Nokea
Peripheral vasodilation results in heat loss through which of the following processes?
- A. conduction
- B. convection
- C. radiation
- D. evaporation
Correct Answer: C
Rationale: Peripheral vasodilation is the widening of blood vessels near the surface of the skin, allowing more blood to flow near the skin's surface. This process enhances heat loss primarily through radiation. Radiation is the transfer of heat energy in the form of electromagnetic waves. Conduction involves direct contact between objects, convection involves the transfer of heat through fluid or gas, and evaporation involves the phase change of a liquid to a gas, which cools the surface.
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What is the function of the gallbladder?
- A. Filters all of the blood in the body and breaks down poisonous substances, such as alcohol and drugs
- B. Make enzymes
- C. Store and concentrate bile, a fluid produced by the liver that helps with fat digestion
- D. Helps to further digest food
Correct Answer: C
Rationale: The correct answer is C: Store and concentrate bile, a fluid produced by the liver that helps with fat digestion. The gallbladder stores bile produced by the liver and releases it to aid in the digestion of fats. Choice A is incorrect as the liver, not the gallbladder, filters blood and detoxifies harmful substances. Choice B is incorrect because the production of enzymes primarily occurs in the pancreas, not the gallbladder. Choice D is incorrect as the gallbladder's main role is not to further digest food but to store and release bile.
Calcium concentration in the blood is controlled by which of the following glands?
- A. Hypothalamus gland
- B. Thyroid gland
- C. Pituitary gland
- D. Parathyroid glands
Correct Answer: D
Rationale: The correct answer is Parathyroid glands. The parathyroid glands are responsible for regulating calcium levels in the blood by secreting parathyroid hormone (PTH). PTH helps increase calcium levels in the blood when they are too low. The other glands listed, such as the Hypothalamus, Thyroid, and Pituitary glands, do not directly control calcium concentration in the blood.
In a normally functioning cardiovascular system, where does the heartbeat originate?
- A. Atrioventricular nodes
- B. Bundle of His
- C. Purkinje fibers
- D. Sinoatrial node
Correct Answer: D
Rationale: The correct answer is the Sinoatrial (SA) node. The SA node is known as the natural pacemaker of the heart as it initiates the electrical impulses responsible for the heartbeat. The other choices, such as the Atrioventricular (AV) nodes, Bundle of His, and Purkinje fibers, are involved in conducting the electrical signals generated by the SA node to coordinate the heart's contractions. Therefore, they do not serve as the primary origin of the heartbeat.
What is the maximum capacity of a normal adult bladder before involuntary micturition is likely to occur?
- A. 800-900ml
- B. 300-600ml
- C. 1000-2000ml
- D. 400-700ml
Correct Answer: B
Rationale: The correct answer is B: 300-600ml. A normal adult bladder can hold approximately 300-600ml of urine before the urge to urinate becomes strong and involuntary micturition is likely to occur. Choice A (800-900ml), Choice C (1000-2000ml), and Choice D (400-700ml) all exceed the typical capacity of a normal adult bladder and would generally not be accurate in the context of involuntary micturition.
Which of the following valves prevents backflow of blood from the right ventricle into the right atrium of the heart?
- A. Aortic
- B. Tricuspid valve
- C. Pulmonic
- D. Mitral valve
Correct Answer: B
Rationale: The correct answer is the tricuspid valve. The tricuspid valve is located between the right atrium and the right ventricle of the heart. Its main function is to prevent the backflow of blood from the right ventricle into the right atrium during the heart's pumping cycle. Choice A, the aortic valve, is responsible for preventing backflow from the aorta into the left ventricle. Choice C, the pulmonic valve, prevents backflow from the pulmonary artery into the right ventricle. Choice D, the mitral valve, prevents backflow from the left ventricle into the left atrium.