PATHO CH 13 Structure and Function of the Neurologic System
A nurse is monitoring intracranial pressure. A nurse recalls the normal upper limit of intracranial pressure is _______ mm Hg.
ANS: 14
When a patient wants to know how many vertebrae make up the vertebral column, the nurse responds with _____.
ANS: 33
Blockage of which of the following would cause hydrocephalus? a. Cerebral aqueduct b. Inferior colliculi c. Red nucleus d. Tegmentum
ANS: A Blockage of the cerebral aqueduct leads to hydrocephalus. Hydrocephalus is not a result of dysfunction of the inferior colliculi, red nucleus, or tegmentum.
Cerebrospinal fluid (CSF) can accumulate around the brain when there is injury to the sites of CSF reabsorption, which are called the: a. arachnoid villi. b. epidural foramina. c. lateral apertures. d. choroid plexuses.
ANS: A CSF is reabsorbed through a pressure gradient between the arachnoid villi and the cerebral venous sinuses. CSF absorption does not occur in the epidural foramina, the lateral apertures, or the choroid plexuses.
When a student asks in which region of the neuron do nerve impulses travel the fastest, how should the nurse respond? The: a. large axon. b. axon hillock. c. cell body. d. dendrites.
ANS: A Large axons transmit impulses at a faster rate than cell bodies. The axon hillock has a low threshold level. The dendrites carry impulses toward the cell body, but not as quickly as large axons.
Neurotransmitters interact with the postsynaptic membrane by binding to which structure? a. Receptor b. Nissl body c. Glial cell d. Neurofibril
ANS: A Neurotransmitters bind to a receptor. The Nissl body is involved in protein synthesis. Neurotransmitters do not bind to glial cells. Neurofibrils provide support for the neuron.
When a patient's vagus nerve is stimulated, what does the nurse expect to observe? a. Increased gastrointestinal activity b. Increased heart rate c. Pupil constriction d. Vasoconstriction
ANS: A Stimulation of the vagus nerve increases gastrointestinal activity. Stimulation of the vagus decreases heart rate, causes pupil dilation, and leads to vasodilation.
A nurse is preparing to teach about nerves. Which information should the nurse include? The axon leaves the cell body at the: a. axon hillock. b. Nissl body. c. node of Ranvier. d. myelin sheath.
ANS: A The axon hillock is the cone-shaped process where the axon leaves the cell body. The Nissl body is involved in protein synthesis. Axons branch at the node of Ranvier. The myelin sheath covers the entire membrane.
What term should the nurse use when talking about the outermost membrane surrounding the brain? a. Dura mater b. Arachnoid mater c. Pia mater d. Falx cerebri
ANS: A The dura mater is the outer layer of the brain. The arachnoid is a spongy, web-like structure that loosely follows the contours of the cerebral structures. The pia mater adheres to the contours of the brain. The falx cerebri dips between the two cerebral hemispheres along the longitudinal fissure.
A student nurse asks the nurse what controls reflex activities concerned with heart rate and blood pressure. What is the nurse's best response? These reflex activities are controlled by the: a. medulla oblongata. b. pons. c. midbrain. d. cerebrum.
ANS: A The medulla oblongata, not the pons, controls reflex activities, such as heart rate, respiration, blood pressure, coughing, sneezing, swallowing, and vomiting. The midbrain is primarily a relay center for motor and sensory tracts, as well as a center for auditory and visual reflexes. The cerebrum plays a role in the transfer of information.
A nurse is discussing the membrane that separates the cerebellum from the cerebrum. What term should the nurse use to describe this membrane? a. Tentorium cerebelli b. Falx cerebri c. Arachnoid membrane d. Temporal lobe
ANS: A The tentorium cerebelli, a common landmark, is a membrane that separates the cerebellum below from the cerebral structures above. The cerebellum is not separated by the falx cerebri, the arachnoid membrane, or the temporal lobe.
A patient begins taking a new drug that causes pupil dilation, vasoconstriction, decreased gastrointestinal motility, and goose bumps. Which of the following receptors are activated? a. α1 b. Α2 c. β1 d. Β2
ANS: A α1 stimulation leads to pupil dilation. α2 stimulation leads to inhibition of intestinal secretions. β1 stimulation leads to miosis or pupillary constriction. β2 stimulation leads to pupillary constriction.
Which of the following is a neuroglial cell? (select all that apply) a. Astrocyte b. Oligodendrocyte c. Neuron d. Ependymal cell e. Melanocyte
ANS: A, B, D Neuroglial cells include astrocytes, oligodendrocytes, and ependymal cells. Neurons and melanocytes are not neuroglial cells.
A patient suffers from head trauma that affects cranial nerve I. Which of the following symptoms would the nurse expect? a. Visual disturbances b. Loss of sense of smell c. Loss of ability to taste d. Hearing disturbances
ANS: B Cranial nerve I controls the sense of smell. Visual disturbances are associated with cranial nerve II. Cranial nerve VII is related to tasting. Cranial nerve VIII is related to hearing.
If a neuron's membrane potential is held close to the threshold potential by excitatory postsynaptic potentials (EPSPs), the neuron is said to be: a. hyperpolarized. b. facilitated. c. integrated. d. inhibited.
ANS: B Facilitation refers to the effect of EPSP on the plasma membrane potential. The postsynaptic neuron's plasma membrane may be inhibited, which is called hyperpolarized. When the neuron's membrane potential is held close to the threshold potential, the neuron is facilitated, not integrated or inhibited.
A neurologist is teaching about the region responsible for motor aspects of speech. Which area is the neurologist discussing? a. Wernicke area b. Broca area c. Brodmann area 4 d. Brodmann area 6
ANS: B The Broca area is responsible for the motor aspects of speech. Motor aspects of speech are not the function of the Wernicke area or Brodmann areas 4 and 6.
When a nurse is teaching about the transverse fiber tract that connects the two cerebral hemispheres, what term should the nurse use? a. Peduncle b. Corpus callosum c. Basal ganglia d. Pons
ANS: B The corpus callosum connects the two cerebral hemispheres and is essential in coordinating activities between hemispheres. The peduncle is made up of efferent fibers of the corticospinal, corticobulbar, and corticopontocerebellar tracts. The basal ganglia is a portion of the pyramidal system. The pons (bridge) is easily recognized by its bulging appearance below the midbrain and above the medulla.
A 19-year-old college student reports to his primary care provider that he cannot stay awake in class regardless of how much sleep he gets. Under-stimulation of which area of the brain is likely the site of the problem? a. Corpora quadrigemina b. Reticular activating system c. Cerebellum d. Hypothalamus
ANS: B The reticular activating system is responsible for wakefulness, not the corpora quadrigemina, the cerebellum, or the hypothalamus.
A nurse recalls that characteristics of upper motor neurons include: a. directly innervating muscles. b. influencing and modifying spinal reflex arcs. c. cell bodies located in the gray matter of the spinal cord. d. dendritic processes extending out of the CNS.
ANS: B Upper motor neurons are completely contained within the CNS. Their primary roles are controlling fine motor movement and influencing/modifying spinal reflex arcs and circuits. They do not innervate muscles. Lower motor neurons interact with gray matter. Dendrites are part of neurons.
When a presynaptic neuron is stimulated in a patient's body by an electrical current, neurotransmitters are released from the: a. synapse. b. synaptic bouton. c. synaptic cleft. d. receptor.
ANS: B When an impulse originates in a presynaptic neuron, the impulse reaches the vesicles, where chemicals (neurotransmitters) are stored in the synaptic bouton. Neurons are not physically continuous with one another. The region between adjacent neurons is called a synapse. The synaptic cleft is the space between the neurons. Neurotransmitters attach to the receptor.
The nurse is assessing the patient with a pen light. The integrity of which cranial nerve is being evaluated? a. Olfactory b. Vagus c. Oculomotor d. Trigeminal
ANS: C In evaluating the oculomotor nerve, the pupils are examined for size, shape, and equality; pupillary reflex tested with a pen light (pupils should constrict when illuminated); and ability to follow moving objects. The olfactory nerve is assessed using smells. The vagus nerve is assessed using the ophthalmoscope. The trigeminal nerve is assessed with a safety pin and hot and cold objects for sensations of pain, touch, and temperature.
A cell was isolated from the CNS. A researcher revealed that its main function was to clear cellular debris. What type of cell is the researcher studying? a. Astrocyte b. Ependymal cell c. Microglia d. Schwann cell
ANS: C Microglia remove debris (phagocytosis) in the CNS. Astrocytes and ependymal cells are neuroglial cells and do not have phagocytic properties. Schwann cells help form the myelin sheath in the peripheral nervous system (PNS).
Which neurotransmitter is released when a patient's parasympathetic motor neurons are stimulated? a. Epinephrine b. Serotonin c. Acetylcholine d. Substance P
ANS: C Parasympathetic motor neurons release acetylcholine. Adrenergic motor neurons release epinephrine. Serotonin is associated with the brain. Substance P is a neurotransmitter in pain transmission pathways. Blocking the release of substance P by morphine reduces pain.
An experiment looking at an isolated neuron revealed a sensory nerve with one process containing a dendritic portion extending away from the CNS and an axon extending toward the CNS. Which of the following classifications would this neuron fall into? a. Bipolar b. Multipolar c. Pseudounipolar d. Interpolar
ANS: C Pseudounipolar neurons have one process; the dendritic portion of each of these neurons extends away from the CNS, and the axon portion projects into the CNS. Bipolar neurons have two distinct processes arising from the cell body. Multipolar neurons are the most common and have multiple processes capable of extensive branching. A motor neuron is typically multipolar. Interpolar is not a type of neuron.
Which neurons have the capacity for regeneration? a. Unmyelinated neurons in the brain b. Myelinated neurons in the spinal cord c. Myelinated peripheral neurons d. Postganglionic motor neurons
ANS: C Regeneration is limited to myelinated fibers and generally occurs only in the PNS. Regeneration does not occur in unmyelinated neurons, myelinated neurons in the spinal cord, or postganglionic motor neurons.
Which action will occur when a patient's α1-receptors are stimulated? a. Dilation of the coronary arteries b. Vasoconstriction of arteries c. Increase in the strength of myocardial contraction d. Decrease in the rate of myocardial contraction
ANS: C Stimulation of α1-receptors results in increased strength and rate of myocardial contraction. α1-receptor stimulation does not affect the coronary arteries. α1-receptor simulation leads to dilation.
A nurse remembers the brain receives approximately ____% of the cardiac output. a. 80 b. 40 c. 20 d. 10
ANS: C The brain receives approximately 20% of the cardiac output.
Which structure ensures collateral blood flow from blood vessels supplying the brain? a. Carotid arteries b. Basal artery c. Circle of Willis d. Vertebral arteries
ANS: C The circle of Willis ensures collateral blood circulation. Collateral circulation is not associated with the basal artery or the vertebral arteries. The carotid arteries supply the brain.
A nurse is teaching about the area of the spinal cord that contains cell bodies involved in the autonomic nervous system. Which of the following areas is the nurse discussing? a. Anterior horn b. Ventral horn c. Lateral horn d. Dorsal horn
ANS: C The lateral horn contains cell bodies within the autonomic nervous system. Both the anterior and ventral horns contain the nerve cell bodies for efferent pathways that leave the spinal cord by way of spinal nerves. The dorsal horn contains sensory neurons.
After rehabilitation for severe brain damage following a motor vehicle accident, a patient reports that her thought processes and ability to concentrate are impaired. Which area does the nurse suspect is damaged? a. Thalamus b. Limbic c. Prefrontal d. Occipital
ANS: C The prefrontal area is responsible for goal-oriented behavior (e.g., ability to concentrate), short-term or recall memory, the elaboration of thought, and inhibition of the limbic areas of the CNS. Goal-oriented behavior is not the function of the thalamus, limbic system, or occipital area.
When a patient asks what the somatic nervous system controls, how should the nurse respond? It controls: a. the heart. b. the spinal cord. c. skeletal muscle. d. smooth muscle organs.
ANS: C The somatic nervous system consists of pathways that regulate voluntary motor control, the skeletal muscle system. The somatic nervous system does not control the heart; the autonomic nervous system controls the heart, the spinal cord, and the smooth muscle organs.
A neurologist is teaching about sensory pathways. Which information should the neurologist include? Sensory pathways in the spinal cord to the thalamus are included in the: a. corticospinal tract. b. pyramids. c. spinothalamic tract. d. anterior column.
ANS: C The spinothalamic tract carries nerve impulses from the spinal cord to the thalamus in the diencephalon; the corticospinal tract carries motor impulses. The pyramids assist with motor movements. The anterior column carries nerve impulses.
Where is the primary visual cortex of the brain located? a. Frontal lobe b. Temporal lobe c. Occipital lobe d. Parietal lobe
ANS: C The visual cortex is located in the occipital lobe.
A neurologist is teaching the staff about motor neurons. Which structural classification identifies motor neurons? a. Unipolar b. Pseudounipolar c. Bipolar d. Multipolar
ANS: D A motor neuron is typically multipolar. Unipolar neurons are found in the retina. Pseudounipolar neurons have one process; the dendritic portion of each of these neurons extends away from the CNS, and the axon portion projects into the CNS. Bipolar neurons are found in the eye.
What type of cell supports the forming of the blood-brain barrier (BBB)? a. Endothelial b. Schwann c. Oligodendrocyte d. Astrocyte
ANS: D Endothelial cells in brain capillaries, with their intracellular tight junctions, are the sites of the BBB. Supporting cells include astrocytes, pericytes, and microglia. Schwann cells provide structural support and nutrition for the neurons. Oligodendrocytes form the myelin sheaths.
A patient brought to the emergency room (ER) with severe burns is requesting something for the excruciating pain and is medicated with morphine, which blocks which of the following neurotransmitters, thus reducing the pain? a. Enkephalin b. Dopamine c. Acetylcholine d. Substance P
ANS: D Substance P is a neurotransmitter in pain transmission pathways. Blocking the release of substance P by morphine reduces pain. The opiates morphine and heroin bind to endorphin and enkephalin receptors on presynaptic neurons. Dopamine is a neurotransmitter involved in activity. Acetylcholine plays a role in nerve conduction presynaptically.
A nurse is preparing to teach about functions to maintain homeostasis and instinctive behavioral patterns. Which area of the brain is the nurse discussing? a. Thalamus b. Medulla c. Cerebellum d. Hypothalamus
ANS: D The hypothalamus functions to maintain a constant internal environment and instinctive behavioral patterns. The thalamus serves as a relay center for information from the basal ganglia and cerebellum to the appropriate motor area. The medulla controls reflex activities, such as heart rate, respiration, blood pressure, coughing, sneezing, swallowing, and vomiting. The cerebellum is responsible for reflexive, involuntary fine-tuning of motor control, for maintaining balance and posture through extensive neural connections.
A patient presents with altered respiratory patterns following head trauma. Based on the symptoms, which of the following areas does the nurse suspect is injured? a. Cerebrum b. Cerebellum c. Midbrain d. Reticular formation
ANS: D The reticular formation is a large network of diffuse nuclei that control vital reflexes, such as those controlling cardiovascular function and respiration. Respiratory function is not controlled by the cerebrum, cerebellum, or midbrain.
A patient is looking at a picture of the brain and points to the convolutions on the surface of the cerebrum. The nurse should tell the patient these are called: a. sulci. b. fissures. c. reticular formations. d. gyri.
ANS: D The surface of the cerebrum (cerebral cortex) is covered with convolutions called gyri, which greatly increase the cortical surface area and the number of neurons. Neither sulci, fissures, nor reticular formations cover the cerebrum in a fashion that increases its surface.