Nokea
Which of the heart's four chambers is the largest and the strongest?
- A. Right atrium
- B. Left ventricle
- C. Right ventricle
- D. Left atrium
Correct Answer: B
Rationale: The left ventricle is the largest and strongest chamber of the heart. It pumps oxygenated blood to the body, making it vital for systemic circulation. The right atrium receives deoxygenated blood from the body, the right ventricle pumps this blood to the lungs, and the left atrium receives oxygenated blood from the lungs.
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When an individual is under stress, hormones are released. Which of the following is not one of the locations in which hormones are released when under stress?
- A. Posterior pituitary
- B. Hypothalamus
- C. Adrenal cortex
- D. Parathyroid
Correct Answer: D
Rationale: During stress, hormones are released from the adrenal cortex, posterior pituitary, and hypothalamus to help the body respond. The parathyroid gland, however, is not typically involved in the stress response by releasing hormones. The posterior pituitary releases hormones like oxytocin and vasopressin, the hypothalamus secretes corticotropin-releasing hormone (CRH) and vasopressin, while the adrenal cortex releases cortisol and aldosterone in response to stress. Therefore, the correct answer is 'Parathyroid.'
Which hormone is involved in regulating the sleep-wake cycle?
- A. Insulin
- B. Melatonin
- C. Cortisol
- D. Thyroxine
Correct Answer: B
Rationale: The correct answer is B: Melatonin. Melatonin, produced by the pineal gland, is the hormone involved in regulating the sleep-wake cycle. It plays a crucial role in signaling the body that it is time to sleep and is influenced by light exposure. Melatonin levels typically rise in the evening, promoting sleep, and decrease in the morning, helping in waking up. Choice A, Insulin, is involved in regulating blood sugar levels, not the sleep-wake cycle. Choice C, Cortisol, is a stress hormone that helps regulate metabolism and immune response but is not primarily involved in the sleep-wake cycle. Choice D, Thyroxine, is a hormone produced by the thyroid gland that regulates metabolism, growth, and development, but it is not directly involved in regulating the sleep-wake cycle.
A person who has damage to their ulnar nerve will have decreased sensation in which part of the body?
- A. Hand
- B. Arm
- C. Leg
- D. Foot
Correct Answer: A
Rationale: Corrected Rationale: Damage to the ulnar nerve typically results in decreased sensation in the hand, particularly affecting the little finger and half of the ring finger. The ulnar nerve innervates the hand and is responsible for providing sensation to these areas. This nerve does not extend to the leg or foot, so choices C and D are incorrect. While the ulnar nerve travels through the arm, its primary sensory impact is felt in the hand, making choice B less specific and therefore not the best answer.
What role does the liver play in metabolism?
- A. To produce bile
- B. To detoxify harmful substances
- C. To store glucose
- D. To produce insulin
Correct Answer: B
Rationale: The correct answer is B: 'To detoxify harmful substances.' The liver is primarily responsible for detoxifying harmful substances present in the blood as part of its role in metabolism. While the liver does produce bile to aid in digestion and stores glucose for energy regulation, its main function in metabolism is detoxification. The liver does not produce insulin; insulin is produced by the pancreas to regulate blood sugar levels.
Which vitamin is essential for maintaining healthy skin and vision?
- A. Vitamin C
- B. Vitamin A
- C. Vitamin D
- D. Vitamin K
Correct Answer: B
Rationale: Vitamin A is the correct answer. It is essential for maintaining healthy skin and vision, especially in low-light conditions. Vitamin A helps in the production of retinal pigments necessary for vision in dim light and supports skin health by promoting cell turnover and repair.
Choice A, Vitamin C, is important for the immune system and collagen production but is not specifically known for maintaining skin and vision health.
Choice C, Vitamin D, is crucial for bone health and immune function but is not directly related to skin and vision health.
Choice D, Vitamin K, is necessary for blood clotting and bone health but does not play a significant role in maintaining healthy skin and vision.