Nokea
Which endocrine gland normally produces insulin?
- A. Adrenal
- B. Parathyroid
- C. Pancreas
- D. Liver
Correct Answer: C
Rationale: The correct answer is C: Pancreas. The pancreas is the endocrine gland responsible for producing insulin, which regulates blood sugar levels. It is located behind the stomach and plays a crucial role in maintaining glucose balance in the body. The other choices, A: Adrenal, B: Parathyroid, and D: Liver, do not normally produce insulin. Adrenal glands produce hormones like adrenaline and cortisol, the parathyroid regulates calcium levels, and the liver performs various metabolic functions but does not produce insulin. Therefore, the pancreas is the correct choice for insulin production.
You may also like to solve these questions
Which artery generally gives rise to inferior thyroid artery?
- A. External carotid artery
- B. Internal carotid artery
- C. Brachiocephalic trunk
- D. Thyrocervical trunk
Correct Answer: D
Rationale: Step-by-step rationale:
1. The inferior thyroid artery typically arises from the thyrocervical trunk.
2. The thyrocervical trunk is a branch of the subclavian artery.
3. This artery supplies blood to the thyroid gland.
4. The external carotid artery and internal carotid artery do not give rise to the inferior thyroid artery.
5. The brachiocephalic trunk does not directly supply blood to the thyroid gland.
In conclusion, the correct answer is D because the thyrocervical trunk is the main artery that gives rise to the inferior thyroid artery, providing blood supply to the thyroid gland.
A 33-year-old woman becomes poisoned after receiving an injection of concentrated botulinum toxin. Which of the following is the main neurochemical mechanism by which this Clostridium toxin causes its effects?
- A. Directly activates all muscarinic and nicotinic receptors
- B. Inhibits ACh release from all cholinergic nerves
- C. Prevents neuronal norepinephrine reuptake
- D. Releases norepinephrine via a nonexocytotic process
Correct Answer: B
Rationale: The correct answer is B: Inhibits ACh release from all cholinergic nerves. Botulinum toxin blocks the release of acetylcholine (ACh) from cholinergic nerve terminals, leading to muscle paralysis. This occurs through the cleavage of SNARE proteins, preventing vesicle fusion and neurotransmitter release. Choice A is incorrect because botulinum toxin does not directly activate receptors. Choice C is incorrect as botulinum toxin does not affect neuronal norepinephrine reuptake. Choice D is incorrect because botulinum toxin does not release norepinephrine via a nonexocytotic process.
Atropine has the following pharmacological effects EXCEPT:
- A. It increases the heart rate
- B. Stimulates the respiratory center
- C. Has a mydriatic effect
- D. Produces bronchoconstriction
Correct Answer: D
Rationale: The correct answer is D: Atropine does not produce bronchoconstriction. Atropine is an anticholinergic drug that blocks the action of acetylcholine, leading to increased heart rate (A), stimulation of the respiratory center (B), and mydriatic effect (C). Bronchoconstriction is not a pharmacological effect of atropine because it actually helps dilate the bronchi, making it a useful treatment in cases of bronchospasm.
Saliva contains the enzyme salivary amylase. Which food type does salivary amylase begin to break down?
- A. Proteins
- B. Starches
- C. Roughage
- D. Fats
Correct Answer: B
Rationale: Salivary amylase breaks down starches into simple sugars like maltose. Starch is a complex carbohydrate found in foods like bread, pasta, and rice. When you chew food, salivary amylase in saliva starts the digestion process by breaking down starch molecules. Proteins are broken down by stomach enzymes, roughage (fiber) is not digested by enzymes in the mouth, and fats are primarily digested in the small intestine by pancreatic lipase. Therefore, choice B, starches, is the correct answer as salivary amylase specifically targets this food type for initial breakdown.
Which of the following hormones is found within the hypophyseal-hypothalamic portal capillaries?
- A. Gonadotropins
- B. Releasing hormones
- C. Catecholamines
- D. Mineralocorticoids
Correct Answer: B
Rationale: The correct answer is B: Releasing hormones. Releasing hormones are produced in the hypothalamus and travel through the hypophyseal-hypothalamic portal capillaries to reach the anterior pituitary gland. This is where they stimulate the release of specific hormones. Gonadotropins (A) are produced by the anterior pituitary gland, not found within the portal capillaries. Catecholamines (C) are produced by the adrenal glands, not within the portal capillaries. Mineralocorticoids (D) are steroid hormones produced by the adrenal cortex, not found within the portal capillaries.