Nokea
Regarding the islets of Langerhans:
- A. D cells secrete pancreatic polypeptide
- B. A cells are the most common
- C. they are most plentiful in the body of the pancreas
- D. blood from the islets drain into the hepatic portal vein
Correct Answer: D
Rationale: The correct answer is D because blood from the islets of Langerhans drains into the hepatic portal vein. This is important for the regulation of blood glucose levels by allowing insulin and glucagon produced by the islets to reach the liver directly. Choice A is incorrect because D cells secrete somatostatin, not pancreatic polypeptide. Choice B is incorrect as beta cells, not A cells, are the most common in the islets. Choice C is incorrect as the islets are most plentiful in the tail of the pancreas.
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Pituitary disorder caused by excess growth of the body:
- A. Dwarfism
- B. Gigantism
- C. Goiter
- D. Cretinism
Correct Answer: B
Rationale: The correct answer is B: Gigantism. Gigantism is caused by excess growth hormone production from the pituitary gland before puberty, leading to abnormal growth and height. Dwarfism (choice A) is the opposite condition, characterized by stunted growth. Goiter (choice C) is a thyroid disorder, not related to pituitary gland. Cretinism (choice D) is a condition caused by thyroid hormone deficiency, not pituitary gland disorder.
Acute attack of migraine can be treated by:
- A. Prazosin
- B. Ergotamine
- C. Propranolol
- D. Amphetamine
Correct Answer: B
Rationale: The correct answer is B: Ergotamine. Ergotamine is a vasoconstrictor that helps alleviate migraine symptoms by constricting blood vessels in the brain. It is commonly used to treat acute migraine attacks. Prazosin (A) is an alpha-blocker used for hypertension, not migraines. Propranolol (C) is a beta-blocker used for migraine prevention, not acute treatment. Amphetamine (D) is a stimulant used for ADHD, not migraine treatment. Ergotamine's vasoconstrictive properties make it effective for treating acute migraines.
Which of the following hormones does NOT aid in regulating fuel metabolism?
- A. insulin
- B. aldosterone
- C. glucagon
- D. cortisol
Correct Answer: B
Rationale: Correct Answer: B - aldosterone
Rationale:
1. Aldosterone is a hormone produced by the adrenal glands that primarily regulates salt and water balance, not fuel metabolism.
2. Insulin helps in lowering blood sugar levels by facilitating glucose uptake by cells.
3. Glucagon stimulates the release of glucose from the liver to raise blood sugar levels.
4. Cortisol plays a role in mobilizing energy stores during stress.
Summary:
Aldosterone does not directly impact fuel metabolism like insulin, glucagon, and cortisol do. Insulin lowers blood sugar levels, glucagon raises blood sugar levels, and cortisol mobilizes energy stores during stress.
A child overdoses on a drug that affects both the autonomic and somatic nervous systems. As blood level of the drug rises, he experiences hypertension and tachycardia, accompanied by skeletal muscle tremor. Further elevations of the drug cause all the expected signs and symptoms of autonomic ganglionic blockade, plus weakness and eventual paralysis of skeletal muscle. Which of the following drugs did the child most likely ingest?
- A. Bethanechol
- B. Nicotine
- C. Pilocarpine
- D. Scopolamine
Correct Answer: B
Rationale: The correct answer is B: Nicotine. Nicotine affects both the autonomic and somatic nervous systems. Initially, the child experiences hypertension, tachycardia, and skeletal muscle tremor due to stimulation of both systems. As the blood level rises, autonomic ganglionic blockade occurs, leading to weakness and paralysis. Bethanechol (A) is a cholinergic agonist, unlikely to cause these symptoms. Pilocarpine (C) is also a cholinergic agonist but does not affect the somatic nervous system. Scopolamine (D) is an anticholinergic drug, which would not cause the symptoms described.
In circumstances where the body requires prolonged or increased levels of a hormone, the DNA of target cells will specify the synthesis of more receptors on the surface of the cells of the target organ. This is known as ________.
- A. the cellʹs sensitivity reaction
- B. cellular affinity
- C. up-regulation
- D. a reaction to a stressor
Correct Answer: C
Rationale: Step 1: Up-regulation refers to the process where cells increase the number of receptors in response to increased hormone levels.
Step 2: This allows cells to become more sensitive to the hormone and maintain homeostasis.
Step 3: The other choices are incorrect because they do not accurately describe the phenomenon of up-regulation.
Step 4: Option A refers to sensitivity reaction in general, not specifically related to hormone receptors.
Step 5: Option B does not accurately describe the process of increasing receptor numbers.
Step 6: Option D mentions a reaction to a stressor, which is not directly related to the regulation of hormone receptors.