Nursing Elites

1. Which structure of the nervous system carries an action potential in the direction of a synapse?

• A. Cell body
• B. Axon
• C. Neuron
• D. Myelin

Correct answer: B

Rationale: The correct answer is the axon. The axon is the elongated, threadlike part of a neuron that carries nerve impulses away from the cell body towards other neurons or target cells, such as muscles or glands, in the direction of a synapse. Action potentials travel along the axon as electrical signals to communicate with neighboring cells. The cell body (choice A) contains the nucleus and organelles but does not transmit action potentials. Neuron (choice C) is a broad term that includes the entire nerve cell, not a specific structure. Myelin (choice D) is a fatty substance that surrounds and insulates axons, aiding in the conduction of nerve impulses, but it does not directly carry the action potential towards a synapse.

2. What does half-life refer to?

• A. Radioactive intensity to completely disappear
• B. The number of neutrons in a nucleus to double
• C. The number of protons in a nucleus to change
• D. An isotope to decay by half of its initial quantity

Correct answer: D

Rationale: Half-life refers to the time it takes for half of the radioactive atoms in a sample to decay. This means that after one half-life, half of the initial quantity of the radioactive substance will have decayed. Choice A is incorrect because radioactive intensity doesn't completely disappear during half-life. Choice B is incorrect as half-life doesn't refer to the number of neutrons doubling. Choice C is incorrect as half-life doesn't relate to the number of protons changing.

3. Which of the following represents different types of electromagnetic waves based on their wavelengths and frequencies?

• A. Visible light, X-rays, radio waves, gamma rays
• B. Sound waves, water waves, seismic waves, shock waves
• C. Longitudinal waves, transverse waves, mechanical waves, non-mechanical waves
• D. None of the above

Correct answer: A

Rationale: Electromagnetic waves are categorized based on their wavelengths and frequencies. Visible light, X-rays, radio waves, and gamma rays are all examples of electromagnetic waves with distinct wavelengths and frequencies. The correct answer choice, A, accurately represents different types of electromagnetic waves. Sound waves, water waves, seismic waves, and shock waves are mechanical waves that propagate through a medium via particle interactions, not electromagnetic waves. Longitudinal waves, transverse waves, mechanical waves, and non-mechanical waves are classifications based on the nature of the wave propagation and do not relate to the types of electromagnetic waves which are differentiated by their electromagnetic properties.

4. Deuterium, a stable isotope of hydrogen, has a nucleus containing:

• A. A single proton
• B. A proton and a neutron
• C. Two protons and an electron
• D. Two neutrons

Correct answer: B

Rationale: Deuterium, as an isotope of hydrogen, has an atomic number of 1 and a mass number of 2. The nucleus of deuterium contains one proton (as in all hydrogen atoms) and one neutron, totaling 2 nucleons in the nucleus. Therefore, the correct answer is that deuterium's nucleus contains a proton and a neutron. Choices A, C, and D are incorrect. Deuterium is not just a single proton (A), doesn't have two protons and an electron (C), and doesn't contain two neutrons (D). The correct composition of deuterium's nucleus is one proton and one neutron.

5. What is the fatty sheath that insulates some nerve fibers and speeds up signal transmission called?

• A. Myelin sheath
• B. Dura mater
• C. Pia mater
• D. Arachnoid mater

Correct answer: A

Rationale: The correct answer is A: Myelin sheath. The myelin sheath is a fatty layer that surrounds and insulates some nerve fibers, facilitating the rapid transmission of signals along the nerve fibers. Choices B, C, and D (Dura mater, Pia mater, and Arachnoid mater) are layers of the meninges, protective membranes that surround the brain and spinal cord. The primary function of the meninges is to protect and support the central nervous system, not to insulate nerve fibers for signal transmission.

Similar Questions