Which of the following structures is responsible for the initial mechanical breakdown of food during mastication?

Correct Answer: D

Rationale: The correct answer is D: Teeth. Teeth are responsible for the initial mechanical breakdown of food during mastication. Step 1: Teeth use their hard surfaces to chew and grind food into smaller pieces. Step 2: This process increases the surface area of the food, making it easier for digestive enzymes to break down. Step 3: The tongue aids in moving the food around the mouth but does not break down the food mechanically. Pharynx is responsible for swallowing, not mastication. Salivary glands produce saliva that helps in the lubrication and digestion of food, but they do not directly participate in the mechanical breakdown of food.

Correct Answer: C

Rationale: The correct answer is C: Abrasion. Abrasion is the wearing away of tooth structure due to friction from external sources like toothbrushing or abrasive toothpaste. Dental caries (A) refers to tooth decay caused by bacteria. Attrition (B) is the wearing down of tooth structure due to tooth-to-tooth contact. Erosion (D) is the loss of tooth structure from acid attacks, not friction. Therefore, option C is the most fitting choice based on the description given.

Correct Answer: D

Rationale: The correct answer is D: Assess the severity of the reaction. This should be the first action taken because it helps determine the urgency of the situation and guides subsequent steps. Assessing the severity allows for appropriate intervention - from calling emergency services if the reaction is severe, to administering medication if necessary. A: Administering an epinephrine auto-injector should only be done if the severity of the reaction warrants it, as it is a potent medication that can have serious side effects if used inappropriately. B: Positioning the person comfortably is important, but assessing the severity of the reaction takes precedence to ensure prompt and appropriate care. C: Monitoring vital signs is important, but assessing the severity of the reaction is crucial in determining the immediate course of action.

Correct Answer: D

Rationale: The correct answer is D: Transporting the patient to a medical facility for antivenom administration. This is recommended because antivenom is the definitive treatment for snakebites. Tourniquets (choice A) can worsen tissue damage and should be avoided. Elevating the limb (choice B) may not prevent venom spread. Making an incision (choice C) can lead to infection and increased venom absorption. Antivenom administration at a medical facility is crucial for proper management of snakebites.

Correct Answer: B

Rationale: The primary goal of CPR is to restore spontaneous circulation and oxygenation to the body to maintain vital organ function. By performing chest compressions and rescue breaths, CPR aims to circulate oxygenated blood to the brain and other vital organs. This is crucial to prevent brain damage and increase the chances of survival. The other choices are incorrect because CPR does not address the underlying cause of cardiac arrest (A), provide pain relief (C), or prevent further complications such as organ failure (D). The immediate focus in a cardiac arrest situation is to maintain blood flow and oxygen delivery to vital organs until advanced medical care can be provided.