PrepU Patho Ch 34
A practitioner is preparing to do a lumbar puncture on a client with suspected meningitis. Which area on the spine does the practitioner choose to obtain a cerebrospinal fluid (CSF) sample?
Between L3 and L4 The adult cord usually terminates at the inferior border of L1. The arachnoid and its enclosed subarachnoid space, which is filled with CSF, do not close down on the filum terminale until they reach the second sacral vertebra. This results in a formation of a pocket of CSF, the dural cisterna spinalis, which extends from approximately L2 to S2. Because this has an abundant supply of CSF and the spinal cord does not extend this far, the area (L3 or L4) is often used to perform a lumbar puncture to obtain CSF.
A nurse educator is explaining basic neuroanatomy to a class of prospective nursing students. Which statement best conveys an aspect of the role of cerebrospinal fluid (CSF)?
CSF cushions the brain and provides a near-water medium for diffusion of nutrients. In addition to providing a cushion for the CNS, CSF provides a medium that is 99% water in which nutrients, electrolytes, and wastes can be diffused. It is not centrally involved in the distribution of oxygen, plasma proteins, or blood cells.
The thick area of myelinated axons that connects the two sides of the cerebral cortex is known as which component?
Corpus callosum The thick area of myelinated axons that connects the two sides of the cerebral cortex is known as the corpus callosum. The remaining options are all components of the basal ganglia.
A client has sustained damage to cranial nerve VIII. The nurse recognizes that the client may experience difficulty with:
Hearing Cranial nerve VIII (vestibulocochlear nerve) is associated with hearing. The other options involve different nerves.
A client arrives in the clinic after having a tongue piercing performed and is unable to control the movement of the tongue. The nurse is aware that which nerve may have been damaged from the piercing?
Hypoglossal The general somatic efferent LMNs of the lower segments of the medulla supply the extrinsic and intrinsic muscles of the tongue by means of the hypoglossal nerve (CN XII). Damage to the hypoglossal nerve results in weakness or paralysis of tongue muscles. When the tongue is protruded, it deviates toward the damaged and therefore weaker side because of the greater protrusion strength on the normal side.
Maintenance of blood gas concentrations, water balance, and food consumption are controlled by which part of the brain?
Hypothalamus The hypothalamus is the area of master level integration of homeostatic control of the body's internal environment. Maintenance of blood gas concentrations, water balance, food consumption, and major aspects of endocrine and autonomic nervous system control require hypothalamic function.
A nurse educator is explaining the divisions of the nervous system to a class of prospective nursing students. Which characterization of the organization of the nervous system is most accurate?
The ANS is represented in both the CNS and PNS. The ANS has components in both the CNS and PNS. These are not, however, the two components of the ANS. The ANS is normally divided into sympathetic and parasympathetic branches.
A 21-year-old male is brought to the ED following a night of partying in his fraternity. His friends found him "asleep" and couldn't get him to respond. They cannot recall how many alcoholic beverages he drank the night before. While educating a student nurse and the man's friends, the nurse begins by explaining that alcohol is:
Very lipid-soluble and rapidly crosses the blood-brain barrier. The blood-brain barrier prevents many drugs from entering the brain. Most highly water-soluble compounds are excluded from the brain. Many lipid-soluble molecules cross the lipid layers of the blood-brain barrier with ease. Alcohol, nicotine, and heroin are very lipid-soluble and rapidly enter the brain. Alcohol toxicity can kill clients, especially if they are not used to consuming beverages. These clients should never be left alone to "sleep it off."
A client has been recently diagnosed with Alzheimer disease and has been prescribed a cholinesterase inhibitor. This drug will slow the progression of the client's symptoms by:
decreasing ACh breakdown. Acetylcholine is secreted by the cholinergic nerve endings and is rapidly broken down by the enzyme acetylcholinesterase. The cholinesterase inhibitor inhibits the breakdown of the neurotransmitter in the synaptic space, thereby increasing the effect of ACh. ACh levels do not affect action potentials in presynaptic or postsynaptic membranes.
When educating a client about to undergo a pacemaker insertion, the nurse explains the normal phases of cardiac muscle tissue. During the repolarization phase, the nurse will stress that membranes must be repolarized before they can be re-excited. Within the cell, the nurse understands that:
potassium channels open while sodium channels close, causing repolarization to the resting state. Repolarization is the phase during which the polarity of the resting membrane potential is re-established. This occurs with the closure of the sodium channels and opening of the potassium channels.
