Nokea
Which structure of the respiratory system is involved in gas exchange?
- A. Trachea
- B. Bronchioles
- C. Alveoli
- D. Larynx
Correct Answer: C
Rationale: The alveoli are the primary site for gas exchange in the respiratory system. These tiny air sacs in the lungs are where oxygen is taken up into the bloodstream and carbon dioxide is released from the bloodstream into the lungs to be exhaled. The trachea (Choice A) is the windpipe that carries air to and from the lungs but is not directly involved in gas exchange. Bronchioles (Choice B) are smaller airway branches that lead to the alveoli but do not participate in gas exchange themselves. The larynx (Choice D) plays a role in producing sound and protecting the airway but is not primarily responsible for gas exchange.
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Which hormone is not produced by the pituitary gland?
- A. FSH
- B. TRH
- C. LH
- D. ADH
Correct Answer: B
Rationale: Thyrotropin-releasing hormone (TRH) is not produced by the pituitary gland. TRH is actually produced by the hypothalamus and acts on the pituitary gland to stimulate the release of thyroid-stimulating hormone (TSH). On the other hand, FSH (follicle-stimulating hormone), LH (luteinizing hormone), and ADH (antidiuretic hormone) are all hormones directly produced by the pituitary gland.
In the human body, the ribs are ___________ to the lungs.
- A. medial
- B. superior
- C. anterior
- D. deep
Correct Answer: C
Rationale: The correct answer is 'C: anterior.' The term 'anterior' refers to a position in front of or toward the front of the body. In this case, the ribs are positioned in front of the lungs when considering the anatomical position. The term 'medial' means toward the midline of the body, 'superior' means above or higher in position, and 'deep' refers to a position farther from the surface or external part. Therefore, the most appropriate choice is 'anterior' when describing the relationship between the ribs and the lungs.
What is the normal pH of human arterial blood?
- A. 6.8
- B. 7.4
- C. 7.9
- D. 8.2
Correct Answer: B
Rationale: The normal pH of human arterial blood is approximately 7.4. This slightly alkaline pH is crucial for the proper functioning of enzymes and biochemical processes in the body. Any significant deviation from this pH level can result in serious health issues such as acidosis or alkalosis. Choice A (6.8) is incorrect as it is lower than the normal pH of arterial blood, indicating acidity. Choice C (7.9) and Choice D (8.2) are incorrect as they are higher than the normal pH of arterial blood, indicating alkalinity.
Enlargement of the thyroid, commonly known as a goiter, might be expected to affect ___________.
- A. swallowing
- B. insulin levels
- C. sleep
- D. digestion
Correct Answer: A
Rationale: Enlargement of the thyroid, known as a goiter, can compress the nearby structures in the neck, including the esophagus. This compression can lead to symptoms such as difficulty swallowing (dysphagia) or a sensation of pressure in the throat. Therefore, an enlarged thyroid gland is expected to affect swallowing. Choices B, C, and D are incorrect because a goiter primarily affects structures in the neck due to its physical enlargement, rather than directly impacting insulin levels, sleep, or digestion.
What is the primary hormone secreted by the thyroid gland?
- A. Oxytocin
- B. TSH
- C. Adrenaline
- D. T4
Correct Answer: D
Rationale: The correct answer is D: T4. The primary hormone secreted by the thyroid gland is thyroxine, also known as T4. T4 plays a crucial role in regulating metabolism, growth, and energy levels in the body. It is converted into the more active form, triiodothyronine (T3), which exerts most of the biological effects of thyroid hormones. Choices A, B, and C are incorrect. Oxytocin is not produced by the thyroid gland but by the pituitary gland, TSH (thyroid-stimulating hormone) is secreted by the pituitary gland to stimulate the thyroid gland, and adrenaline is produced by the adrenal glands, not the thyroid gland.