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143 Cards in this Set
- Front
- Back
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embryological dvlp of CAN |
sheet of ectodermal cells that fols over to form the neural tube |
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prosencephalon |
forebrain |
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mesencephalon |
midbrain (cerebral peduncles, tectum, tegmentum) |
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rhombencephalon |
hindbrain |
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forebrain divisions |
telencephalon and diencephalon |
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telencephalon |
cerebral hemispheres |
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diencephalon |
thalamus, hypothalamus, epithalamus |
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midbrain |
relatively short and narrow region connecting the forebrain and hindbrain |
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hindbrain |
pons, cerebellum, medulla |
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metencephalon |
pons, cerebellum |
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myelencephalon |
medulla |
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what does the brainstem control |
basic body fxns: respiration, BP, heart rate |
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where is CSF made |
choroid plexus |
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CSF circulation |
lateral ventricles to third ventricle, to fourth ventricle, to outside of brain and spinal cord |
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meninges |
pia, arachnoid, and dura |
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where is CSF absorbed into the venous system |
btwn the arachnoid and pia mater |
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where does the 90 bend occur btwn spinal cord and forebrain in humans |
region of midbrain-diencephalic jxn |
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where are bipolar neurons often found |
sensory like vision or olfaction |
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pseudounipolar |
processes initially fused, then split to produce two long axons (ex dorsal root ganglion sensory neurons) |
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where do unipolar neurons occur |
invertebrates |
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how long does an AP last |
~1 ms; propagate up to 60 m/s |
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myelin-forming glial cells in the CNS |
oligodendrocytes |
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myelin-forming glial cells in the PNS |
Schwann cells |
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what are located in the nodes of Ranvier |
Voltage gated ion channels concentrated; saltatory conduction |
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neuromodulation |
slower time scale of regulating neuron via signaling cascades, growth, other fxns |
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most common excitatory neurotransmitter |
glutamate |
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most common inhibitory neurotransmitter |
GABA (gamma-aminobutyric acid) |
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cerebral cortex |
surface of cerebral hemispheres covered by a unique mantle of gray matter |
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nuclei |
large clusters of gray matter deep in cerebral hemispheres and brainstem |
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examples of nuclei |
basal ganglia, thalamus, cranial nerve nuclei |
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spinal cord white/gray matter |
white outside gray inside |
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varous names for white matter tracts in the CNS |
tract, fascicle, lemniscus, bundle |
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commisure |
white matter pathway that connects identical structures on right and left sides of the CNS |
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afferent |
pathwyas carrying signals toward a structure; arrive |
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efferent |
carrying signals away from a structure; exit |
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general orientation of motor and sensory systems |
motor generally ventral/anterior and sensory dorsal/posterior |
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where does the spinal cord typically end |
L1 or L2 |
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what is below the spinal cord |
cauda equina |
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What nerves/cranial nerves have parasympathetics |
CN III, VII, IX, and X; S2-4 |
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where does sympathetic division arise |
T1 to L2 |
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what does enteric nervous system control |
peristalsis and GI secretions |
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sulci |
numerous infoldings or crevices of brain |
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gyri |
bumps or ridges btwn sulci |
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four major lobes of the cerebral hemispheres |
frontal, temporal, parietal, occipital |
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where do the frontal lobes extend back to |
central sulcus of Rolando |
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what are the frontal lobes separately inferiorly and laterally from the temporal lobes by |
Sylvian fissure aka lateral fissure |
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fissure |
refers to deep sulci |
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parietal lobe boundaries |
anteriorly by central sulcus, no sharp demarcation from temporal lobes or occipital lobes viewed from lateral side |
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parieto-occipital sulcus can be viewed how |
viewed from medial aspect |
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insular cortex |
additional region of cortex buried within depth of Sylvian fissure |
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what are the lips of frontal and parietal cortex covering the insular cortex called |
frontal and occipital operculums (means covering/lid in latin) |
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what fissue divides the two cerebral hemispheres |
interhemisphereic fissure aka longitudinal fissure |
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corpus callosum |
large C-shape band of white matter that connects homologous areas in the two hemispheres |
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gyrus running in front of the central sulcus |
precentral gyrus |
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most anterior portion of the parietal lobe behind the central sulcus |
postcentral gyrus |
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what parietal lobule surrounds the end of the Sylvian fissure |
supramarginal gyrus |
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What parietal lobule surrounds the end of the superior temporal gyrus |
angular gyrus |
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what does the corpus callosum consist of |
rostrum, genu, body, splenium |
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what gyrus surrounds the corpus callosum |
cingulate gyrus (means girdle/belt) |
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region surrounding the central sulcus |
paracentral lobule |
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portion of the medial occipital lobe below the calcarine fussure |
lingula |
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portion of the medial occipital lobe above the calcarine fussure |
cuneus (wedge) |
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where is the primary visual cortex |
occipital lobes along the banks of a deep sulcus called the calcarine fissure |
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where is the primary auditory cortex |
transverse gyri of Heschl inside the Sylvian fissure on the superior surface of each temporal lobe |
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homunculus |
somatotopic maps on the cortex (either sensory or motor) |
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neocortex |
majority of the cerbral cortex-consists of 6 layers from the surface inwards |
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Layer I consists of |
dendrites of neurons from deeper layers and axons |
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Layer II and III consist of |
neurons that project mainly to other areas of cortex |
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Layer IV consists of |
receives majority of inputs from thalamus |
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Layer V consists of |
projects mostly subcortical structures other than thalamus (brainstem, spinal cord, basal ganglia) |
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Layer VI consists of |
projects primarily to the thalamus |
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primary motor cortex job |
large efferent projections to brainstem and spinal cord to control movement; little sensory info from thalamic relay centers |
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primary motor cortex layers |
V is thiker and has many more cell bodies that IV |
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primary visual cortex layers |
IV contains many cell bodies and layer V is relatively cell poor |
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Brodman classification |
52 cytoarchitectonic areas that correlate fairly well with fxn |
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Name for Layer 1 |
molecular layer |
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Name for Layer 2 |
small pyrimidal layer |
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Name for Layer 3 |
medium pyrimidal layer |
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Name for Layer 4 |
granular layer |
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Name for Layer 5 |
large pyramidal layer |
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Name for Layer 6 |
polymorphic layer |
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most important motor pathway |
corticospinal tract |
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where do 85% of the fibers in the corticospinal tract cross |
jxn between medulla and spinal cord (pyramidal decussation) |
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lesions above the pyramidal decussation produce |
contralateral weakness |
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lesions below the pyramidal decussation produce |
ipsilateral weakness |
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upper motor neurons |
project from cortex down to the spinal cord or brainstem; UMNs |
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Lower motor neurons |
located in anterior horns of central gray matter of the spinal cord or in brainstem motor nuclei |
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where do LMNs travel |
out of the CNS via anterior spinal roots or cranial nerves to reach muscle cells in the periphery |
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lesions in cerebellum lead to |
disorders in coordination and balance (ataxia) |
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lesions in basal ganglia cause |
hypokinetic movement disorders (Parkinsonism) and hyperkinetic movement disorders (huntingtons's) |
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Parkinsonism movements |
movements are infrequent, slow, and rigid |
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Huntinton's movements |
dancelike involumtary movements |
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Why do lesions in cerebellum and basal ganglia cuase motor impairments |
modulate output of the corticospinal and other descending motor systems |
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major relay center for signals traveling to cerebral cortex |
thalamus |
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proprioception |
limb or joint position sense |
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Posterior column pathways transmit |
convey proprioception, vibration sense, and fine discriminative touch |
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Antereolateral Pathways transmit |
convey pain, temperature sense, and crude touch |
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where are the primary sensory neuron cell bodies located |
dorsal root ganglia (bifurcating neurons) |
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where does the posterior column pathway cross over |
synapse in dorsal column nuclei in medulla which cross over to the other side of the medulla, synapse in thalamus, and go to primary somatosensory cortex in postcentral gyrus |
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where does the anterolateral pathway cross over |
enter spinal cord and synapse in gray matter, cross over and ascend, synapse in thalamus, continues to primary somatosensory cortex |
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thalami location |
grey matter structures located deep within the cerebral white matter just above brainstem and behind basal ganglia; egg-shaped with posterior ends angled outward |
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what does hypothalamus regulate |
autonomic, neuroendocrine, limbic, and other circuits |
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what is the epithalamus |
several small nuclei including the pineal body, habenula, and parts of the pretectum |
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monosynaptic stretch reflex |
reflex arc that provides rapid local feedback for motoe control |
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what does a reflex arc start with |
muscle spindles-detect amount and rate of stretch in muscles |
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where do muscle spindles send info |
distal processes of sensory neurons, then to dorsal roots into spinal gray matter |
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what occurs to signal once in spinal cord gray matter |
multiple synapses: 1) directly to LMNs in anterior horn 2) excitatory and inhibitory interneurons (which may synapse on LMNs) |
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are there descending pathways that modulate the activity of the stretch reflex |
yes; if absent the reflex may be hyperactive or hypoactive |
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what does the brainstem connect to |
diencephalon rostrally, cerebellum dorsally, and spinal cord caudally |
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reticular formation location |
throughout the central portions of the brainstem from medulla to midbrain |
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reticular formation in medulla and pons |
tends to be involved in mainly motor and autonomic fxns |
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rostral reticular formation involvement |
level of consciousness by modulation of thalamic activity |
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what other areas are important for maintaining consciousness |
cortical, thalamic, and other forebrain networks |
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limbic system includes |
certain cortical areas in medial and temporal lobes, anterior insula, inferior medial frontal lobes, and cingulate gyri; hippocampal formation and amygdala, several nuclei in medial thalamus, hypothalamus, basal ganglia, septal area, and brainstem |
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what are the areas of the limbic system connected by |
fornix and a variety of other pathways |
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fornix |
paired, arch-shaped white matter structure that connects the hippocampal formation to the hypothalamus and septal nuclei |
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lesions in limbic system can cause |
deficit in consolidation of immediate recall into longer-term memories |
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where do epileptic seizures most commonly arise from |
limbic structure of the medial temporal lobe |
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where is unimodal association cortex generally located |
adjacent to primary motor or sensory area |
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heteromodal association cortex fxn |
integrate fxns from multiple sensory and/or motor modalities |
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where is language usually perceived first |
primary auditory cortex in superior temporal lobe for speech or primary visual cortex when reading |
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where do cortical-cortical association fibers convey information |
to Wernicke's area in the dominant hemisphere (usually L) |
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lesions in Wernicke's area cause |
deficit in language comprehension (recaptive or sensory aphasia or Wernicke's aphasia) |
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Broca's area location |
frontal lobe (L hemisphere) adjacent to areas of primary motor cortex involved in moving the lips, tongue, face, and larynx |
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lesion in Broca's area causes |
deficit in production of language; expressive or motor aphasia |
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lesions in inferior parietal lobule in L hemisphere can produce |
difficulty with calculations, right-left confusion, inability to identify figers by name (finger agnosia), difficulties with written language; called Gertmann's syndrome |
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where does motor planning occur |
in diffuse areas of cortex |
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apraxia |
abnormalities in motor conceptualization, planning, and execution |
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lesions in parietal lobe, especially non-dominant hemisphere cause |
distortion of percieved space and neglect of contralateral side |
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anosognosia |
unawareness of a deficit |
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frontal release signs |
primitive reflexes normal in infants (grasp, root, suck, snout reflexes) |
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perseverate |
repeat single action over and over without moving on to next one |
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abulic |
Loss or impairment of the ability to make decisions or act independently |
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magnetic gait |
feet shuffle close to floor |
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prosopagnosia |
inability to recognize faces |
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achromatopsia |
inability to recognize colors |
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palinopsia |
persistance or reappearance of an object viewed earlier |
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anterior blood supply to brain |
internal carotids |
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what forms the basilar artery |
the two vertebral arteries |
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venous drainage for brain |
almost entirely by internal jugular veins |
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where does the spinal cord receive blood supply |
anterior spinal artery along ventral surface and paired posterior spinal arteries along R and L dorsal surfaces |
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what supplies anterior and posterior spinal arteries in cervical region |
branches from vertebral arteries |
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what supplies anterior and posterior spinal arteries in thoracic and lumbar regions |
radicular arteries arising from aorta |
