Nokea
Which row shows active transport?
- A. particles move from high concentration to low concentration, particles move from low concentration to high concentration, requires energy
- B. particles move from high concentration to low concentration, particles move from low concentration to high concentration, requires energy
- C. particles move from high concentration to low concentration, particles move from low concentration to high concentration, requires energy
- D. particles move from high concentration to low concentration, particles move from low concentration to high concentration, requires energy
Correct Answer: C
Rationale: The correct answer is C because active transport involves the movement of particles from low concentration to high concentration, which goes against the natural flow of diffusion and requires energy input. In active transport, cells use ATP to pump substances across the cell membrane against their concentration gradient. This process allows cells to accumulate essential molecules or ions that are needed in higher concentrations inside the cell. Choices A, B, and D all describe passive transport processes where particles move with the concentration gradient and do not require energy input.
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Which of the following is most responsive to treatment with thyroxine?
- A. Diabetes mellitus
- B. Hyperglycemia
- C. Myxedema
- D. Graves’ disease
Correct Answer: C
Rationale: Rationale:
1. Myxedema is caused by hypothyroidism, which can be effectively treated with thyroxine.
2. Thyroxine is a synthetic form of thyroid hormone that helps restore thyroid hormone levels.
3. Myxedema symptoms such as fatigue, weight gain, and cold intolerance improve with thyroxine treatment.
Summary of Incorrect Choices:
A. Diabetes mellitus and hyperglycemia are not directly related to thyroid hormone levels.
B. Hyperglycemia is not primarily treated with thyroxine.
D. Graves' disease is a thyroid disorder characterized by hyperthyroidism, which requires different treatments than hypothyroidism.
All the following adverse effects can be produced by beta-blockers EXCEPT:
- A. Hypotension
- B. Heart failure
- C. Bronchodilation
- D. Heart block
Correct Answer: C
Rationale: The correct answer is C: Bronchodilation. Beta-blockers primarily work by blocking the beta-adrenergic receptors, leading to a decrease in heart rate and contractility. This can result in adverse effects such as hypotension, heart failure, and heart block due to the reduced cardiac output. However, bronchodilation is not a typical adverse effect of beta-blockers. In fact, beta-blockers can cause bronchoconstriction in patients with underlying respiratory conditions like asthma, making choice C the correct answer. Choices A, B, and D are incorrect because hypotension, heart failure, and heart block are known adverse effects associated with beta-blockers due to their mechanism of action on the cardiovascular system.
The chemical classification of hormones does NOT include __________.
- A. glucose-containing hormones
- B. steroid hormones
- C. protein-based hormones
- D. amino acid-based hormones
Correct Answer: A
Rationale: The correct answer is A: glucose-containing hormones. Hormones are classified based on their chemical structure, and glucose-containing hormones do not fit into any of the main categories (steroid, protein-based, amino acid-based). Glucose is a sugar molecule and not typically found as the primary chemical structure of hormones. Steroid hormones are derived from cholesterol, protein-based hormones are made of amino acids, and amino acid-based hormones are derived from single amino acids or peptides. Therefore, glucose-containing hormones do not align with the traditional chemical classifications of hormones.
What is the most critical need for the child with newly diagnosed cretinism?
- A. Thyroidectomy
- B. Administration of a radioactive cocktail of 131I (radioactive iodine)
- C. Replacement dose of thyroid hormones
- D. Replacement dose of calcitonin
Correct Answer: C
Rationale: The correct answer is C: Replacement dose of thyroid hormones. In newly diagnosed cretinism, there is a deficiency of thyroid hormones, leading to developmental delays and other health issues. Administering replacement thyroid hormones is crucial to normalize hormone levels and support proper growth and development. Thyroidectomy (choice A) is not necessary in this case as the goal is to supplement the missing hormones. Option B, the administration of radioactive iodine cocktail, is used to treat hyperthyroidism, not hypothyroidism. Choice D, replacement dose of calcitonin, is not relevant as calcitonin is involved in calcium regulation, not thyroid hormone production. Thus, the most critical need for the child with newly diagnosed cretinism is the replacement dose of thyroid hormones to address the underlying hormonal deficiency.
Which of the following statements is true?
- A. The hypothalamus makes oxytocin and antidiuretic hormone, which are transported to the posterior pituitary for storage.
- B. Antidiuretic hormone, released by the posterior pituitary, causes urine volume to increase and blood volume to decrease.
- C. Luteinizing hormone, an anterior pituitary hormone, triggers ovulation of an egg from the ovary and causes the ruptured follicle to produce progesterone and some estrogens.
- D. Hyposecretion of follicle-stimulating hormone or luteinizing hormone leads to sterility in both males and females.
Correct Answer: A
Rationale: Rationale for Choice A:
1. The hypothalamus produces oxytocin and antidiuretic hormone (ADH).
2. These hormones are transported via the hypothalamic-pituitary portal system to the posterior pituitary for storage.
3. When needed, the posterior pituitary releases these hormones into the bloodstream.
4. Oxytocin is involved in labor and milk ejection, while ADH regulates water balance by increasing water reabsorption in the kidneys.
Summary of other Choices:
B. Incorrect - ADH, when released, causes urine volume to decrease and blood volume to increase by increasing water reabsorption.
C. Incorrect - Luteinizing hormone triggers ovulation and stimulates progesterone production but is released by the anterior pituitary, not the hypothalamus.
D. Incorrect - Hyposecretion of FSH or LH can lead to infertility, not necessarily sterility, and the effects differ between males and females.