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99 Cards in this Set
- Front
- Back
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What are the three main functions of the nervous system?
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1. to receive sensory input
2. process and interpret sensory input 3. respond by activating effector organs |
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What are the three meningeal layers?
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Dura mater, arachnoid mater, and pia mater.
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In which meningeal space can cerebrospinal fluid (CSF) be found?
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Subarachnoid space.
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Where can neurons be found?
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In gray matter of the central nervous system and ganglia.
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What is the conus medullaris? What vertebrae is it found at?
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The terminal end of the spinal cord, at the level L1-L2.
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What is the cauda equina?
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A bundle like structure of nerve fibers that extends downwards from the conus medullaris.
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What is the filum terminale?
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Fibrous tissue which extends from the apex of the conus medullaris.
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Where does the spinal cord terminate in an adult? In an infant?
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L1 for adults and L3 for infants.
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Why is the spinal cord shorter than the vertebral column?
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The spinal cord grows slower than the vertebral column.
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At what vertebral level is a lumbar puncture performed?
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Between L3 and L5.
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Where is epidural anesthesia administered?
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Epidural anesthesia doesn't puncture the dural sac, but is delivered into the epidural space.
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Why might a spinal block be performed, and where is the anesthesia delivered?
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A spinal block is used to avoid using general anesthesia and is delivered directly into the dural sac and CSF.
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Where is caudal anesthesia administered and what is its most common use?
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Caudal anesthesia is administered through the sacral hiatus in the area of S2. Mostly used for labor and often referred to as an epidural.
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What does a positive Queckenstedt's sign indicate?
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A blockage of CSF in the subarachnoid space, most likely due to a tumor.
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What part of the brain are the majority of cranial nerves attached to?
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The brain stem.
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What are the three main functions of the brain stem?
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Regulates automatic behaviors, provides a passageway for fibers between the cerebrum and spinal cord, and innervation of the head and face.
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What is the main function of the cerebellum?
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Helps maintain equilibrium and coordinates body movements.
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What two parts of the brain does the transverse fissure separate?
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The cerebrum and cerebellum.
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What two parts of the brain does the longitudinal fissure separate?
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The two cerebral hemispheres (left and right).
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What two lobes of the brain are separated by the central sulcus?
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Frontal and parietal.
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What lobes of the brain are separated by the lateral sulcus?
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Temporal from frontal and parietal lobes.
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Where in the brain is the primary motor cortex located?
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In the precentral gyrus (Brodmann area 4).
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Where is the main sensory region of the brain?
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Along the postcentral gyrus (Brodmann areas 1-3).
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What are the main functions of the basal nuclei?
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Help control movement and regulate voluntary movement.
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What are the basal nuclei?
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Gray areas in the white matter of the brain which contains neurons.
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Where are the lateral ventricles located?
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In the cerebral hemispheres.
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Where is the third ventricle located?
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In the diencephalon.
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How are the lateral and third ventricles connected?
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By the interventricular foramen of Monro.
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Where is the fourth ventricle located?
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In the hindbrain; connects to the central canal of the spinal cord.
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How are the third and fourth ventricles connected?
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By the cerebral aqueduct of Sylvius.
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What would a spinal injury in the cervical region cause?
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It is unlikely that severe injury to the spinal cord will occur because the vertebral canal is large in this region.
If the injury occurs above C5, respiration ceases due to injury of the phrenic nerve and paralysis of the diaphragm and intercostal muscles. |
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What would a spinal injury in the thoracic region cause?
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Severe injury of the spinal cord because the vertebral canal is narrow.
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What would a spinal injury in the lumbar region cause?
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Minimal injury since the spinal cord terminates at L1 and the vertebral canal is large, so roots are unlikely to be damaged.
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What would a cervical disc herniation cause?
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Pain in the lower neck and shoulders. A lateral protrusion would compress the spinal nerve while a central protrusion would compress the spinal cord.
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What would a lumbar disc herniation cause?
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Lateral herniation would press roots while a central herniation would press the cauda equina and cause paraplegia.
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What is sciatica and what injury causes it?
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Pain down the back and lateral side of the leg and foot caused by lumbar disc herniation. Weakness in dorisflexion (L5) and / or plantar flexion (S1).
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How do head injuries differ in children and adults?
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In children, head trauma usually produces a depression with no splintering of the skull bones (fractures less common). In adults, head trauma would cause local indentation as well as splintering of the bone.
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What might displacement of the brain cause?
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Cerebral and brain stem damage. A suctioning effect on the brain surface ruptures blood vessels.
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What is a contrecoup injury?
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A severe blow to the head which results in brain damage at the point of impact and at the opposite pole of the brain.
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What is an epidural hemorrhage and what are its symptoms?
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Rupture of meningeal arteries which causes increased intracranial pressure and headache.
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What is a subdural hemorrhage and what are its symptoms?
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Rupture of superior cerebral veins due to displacement of the brain within the skull (severe head trauma). Causes increased intracranial pressure.
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What is a subarachnoid hemorrhage and what are its symptoms?
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Bleeding or aneurysm rupture of intracranial vessels; nontramatic bleeding. Signs include severe headache, neck stiffness, and Kernig's sign (stretching nerve roots by extending the knee causes pain).
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Why can't a lumbar puncture be performed when a patient has increased intracranial pressure?
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Extraction of CSF might cause a dangerous drop in pressure, leading to the brain dropping into the spinal column and causing instant death.
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What would a tumor, hematoma, or abscess in the skull cause?
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Increased intracranial pressure due to compression of veins as well as interference with circulation of blood and CSF. Leads to severe headache due to compression of dura mater and vomitting due to pressure on the brain stem.
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What are computed tomography (CT) scans used for?
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Detection of intracranial legions. The process is similar to that of an x-ray.
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How does a magnetic resonance imaging (MRI) machine work?
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The patient is subjected to a strong magnetic field and radio waves. An MRI differentiates between gray and white matter better than a CT.
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What is the main advantage of doing a positron emission tomography (PET) scan?
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It contains messages about chemical, physiological, and pharmacological processes in the body.
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What is a positron emission tomography (PET) scan used for?
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To asses functional blood flow to the brain and heart; determines which parts of the brain are most active during different processes. It produces images by detecting radioactive isotopes injected in the body.
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What are the six basic characteristics of a neuron?
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1. conduct electrical impulses along the plasma membrane
2. produce nerve impulse 3. produce action potential 4. live and function a long time 5. do not divide 6. high metabolic rate |
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What are Nissl bodies?
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The rough endoplasmic reticulum (rER) of a neuron.
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What is the most excitable part of an axon, the site of an action potential?
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The initial segment, which is after the axon hillock.
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Where can unipolar neurons be found?
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Posterior root ganglion.
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Where can bipolar neurons be found?
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Sensory organs including the retina, sensory cochlear, and vestibular ganglia.
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Where can multipolar neurons be found?
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Brain, spinal cord, peripheral nerves, and motor cells of the spinal cord.
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Where can Golgi type I neurons be found?
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Brain, spinal cord, peripheral nerves, and motor cells of the spinal cord.
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Where can Golgi type II neurons be found?
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Cerebral and cerebellar cortex.
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What type of proteins are most abundant in a cell membrane?
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Integral proteins, which may act as receptors.
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Where are peripheral proteins found?
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On the cytoplasmic side of the membrane, loosely attached to the membrane. They support the membrane with a network of filaments.
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What is glycocalyx? What is its function?
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Glycocalyx is a short carbohydrate chain that is attached to glycoproteins and glycolipids. Its main function is for cell to cell binding and recognition.
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Fatigue or injury of a neuron causes a concentration of ____ in the cell body.
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Nissl bodies.
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Name the three types of cytoskeleton.
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Microfilament, neurofilament, and microtubules.
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What kind of microfilament determines the shape of a neuron?
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Neurofibrils.
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What is the name of the contractile protein in microfilaments?
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Actin.
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What are the three main functions of microfilament?
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1. generate contractile forces within the cell
2. formation and retraction of cell processes 3. involved in cell transport |
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What are the two main functions of microtubules?
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They give the cell its shape and organize the distribution and transport of organelles within the cytoplasm.
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What does the Nerst equation describe?
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The membrane potential needed to balance an ionic concentration gradient across the membrane.
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What is the average resting membrane potential?
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-70 mV (negative inside).
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Which ion contributes most to the resting membrane potential?
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Potassium (K+).
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What happens during action potential when the membrane depolarizes?
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Sodium channels open, which changes the polarity inside the cell to +40 mV.
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What happens during a nerve impulse?
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The action potential spreads away from the site of initiation and is conducted along the axon as a nerve impulse (size of spread depends on strength of stimulus).
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Will we say?
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An ndéarfaidh muid?
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Which ion is an inhibitory stimulus?
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Chloride (Cl-) produces hyperpolarization and reduces the excitatory state of the cell.
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Define summation.
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Insufficient stimuli add up on the root of an axon to initiate an action potential.
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Define conductance.
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A measure of permeability of a cell membrane to a given ion.
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What are some symptoms of ion channel dysfunction (channelopathy)?
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Periodic paralysis; attacks are often triggered by exercise, temperature changes, drugs, etc.
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Ion channels are regulated by concentration of which two ions?
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Calcium and hydrogen.
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_____ channels open during stimulation, _____ channels are open during rest.
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Na+; K+.
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During the absolute refractory period, _____ channels are closed.
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Na+.
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Define antrograde axonal transport.
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Materials are transported from the cell body to the axon terminal.
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Define retrograde axonal transport.
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Materials are transported from the axon to the cell body.
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Define rabies.
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A viral disease of the central nervous system which travels through axonal transport in sensory and motor nerves.
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Define herpes simplex / zoster.
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A viral disease that is spread by axonal transport, usually in the sensory nerurons.
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Define poliomyelitis.
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A viral disease that spreads through axonal transport from the gastrointestinal tract to the motor neurons of the anterior horn of the spinal cord.
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What is the reaction of a neuron to a minor injury?
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The neuron loses function, then the nucleus becomes swollen which displaces the Nissl bodies and nucleus.
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What phagocytizes damaged neurons in the central nervous system? The peripheral nervous system?
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Microglia; macrophages.
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How soon after injury do morophological changes from neuron death appear?
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6 to 12 hours.
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How soon after injury do degenerative changes start to appear?
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24 to 48 hours; degeneration is greater if the injury is closer to the cell body.
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How are neurons of the dorsal root ganglion an exception to the general regeneration rule?
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If the peripheral axon is cut, the cell body degenerates, but if the central axon is cut, the cell body will not degenerate.
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Define neuroblastoma.
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A highly malignant tumor associated with suprarenal gland in children.
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Define ganglioneuroma.
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A benign tumor in the adrenal medulla or sympathetic ganglia.
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Define pheochromocytoma.
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Normally a benign tumor in the suprarenal medulla which gives rise to hypertension because of increased epinephrine and norepinephrine secretion.
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What are the three forms of synapses?
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Axodendritic, axosomatic, and axoaxonic.
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What are the two types of synapses and which is more common?
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Chemical (most common) and electrical.
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Where can acetylcholine (ach) be found?
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Neuromuscular junction, autonomic ganglia, parasympathetic nerves, motorneuron collaterals, hippocampus, ascending reticular pathways, and visual / auditory afferent fibers.
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Where can norepinepherine be found?
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At sympathetic nerve endings and the hypothalamus.
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Where can dopamine be found?
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In basal ganglia.
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Where can glycine be found?
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Synapses in the spinal cord.
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Where can glutamite be found?
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Neurons in the central nervous system.
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What does Dale's principle state?
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A neuron contains and releases only one neurotransmitter and exerts the same functional effect at all of its terminals (not universally true).
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