Nokea
What is the primary function of the heart in the circulatory system?
- A. To filter blood
- B. To pump blood throughout the body
- C. To absorb oxygen
- D. To remove carbon dioxide
Correct Answer: B
Rationale: The correct answer is B: 'To pump blood throughout the body.' The primary function of the heart in the circulatory system is to pump blood, which carries oxygen and nutrients, throughout the body. Choice A, 'To filter blood,' is incorrect as the heart does not filter blood; that is primarily done by the kidneys. Choice C, 'To absorb oxygen,' is incorrect as the lungs are responsible for oxygen absorption. Choice D, 'To remove carbon dioxide,' is incorrect as the lungs facilitate the removal of carbon dioxide from the body.
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Which organ is responsible for filtering and cleaning the blood?
- A. Lungs
- B. Heart
- C. Kidneys
- D. Liver
Correct Answer: C
Rationale: The correct answer is C: Kidneys. The kidneys are the organs responsible for filtering and cleaning the blood. They remove waste products, regulate electrolyte levels, and help maintain fluid balance in the body through the production of urine. The other choices are incorrect because: A) Lungs are primarily responsible for gas exchange, not blood filtration. B) The heart is responsible for pumping blood, not filtering it. D) The liver plays a role in detoxification and metabolism, but it is not primarily responsible for filtering and cleaning the blood.
Which of the following structures is located in the respiratory system?
- A. Larynx
- B. Trachea
- C. Pharynx
- D. Esophagus
Correct Answer: A
Rationale: The larynx, also known as the voice box, is a crucial structure in the respiratory system. It is located in the upper part of the trachea and houses the vocal cords. The larynx plays a key role in producing sound and protecting the trachea by closing during swallowing to prevent food from entering the airway. This makes the larynx the correct answer in this context. The trachea (Choice B) is a respiratory structure that connects the larynx to the lungs, allowing air to pass through. The pharynx (Choice C) is a shared pathway for both air and food, located at the back of the throat. The esophagus (Choice D) is part of the digestive system, responsible for transporting food from the mouth to the stomach. Therefore, Choices B, C, and D are not located in the respiratory system.
Which muscle is responsible for the extension of the elbow?
- A. Biceps brachii
- B. Triceps brachii
- C. Deltoid
- D. Pectoralis major
Correct Answer: B
Rationale: The correct answer is B: Triceps brachii. The triceps brachii muscle is responsible for extending the elbow joint. It is located on the back of the upper arm and acts in opposition to the biceps brachii, which is responsible for elbow flexion. The deltoid muscle is primarily responsible for shoulder abduction, not elbow extension. The pectoralis major muscle is involved in movements of the shoulder joint, not the elbow.
What is the function of the liver in digestion?
- A. To produce bile
- B. To store glucose
- C. To secrete digestive enzymes
- D. To detoxify harmful substances
Correct Answer: A
Rationale: The liver's main role in digestion is to produce bile, a substance that aids in the breakdown and absorption of fats in the small intestine. Bile emulsifies fats, helping enzymes break them down into smaller molecules for easier absorption in the digestive tract. Therefore, the correct answer is A: 'To produce bile.' Storing glucose, secreting digestive enzymes, and detoxifying harmful substances are functions of the liver, but they are not primarily related to digestion.
Which vitamin is essential for the synthesis of collagen?
- A. Vitamin C
- B. Vitamin D
- C. Vitamin B12
- D. Vitamin K
Correct Answer: A
Rationale: The correct answer is Vitamin C. Vitamin C is essential for the synthesis of collagen, a protein crucial for maintaining the structure and integrity of skin, blood vessels, and bones. It plays a key role in the hydroxylation of proline and lysine residues in collagen synthesis, which is necessary for the stability and strength of collagen fibers.
Choice B: Vitamin D is essential for bone health and calcium absorption but is not directly involved in collagen synthesis.
Choice C: Vitamin B12 is important for red blood cell formation and neurological function but is not directly related to collagen synthesis.
Choice D: Vitamin K is necessary for blood clotting and bone metabolism but does not play a direct role in collagen synthesis.