LectureNotesJanuary27
Precentral gyrus (primary motor cortex)
-anterior to the central fissure.
Postcentral gyrus (primary somato sensory-primary sensory cortex)
-posterior to ventral fissure (fissure of rolando)
Association areas (secondary areas)
-angular gyrus near temporal, occipital and parietal junction.
-arcuate fasciculus-major fiber tract that connects temporal and frontal lobes
Review these terms and draw these fissures
Longitudinal fissure: largest fissure: anterior/posterior
central fissure: fissure of rolando
lateral cerebral fissure: fissure of sylvius
calcarine fissure: the blue line
pre central gyrus or primary motor cortex-motor before sensory, the dividing line is central fissure
a. other mnemonic is M.S. degree
primary somato-sensory or post central gyrus-sensory after motor, divided by the central fissure
Associated cortex: (2)
a. angular gyrus: posterior to the Sylvain fissure, overlaps temporal, partial, occipital lobes
b,arcuate fissure- start in the temporal lobe and ends in the frontal lobe
-inferior
-superior temporal
Broca’s aphasia: video: inferior frontal area is damaged
Wernickes’s aphasia: superior temporal area is damaged as well as posterior temporal
More Knowledge:
Frontal lobe: defining the boundary of the front lobe?
-Where is the inferior boundary?
-lateral fissure or Sylvain fissure
-Where is the posterior boundary?
-fissure of Rolando or the central fissure
What is the PMC (primary motor cortex) responsible for?
-motor movement on the contra lateral side of the body-opposite side of the body (contra lateral)
Where is the prefrontal lobe?
-above the eyebrow, lower than eyes
What is the prefrontal lobe role and responsible?
-make a person unique
-responsible for executive function.
What are the 7deadly executive functions? 3 ins, 1 imp, 1consequence, 1 judgment, 1 organization
-initiation an action
-impulsivity (stop being impulsive)
-inhibition (
-insight (
-consequence of actions (
-other judgments
-organizations
How do we teach the deadly 7?
The prefrontal area can be damage by injury as well as by stroke.
-If a person has a stroke in prefrontal area, then the person’s language is intact, but cognitive
function is deficit.
-e.g. professor could not remember: he had bad organization skills. Think of the professor from
Berkeley.
What is the Temporal lobe responsible for?
-hearing and auditory comprehension
-What is the difference between hearing and auditory comprehension?
-Wernicke’s aphasia clients can hear something, but they are not able to comprehend X.
-SLP need to know the differences
Temporal Lobe: define the boundaries?
-Where is the superior boundary of the temporal lobe?
-Sylvain fissure or lateral fissure
-Where is the inferior boundary?
-underside of the hemisphere
-Where is the posterior boundary?
-imagery line (not well defined)
E.g. wernicke aphasia-hearing what is sound, but did not comprehend the situation
Why is the temporal lobe important?
1. It is important to discriminate pitch
2. it is important for discriminating language from background noise
3. It is important for discriminating background noise from language.
How is the temporal lobe related to language?
1. the temporal lobe is important for semantic and syntax because if the patient can not
make meaning from his language, the patient will be incoherent.
if the temporal lobe is damaged, then the patient can not make meaningful
language: no meaning and no comprehension
What is the Parietal lobe responsible for?
1. the parietal area is responsible for sensation (touch, pain, temperature)
Parietal Lobe: define the parietal boundaries?
-What is the anterior boundary of the parietal lobe?
-central fissure or fissure of Rolando
-Where is the inferior boundary of the parietal lobe?
-lateral fissure or Sylvain fissure
-Where is the posterior boundary of the parietal lobe?
-invisible line
What is the Occipital lobe responsible for?
-contains the primary visual cortex (must have association cortex)
-What is the anterior/inferior/posterior boundary of the occipital?
-all are imagery lines
-What happens when you damage the occipital lobe? Cortical Blindness-the patient can only
discriminate shades of gray (darker or lighter). Patients can not read.
Cerebral cortex (Neo cortex) outer surface of cortex of both hemisphere –very thin (1.5mm-4mm thick)
–large (contains 7-8 billion neurons) -2/3 of the cerebral cortex is within fissure (makes us unique for
humans)
- The cerebral cortex is the layer of the brain often referred to as gray matter. It is the outer
portion of the cerebrum.
Primary cortical areas
-1. PMC (primary motor cortex) responsible for
-initiate and control voluntary skilled movements on the contra lateral side.
e.g. fine (typing) vs. gross movements
-2. PSC (primary somatic-sensory cortex) responsible for
-somatic sensations on the contra lateral side
e.g hemiparies-if you lose the motor, you usually lose sensation. the client will
not feel their hands. Remember,
3. Primary auditory cortex
-herschel gyrus
-each of the auditory cortex receive info from both ears
-both sides go into one hemispheres
4. Primary visual cortex
-look at the pathway.
5. Primary olfactory cortex
-Where is the olfactory cortex?
-posterior-inferior frontal lobe, inferior frontal lobe.
-olfactory bulbs can be damaged by picking your nose.
The cortex are viewed from the top, but they are deep up to 4mm
Associative area
Secondary motor cortex-improves or refines what the primary area does (defines PMC)
-anterior to the PMC
-no clearly defined.
Secondary somatic-sensory cortex-processing tactile information and spatial information
-posterior PSC
- (e.g. hot stove, take away hand is spatial)
Secondary temporal area-discriminates and processes auditory information and language related
information
Secondary parietal/occipital area-discriminated visual information
No secondary olfactory area because you can directly damage the olfactory bulbs. (damaged or
not)
DEEP STRUCTURES OF THE BRAIN
Diencephalon-deep within the cerebrum on top of the brain stem.
thalamus-oval-egg shaped and lateral to the 3rd ventricle and within the diencephalon.
-relay station for efferent (motor) and afferent (sensory) fibers E for efferent, e for exit,
-connection to other areas of cerebellum, basal ganglia, subcortical regions, brainstem
What is the thalamus responsible for?
-regulates consciousness, alertness, attention
Hypothalamus-all aspects of behavior (graduate brain-emotions,feed/eating, natural rhythms)
Pineal body (center of the soul)
–regulates body rthyms-calcium at 30 yrs…marker for CAT scan
Third ventricle
-within the diencephalon
Basal Ganglia: What is the Basal Ganglia role and responsible?
-receive and relays information from multi-cortex sites
-many connection to the frontal lobe
-Responsible- adjust major group of muscles in the trunk and limbs.
-Responsible-(poor)posture, muscle tone, sequence smooth movements and habit
learning (stimulus and response).
-damage to the Basal Ganglia=dyskinesia-involunatry movements
Caudate Nuclues, Lenticular Nucleus (putamen, globus pallidus) Substantia Nigra
Globus pallidus-responsible for movement, Parkinson’s disease.
-pallitomy
Substantia Nigra-releases dopamine..festernation-tiny steps
Amygdala-
Internal capsule-efferent and afferent fibers pass via thalamus and basal ganglia
-resp. for motor movement information from the PMC to lower centers (afferent fibers)
-resp. also from lower center to PMC (efferent fibers)
damage results in : muscle paralysis or sensory disturbances
MOTOR PART of the Internal Capsule
3 categories of movement fibers (look at picture)
cortical pontine fibers-anterior limb cortex to pons
cortical bulbar fibers-cortex to medulla genu portion
cortical spinal fibers-cortex to spinal cord-know as the posterior limb
SENSORY PART of the Internal Capsule
Sensory fiber--ascended via posterior limb, travel together
What is the Brainstem role?
-communicative and structural link between the brain and spinal cord
-cranial nerves originate in brain stem
-pathways for efferent/afferent fibers
What is the Brainstem responsible for?
brainstem is resp.=controls breathing, heart rate, and consciousness (reticular formation)
What is the midbrain responsible for?
-resp. motor control and muscle tension connects the brain stem to cerebrum
What is the pons responsible for?
-resp. bulge in the brainstem-hearing and balance-contains the 4th ventricle
damage results in lock-in syndrome-cognitive, but diving bell and the butterfly
What is the medulla responsible for?
-resp.located between pons and spinal cord
Nerve fiber tracts decussate (cross) from one side CNS to the other
Damage results in vertigo and paralysis of throat and larynx and sensory loss of
limbs and face good candidate for AAC.
Cerebellum (Ataxia)-responsible for regulating rates, range, direction and force to movement
Damage to the cerebellum results in Ataxia (clumsiness)-over-shooting and undershooting
1. it is important for motor movement.
BLOOD SUPPLY to the BRAIN
Lateral Ventricle (2)-organize chucks of brain
15% of CSF in CNS
-contains choroid plexus-soft sponge materials that produces CSF
2 lateral V-one in each hemisphere connected to 3rd ventricle with interventricle foramen below and
between the lateral ventricle then connects to the 4th by the cerebral aqueduct.
4th ventricle opens in subarachnoid space (loopy)
Overpressure of ventricle results in brain damage
Limbic lobe: (cingulated cortex, septum, mamillary body)
-Hippocampus-used for working memory-actively keeping a moment in storage before you recall
-digit span
-amygdala-episodic memory
-perirhinal area-auditory and visual memory-sensitive to lack of oxygen
Neurons-small
-axon, dendrites, cell body
-multi-dendrites
-one-axon (1mm-1ft)
-myelin increase the speed of electrical impulse
-cell body-tells the neuron what to do
Axons are white-fiber tracts
-projection fiber-long distance CNS carrier from brain to spinal cord or
peripheral sensory nerves
-efferent fibers carry info from brain to muscle and glands
-dense fibers
-afferent fibers receive info from periphera through the spinal cord
LARGER VIEW of NEURONS
Regional carrier
-commissural fibers
-corpus collusum-3 parts-anterior, central (genu), posterior
Anterior and Posterior Commissural Fiber
-anterior crosses midline via thalamus
-posterior crosses midline at the posterior end of the corpus collosum
Association Fiber-local carriers and intra-hemispheric (short carrier)
fascicles fibers (uncinate, arcuate, cingulum)
arcuate via temporal to the frontal
Parimental Pyramidal system-nerve cells that look like pyrmanids
resp. initiate in skilled voluntary movement
contains motor neurons of PMC and axons synapse in the spinal cord
-direct system (no breaking of synpnases)
Upper motor neurons (UMNS in the CNS)
starts in PMC and syn in LMN which are in the brain stem and spinal cord
LMS related to peripheral
Vestibular reticular system-neurons within the brain stem and cere
Resp-balance attention and alertness
Extra pyramidal system-arises from many CNS locations especially basal ganglia and projection to the
cranial and spinal nerves and it is an indirect pathway. Mult-synp. from origin to
resp for muscle tone and posture for volitional movements
damage results in affects muscle tone, posture and volitional movements
Motor speechPeripheral nervous system-not encased in bone
-somatic-sensory perception and volitional motor movement. contain cranial nerve and spinal
nerves
-automatic nervous system
Cranial Nerve # (Sensory/Motor), Function use brookshire (highlight SLP)
leave the spinal cords (31 pairs of spinal cords)
-name location
posterior dorsal (back)=sensory infor
anterior venteral root front=motor info
Avg. 18ins. Central core is gray(neurons) white is axon
-motor pathways
-cortical spinal pathway
start-PNC syn cranial nerves at anterior horns of spinal cord (it is crossed-contralateral)
-spinal celleballer pathway
-start with PNS connects with cerebellum (isplateral-same side)
-sensory pathways (pain and temperature)
-ascend in the laterl aspinal cord to the thalamus then to PNC (contralateral) pathway
-proprio-ception-id location head and limbs without vision
-sterogenosis-id by touch (objects)
sensory from dorsal posterior spinal cord to the cerebellum and secondary
somaticsenorry cortex (contra lateral pathway)
-light touch-ascends in the ventral anterior spinal cord to brain stem to PSC, touch is
cross and uncrossed.
Should have an idea before we see the patient?