Rahmatina B. Herman Bagian Fisiologi FK-UNAND Slide 2 Overview
Central Nervous System (CNS) CNS consists of brain and spinal cord
Estimated 100 billion neurons in brain are assembled into complex
networks that enable human to: 1. subconsciously regulate internal
environment 2. experience emotions 3.voluntarily control movements
4. perceive (be consciously aware of) body and surroundings
5.engage in other higher cognitive processes such as thought and
memory Slide 3 Overview .Central Nervous System (CNS) No part in
brain acts in isolation from other brain regions Networks of
neurons are anatomically linked by synapses Neurons throughout
brain communicate extensively with each other by electrical and
chemical means Even though the brain is a functional whole, it is
organized into different regions Slide 4 Overview .Central Nervous
System (CNS) Physiologically parts of brain can be grouped into:
1.Forebrain: a.Cerebrum:-cerebral cortex -basal nuclei
b.Diencephalon:-thalamus -hypothalamus 2. Cerebellum 3.Brain stem
Slide 5 Slide 6 Overview Functions of Brain FOREBRAIN: CEREBRUM
Cerebral cortex 1.Sensory perception 2.Voluntary control of
movement 3.Language 4.Personality traits 5.Sophisticated mental
events, such as thinking, memory, decision making, creativity, self
consciousness Basal nuclei 1.Inhibition of muscle tone
2.Coordination of slow, sustained movements 3.Suppression of
useless patterns of movements Slide 7 Overview Functions of Brain
FOREBRAIN: DIENCEPHALON Thalamus 1.Relay station for all synaptic
input 2.Crude awareness of sensation 3.Some degree of consciousness
4.Role in motor control Hypo- thalamus 1.Regulations of many
homeostatic functions, such as temperature control, thirst, urine
output, food intake 2.Important link between nervous and endocrine
systems 3.Extensive involvement with emotion and basic behavioral
patterns Slide 8 Overview Functions of Brain CEREBELLUM
1.Maintenance of balance 2.Enhancement of muscle tone
3.Coordination and planning of skilled voluntary muscle activity
BRAIN STEM ( MIDBRAIN, PONS, MEDULLA ) 1.Origin of majority
peripheral cranial nerves 2.Cardiovascular, respiratory, digestive
control centers 3.Regulations of muscle reflexes involved with
equilibrium and posture 4.Reception and integration of all synaptic
input from spinal cord: arousal and activation of cerebral cortex
5.Role in sleep-wake cycle Slide 9 Cerebral Cortex 4 pairs of lobes
for different activities: 1. Occipital lobes: initial processing of
visual input 2.Temporal lobes:initial receiving of sound sensation
3.Parietal lobes:receiving and processing sensory input 4.Frontal
lobes:- voluntary motor activity - speaking ability - elaboration
of thought Slide 10 Slide 11 Parietal lobes: Somatosensory Cortex
Somesthetic sensation: sensation from surface of body: touch,
pressure, heat, cold, pain, etc Proprioception: awareness of body
position Sensory homunculus Slide 12 Parietal lobes:
..Somatosensory Cortex Localizes source Perceives level of
intensity of stimulus Spatial discrimination: shapes of object,
distinguish differences in similar subject Projects the sensory
input to adjacent higher sensory areas for further elaboration,
analysis, and integration Receive sensory input from the opposite
side of body Damage: sensory deficit/losses of the opposite side
Slide 13 Frontal lobes: Primary Motor Cortex Voluntary control over
movement produced by skeletal muscle Motor homunculus Extent of
representation in motor cortex is proportional to the precision and
complexity of motor skills Controls muscle on the opposite side of
body Damage: paralysis on the opposite side Slide 14 Other Region
for Motor Control Supplementary motor area: -Programming complex
sequences of movement Premotor cortex -Orienting body and arms
toward target Posterior parietal cortex -integration of
somatosensory and visual input, important for complex movement
Lesions: interfere with performance of integrated movements (not
paralysis) Slide 15 Slide 16 Slide 17 Slide 18 Aspects of
Communication Two aspects of communication 1.The sensory aspect
(language input) that involving: -ears, and -eyes 2.The motor
aspect (language output) that involving: -vocalization, and -its
control Slide 19 Wernickes area Brocas area Slide 20 Brocas and
Wernickes Area: Complex Form of Communication Brocas area: speaking
ability Wernickes area: -critical role in understanding both spoken
and written massage -formulating coherent patterns of speech
-controls articulation of speech 1. Formation in mind of thoughts
to be expressed and choice of words to be used 2. Motor control of
vocalization and actual act of vocalization itself Slide 21 Slide
22 Language Disorders Destruction of portions of auditory and
visual association areas of cortex can result in inability to
understand: -the spoken word, and/or -the written word These
conditions are called respectively: -auditory receptive aphasia
(word deafness) -visual receptive aphasia (word blindness =
dyslexia) Slide 23 .Language Disorders Destruction of Brocas area:
-capable of deciding what he wants to say and vocalizing but cannot
make vocal system emit words instead of noises These conditions is
called: -motor aphasia Slide 24 .Language Disorders Destruction of
Wernickes area: -capable of understanding either the spoken word or
the written word but are unable to interpret the thought to be
expressed and choice of words to be used These conditions is
called: -Wernickes aphasia Slide 25 Basal Nuclei (Ganglia Basalis)
Play an important inhibitory role in motor control Lesions in
globus pallidus frequently lead to spontaneous and often continuous
writhing movements of a hand, an arm, the neck, or the face which
is called athetosis Slide 26 .Basal Nuclei (Ganglia Basalis) Lesion
in subthalamus often leads to flailing movements of entire which is
called hemiballismus Lesions in putamen leads to flicking movements
in hands, face and other parts of body, which is called chorea
Lesions of substantia nigra leads to common and extremely severe
disease of rigidity, akinesia, and tremors known as Parkinsons
disease Slide 27 Limbic System Is not a separate structure A ring
of forebrain structures that surround brain stem and interconnected
by intricate neurons pathway Complex interacting networks which is
associated with emotions, basic survival and sociosexual behavioral
patterns, motivation and learning Slide 28 Slide 29 Memory
Physiologically, memories caused by changes in capability of
synaptic transmission from one neuron to the next as a result of
previous neural activity The changes in turn cause new pathways or
facilitated pathways to develop for transmission of signals through
the neural circuits of the brain The new or facilitated pathways
are called memory traces Slide 30 Consolidation of Memory
Short-term memory to be converted into long-term memory, it must
become consolidated That is, chemical, physical and anatomical
changes in synapses which are responsible for long-term type of
memory This process requires 5-10 minutes for minimal consolidation
and 1 hour for strong consolidation Slide 31 ..Consolidation of
Memory Specific parts of brain in memory process is hippocampus
Hippocampus can promote storage of memories Hippocampus is not
important in reflexive learning Slide 32 Hippocampus Is one of the
most important output pathways from reward and punishment areas at
limbic system These provide background mood and motivations
Motivations is the drive in brain to remember experiences and
thoughts that are either pleasant or unpleasant Slide 33 Amnesia
Anterograde After removal of hippocampi: -memory for information
stored in brain before hippocampal removal is not seriously
affected -but after removal that person has no capability for
storing verbal and symbolic types of memories in long-term memory,
or even in intermediate long-term memory > So this person is
unable to establish new long-term memory which is basis of
intelligence or learning. >This is called anterograde amnesia
Slide 34 Amnesia Retrograde Inability to recall memories from the
past Degree of amnesia for recent events is likely to be much
greater than for events the distant past, because memories for
events distant past have been rehearsed so many times Caused by
damage in some area of thalamus, because thalamus might play a role
in helping search memory store house and thus read out the memories
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