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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Which of the following is not a function of the stomach?
- A. To digest proteins
- B. To digest carbohydrates
- C. Temporary store of food
- D. To neutralize alkali from the mouth
Correct Answer: B
Rationale: The correct answer is B: To digest carbohydrates. The stomach primarily digests proteins through the action of pepsin and hydrochloric acid. Carbohydrates are primarily broken down in the mouth by salivary amylase, not in the stomach. Choices A, C, and D are incorrect because the stomach does play a role in digesting proteins, temporarily storing food, and neutralizing alkali from the mouth, respectively.
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.
Mrs. A. asks why her urine is being tested so often for sugar since she does not have diabetes. The nurse's best response is which of the following?
- A. Your adrenal gland is producing too much hormone causing your blood sugar to increase and it is spilling into your urine.
- B. I can't tell you that information; you will have to ask your doctor to tell you when he comes in.
- C. The medicine we are giving you for your Cushing syndrome can sometimes cause diabetes, so we are checking for it.
- D. Your pancreas is not producing enough insulin to take care of the sugar in your blood.
Correct Answer: A
Rationale: In Cushing syndrome, excess cortisol can increase blood sugar, leading to glucosuria, so urine is monitored for sugar.
Diabetes mellitus occurs due to deficiency of:
- A. Glucagon
- B. Thyroxin
- C. Insulin
- D. Melatonin
Correct Answer: C
Rationale: Step-by-step rationale for why choice C (Insulin) is correct:
1. Insulin is a hormone produced by the pancreas that regulates blood sugar levels.
2. Diabetes mellitus is a condition characterized by high blood sugar levels due to inadequate insulin production or ineffective use of insulin.
3. The deficiency of insulin leads to the inability to properly regulate blood sugar levels, resulting in diabetes mellitus.
4. Glucagon (choice A) is a hormone that increases blood sugar levels, so its deficiency would not cause diabetes.
5. Thyroxin (choice B) is a hormone produced by the thyroid gland and is not directly related to diabetes.
6. Melatonin (choice D) is a hormone that regulates sleep-wake cycles and is not involved in blood sugar regulation.
Summary:
Insulin is the correct choice because its deficiency directly leads to diabetes mellitus, while the other choices do not play a significant role in the development of this condition.
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.