Which type of muscle is under voluntary control?
- A. Smooth muscle
- B. Cardiac muscle
- C. Skeletal muscle
- D. Striated muscle
Correct Answer: C
Rationale: The correct answer is C: Skeletal muscle. Skeletal muscle is under voluntary control, allowing individuals to consciously regulate its contractions for movement. Examples of skeletal muscle control include actions like walking, running, and lifting weights. Smooth muscle (choice A) and cardiac muscle (choice B) are both involuntary muscles, meaning they are not under conscious control. While skeletal muscle is striated (choice D), striated muscle is a broader category that includes both voluntary (skeletal) and involuntary (cardiac) muscles.
You may also like to solve these questions
Which nutrients are important for bone health?
- A. Vitamin D
- B. Calcium and phosphorus
- C. Iron and zinc
- D. Magnesium and sodium
Correct Answer: B
Rationale: Calcium and phosphorus are crucial nutrients for bone health as they are essential minerals required for bone strength, density, and various body functions. Adequate intake of calcium and phosphorus through the diet is important for maintaining healthy bones and preventing conditions like osteoporosis. Vitamin D helps with calcium absorption, but it is not the main nutrient responsible for bone health. Iron and zinc are important for other bodily functions, not specifically bone health. Magnesium and sodium, while important for overall health, are not as directly linked to bone health as calcium and phosphorus.
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.
Which of the following is an organ of the respiratory system?
- A. Pancreas
- B. Brain
- C. Urethra
- D. Larynx
Correct Answer: D
Rationale: The larynx is a vital organ of the respiratory system, responsible for producing sound and connecting the pharynx to the trachea. It plays a crucial role in breathing, swallowing, and vocalization. The brain, pancreas, and urethra are not part of the respiratory system; the brain is part of the nervous system, the pancreas is part of the digestive system, and the urethra is part of the urinary system. Therefore, the correct answer is the larynx.
Which hormone is released by the adrenal glands during stress?
- A. Insulin
- B. Adrenaline
- C. Melatonin
- D. Cortisol
Correct Answer: B
Rationale: Adrenaline, also known as epinephrine, is released by the adrenal glands during stress to prepare the body for rapid action. It helps in triggering the body's fight-or-flight response, increasing heart rate, and providing a burst of energy when faced with stressful situations. Insulin (Choice A) is produced by the pancreas to regulate blood sugar levels, not by the adrenal glands. Melatonin (Choice C) is a hormone that regulates sleep-wake cycles and is produced by the pineal gland, not the adrenal glands. Cortisol (Choice D) is another hormone produced by the adrenal glands, but it is not the primary hormone released during immediate stress responses; it is more involved in long-term stress regulation.
The motor cortex helps the brain by monitoring and controlling the body's movement. Where is the motor cortex located within the brain?
- A. Back of the head
- B. Top middle portion of the parietal lobe
- C. Front portion of the parietal lobe
- D. Around the auditory cortex
Correct Answer: C
Rationale: The correct answer is C: Front portion of the parietal lobe. The motor cortex is located in the frontal lobe, specifically in the front portion of the parietal lobe. It is responsible for planning, controlling, and executing voluntary movements. Choices A, B, and D are incorrect as the motor cortex is not located at the back of the head, top middle portion of the parietal lobe, or around the auditory cortex.