Nursing Elites

1. Where does the nerve impulses send neurotransmitters across a synapse to a muscle cell to stimulate muscle contraction?

• A. sarcomere
• B. tendon
• C. myelin sheath
• D. neuromuscular junction

Correct answer: D

Rationale: The neuromuscular junction is the specific area where nerve impulses trigger the release of neurotransmitters that cross the synaptic gap to bind to receptors on the muscle cell membrane. This binding initiates muscle contraction by stimulating the muscle cell. The sarcomere is the basic contractile unit in a muscle fiber, not the location where nerve impulses communicate with muscle cells. Tendons are connective tissues that attach muscles to bones and are not involved in transmitting nerve impulses. The myelin sheath is a protective covering around nerve fibers but is not directly involved in transmitting neurotransmitters to muscle cells for muscle contraction.

2. Which types of glial cells are found in the CNS?

• A. Schwann cells, satellite cells
• B. Astrocytes, microglia, ependymal cells, oligodendrocytes
• C. Satellite cells, microglia, oligodendrocytes
• D. Astrocytes, Schwann cells, satellite cells

Correct answer: B

Rationale: The correct answer is B. Glial cells in the CNS include astrocytes, microglia, ependymal cells, and oligodendrocytes. Schwann cells and satellite cells are found in the PNS. Astrocytes are the most abundant type of glial cells and are involved in nutrient support, repair, and maintenance of the extracellular environment. Microglia are the resident immune cells of the CNS, playing a role in immune defense. Ependymal cells line the ventricles of the brain and the central canal of the spinal cord, contributing to the production and circulation of cerebrospinal fluid. Oligodendrocytes are responsible for producing myelin, which insulates axons in the CNS. Understanding the specific functions of each type of glial cell is essential in grasping the complexity of the central nervous system's support and protective mechanisms.

3. A physician prescribes a drug to help control a person's anxiety attacks. This drug most likely targets the

• A. Amygdala.
• B. Parietal lobe.
• C. Hypothalamus.
• D. Sensory neuron.

Correct answer: A

Rationale: The correct answer is A: Amygdala. The amygdala is a key brain structure involved in the processing of emotions, including anxiety. Medications for anxiety disorders often target the amygdala to help regulate emotional responses and control anxiety attacks. The amygdala plays a crucial role in the brain's fear circuit and is essential for the appropriate response to stress and threat perception. Choices B, C, and D are incorrect because the parietal lobe is primarily involved in sensory processing and spatial reasoning, the hypothalamus regulates basic functions like hunger, thirst, and body temperature, and sensory neurons transmit signals from sensory receptors to the central nervous system, none of which are directly related to the regulation of anxiety attacks.

4. Which type of muscle is characterized by involuntary contractions, is striated, and is primarily found in the heart?

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

Correct answer: C

Rationale: The correct answer is C, Cardiac muscle. Cardiac muscle fits the description provided in the question as it exhibits involuntary contractions, striations, and is predominantly located in the heart. Skeletal muscle, while also striated, is voluntary and not involuntary like cardiac muscle. Smooth muscle lacks striations and is typically found in the walls of internal organs. Elastic muscle is not a recognized type of muscle tissue in human anatomy, making it an incorrect choice.

5. The muscular diaphragm plays a vital role in respiration. When it contracts, it:

• A. Increases lung volume for inhalation
• B. Decreases lung volume for exhalation
• C. Filters dust and particles from inhaled air
• D. Produces mucus to lubricate the airways

Correct answer: A

Rationale: The muscular diaphragm plays a crucial role in respiration by contracting and flattening during inhalation. This action increases the volume of the thoracic cavity, which leads to a decrease in pressure within the lungs, allowing air to rush in and fill the expanded space. Choice B is incorrect because the diaphragm contracting increases the lung volume for inhalation, not decreases it for exhalation. Choice C is incorrect as the role of filtering dust and particles is primarily performed by the respiratory system's other structures like the nasal passages and the mucous membranes. Choice D is incorrect as mucus production is mainly carried out by specialized cells in the respiratory system and not by the diaphragm.

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