Nokea
Adonis arrives at the gym and spots a dumbbell he wants to use. When attempting to lift the weight, his biceps brachii contract, but the weight is not moved because it is too heavy. This is called?
- A. Isometric contraction
- B. Concentric contraction
- C. Eccentric contraction
- D. Incomplete tetanus
Correct Answer: a
Rationale: The correct answer is A: Isometric contraction. In isometric contraction, the muscle contracts but there is no movement at the joint. In this scenario, Adonis's biceps brachii contract but the weight is not moved, indicating an isometric contraction. In concentric contraction (B), the muscle shortens to move the weight upward. In eccentric contraction (C), the muscle lengthens while under tension, controlling the descent of the weight. Incomplete tetanus (D) refers to a state where muscle fibers are stimulated rapidly but not at the maximum rate to produce sustained contractions.
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Thyroxine is a peptide hormone, but its mechanism is different from other peptide hormones. Which of the following statements is true concerning this difference?
- A. It causes positive feedback.
- B. It does not require a second messenger to effect a response.
- C. It is very specific in the cell type it targets.
- D. It is a stimulant of cellular metabolism and targets all cells.
Correct Answer: B
Rationale: The correct answer is B: Thyroxine does not require a second messenger to effect a response. Thyroxine is a non-peptide hormone derived from the amino acid tyrosine, not a peptide hormone. It acts directly on the cell by binding to nuclear receptors, which then bind to specific regions of DNA to regulate gene expression. This mechanism is different from peptide hormones, which typically require second messengers like cAMP or calcium to transmit their signal inside the cell. Therefore, choice B is correct. Choices A, C, and D are incorrect because thyroxine does not cause positive feedback, is not highly specific in cell targeting, and does not target all cells for cellular metabolism stimulation.
PTH activates vitamin D, which aids in the absorption of:
- A. calcium.
- B. Vitamin C.
- C. iron.
- D. phosphate.
Correct Answer: A
Rationale: The correct answer is A: calcium. PTH (parathyroid hormone) activates vitamin D, which in turn helps in the absorption of calcium in the intestines. This is crucial for maintaining bone health and normal calcium levels in the blood. Vitamin C (Choice B) is not directly related to PTH or vitamin D in calcium absorption. Iron (Choice C) absorption is influenced by factors other than PTH and vitamin D. Phosphate (Choice D) absorption is primarily regulated by fibroblast growth factor 23 and not by PTH or vitamin D. Thus, the correct answer is A as it directly corresponds to the role of PTH and vitamin D in calcium absorption.
Ipratropium is a synthetic bronchodilator atropine substitute administered by:
- A. Oral route
- B. Intravenous injection
- C. Subcutaneous injection
- D. Inhalation
Correct Answer: D
Rationale: The correct answer is D: Inhalation. Ipratropium is a bronchodilator used to treat conditions like asthma and chronic obstructive pulmonary disease (COPD). Inhalation allows direct delivery to the lungs, where it acts locally to relax the smooth muscle and dilate the airways, providing rapid relief of bronchospasm. Oral route (A) would result in poor absorption and systemic side effects. Intravenous (B) and subcutaneous (C) injections are not preferred due to the risk of systemic effects and lack of targeted action. Thus, inhalation is the most effective and appropriate route for ipratropium administration.
Identify a gland that is controlled by an anterior pituitary hormone.
- A. pancreas
- B. parathyroid
- C. adrenal medulla
- D. ovary
Correct Answer: D
Rationale: The correct answer is D: ovary. The anterior pituitary gland secretes follicle-stimulating hormone (FSH) and luteinizing hormone (LH) that regulate the function of the ovaries. FSH stimulates the growth of ovarian follicles, while LH triggers ovulation and stimulates the production of progesterone and estrogen. The pancreas (A) is mainly controlled by insulin and glucagon from the pancreas itself. The parathyroid gland (B) is regulated by parathyroid hormone (PTH) secreted by the parathyroid glands. The adrenal medulla (C) is controlled by the sympathetic nervous system, not by anterior pituitary hormones.
A patient with Addison's disease comes to the emergency department with complaints of nausea, vomiting, diarrhea, and fever. What collaborative care should the nurse expect?
- A. IV administration of vasopressors
- B. IV administration of hydrocortisone
- C. IV administration of D5W with 20 mEq KCl
- D. Parenteral injections of adrenocorticotropic hormone (ACTH)
Correct Answer: B
Rationale: In Addison's disease, patients may experience adrenal crisis, requiring immediate administration of hydrocortisone to replace cortisol levels and manage the acute symptoms.