Nursing Elites

1. Which of the following structures regulates the transport of substances in and out of a cell?

• A. Nucleus
• B. Cell membrane
• C. Cytoplasm
• D. Mitochondria

Correct answer: B

Rationale: The cell membrane, also known as the plasma membrane, is responsible for regulating the transport of substances in and out of the cell. It acts as a selective barrier, allowing the passage of certain molecules while restricting others. This selective permeability helps maintain homeostasis within the cell by controlling the movement of essential substances like nutrients and waste products. The nucleus (Choice A) is the organelle that houses the cell's genetic material and is not directly involved in regulating substance transport. Cytoplasm (Choice C) is the gel-like substance that fills the cell and does not play a direct role in regulating substance transport. Mitochondria (Choice D) are responsible for energy production in the cell through cellular respiration and are not primarily involved in substance transport.

2. Which structure in the ear is responsible for hearing?

• A. Cochlea
• B. Semicircular canals
• C. Ossicles
• D. Eustachian tube

Correct answer: A

Rationale: The cochlea, located in the inner ear, is responsible for detecting sound waves and converting them into neural signals that are sent to the brain for processing. It plays a crucial role in the process of hearing by translating mechanical vibrations into electrical signals that the brain can interpret as sound. The semicircular canals (Choice B) are responsible for balance and detecting head movements, not hearing. The ossicles (Choice C) are three tiny bones in the middle ear that transmit sound vibrations from the eardrum to the cochlea. The Eustachian tube (Choice D) helps equalize pressure between the middle ear and the atmosphere, but it is not directly involved in the process of hearing.

3. What is the primary function of platelets in the blood?

• A. To carry oxygen
• B. To fight infections
• C. To clot blood
• D. To transport nutrients

Correct answer: C

Rationale: The correct answer is C: To clot blood. Platelets, also known as thrombocytes, have a primary function in blood clotting. They help in the process of coagulation, forming clots to prevent excessive bleeding when injuries occur. Platelets play a crucial role in maintaining the integrity of the circulatory system by sealing off damaged blood vessels and promoting wound healing. Choices A, B, and D are incorrect because platelets do not carry oxygen, fight infections, or transport nutrients in the blood.

4. What is the most visible part of the ear called?

• A. Cochlea
• B. Pinna
• C. Ear canal
• D. Organ of Corti

Correct answer: B

Rationale: The pinna, also known as the auricle, is the most visible part of the ear. It is responsible for capturing sound waves and directing them into the ear canal, where the process of hearing begins. The other structures mentioned, such as the cochlea, ear canal, and organ of Corti, play crucial roles in the auditory system but are not the most visible parts of the ear. The cochlea is a spiral-shaped cavity responsible for converting sound vibrations into neural signals. The ear canal is a tube that connects the outer ear to the eardrum. The organ of Corti is the actual sensory organ of hearing located in the cochlea.

5. What is the primary function of the heart?

• A. To filter blood
• B. To transport oxygen and nutrients
• C. To remove waste
• D. To regulate temperature

Correct answer: B

Rationale: The primary function of the heart is to pump oxygenated blood and nutrients throughout the body, supplying cells with vital substances. Choice A is incorrect as the kidneys are responsible for filtering blood. Choice C is incorrect as waste removal is primarily handled by organs like the kidneys and liver. Choice D is incorrect as regulating body temperature is mainly controlled by mechanisms such as sweating and shivering, not the heart.

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