regulated?
- A. by the nervous system
- B. by other hormones
- C. by changes in blood composition
- D. all of the above
Correct Answer: D
Rationale: The correct answer is D because hormone secretion is regulated by various factors. The nervous system can directly stimulate or inhibit hormone release. Other hormones can act as signals to trigger or suppress the secretion of specific hormones. Changes in blood composition, such as glucose levels or electrolyte concentrations, can also influence hormone production and release. Therefore, all of the options play a role in regulating hormone secretion, making choice D the correct answer.
Tropic hormones:
- A. stimulate the pineal gland to secrete hormones
- B. stimulate the thymus gland to secrete hormones
- C. stimulate other endocrine glands to secrete hormones
- D. stimulate nervous tissue
Correct Answer: C
Rationale: The correct answer is C: Tropic hormones stimulate other endocrine glands to secrete hormones. Tropic hormones are released from the anterior pituitary gland and act on target glands to regulate the secretion of specific hormones. They help maintain homeostasis by controlling hormone levels in the body. Choices A and B are incorrect because tropic hormones do not target the pineal gland or thymus gland. Choice D is incorrect because tropic hormones primarily target endocrine glands, not nervous tissue. In summary, tropic hormones play a key role in regulating hormone production in other endocrine glands, making choice C the correct answer.
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.
Peptide hormones _______________.
- A. are hydrophilic
- B. cannot enter the target cell
- C. bind to a receptor on the cell surface
- D. all of these
Correct Answer: D
Rationale: The correct answer is D because peptide hormones are hydrophilic molecules that cannot pass through the cell membrane, so they bind to receptors on the cell surface to initiate signaling pathways within the cell. Therefore, they are unable to enter the target cell like lipid-soluble hormones do. By binding to specific receptors on the cell surface, peptide hormones trigger a series of events that ultimately lead to a cellular response. Therefore, all of the given statements are true, making D the correct choice.
Virtually all of the protein or amino acid-based hormones exert their effects through intracellular ________.
- A. ions
- B. deactivators
- C. nucleotides
- D. second messengers
Correct Answer: D
Rationale: The correct answer is D: second messengers. Protein or amino acid-based hormones are unable to pass through the cell membrane due to their large size and hydrophilic nature. Therefore, they bind to specific receptors on the cell surface, triggering a series of events that lead to the production of second messengers inside the cell. These second messengers, such as cyclic AMP or calcium ions, then transmit the hormonal signal to the target cell's interior to initiate a physiological response. Choices A, B, and C are incorrect because protein or amino acid-based hormones do not directly exert their effects through ions, deactivators, or nucleotides intracellularly.