1. FISIOLOGI SUSUNAN SYARAF PUSAT & KELAINAN YANG MUNGKIN TIMBUL
Rahmatina B. Herman
Bagian Fisiologi
FK-UNAND

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

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

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

6. Overview Functions of Brain
FOREBRAIN: CEREBRUM
Cerebral cortex
Sensory perception
Voluntary control of movement
Language
Personality traits
Sophisticated mental events, such as thinking, memory, decision making, creativity, self consciousness
Basal nuclei
Inhibition of muscle tone
Coordination of slow, sustained movements
Suppression of useless patterns of movements

7. Overview Functions of Brain
FOREBRAIN: DIENCEPHALON
Thalamus
Relay station for all synaptic input
Crude awareness of sensation
Some degree of consciousness
Role in motor control
Hypo-thalamus
Regulations of many homeostatic functions, such as temperature control, thirst, urine output, food intake
Important link between nervous and endocrine systems
Extensive involvement with emotion and basic behavioral patterns

8. Overview Functions of Brain
CEREBELLUM
Maintenance of balance
Enhancement of muscle tone
Coordination and planning of skilled voluntary muscle activity
BRAIN STEM (MIDBRAIN, PONS, MEDULLA)
Origin of majority peripheral cranial nerves
Cardiovascular, respiratory, digestive control centers
Regulations of muscle reflexes involved with equilibrium and posture
Reception and integration of all synaptic input from spinal cord: arousal and activation of cerebral cortex
Role in sleep-wake cycle

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

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

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

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

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)

18. Aspects of Communication
Two aspects of communication
The sensory aspect (language input) that involving:
- ears, and
- eyes
The motor aspect (language output) that involving:
- vocalization, and
- its control

19. Wernicke’s area
Broca’s area

20. Broca’s and Wernicke’s Area: Complex Form of Communication
Broca’s area: speaking ability
Wernicke’s area:
- critical role in understanding both spoken and written massage
- formulating coherent patterns of speech
- controls articulation of speech
Formation in mind of thoughts to be expressed and choice of words to be used
Motor control of vocalization and actual act of vocalization itself

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)

23. ………………….Language Disorders
Destruction of Broca’s 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

24. ………………….Language Disorders
Destruction of Wernicke’s 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:
- Wernicke’s aphasia

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

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 Parkinson’s disease

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

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

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

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

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

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

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

41. Thank You