Nursing Elites

1. Which type of muscle is found in the walls of hollow organs, such as the stomach and intestines, and is responsible for involuntary contractions to propel substances through the organs?

• A. Cardiac muscle
• B. Smooth muscle
• C. Skeletal muscle
• D. Striated muscle

Correct answer: b

Rationale: The correct answer is B: Smooth muscle. Smooth muscle is found in the walls of hollow organs like the stomach and intestines. It is responsible for involuntary contractions to move substances through these organs. Unlike skeletal muscle (answer C) and cardiac muscle (answer A), smooth muscle is not under voluntary control. Striated muscle (answer D) is a term that refers to both skeletal and cardiac muscle due to their striped appearance under a microscope, but smooth muscle does not have this striped appearance.

2. Action potentials, the all-or-nothing electrical signals traveling along neurons, are generated by the movement of:

• A. Glucose
• B. Sodium and potassium ions
• C. Neurotransmitters
• D. Myelin

Correct answer: B

Rationale: The correct answer is B: Sodium and potassium ions. Action potentials are generated by the movement of sodium and potassium ions across the neuronal membrane. During depolarization, sodium ions rush into the cell, causing a change in electrical charge. This influx of positive ions triggers the opening of voltage-gated potassium channels, allowing potassium ions to exit the cell during repolarization. Glucose is a source of energy for cells but does not directly generate action potentials. Neurotransmitters are chemical messengers released at synapses, while myelin is a fatty substance that insulates axons, speeding up the conduction of action potentials but not directly generating them.

3. The involuntary reflex arc that withdraws your hand from a hot object involves the:

• A. Central nervous system only
• B. Peripheral nervous system only
• C. Both CNS and PNS
• D. Sensory neurons only

Correct answer: C

Rationale: The correct answer is C: 'Both CNS and PNS'. This is because the reflex arc involves both the central nervous system (CNS) and the peripheral nervous system (PNS). The sensory neurons in the PNS detect the stimulus (hot object), then send signals to the spinal cord in the CNS. The spinal cord processes the information and immediately sends a motor response signal back out through the PNS to move the hand away from the hot object. This rapid and involuntary response demonstrates the coordination between the CNS and PNS in executing the reflex arc.

4. What is the term for the process of breaking a large molecule into smaller fragments by applying heat?

• A. Polymerization
• B. Hydrogenation
• C. Isomerization
• D. Pyrolysis

Correct answer: D

Rationale: Pyrolysis is the process of breaking down large molecules into smaller fragments by applying heat. The other choices involve different chemical processes.

5. The framework of bones, cartilage, ligaments, and tendons that provides structure, support, and facilitates movement is the:

• A. Muscular system
• B. Skeletal system
• C. Nervous system
• D. Endocrine system

Correct answer: B

Rationale: The correct answer is B: Skeletal system. The skeletal system is composed of bones, cartilage, ligaments, and tendons that work together to provide structure, support, and facilitate movement in the body. The bones serve as the framework that supports and protects the body's organs, while cartilage cushions the joints. Ligaments connect bones to each other, and tendons connect muscles to bones, allowing for movement. The muscular system (choice A) consists of muscles that work with the skeletal system to produce movement. The nervous system (choice C) controls and coordinates bodily functions through the brain, spinal cord, and nerves. The endocrine system (choice D) regulates various bodily functions through the release of hormones. Therefore, the skeletal system is the correct answer as it specifically refers to the framework of bones, cartilage, ligaments, and tendons that support and enable movement in the body.

6. Which element is used in fertilizers due to its role in plant cell division and growth?

• A. Potassium
• B. Phosphorus
• C. Calcium
• D. Magnesium

Correct answer: B

Rationale: Phosphorus is crucial for cell division and metabolism, making it essential for plant growth and development.

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