Chapter 13: Organization and Control of Neural Function #1

What percentage of the body's oxygen does the brain consume?

20%

A client has just begun to experience an ischemic stroke. The blood supply from the middle cerebral artery is being blocked by a large blood clot. How long before brain cells begin to die due to lack of ATP?

4 to 6 minutes

The nurse witnesses a client go into cardiac arrest. If the nurse delays intervention, when will the death of brain cells begin?

4-6 minutes

Which of the following are the main neurotransmitters of the autonomic nervous system (ANS)? - 3

Acetylcholine Epinephrine Norepinephrine

What cells provide protection and metabolic support to neurons? - 4

Astrocytes Ependymal cells Microglia cells Oligodendrocytes

The parasympathetic nervous system is part of which of the following systems?

Autonomic nervous system The autonomic nervous system is a control system that acts largely unconsciously and regulates bodily functions, such as the heart rate, digestion, respiratory rate, pupillary response, urination, and sexual arousal. This system is the primary mechanism in control of the fight-or-flight response.

Which components of the nervous system make up the central nervous system?

Brain and spinal cord

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.

Myelinated neurons are found in which of the following component(s) of the nervous system?- 2

Central peripheral

Neurons communicate through the use of synapses. These synapses may link neurons into functional circuits. What is the most common type of synapse? synapse: a junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter.

Chemical synapse

the functions of the occipital lobe - 3

Color motion depth perception

A client has been diagnosed with amyotrophic lateral sclerosis, a disease resulting in the loss of efferent signals. Which aspect of neurologic function will be primarily affected by this client's condition?

Conduction of information away from CNS

Which of the following characterizes a function of the parasympathetic nervous system (PNS)?

Conservation of energy

The cerebellum (part of the brain is responsible for coordinating voluntary movements. It is also responsible for a number of functions including motor skills such as balance, coordination, and posture.), separated from the cerebral hemispheres by the tentorium cerebelli, lies in the posterior fossa of the cranium. What is one of the functions of the cerebellum?

Coordinates smooth and accurate movements of the body

The thick area of myelinated axons that connects the two sides of the cerebral cortex is known as what?

Corpus callosum The corpus callosum is a large, C-shaped nerve fiber bundle found beneath the cerebral cortex. It stretches across the midline of the brain, connecting the left and right cerebral hemispheres. It makes up the largest collection of white matter tissue found in the brain

The thalamus is located in which of the following parts of the brain?

Diencephalon the caudal (posterior) part of the forebrain, containing the epithalamus, thalamus, hypothalamus, and ventral thalamus and the third ventricle.

Which meninges provides the major protection for the brain and spinal cord?

Dura mater

Which structures do neurons communicate with? - 2.

Electrical synapses Chemical synapses

Which of the following catecholamines is formed in the adrenal gland? Catecholamines are hormones made by your adrenal glands, which are located on top of your kidneys.

Epinephrine

Which of the following potentials, when combining a neurotransmitter with a receptor site, causes partial depolarization of the postsynaptic membrane?

Excitatory postsynaptic In neuroscience, an excitatory postsynaptic potential (EPSP) is a postsynaptic potential that makes the postsynaptic neuron more likely to fire an action potential.

The adrenal medulla is innervated by parasympathetic nerve fibers. true or false

False

A client is having an upper endoscopy (a procedure a doctor uses to look at the inner lining of the upper digestive tract (the esophagus, stomach, and duodenum, which is the first part of the small intestine).) to determine the presence of a gastric ulcer (Ulcers occur when stomach acid damages the lining of the digestive tract.). After the procedure is performed, the nurse instructs the client that he cannot have anything to eat or drink until the return of the gag reflex. Which nerve is the nurse testing for return of function?

Glossopharyngeal The glossopharyngeal nerve, known as the ninth cranial nerve (CN IX), is a mixed nerve that carries afferent sensory and efferent motor information. It exits the brainstem out from the sides of the upper medulla, just anterior (closer to the nose) to the vagus nerve.

Nutrition students are studying the nervous system, which has a high rate of metabolism. What is its major fuel source?

Glucose

The nurse measures a blood glucose level of 40 mg/dL for a client with diabetes type I. Why would it be important for the nurse to institute an intervention to elevate the glucose level in this client? So it's most commonly done before breakfast in the morning; and the normal range there is 70 to 100 milligrams per deciliter. Now when you eat a meal, blood sugar generally rises and in a normal individual it usually does not get above a 135 to 140 milligrams per deciliter

Glucose is not stored in the brain and is a major fuel source for brain function.

A client has sustained damage to cranial nerve VIII. The nurse recognizes that the client may experience difficulty with:

Hearing

Not realizing that its surface was hot, a woman has quickly withdrawn her hand from the surface of a bowl that she was removing from a microwave. Which of the following phenomena has facilitated the rapid movement of her hand in response to the painful stimulus?

Her CNS has enacted a protective response received by neurons that innervate her arm muscles.

A client is unable to stick out his tongue as a result of injury to cranial nerve XII. The nurse recognizes that the client has sustained as damage to which nerve?

Hypoglossal The hypoglossal nerve is the twelfth cranial nerve, and innervates all the extrinsic and intrinsic muscles of the tongue, except for the palatoglossus which is innervated by the vagus nerve. It is a nerve with a solely motor function

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 hypoglossal nerve is the twelfth cranial nerve, and innervates all the extrinsic and intrinsic muscles of the tongue, except for the palatoglossus which is innervated by the vagus nerve. It is a nerve with a solely motor function.

Maintenance of blood gas concentrations, water balance, and food consumption are controlled by which of the following parts of the brain?

Hypothalamus

A 9 year-old girl has a diffuse collection of symptoms that are indicative of deficits in endocrine and autonomic nervous system control. She also suffers from persistent fluid and electrolyte imbalances. The nurse knows which of the following aspects of the nervous system listed below would her healthcare providers focus their diagnostic efforts?

Impaired function of her hypothalamus

Neurotransmitters are small molecules that exert their actions through specific proteins, called receptors, embedded in the postsynaptic membrane. Where are neurotransmitters synthesized? the postsynaptic membrane is the membrane that receives a signal (binds neurotransmitter) from the presynaptic cell and responds via depolarisation or hyperpolarisation. The postsynaptic membrane is separated from the presynaptic membrane by the synaptic cleft.

In the axon terminal

Neurons that connect sensory and motor neurons are known as which of the following?

Interneurons a neuron which transmits impulses between other neurons, especially as part of a reflex arc.

While assessing a critically ill patient in the emergency department, the nurse notes on the cardiac monitor an R-on-T premature ventricular beat which develops into ventricular tachycardia (VT). Immediately, the patient became unresponsive. The nurse knows that based on pathophysiologic principles, the most likely cause of the unresponsiveness is:

Interruption of the blood/oxygen supply to the brain.

The health care provider is performing a spinal tap on a client with suspected infection. The provider would perform the procedure at: A lumbar puncture (spinal tap) is performed in your lower back, in the lumbar region. During a lumbar puncture, a needle is inserted between two lumbar bones (vertebrae) to remove a sample of cerebrospinal fluid. This is the fluid that surrounds your brain and spinal cord to protect them from injury.

L3 or L4

Feelings of dread, high anxiety, or exquisite pleasure can be elicited by stimulation of areas in which of the following structures?

Limbic system The limbic system is a set of structures in the brain that deal with emotions and memory. It regulates autonomic or endocrine function in response to emotional stimuli and also is involved in reinforcing behavior .

The nurse is aware that the primary function of the sympathetic nervous system is:

Maintenance of vital functions and responding when there is a critical threat to the integrity of the individual

Which structures are part of the brain stem? - 3

Medulla oblongata Pons Midbrain The pons contains nuclei that relay signals from the forebrain to the cerebellum, along with nuclei that deal primarily with sleep, respiration, swallowing, bladder control, hearing, equilibrium, taste, eye movement, facial expressions, facial sensation, and posture.

A client with a diagnosis of depression has been prescribed a medication that ultimately increases the levels of the neurotransmitter serotonin between neurons. Which of the following processes will accompany the actions of the neurotransmitter in a chemical synapse? Serotonin is a chemical that has a wide variety of functions in the human body. It is sometimes called the happy chemical, because it contributes to wellbeing and happiness. The scientific name for serotonin is 5-hydroxytryptamine, or 5-HT. It is mainly found in the brain, bowels, and blood platelets.

More neurotransmitters will cross the synaptic cleft and bond with postsynaptic receptors.

Which of the following is the primary component of white matter? White matter is the tissue through which messages pass between different areas of grey matter within the central nervous system. The white matter is white because of the fatty substance that surrounds the nerve fibers (axons).

Myelinated fibers

During embryonic development, which of the following structures develops into the central nervous system (CNS)?

Neural tube

The density of voltage-gated channels is greatest in which of the following components of the neuron?

Nodes of Ranvier a gap in the myelin sheath of a nerve, between adjacent Schwann cells.

Rapid removal of a neurotransmitter, once it has exerted its effect on the postsynaptic membrane, is necessary to maintain precise control of neural transmission. Which of the following transmitters is largely removed by the reuptake process?

Norepinephrine

Which occurrence in the action potential process causes polarization?

Period of action potential during which the nerve is not transmitting impulses

A nursing student having trouble moving their head from side to side is likely experiencing a problem with which type of neurons?

Pharyngeal efferent neurons. Pharyngeal: relating to the pharynx. efferent neuron: are motor neurons carrying neural impulses away from the central nervous system and toward muscles to cause movement

Which parts of the brain make up the brain stem? - 2

Pons medulla oblongata

When educating a patient 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 and while sodium channels close causing repolarization to the resting state.

Release of neurotransmitters occurs at which of the following locations in the neuron?

Presynaptic terminal

What is the role of a neuromodulator when it acts on a postsynaptic receptor? A neuromodulator is a messenger released from a neuron in the central nervous system, or in the periphery, that affects groups of neurons, or effector cells that have the appropriate receptors. In postsynaptic cells, neurotransmitter receptors receive signals that trigger an electrical signal, by regulating the activity of ion channels.

Produces slower and longer-lasting changes in membrane excitability

Neurotransmitters exert their actions through specific proteins that are known as: Neurotransmitters: a chemical substance that is released at the end of a nerve fiber by the arrival of a nerve impulse and, by diffusing across the synapse or junction, causes the transfer of the impulse to another nerve fiber, a muscle fiber, or some other structure.

Receptors

Which of the following is the period during repolarization when a portion of the recovery period is where the membrane can be excited, although only by a stronger-than-normal stimulus?

Relative refractory period The relative refractory period is the interval of time during which a second action potential can be initiated, but initiation will require a greater stimulus than before. Refractory periods are caused by the inactivation gate of the Na+ channel.

Potassium outflow from the cell is characteristic of which of the following phases of the action potential?

Repolarization

Select the actions of β2 receptors. Select all that apply. beta-2 adrenergic receptor (β2 adrenoreceptor), also known as ADRB2, is a cell membrane-spanning beta-adrenergic receptor that binds epinephrine (adrenaline),

Respiration Delaying labor

A 45 year old diabetic male is experiencing erectile dysfunction. If his erectile dysfunction is caused by the nervous system, then the nurse can educate the patient that the venous blood supply to the penis is controlled by:

Sacral parasympathetic fibers. The sacral parasympathetic outflow acts on the pelvic viscera. It causes the relaxation of the internal sphincter of urinary bladder and simultaneous contraction of the detrusor muscle of the urinary bladder wall. This increases the intraluminal pressure within the bladder, thereby promoting urination.

Which types of cells are supporting cells of the peripheral nervous system?

Schwann cells Schwann cells are a variety of glial cells that keep peripheral nerve fibres (both myelinated and unmyelinated) alive. In myelinated axons, Schwann cells form the myelin sheath. The sheath is not continuous.

A child is experiencing difficulty with chewing and swallowing. The nurse knows that which of the following cells may be innervating specialized gut-related receptors that provide taste and smell?

Special visceral afferent cells Special visceral afferent fibers (SVA) are the afferent fibers that develop in association with the gastrointestinal tract. They carry the special senses of smell (olfaction) and taste (gustation).

Which of the following afferent (sensory) neurons in the dorsal root ganglia innervate specialized gut-related receptors, such as taste buds and receptors of olfactory mucosa? A dorsal root ganglion (or spinal ganglion; also known as a posterior root ganglion) is a cluster of neurons (a ganglion) in a dorsal root of a spinal nerve. The cell bodies of sensory neurons known as first-order neurons are located in the dorsal root ganglia. The olfactory mucosa is located in the upper region of the nasal cavity and is made up of the olfactory epithelium and the underlying lamina propria, connective tissue containing fibroblasts, blood vessels, Bowman's glands and bundles of fine axons from the olfactory neurons.

Special visceral afferents

Through what specific component do neurotransmitters exert their action?

Specific proteins

The vertebral column provides protection of what? - 3

Spinal cord Spinal nerves Supporting structures

Neurons communicate with each other through which of the following structures?

Synapses

After neurotransmitters are synthesized, in which of the following structures are they stored in the axon terminal? At the end of an axon, there is a so-called axon terminal that is button-like and is responsible for providing synapse between neurons. In humans, the axon can be over a foot long.

Synaptic vesicles synaptic vesicles (or neurotransmitter vesicles) store various neurotransmitters that are released at the synapse. The release is regulated by a voltage-dependent calcium channel. Vesicles are essential for propagating nerve impulses between neurons and are constantly recreated by the cell.

Which of the following is the lobe of the brain with functions of perception, long-term memory, and recognition of auditory stimuli?

Temporal lobe

The nurse is aware that some drugs may be prevented from entering the brain as a function of:

The blood-brain barrier The blood-brain barrier (BBB) is a highly selective semipermeable border of endothelial cells that prevents solutes in the circulating blood from non-selectively crossing into the extracellular fluid of the central nervous system where neurons reside.

The nurse is performing a test to determine a client's neurological function related to a suspected lesion (a region in an organ or tissue which has suffered damage through injury or disease, such as a wound, ulcer, abscess, or tumor.) in the parietal lobe. What would the nurse determine is a normal finding after assessment? The parietal lobe is one of the major lobes in the brain, roughly located at the upper back area in the skull. It processes sensory information it receives from the outside world, mainly relating to touch, taste, and temperature

The client is able to determine correctly that the item placed in his hand is a paper clip.

The neurotransmitter GABA mainly functions to trigger inhibitory postsynaptic potentials (IPSPs). Therefore, when explaining this to a group of nursing students, the nurse will state: GABA (gamma-aminobutyric acid) is an inhibitory neurotransmitter that is very widely distributed in the neurons of the cortex. GABA contributes to motor control, vision, and many other cortical functions. It also regulates anxiety. An inhibitory postsynaptic potential (IPSP) is a kind of synaptic potential that makes a postsynaptic neuron less likely to generate an action potential.

The combination of GABA with a receptor site is inhibitory since it causes the local nerve membrane to become hyperpolarized and less excitable.

A client is being treated for the ingestion of a neurotoxin that interferes with the depolarization phase of action potentials. What physiologic process will be disrupted?

The inflow of sodium ions

The spinal cord does not hang freely within the spinal column. What is it supported by?

The pia mater and the denticulate ligaments The pia mater is a thin fibrous tissue that is permeable to water and small solutes. The pia mater allows blood vessels to pass through and nourish the brain. The perivascular space between blood vessels and pia mater is proposed to be part of a pseudolymphatic system for the brain (glymphatic system). The denticulate ligaments are triangular shaped ligaments that anchor the spinal cord along its length, at each side, to the dura mater. The bases of the ligaments arise in the pia mater and they are firmly attached to the arachnoid mater and dura mater at the apex.

The nurse is working with a client who has an addiction to cocaine. The nurse is aware that the high associated with cocaine is due to the inhibition of reuptake. What physiologic phenomenon is affected?

The resorption of the neurotransmitter to remove it from action

Which of the following is true during the phase where polarized cells are not transmitting?

They are more negative inside the cell as compared to the outside of the cell.

The sympathetic and the parasympathetic nervous systems are continuously at work in our bodies. This continual action gives a basal activity to all parts of the body. What is this basal activity referred to as? The basal activity of the receptor, and its ability to activate intracellular signaling pathways, is defined by the probability that a fraction of the receptor adopts the active state in the absence of ligand

Tone

What increase(s) the permeability of the blood-brain barrier? - 3

Trauma Infection Newborn child

The nurse teaches a client about a new diagnosis of astrocytoma. Which statement indicates an accurate understanding? Astrocytoma is a type of cancer that can form in the brain or spinal cord. Astrocytoma begins in cells called astrocytes that support nerve cells. Astrocytoma signs and symptoms depend on the location of your tumor. Astrocytomas that occur in the brain can cause seizures, headaches and nausea.

Treatment is hard since glial cells support neurons and blood vessels in the brain. Glia, also called glial cells or neuroglia, are non-neuronal cells in the central nervous system (brain and spinal cord) and the peripheral nervous system that do not produce electrical impulses. They maintain homeostasis, form myelin, and provide support and protection for neurons.

Which of the following nerves exits the pons and conveys the modalities of pain, temperature, touch, and proprioception to the superficial and deep regions of the face?

Trigeminal nerve The trigeminal nerve (the fifth cranial nerve, or simply CN V) is a nerve responsible for sensation in the face and motor functions such as biting and chewing; it is the most complex of the cranial nerves.

The arachnoid membrane (a fine, delicate membrane of the three membranes or meninges that surround the brain and spinal cord) is the middle layer of the three meninges.

True

The vertebral column provides protection for the spinal cord, spinal nerves, and supporting structures. true or false

True

An adult male has a new diagnosis of Guillain-Barre syndrome (a rare disorder in which your body's immune system attacks your nerves). The nurse knows which of the following pathophysiological processes underlie the deficits that accompany the degeneration of myelin in his peripheral nervous system (PNS)?

Unless remyelination (the process of propagating oligodendrocyte precursor cells to form oligodendrocytes to create new myelin sheaths on demyelinated axons in the CNS) occurs, the axon will eventually die.

Dopamine is an intermediate compound made during the synthesis of norepinephrine. It is the principal inhibitory transmitter of the internuncial neurons in the sympathetic ganglia. What other action does it have? dopamine: Blood pressure support; It can treat symptoms of shock by improving blood flow. Norepinephrine is a naturally occurring chemical in the body that acts as both a stress hormone and neurotransmitter Internuncial neurons or Interneurons are neurons that run "between" other neurons.

Vasodilates renal and coronary blood vessels when given intravenously

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 roommates in the fraternity, the nurse begins by explaining that alcohol is:`

Very lipid soluble and rapidly crosses the blood-brain barrier.

Ion channels in nervous system cells generate action potentials in the cells. What are the ion channels guarded by?

Voltage-dependent gates Voltage-gated ion channels are a class of transmembrane proteins that form ion channels that are activated by changes in the electrical membrane potential near the channel. ... Cell membranes are generally impermeable to ions, thus they must diffuse through the membrane through transmembrane protein channels.

A client asks the nurse when during embryonic growth the nervous system develops. The best response would be:

Week 3

Which of the following types of reflex is stimulated by a nociceptive stimulus? Nociception is the process by which noxious stimulation is communicated through the peripheral and central nervous system. Nociceptors are specific receptors within the skin, muscle, skeletal structures, and viscera that detect potentially damaging stimuli. A noxious stimulus is "an actually or potentially tissue damaging event." It is a prerequisite for nociception, which itself is a prerequisite for nociceptive pain.

Withdrawal reflex