Nokea
Most endocrine organs are prodded into action by other hormones; this type of stimulus is called:
- A. hormonal stimulus
- B. humoral stimulus
- C. neural stimulus
- D. receptor-mediated stimulus
Correct Answer: A
Rationale: The correct answer is A: hormonal stimulus. Endocrine organs are typically activated by other hormones circulating in the bloodstream, triggering a chain reaction of hormonal responses. This is known as hormonal stimulus. Other choices are incorrect because humoral stimulus refers to changes in blood levels of ions or nutrients, neural stimulus involves nerve impulses, and receptor-mediated stimulus is not a recognized term in endocrine physiology.
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Which gland produces cortisol?
- A. the testes
- B. the ovaries
- C. the adrenal glands
- D. the hypothalamus
Correct Answer: C
Rationale: The correct answer is C, the adrenal glands. The adrenal glands are responsible for producing cortisol, a hormone that helps regulate various functions in the body, such as metabolism, immune response, and stress response. The testes (A) produce testosterone, the ovaries (B) produce estrogen and progesterone, and the hypothalamus (D) regulates the release of hormones from the pituitary gland but does not produce cortisol directly. Therefore, choices A, B, and D are incorrect in this context.
What is meant by antibiotic resistance?
- A. No bacteria will be killed by any antibiotic.
- B. Only some bacteria will be killed by some antibiotics.
- C. No viruses will be killed by any antibiotic.
- D. Only some viruses will be killed by some antibiotics.
Correct Answer: B
Rationale: The correct answer is B: Only some bacteria will be killed by some antibiotics. Antibiotic resistance refers to the ability of bacteria to survive and grow despite the presence of an antibiotic. This occurs when bacteria evolve and develop mechanisms to defend against antibiotics. It is not accurate to say that no bacteria will be killed by any antibiotic (choice A) as some bacteria may still be susceptible to certain antibiotics. Antibiotics are not effective against viruses, so choice C and D are incorrect. In summary, antibiotic resistance specifically pertains to bacteria developing the ability to survive some antibiotics, making choice B the correct answer.
Alpha methyl dopa can produce:
- A. Inhibition of decarboxylase enzyme
- B. Increases renin
- C. Stimulation of Alpha2 receptor centrally
- D. Decreases blood pressure
Correct Answer: D
Rationale: Step 1: Alpha methyl dopa is a centrally acting antihypertensive medication.
Step 2: It is a prodrug that is converted to alpha-methyl norepinephrine in the brain.
Step 3: This metabolite stimulates alpha2 receptors in the brain, leading to decreased sympathetic outflow.
Step 4: Decreased sympathetic outflow results in decreased peripheral vascular resistance and ultimately decreases blood pressure.
Summary: Option D is correct because alpha methyl dopa decreases blood pressure by acting centrally on alpha2 receptors. Options A, B, and C are incorrect as alpha methyl dopa does not inhibit decarboxylase enzyme, increase renin, or stimulate alpha2 receptors centrally.
Hyposecretion of adrenal cortex hormones can lead to ___.
- A. Addison disease.
- B. diabetes mellitus.
- C. Cushing syndrome.
- D. cretinism.
Correct Answer: A
Rationale: The correct answer is A: Addison disease. Hyposecretion of adrenal cortex hormones can lead to Addison disease, characterized by fatigue, weight loss, low blood pressure, and skin discoloration. This is because insufficient cortisol and aldosterone production from the adrenal cortex can disrupt the body's stress response and electrolyte balance.
Summary of why other choices are incorrect:
B: Diabetes mellitus is primarily related to insulin regulation issues, not adrenal cortex hormones.
C: Cushing syndrome is caused by hypersecretion, not hyposecretion, of adrenal cortex hormones.
D: Cretinism is associated with thyroid hormone deficiency, not adrenal cortex hormone deficiency.
Which row shows the type of reaction that occurs and the colour of the mixture at the end of the reaction?
- A. neutralisation, orange
- B. neutralisation, yellow
- C. redox, orange
- D. redox, yellow
Correct Answer: B
Rationale: The correct answer is B: neutralisation, yellow. In a neutralization reaction between an acid and a base, the acidic and basic properties neutralize each other, resulting in a salt and water. The indicator phenolphthalein is commonly used in acid-base titrations, turning pink in basic solutions and colorless in acidic solutions. When the reaction is complete and the solution is neutral (pH 7), phenolphthalein appears yellow. Therefore, the color of the mixture at the end of a neutralization reaction is yellow. Choices A, C, and D are incorrect because neutralization reactions typically result in a yellow color, not orange, and redox reactions do not involve the same color changes as neutralization reactions.