Nokea
Schwann cells are one of several types of ________ cells in the nervous system.
- A. sensory
- B. motor
- C. association
- D. neuroglial
Correct Answer: D
Rationale: Schwann cells are a type of neuroglial cell found in the peripheral nervous system (PNS). They are responsible for producing myelin, which insulates axons and enhances the speed of nerve impulse transmission. Other types of neuroglial cells include astrocytes, oligodendrocytes, and microglia, each of which supports and protects neurons in different ways. Schwann cells are essential for maintaining the health and function of peripheral neurons.
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What hormone is important in milk production and maintaining lactation?
- A. Estrogen
- B. Oxytocin
- C. Prolactin
- D. Adrenaline
Correct Answer: C
Rationale: Prolactin is the correct answer because it is the hormone produced by the pituitary gland that stimulates milk production in the mammary glands. During lactation, prolactin levels remain elevated to ensure a continuous supply of milk. While oxytocin is involved in milk ejection, prolactin is primarily responsible for milk synthesis and maintenance of lactation.
Priority Decision: A patient is admitted to the emergency department with a possible cervical spinal cord injury following an automobile crash. During admission of the patient, what is the highest priority for the nurse?
- A. Maintaining a patent airway
- B. Maintaining immobilization of the cervical spine
- C. Assessing the patient for head and other injuries
- D. Assessing the patient's motor and sensory function
Correct Answer: B
Rationale: Immobilization prevents further injury.
Which part of the brain has a blood-brain barrier?
- A. anterior pituitary
- B. posterior pituitary
- C. pineal body
- D. area postrema of the fourth ventricle
Correct Answer: D
Rationale: The area postrema of the fourth ventricle lacks a blood-brain barrier, allowing it to detect toxins in the blood and trigger vomiting. Other regions listed, such as the anterior pituitary and pineal body, have a blood-brain barrier.
Dilatation of the peripheral arterial blood vessels can be caused by:
- A. thromboxane A2
- B. adenosine diphosphate
- C. endothelin
- D. prostaglandins
Correct Answer: D
Rationale: Prostaglandins, particularly prostacyclin (PGI2), are potent vasodilators. Thromboxane A2, adenosine diphosphate, and endothelin are vasoconstrictors and do not cause peripheral arterial dilatation.
A patient recently started on phenytoin (Dilantin) to control simple complex seizures is seen in the outpatient clinic. Which information obtained during his chart review and assessment will be of greatest concern?
- A. The gums appear enlarged and inflamed.
- B. The white blood cell count is 2300/mm³.
- C. Patient occasionally forgets to take the phenytoin until after lunch.
- D. Patient wants to renew his driver's license in the next month.
Correct Answer: B
Rationale: A low white blood cell count could indicate bone marrow suppression, a serious side effect of phenytoin.