Nokea
All are characteristics of smooth muscle, except?
- A. Usually forms 2 layers at right angles to each other
- B. Utilizes troponin to help initiate muscle contraction
- C. Contains no striations
- D. Action potentials travel between muscle fibers quickly via tight junctions
Correct Answer: b
Rationale: The correct answer is B because smooth muscle does not utilize troponin to help initiate muscle contraction. Instead, smooth muscle contraction is regulated by calcium-calmodulin complex.
A: True - Smooth muscle usually forms 2 layers at right angles to each other.
C: True - Smooth muscle contains no striations.
D: False - Action potentials in smooth muscle travel slowly via gap junctions, not tight junctions.
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Growth hormone ________.
- A. is also called somatostatin
- B. is regulated by humoral mechanisms
- C. secretion results in a decrease in muscle mass
- D. promotes long bone growth during the formative years
Correct Answer: D
Rationale: The correct answer is D because growth hormone promotes long bone growth during the formative years by stimulating the growth plates in bones. This hormone plays a crucial role in skeletal growth and development. Choice A is incorrect because somatostatin is a different hormone that inhibits growth hormone release. Choice B is incorrect because growth hormone is primarily regulated by neural mechanisms. Choice C is incorrect because growth hormone actually promotes muscle growth and reduces fat mass.
When providing discharge instructions to a patient who had a subtotal thyroidectomy for hyperthyroidism, what should the nurse teach the patient?
- A. Never miss a daily dose of thyroid replacement therapy.
- B. Avoid regular exercise until thyroid function is normalized.
- C. Use warm saltwater gargles several times a day to relieve throat pain.
- D. Substantially reduce caloric intake compared to what was eaten before surgery.
Correct Answer: A
Rationale: After thyroidectomy, patients will need lifelong thyroid replacement therapy, so it is critical to ensure they understand the importance of not missing doses.
The 'hormone response element' is located on the cell __________.
- A. membrane
- B. DNA
- C. RNA
- D. enzymes
Correct Answer: B
Rationale: The correct answer is B: DNA. Hormone response elements are specific DNA sequences where hormone receptors bind to regulate gene expression. This binding initiates the transcription of target genes. Choices A, C, and D are incorrect because hormone response elements are not located on the cell membrane, RNA, or enzymes. The key is understanding that hormone receptors act on DNA to regulate gene expression, making choice B the most appropriate answer.
Nitroglycerin is a vasodilator used in the treatment of angina. A common side effect of its vasodilator activity is a reflex increase in heart rate, which is sometimes dangerous. Which drug could inhibit this reflex cardiac stimulation?
- A. Atropine
- B. Cocaine
- C. Phentolamine
- D. Propranolol
Correct Answer: D
Rationale: The correct answer is D: Propranolol. Propranolol is a beta-blocker that blocks the beta-adrenergic receptors in the heart, preventing the reflex increase in heart rate caused by nitroglycerin. This action helps to counteract the potentially dangerous side effect of increased heart rate.
A: Atropine is not the correct answer because it is an anticholinergic drug that increases heart rate, which would exacerbate the reflex cardiac stimulation caused by nitroglycerin.
B: Cocaine is a stimulant drug that can further increase heart rate and is not used to inhibit reflex cardiac stimulation.
C: Phentolamine is an alpha-blocker that primarily acts on alpha-adrenergic receptors and is not the preferred drug for inhibiting the reflex increase in heart rate caused by nitroglycerin.
Hormones that bind to receptors inside of target cells are usually
- A. lipid soluble.
- B. water soluble.
- C. second messengers.
- D. proteins.
Correct Answer: A
Rationale: The correct answer is A: lipid soluble. Lipid-soluble hormones can easily pass through the cell membrane and bind to intracellular receptors. This binding activates gene expression and affects protein synthesis within the cell. Water-soluble hormones, like choice B, bind to cell surface receptors and activate signaling pathways through second messengers (choice C). Proteins (choice D) are not hormones but rather macromolecules that can act as signaling molecules or receptors. Lipid solubility is crucial for hormones to exert their effects inside target cells, making choice A the correct answer.