Nursing Elites

1. What is the pH of a solution with a hydrogen ion concentration of \(1 \times 10^{-9}\) M?

• A. 5
• B. 7
• C. 9
• D. 11

Correct answer: c

Rationale: The pH is calculated as the negative logarithm (base 10) of the hydrogen ion concentration. In this case, \(-\log(1 \times 10^{-9}) = 9\).

2. The basic unit of communication in the nervous system is called a:

• A. Neuron
• B. Astrocyte
• C. Neurotransmitter
• D. Synapse

Correct answer: A

Rationale: The basic unit of communication in the nervous system is a neuron. Neurons are specialized cells that transmit information through electrical and chemical signals. They form complex networks to relay messages throughout the body. Astrocytes are support cells that help maintain the environment around neurons. Neurotransmitters are chemicals that transmit signals between neurons at synapses. A synapse is a junction between two neurons where communication occurs. However, the primary unit responsible for communication in the nervous system is the neuron, making it the correct answer.

3. Which sentence uses the comparative degree of an adjective correctly?

• A. This movie is good, but the other one is better.
• B. She is the tallest player on the team.
• C. He worked hardest than everyone else.
• D. My coffee is hotter than yours.

Correct answer: A

Rationale: Option A uses "better" to compare the quality of two movies.

4. What is the function of arrector pili muscles?

• A. To control sweat production
• B. To contract and cause goosebumps
• C. To produce sebum
• D. To sense touch

Correct answer: B

Rationale: The correct answer is B: 'To contract and cause goosebumps.' Arrector pili muscles are small muscles attached to hair follicles in the skin. When these muscles contract, they cause the hair to stand upright, resulting in the appearance of goosebumps. This physiological response is a remnant of our evolutionary past when our ancestors had more hair, and the raised hair helped to trap air for insulation or to make them look larger when threatened. Therefore, the function of arrector pili muscles is not to control sweat production (A), produce sebum (C), or sense touch (D), but rather to create the physical response of goosebumps.

5. Which part of the neuron insulates and speeds up the transmission of nerve impulses along the axon?

• A. Dendrite
• B. Myelin sheath
• C. Synapse
• D. Cell body

Correct answer: b

Rationale: The correct answer is B: Myelin sheath. The myelin sheath is a fatty substance that surrounds the axon of a neuron, acting as an insulator to speed up the transmission of nerve impulses. It does this by creating gaps called nodes of Ranvier where the nerve impulses jump from one node to the next, allowing for faster signal conduction. Dendrites are branch-like extensions that receive signals from other neurons, the synapse is the junction between two neurons where neurotransmitters are released, and the cell body contains the nucleus and organelles of the neuron, but it is the myelin sheath that specifically insulates and speeds up the transmission of nerve impulses along the axon.

6. What is the name of the sheath of connective tissue that surrounds a skeletal muscle?

• A. Epimysium
• B. Perimysium
• C. Endomysium
• D. Myofibril

Correct answer: A

Rationale: The correct answer is A: Epimysium. The epimysium is the outermost layer of connective tissue that surrounds a skeletal muscle. It provides protection and support to the muscle fibers within, as well as helps in transmitting forces generated by the muscle. Perimysium (B) is the connective tissue that surrounds bundles of muscle fibers called fascicles, while endomysium (C) is the connective tissue that surrounds individual muscle fibers. Myofibril (D) is a structure within muscle fibers that contains the contractile units responsible for muscle contraction. Therefore, in this context, the sheath of connective tissue surrounding a skeletal muscle is specifically referred to as the epimysium.

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