ch12 exam

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ch12 exam
2014-03-12 04:22:50
chapter 12 nervous system
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  1. cephalization
    • evolutionary development of (anterior portion of CNS)
    • increased number of neurons in head
    • highest level reached in human brain
  2. what are the four adult brain regions
    • cerebral hemispheres
    • diencephalon
    • brain stem (midbrain, pons, medulla)
    • cerebellum
  3. spinal cord
    • central cavity surrounded by gray matter
    • external white matter composed of myelinated fiber tracts
  4. what is the outer gray matter called in the cerebral hemispheres and cerebellum
  5. where does the cortex disappear
    the brain stem
  6. what are the ventricles of the brain filled with
    cerebral spinal fluid
  7. how are the ventricles connected to one another
    • they are connected to one another and to central canal of spinal cord
    • later ventricles -> third centricle via interventricular foramen
    • third ventricle-> fourth ventricle via cerebral aqueduct
  8. what are the C shaped lateral ventricles in the cerebral hemispheres separated by anteriorly
    septum pellucidum
  9. where is third ventricle located
  10. where is the fourth ventricle located
    • in hindbrain; three openings include paired lateral apertures in side walls and median aperture in roof
    • connected ventricles to subarachnoid space
  11. what are the three types of surface markings and describe them
    • gyri: ridges
    • sulci: shallow grooves
    • fissures: deep grooves
  12. what is the name of the fissure that separated the two hemispheres
    the longitudinal fissure
  13. what is the name of the fissure that separates the cerebrum and cerebellum
    transverse cerebral fissure
  14. what are the five lobes of of the cerebral hemispheres
    • frontal
    • parietal
    • occipital
    • temporal
    • insula
  15. central sulcus
    separates precentral gyrus of frontal lobe and postcentral gyrus of parietal love
  16. parieto-occipital sulcus
    separates occipital and parietal lobes
  17. lateral sulcus
    outlines temporal lobes
  18. what are the three basic regions of the cerebral hemispheres
    • cerebral cortex: gray matter superficially
    • white matter: internally
    • basal nuclei: deep within white matter
  19. cerebral cortex
    • thin superficial layer of gray matter
    • 40% of brain mass
    • site of conscious mind: awareness, sensory perception, voluntary motor initiation, communication, memory storage, understanding
  20. the 4 general considerations of cerebral cortex
    • 1. three types of functional areas:
    •    motor: control voluntary movement
    •    sensory: conscious awareness of sensation
    •    association: integrate diverse information

    2. each hemisphere is concerned with contralateral side of body.

    3. lateralization of cortical function in hemispheres

    4. conscious behavior involves entire cortex in some way
  21. what are the motor areas of the cerebral cortex
    in the frontal love; control voluntary movement

    • 1. primary (somatic) motor cortex: in precentral gyrus
    • 2. premotor cortex: anterior to precentral gyrus
    • 3. broca's area: anterior to inferior premotor area
    • 4. frontal eye field: within and anterior to premotor cortex; superior to broca's area
  22. primary motor cortex
    • large pyramidal cells of precentral gyri
    • long acorns -> pyramidal tracts of spinal cord
    • allows conscious control of precise, skilled, skeletal muscle movements
  23. premotor cortex
    • helps plan movements, staging area for skilled motor activities
    • controls learned, repetitious or patterned motor skills
    • coordinates simultaneous or sequential actions
    • controls voluntary actions that depend on sensory feedback
  24. give an example of sensory feedback
    walking up a hill thats wet and sandy requires thought, and changing your stance, etc. you constantly are getting feedback from muscles ot make sure you're doing everything right.
  25. broca's area
    • present in one hemisphere (usually left)
    • motor speech area that directs muscles of speech production
    • active in planing speech and voluntary motor activities
  26. frontal eye field
    • controls voluntary eye movements
    • muscle movement and your ability to look around the classroom
    • can be linked to startle reflex
  27. what links the right to the left of the brain
    corpus collosom
  28. what are the sensory areas of the brain
    • primary somatosensory cortex
    • somatosensory association cortex
    • visual areas
    • auditory areas
    • vestibular cortex
    • olfactory cortex
    • gustatory cortex
    • visceral sensory area
  29. what takes place in the sensory areas of cerebral cortex
    • conscious awareness of sensation
    • occur in parietal, insular, temporal, and occipital lobes
  30. primary somatosensory cortex
    • in postcentral gyri of parietal lobe
    • receives general sensory info from skin and proprioceptors of skeletal muscles, joints, tendons
    • capable of spatial discrimination; identification of body region being stimulated
    • somatosensory homunculus upside down caricatures represent contralateral sensory input from body regions
  31. what does proprioceptors do
    tells you where you are in space and time, what muscles are being affected, etc.
  32. somatosensory association cortex
    • posterior to primary somatosensory cortex
    • integrates sensory input from primary somatosensory cortex for understanding of object
    • determines size, texture, and relationship of parts of objects being felt
    • ie. rubbing the desk top vs. rubbing paper; you can distinguish
  33. primary visual striate cortex
    • extreme posterior tip of occipital lobe
    • most buried in calcarine sulcus of occipital lobe
    • receives visual information from retinas
  34. visual association areas
    • surrounds primary visual cortex
    • uses past visual experiences to interpret visual stimuli (ability to recognize faces)
    • complex processing involves entire posterior half of cerebral hemispheres
  35. auditory areas
    primary auditory cortex and auditory association areas
  36. primary auditory cortex
    • superior margin of temporal lobes
    • interprets information from inner ear as pitch, loudness, and location
  37. auditory association areas
    • located posterior to primary auditory cortex
    • stores memories of sounds and permits perception of sound stimulus
  38. vestibular cortex
    • posterior part of insula and adjacent parietal cortex
    • responsible for conscious awareness of balance
  39. primary olfactory cortex
    • medial aspect of temporal lobes
    • part of primitive rhinencephalon, along with olfactory bulbs and tracts
    • remainder of rhinencephalon in humans part of limbic system
    • region of conscious awareness of odors
  40. limbic system
    primitive; its who we are; emotions
  41. gustatory cortex
    • in insula just deep to temporal lobe
    • involved in perception of taste
  42. visceral sensory area
    • posterior to gustatory cortex
    • conscious perception of visceral sensations e.g. upset stomach of full bladder
  43. multimodal association areas
    • receive inputs from multiple sensory areas
    • send outputs to multiple areas including premotor cortex
    • allows meaning to information received, store in memory, tying to previous experience, and deciding on actions
    • sensations, thoughts, emotions become conscious
  44. what are the three broad parts of the multimodal association areas
    • anterior association area (prefrontal cortex)
    • posterior association areas
    • limbic association areas
  45. anterior association area
    • most complicated cortical region
    • involved with intellect, cognition, recall, and personality
    • contains working memory needed for abstract ideas, judgement, reasoning, persistence, planning
    • development depends on feedback from social environment
  46. posterior association area
    • large region in temporal parietal and occipital lobes
    • plays role in recognizing patterns and faces and localizing us in space
    • involved in understanding written and spoken language (wernicke's area)
  47. limbic association area
    • part of limbic system
    • involves cingulate gyrus, parahippocampal gyrus, and hippocampus
    • provides emotional impact that makes scene important and helps establish memories
    • e.g. rage, fear, jealously, all emotions
  48. are the hemispheres identical?
    yes; almost identical
  49. lateralization
    division of labor between hemispheres
  50. cerebral dominance
    • hemisphere dominant for language 
    • left hemisphere for 90% of people
  51. left hemisphere
    controls language, math, and logic
  52. right hemisphere
    controls visual spatial skills, intuition, emotion, and artistic and musical skills
  53. how do the two hemispheres communicate
    via fiber tracts and functional integration almost instantaneously
  54. cerebral white matter
    • myelinated fibers and tracts
    • communication between cerebral areas and between cortex and lower CNS
    • association, commissural, and projection fibers
  55. association fibers
    horizontal; connect different parts of same hemisphere
  56. commissural fibers
    horizontal; connect gray matter of two hemispheres
  57. projection fibers
    vertical; connect hemispheres with lower brain or spinal cord
  58. decussation
  59. basal nuclei (ganglia)
    • subcortical nuclei (caudate nucleus, putamen, globus pallidus)
    • associated with diencephalon and midbrain
    • influence muscle movements
    • role in cognition and emotion
    • regulate intensity of slow or stereotyped movements
    • filter out incorrect/inappropriate responses
    • inhibit antagonistic/unnecessary movements
    • it influences THROUGH the thalamus
  60. where does the fourth ventricle go
    to the central canal of the spinal cord
  61. diencephalon
    • three paired structures: thalamus, hypothalamus, epithalamus
    • encloses third ventricle
  62. thalamus
    • 80% of diencephalon
    • superolateral walls of third ventricle
    • bilateral nuclei connected by interthalamic adhesion
    • primary function is to move things in and out as a gateway
    • sorts, edits and relays ASCENDING input
    • mediates sensation, motor activities, cortical arousal, learning, and memory
  63. infundibulum
    stalk that connects to pituitary gland
  64. hypothalamus
    • forms inferolateral walls of third ventricle
    • contains many nuclei
    • infundibulum 
    • controls autonomic nervous system (blood pressure, heartbeat, etc)
    • physical responses to emotions (limbic system)
    • regulates body temp; sweating/shivering
    • regulates hunger
    • regulates water balance and thirst
    • regulates sleep=wake cycles
    • controls endocrine system (pituitary hormones and pituitary glands)
  65. suprachiasmatic nucleus
    biological clock
  66. epithalamus
    • most dorsal portion of diencaphalon; forms roof of third ventricle
    • pineal gland extends from posterior border and secretes melatonin
  67. what does melatonin do
    helps regulate sleep-wake cycle
  68. chiasma
  69. what are the three regions of the brain stem
    • midbrain
    • pons
    • medulla oblongata
  70. brain stem
    • similar structure to spinal cord bu contains nuclei embedded in white matter
    • controls automatic behaviors necessary for survival
    • contains fiber tracts connecting higher and lower neural centers
    • nuclei associated with 10 of the 12 pairs of cranial nerves
  71. what is the name of the only cranial nerve to leave the brain
    vagus nerve; #10
  72. midbrain
    • between diencaphalon and pons
    • cerebral peduncles: ventrally contain pyramidal motor tracts
    • cerebral aqueduct: channel connected third and fourth ventricles
  73. what is connected to the fourth ventricle going inferior
    central canal
  74. what is the prupose of a ventricle
    hold and cleanse and produce cerebral spinal fluid
  75. what cells help circulate CSF
    epidymal cells
  76. midbrain nuclei
    • periaqueductal gray matter: pain suppresion
    • corpora quadrigemina: dorsal protrusions; superior colliculi (visual reflex center) and inferior colliculi (auditory relay centers)
    • substantia nigra: functionally linked to basal nuclei
    • red nucleus: relay nuclei for some descending motor pathways; part of reticular formation
  77. reticular formation
    Not about memory, its about are you awake, are you aware, and are you aware of your surroundings
  78. pons
    • fourth venticle separates pons and cerebellum
    • fibers of pons: connected higher brain center and spinal cord; relay impulses between motor cortex and cerebellum
    • origin of cranial nerves V, VI, and VII
    • some nuclei of reticular formation
    • nuclei help maintain normal rhythm of breathing
  79. medulla oblongata
    • joins spinal cord at foramen magnum
    • forms part of ventral wall of fourth ventricle
    • contains choroid plexus of fourth ventricle
    • pyramids: two ventral longitudinal ridges formed by pyramidal tracts
    • decussation of the pyramids: crossover of corticospinal tracts
    • inferior olivary nuclei: relay sensory info from muscles and joints to cerebellum
    • vestibular nuclei: mediate responses that maintain equilibrium
    • several nuclei relay sensory info
  80. functions of the medulla oblongata
    • autonomic reflex center
    • cardiovascular center: cardiac center (adjusts rate of heart contraction) vasomotor center (adjusts blood vessel diameter for blood pressure)
  81. respiratory centers
    • generate respiratory rhythm
    • control rate and depth of breathing
  82. list the airway controls part of respiratory centers
    • vomiting
    • hiccuping
    • swalloing
    • coughing
    • sneezing
  83. hypoglossal
    swallowing; below the tongue
  84. cerebellum
    • 11% of brain mass
    • dorsal to pons and medulla
    • input from cortex, brain stem, and sensory receptors
    • allows smooth, coordinated movements
  85. anatomy of cerebellum
    • cerebellar hemispheres connected by vermis
    • folia: transversely oriented gyri
    • each hemisphere has three lobes (anterior, posterior, and flocculonodular)
    • arbor vitae: treelike pattern of cerebellar white matter
  86. what are the three paired fiber tracts that connect the cerebellum to brain stem
    • superior cerebellar peduncles: connected cerebellum to midbrain
    • middle cerebellar peduncles: connect pons to cerebellum
    • inferior cerebellar peduncles: connect medulla to cerebellum
  87. cerebellar processing of motor activity
    • cerebellum receives impulses from cerebral cortex of intent to initiate voluntary muscle contraction
    • signals from proprioceptors and visual and equilibrium pathways inform the cerebellum of body's position and momentum
    • cerebellar cortex calculates the best way to smoothly coordinate muscle contraction
    • blueprint of coordinated movement sent to cerebral motor cortex and brain stem nuclei
  88. cognitive function of cerebellum
    • role in thinking, language, and emotion
    • may compare actual with expected output and adjust accordingly
  89. what are the functional systems of the brain
    limbic system and reticular formation
  90. limbic system
    • structures on medial aspects of cerebral hemispheres and diencephalon
    • includes parts of diencephalon and some cerebral structures that encircle brain stem
    • emotional or affective brain (amygdaloid body and cingulate gyrus)
    • puts emotional responses to odors
    • most output relayed via hypothalamus
  91. amygdaloid body
    • recognizes angry or fearful facial expressions, assesses danger, elicits fear response
    • e.g. horror movies
  92. cingulate gyrus
    role in expressing emotions via gestures, and resolves mental conflict
  93. limbic system: emotion and cognition
    • limbic system interacts with prefrontal lobes: react emotionally to things we consciously understand to be happening, consciously aware of emotional richness in our lives
    • hippocampus: recalling traumatic experiences e.g. first car accident
  94. reticular formation
    • three broad columns run length of brain stem: raphe nuclei, medial group of nuclei, and lateral group of nuclei
    • has far-flung (attached) axonal connections with hypothalamus, thalamus, cerebral cortex, cerebellum and spinal cord; 
    • can govern brain arousal
  95. reticular formation: RAS
    • RAS: reticular activating system
    • sends impulses to cerebral cortex to keep it conscious and alert
    • filtres out repetitive familiar or weak stimuli (99% of stimuli)
    • inhibited by sleep centers, alcohol, drugs
    • severe injury results in permanent unconsciousness (coma)
  96. reticular formation: motor function
    • helps control coarse limb movements via reticulospinal tracts
    • reticular autonomic centers regulate visceral motor functions )vasomotor, cardiac and respiratory centers)
  97. EEG
    • electroencephalogram
    • records electrical activity that accompanies brain function
  98. aura
    sensory hallucination (like before a seizure)
  99. absence seizures
    mild seizures of young children; expression goes blank for few seconds
  100. tonic-clonic seizures
    • most severe; last few minutes
    • victim loses consciousness, bones broken during intense convulsions, loss of bowel and bladder control, severe biting of tongue
  101. control of epilepsy
    • anticonvulsive drugs
    • vagus nerve stimulator or deep brain stimulator implanted
  102. consciousness
    • perception of sensation
    • voluntary initiation and control of movement
    • capabilities associated with higher mental processing (memory, logic, judgement)
    • loss of consciousness signal that brain function impaired (fainting or coma)
  103. sleep and sleep wake cycles
    state of partial unconsciousness from which person can be aroused by stimulation
  104. what are the two major types of sleep
    nonrapid eye movement sleep and rapid eye movement sleep
  105. importance of sleep
    • reverse learning process where unimportant info is purged from the brain
    • if you are deprived you become moody and depressed
    • can be restorative
  106. language
    • language implementation system:
    • basal nuclei
    • broca's area and wernicke's area
    • analyzes incoming word sounds
    • produces outgoing word sounds and grammatical structures

    corresponding areas on right side are involved with nonverbal language components
  107. memory
    • storage and retrieval of information
    • two stages: short term and long term
  108. short term memory
    temporary holding of information; limited to seven or eight pieces of information
  109. long term memory
    has limitless capacity
  110. what are the factors affecting transfer from STM to LTM
    • emotional state; best if alert, motivated, aroused
    • rehearsal; repetition and practice
    • association; tying new info with old memories
    • automatic memory; subconscious info stored in LTM
  111. what are the two categories of memory
    declarative and nondeclarative
  112. declarative (fact) memory
    • explicit information
    • related to conscious thoughts and language ability
    • stored in LTM with context in which learned
  113. nondeclarative memory
    • less conscious or unconscious
    • acquired through experience and repetition 
    • best remembered by doing; hard to unlearn
    • includes procedural memory, motor memory, and emotional memory
    • e.g. habits
  114. what are the brain structures associated with memory
    • procedural memory: basal nuclei relay sensory and motor inputs to thalamus and premotor cortex, dopamine from substantia nigra is necessary
    • motor memory: cerebellum
    • emotional memory: amygdala
  115. protection of the brain mechanisms
    • bone (skull)
    • membranes (meninges)
    • watery cushion (CSF)
    • blood brain barrier
  116. meninges
    • cover and protect CNS
    • protect blood vessels and enclose venous sinuses
    • contain cerebrospinal fluid
    • form partitions in skull
    • anchoring point: cristogalli
  117. what are the three layers of the meninges
    • dura mater
    • arachnoid mater
    • pia mater
  118. dura mater
    • strongest meninx
    • two layers of fibrous connective tissue around brain separate to form dural venous sinuses

    • dural septa limit excessive movement of brain:
    • falx cerebri: in longitudinal fissure
    • falx cerebelli: along vermis of cerebellum
    • tentorium cerebelli: horizontal dural fold over cerebellum and in transverse fissure
  119. arachnoid mater
    • middle layer with weblike extensions
    • separated from dur mater by subdural space
    • subarachnoid space contains CSF and largest blood vessels of brain
    • arachnoid villi protrude into superior sagittal sinus and permit CSF reabsorption
  120. pia mater
    delicate vascularized connective tissue that clings tightly to brain
  121. CSF
    • composition: watery solution formed form blood plasma; 90% water
    • gives buoyancy to CNS; reduces weight by 97%
    • protects CNS from blows and other trauma
    • nourishes brain and carries chemical signals
  122. choroid plexus
    • hang from roof of each ventricle; produce CSF at constant rate
    • ependymal cells use ion pumps to control composition of CSF and help cleanse by removing waste
    • normal volume 150 ml; replaced every 8 hours
  123. blood brain barrier
    • helps maintain stable environment for brain
    • separates neurons froms ome bloodborne substances
    • continuous endothelium of capillary walls
    • thick basal lamina around capillaries
    • feet of astrocytes
  124. blood brain barrier functions
    • selective barrier: allows nutrients to move by facilitated diffusions, metabolic wastes, proteins, toxins, K+ denied
    • allows any fat soluable substances to pass like alcohol nicotine and anesthetics
    • absent in some areas; i.e. vomiting center and hypothalamus
  125. list the homeostatic imbalances of the brain
    • concussion: temporary alteration in function
    • contusion: permanent damage
    • subdural or subarachnoid hemorrhage: may force brain stem through foramen magnum, resulting in death
    • cerebral edema: swelling of brain associated with traumatic head injury
    • cerebrovascular accidents: CVAs or strokes
    • degenerative brain disorders: alzheimer's disease
  126. cerebrovascular accidents
    • ischemia: tissue deprived of blood supply; brain tissue dies, blockage of cerebral artery by blood clot
    • hemiplegia: paralysis on one side or sensory/speech deficits
    • transcient ischemic attacks: temporary episodes of reversible cerebral ischemia
    • tissue plasminogen activator: only approved treatment for stroke
  127. spinal cord location and function
    started at foramen magnum and ends at L1 or L2 vertebra

    • provides two way communication to and from brain
    • contains spinal reflex centers

    • contains bone, meninges, and CSF
    • epidural space
  128. epidural space
    cushion of fat and network of veins in space between vertebrae and spinal dura mater
  129. where does the spinal cord terminate
    conus medullaris
  130. spinal nerves
    • 31 pairs
    • cervical and lumbosacral enlargements
    • nerves serving upper and lower limbs emerge at the enlargements
  131. cauda equina
    collection of nerve roots at inferior end of vertebral canal
  132. what are the names of the lengthwise grooves that partially divide cord into right and left
    • ventral median fissure (anterior)
    • dorsal median sulcus (posterior)
  133. gray commissure
    connects masses of gray matter, encloses central canal
  134. gray matter
    • dorsal horns: interneurons that receive somatic and visceral sensory input
    • ventral horns: some interneurons; somatic motor neurons; axons exit cord via ventral roots
    • lateral horns: sympathetic neurons
    • dorsal roots: sensory input to cord
    • dorsal root ganglia: cell bodies of sensory neurons
  135. what are the zones of spinal gray matter
    • per relative involvement in innervating somatic and visceral regions of body
    • somatic sensory (SS)
    • visceral sensory (VS)
    • visceral autonomic motor (VM)
    • somatic motor (SM)
  136. white matter
    • myelinated and nonmyelinated nerve fibers allow communication between parts of spinal cord, and spinal cord and brain
    • run in three directions: ascending, descending, and transverse
  137. what are the names of the three columns to which white matter white columns are divided on each side
    • dorsal 
    • lateral
    • ventral
  138. neuronal pathway generalization
    • decussation: pathways cross to other side
    • relay: consist of two or three neurons
    • somatotopy: precise spatial relationship
    • symmetry: pathways paired symmetrically
  139. ascending pathways
    • consister of three neurons
    • first order, second order, and third order neurons
  140. first order neurons
    • conducts impulses form cutaneous receptors and proprioceptors
    • branches diffusely as enters spinal cord or medulla
    • synapses with second order neuron
  141. second order neuron
    • interneuron
    • cell body in dorsal horn of spinal cord or medullary nuclei
    • axons extend to thalamus or cerebellum
  142. third order neuron
    • interneuron
    • cell body in thalamus
    • axon extends to somatosensory cortex
    • no third order neurons in cerebellum
    • goes to the parietal part of the brain
  143. what are the three main ascending pathways
    • dorsal column-medial lemniscal pathways: somatosensory info to sensory cortex via thalamus
    • spinothalamic pathways: transmit somatosensory info to sensory cortex via thalamus
    • spinocerebellar tracts: terminate in the cerebellum
  144. dorsal column-medial meniscal pathways
    transmit input to somatosensory cortex for discriminative touch and vibrations
  145. spinothalamic pathways
    • lateral and ventral spinothalamic tracts
    • transmit pain, temp, coarse touch, pressure, impulses within lateral spinothalamic tract
  146. spinocerebellar tracts
    • ventral and dorsal tracts
    • convey info about muscle or tendon stretch to cerebellum
    • used to coordinate muscle activity
  147. descending pathways and tracts
    • deliver efferent impulses from brain to spinal cord
    • two groups: direct pathways and indirect pathways
  148. indirect pathways
    all others
  149. direct pathways
    pyramidal tracts
  150. what are the two neurons that motor pathways have
    • upper motor neurons: pyramidal cells in primary motor cortex
    • lower motor neurons: ventral horn motor neurons and innervate skeletal muscles
  151. direct (pyramidal) pathways
    • impulses form pyramidal neurons in precentral gyri pass through pyramidal tracts
    • descend without synapsing
    • axons synapse with interneurons or ventral horn motor neurons
    • direct pathway regulates fast and fine movements (skilled)
  152. indirect (multineuronal) system
    • complex and multisynaptic
    • includes brain stem motor nuclei, and all motor pathways except pyramidal pathways
    • the pathways regulate axial muscles maintaining balance and posture
    • muscles controlling coarse limb movements
    • head neck and eye movements that follow objects in visual field
  153. reticulospinal and vestibulospinal tracts
    maintain balance
  154. rubrospinal tracts
    control flexor muscles
  155. superior colliculi and tectospinal tracts
    mediate head movements in response to visual stimuli
  156. spinal cord trauma
    • transection: cross sectioning of spinal cord at any level, results in total motor and sensory loss in regions inferior to cut
    • paraplegia: transection between T1 and L1
    • quadriplegia: transection in cervical region
    • spinal shock: transient period of functional loss caudal to lesion