Download Temporal Aspects of Visual Extinction

CNS Gross Anatomy
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Roles of the CNS
• Functions of neurons in the CNS (brain and spinal
cord) include:
– Sensor: Receives environmental and body stimuli
– Integrator: Combines information received
– Effector: Initiates body movements
– Regulator: Maintains homeostatic state for body
function
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Nervous System
• The CNS is protected and isolated.
– Bone offers protection from injury
• Skull covers brain
• Vertebral Column covers spinal cord
– The is encased in soft-tissue membranes
– The brain’s blood vessels stop many subastances
from entering the brain (blood-brain barrier)
• Protects from contamination/infection
– The brain floats in cerebral spinal fluid
• Offers protection from impact
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The Meninges
• Dura Mater: Tough outer covering
• Arachnoid Mater: Middle layer
• Pia Mater: Inner closely formed
layer
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Cerebrospinal Fluid (CSF)
• Located between the
meninges and in the
ventricular cavities of the
brain
• Produced in the
ventricular cavities by the
choroid plexus
• Functions
– mechanical buffer
– fluid for metabolic functions
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CSF
• CSF is in ventricles, subarchnoid
space, interventricular foramens, and
around the spine.
• Circulates from ventricles around brain
and spinal column
• Is finally absorbed by venous system
• Replenishes at ventricles every 7 hours
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Divisions of the PNS
• Somatic Nervous System (under voluntary control)
– Sensory and Motor
– Skin and Muscles
• Autonomic Nervous System (can not be voluntarily
controlled).
–
–
–
–
Sensory and Motor
Visceral organs and glands
Two main subdivisions:
Sympathetic: Fight, Flight, Fear
• Prepare to expend energy
– Parasympathetic: Regulates normal function
• Prepare to conserve energy
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Major Structures of the Brain
• Longitudinal Fissure
– Separates Two Hemispheres of the Brain
– Aka ‘Interhemispheric Fissure’
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• The folds of your brain are like a fingerprint – there are
a few general patterns, with individual variability.
• Two main folds
– Central Sulcus
Fissure of Rolando
Rolandic sulcus
– Lateral sulcus
Sylvian fissure
 The central sulcus separates
the frontal and parietal lobes.
 The lateral sulcus separates
the temporal lobe from frontal,
parietal, insula
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The major cortical lobes
Insular Lobe – Tucked
away, but often injured
in patients seen by
speech pathologists
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Major medial sulci
Central Sulcus
Parieto-occipital Sulcus
Calcarine Sulcus
Preoccipital Notch
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Landmarks of the frontal lobe
•
•
•
•
•
•
Frontal Pole
Precentral Gyrus
Precentral Sulcus
Premotor Cortex
Speech, Fine Motor
Prefrontal Cortex
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Frontal Lobe Functions
• Motor Function
• Cognitive Functions
• Reasoning, Abstract
Thinking, SelfMonitoring, Decision
Making, Planning,
Inhibition
• Organization of
Spoken Language
Frontal Motoric Areas
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Broca Area – speech production
Pars triangularis
(Inferior fronal gyrus)
Pars orbitalis
(Inferior frontal gyrus)
Pars opercularis
(Inferior frontal gyrus)
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Parietal Lobe Landmarks
• Post Central Gyrus (PoCG)
– Primary Sensory Cortex
• Superior and Inferior Parietal
Lobules (SPL, AnG,SmG)
– Perceptual Synthesis, Spatial
Orientation, Memory
• Angular Gyrus (AnG)
Supramarginal Gyrus (SMG)
– In Dominant Hemisphere:
Reading, Writing and
Calculation
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The homunculus (little man)
• The motor strip (red, frontal
cortex) and primary sensory
cortex (green, parietal) spatially
map corresponding portions of
the contralateral hemisphere.
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Temporal Lobe – Major External
Gyri
• Superior Temporal Gyrus
• Middle Temporal Gyrus
• Inferior Temporal Gyri
Temporal Pole
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Temporal Operculum
• Dorsal surface of STG is
called the ‘Temporal
Operculum’ (Lip)
– Middle section: Heschel’s Gyri
(Brodmann Areas 41 + 42)
• Auditory Reception Cortex
– Posterior section: Wernicke’s
Area (Brodmann 22)
• Auditory Association Cortex
Heschl’s Gyrus
• Primary auditory cortex
found in Heschl’s gyrus
• This is organized
tonotopically – a high
pitched sound excites a
different region than low
pitched sounds.
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Superior Temporal Gyrus
• Auditory Cortex lies
inside the Superior
Temporal Sulcus
• Part of the superior
temporal gyrus that is
planum temporale
imperative for the
(nonprimary AC)
Heschl’s gyrus
perception of speech is
(primary AC)
Heschl’s gyrus
planum
polare
(nonprimary
AC)
Ventral-Medial Structures
• Temporal Lobe
– Fusiform gyrys (Face
Recognition)
– Hippocampal Gyrus
(places, memory)
– Uncus (smell)
• Occipital lobe
– Cuneus and Lingual
gyrus (primary vision)
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Medial View
Ventral-Medial Structures
Uncus
Parahippocampal Gyrus
Fusiform Gyrus
Lingual Gyrus
Cerebellum and
Brainstem removed
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Occipital Lobe
• Occipital Pole (medial)
– Medially: cuneus and lingual
gyrus: primary visual cortex
– Clinically: field cuts, blindsight
• Lateral occipital structures:
– Superior, Lateral and Superior
Occipital Gyris: Secondary Visual
Cortex (Association)
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Language Areas
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Insular Lobe (Isle of Reil)
• Deep in Lateral Fissure
– Functions: Language(?), taste, disgust,
cravings (e.g. smoking)
Midsagittal Surface
• Corpus Callosum
– Connects Hemispheres
• Limbic System
– Emotions
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•
•
•
Cingulate Gyrus
Fornix
Thalamus
Hypothalamus
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Midsagittal Surface
Corpus
Callosum
Cingulate
Gyrus
Septum
Uncus
Fornix
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Transverse Slice
Fornix
Claustrum
Putamen
Caudate Nucleus
Thalamus
Globus Pallidus
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Brain Stem
Optic
Nerve
Midbrain
Pons
Medulla
Optic
Chiasm
Optic
Tract
Pes
Pedunculi
Pituitary
Stalk
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Basal Ganglia
•
•
•
•
Caudate Nucleus
Putamen
Globus Pallidus (Pallidum)
Caudate Nucleus
+Putamen = Striatum
• Putamen + Globus
Pallidus = Lenticular
Nucleus
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Striatum
Head of
Caudate
Nucleus
Cleft for
Internal Capsule
Thalmus
Putamen
Amygdaloid
Nucleus
Tail of
Caudate Nucleus
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Lateral View