What is an essential nursing action before administering a blood transfusion?

Correct Answer: B

Rationale: Verifying the blood type and patient identity with another nurse is crucial before administering a blood transfusion. This step helps prevent transfusion reactions and ensures that the correct blood is given to the right patient. Checking the patient's blood pressure, although important, is not directly related to verifying blood type and patient identity. Flushing the IV line with saline is a good practice but is not as critical as confirming the blood type and patient identity. Administering pre-transfusion medications would come after verifying the blood type and patient identity.

Correct Answer: A

Rationale: The primary function of surfactant in the lungs is to reduce surface tension in the alveoli. This reduction in surface tension prevents lung collapse and allows for easier breathing. It is particularly crucial in premature infants to help with lung expansion. Choice B is incorrect because surfactant primarily affects surface tension, not oxygen absorption. Choice C is incorrect because surfactant's main role is not in facilitating carbon dioxide release. Choice D is incorrect because surfactant does not directly increase lung volume; its main role is in reducing surface tension.

Correct Answer: A

Rationale: The correct answer is A: Pacemaker of the heart. The SA node, known as the natural pacemaker, initiates the electrical impulses that set the rhythm for the heartbeat. It is responsible for coordinating the heart's contractions by generating electrical signals at regular intervals. Choice B is incorrect as the SA node's primary function is not related to blood pressure regulation. Choice C is incorrect as the SA node does not cause electrical conduction delay but rather initiates and conducts the electrical impulses. Choice D is incorrect as the SA node does not directly stimulate muscle contraction but rather initiates the electrical events that lead to muscle contraction.

Correct Answer: A

Rationale: The correct answer is A: Myasthenia gravis. Myasthenia gravis is characterized by muscle weakness caused by autoimmune attack on acetylcholine receptors at the neuromuscular junction. This results in impaired communication between nerves and muscles. Choice B, Multiple sclerosis, is a condition where the immune system attacks the protective myelin sheath covering the nerves in the central nervous system, leading to communication issues between the brain and the rest of the body. Choice C, Amyotrophic lateral sclerosis, is a progressive neurodegenerative disease affecting motor neurons in the brain and spinal cord, not involving acetylcholine receptors. Choice D, Guillain-Barr© syndrome, is an acute condition where the immune system attacks the peripheral nerves, causing muscle weakness and paralysis, but it does not target acetylcholine receptors.

Correct Answer: A

Rationale: The epiglottis is a flap of tissue that closes over the trachea during swallowing to prevent food and liquids from entering the airway. Choice A is correct because the primary function of the epiglottis is to act as a lid over the trachea, ensuring that food goes down the esophagus and not into the windpipe. Choices B, C, and D are incorrect as they do not describe the specific role of the epiglottis during swallowing.