Nokea
Which of the following is a trigger for the onset of Graves' disease?
- A. Trauma
- B. Iodine deficiency
- C. Stressful life events
- D. Bacterial infection
Correct Answer: C
Rationale: The correct answer is C: Stressful life events. Graves' disease is an autoimmune disorder where the immune system mistakenly attacks the thyroid gland, causing it to produce excess thyroid hormone. Stressful life events can trigger or exacerbate autoimmune conditions like Graves' disease by impacting the immune system's functioning. Trauma, iodine deficiency, and bacterial infection are not direct triggers for Graves' disease. Trauma can cause thyroid issues but not specifically Graves' disease. Iodine deficiency can lead to goiter but is not a direct trigger for Graves' disease. Bacterial infections can cause thyroiditis but are not a common trigger for Graves' disease.
You may also like to solve these questions
A patient presents with food poisoning that is attributed to botulism (Botulinum toxin poisoning). Which of the following is a correct characteristic, finding, or mechanism associated with this toxin?
- A. Complete failure of all cholinergic neurotransmission
- B. Favorable response to administration of pralidoxime
- C. Impairment of parasympathetic, but not sympathetic, nervous system activation
- D. Massive overstimulation of all structures having muscarinic cholinergic receptors
Correct Answer: A
Rationale: The correct answer is A: Complete failure of all cholinergic neurotransmission. Botulinum toxin inhibits acetylcholine release at neuromuscular junctions, leading to complete failure of all cholinergic neurotransmission. This results in flaccid paralysis and characteristic symptoms of botulism. Choice B is incorrect because pralidoxime is used to treat organophosphate poisoning, not botulism. Choice C is incorrect as botulinum toxin affects both parasympathetic and sympathetic nervous systems. Choice D is incorrect as botulinum toxin does not cause overstimulation but rather inhibits neurotransmission.
Which of the following statements regarding pituitary hormones is false?
- 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: B
Rationale: Step 1: Antidiuretic hormone (ADH) is released by the posterior pituitary, and its main function is to increase water reabsorption in the kidneys, leading to decreased urine volume and increased blood volume.
Step 2: If ADH causes urine volume to increase and blood volume to decrease, it would be counterproductive to its known physiological role.
Step 3: Therefore, Choice B is false as it contradicts the established function of ADH.
Summary:
- Choice A is true because oxytocin and antidiuretic hormone are indeed produced in the hypothalamus and stored in the posterior pituitary.
- Choice C is true as luteinizing hormone does trigger ovulation and stimulates the production of progesterone and some estrogens.
- Choice D is true because hyposecretion of follicle-stimulating hormone or luteinizing hormone can lead to infertility in both males and females.
Virilization is characterized by:
- A. excess facial hair.
- B. buffalo hump.
- C. truncal obesity.
- D. gonadal atrophy.
Correct Answer: A
Rationale: The correct answer is A: excess facial hair. Virilization refers to the development of male secondary sexual characteristics in females due to increased androgen levels. Excess facial hair, known as hirsutism, is a classic sign of virilization. Buffalo hump (B) and truncal obesity (C) are associated with Cushing's syndrome, not virilization. Gonadal atrophy (D) refers to the shrinkage of the gonads and is not a typical feature of virilization.
Cellular responses to hormones that initiate second-messenger systems include ________.
- A. possible activation of several different second-messenger systems
- B. cyclic AMP phosphodiesterase formation of an active second messenger
- C. formation of a specific protein kinase that acts on a series of extracellular intermediates
- D. hormone binding to intracellular receptors
Correct Answer: A
Rationale: The correct answer is A because cellular responses to hormones initiating second-messenger systems can activate various pathways. Different hormones can utilize different second messengers such as cAMP, cGMP, IP3, and DAG. This diversity allows for a wide range of responses in target cells.
Choice B is incorrect because cyclic AMP phosphodiesterase degrades cAMP, not forms an active second messenger.
Choice C is incorrect as it describes the mechanism of a specific protein kinase, which is not a characteristic of second-messenger systems.
Choice D is incorrect since hormone binding to intracellular receptors typically leads to gene transcription regulation, not direct activation of second-messenger systems.
Twenty-eight-year-old Alicia has recently been diagnosed with hyperthyroidism. Signs and symptoms of hyperthyroidism include:
- A. Tachycardia, sweating, and tremors.
- B. Fatigue, lethargy, and weight gain.
- C. Muscle twitching, tetany, and galactorrhea.
- D. Scotoma, alopecia, and hirsutism.
Correct Answer: A
Rationale: Symptoms of hyperthyroidism include increased heart rate (tachycardia), excessive sweating, and tremors due to the overactive thyroid gland.