sistem saraf (nervous system)

SISTEM SARAF
(NERVOUS SYSTEM)
DR. HJ. ABDUL RASHID HJ. SAID.
CONSULTANT PSYCHIATRIST
HOSPITAL TUANKU FAUZIAH
CONTENTS
• Anatomi Sistem Saraf
– Sistem Saraf Pusat (CNS)
(otak dan saraf tunjang)
– Sistem Saraf Periferi (PNS)
# sensori (afferent)
# motor (efferent)
@ somatic – motor nervous system
@ autonomic – * simpatetik
* parasimpatetik
Coronal Section
Sagital section
FUNGSI SISTEM SARAF
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Input sensori
Integrasi
Homeostasis
Mental activity – conciousness, memory,
thinking etc.
• Control of muscles, organs and glands
Functions of Nervous System
• Gathers information - sensory
• Transmits the information - sensory
• Processes the information - integrative
• Sends information - motor function
Neuron
• Basic functional unit of the Nervous System
• Cell Body
• Single Axon
• Dendrites
Multiple Sclerosis
CELLS OF THE NERVOUS
SYSTEM
• NEURON - multipolar
- bipolar
- unipolar
● NEUROGLIA - Astrocytes
- Ependymal cells
- Microglia
- Oligodendrocytes
- Schwann cells
Types of Neuron (Function)
• Sensory neurons - Afferent
• Motor neurons - Efferent
• Interneuron - Connect sensory and motor
neuron and carry impulses between them.
Cells of the nervous system
Astrocytes
Microglia
Organization of the Nervous Tissue
• Gray matter (cortex) – groups of neuron cell
bodies and their dendrites. Clusters of gray
matter located deeper in the brain are called
‘nuclei’.
• In the Peripheral Nervous System (PNS) a
cluster of neuron cell bodies – ‘ganglion’ (a
swelling or knot).
• Bundles of paralled axons with their myeline
sheaths are whitish in colour – white matter
ELECTRICAL SIGNAL AND
NEURAL PATHWAY
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Action potential
Resting membrane potential
Impulse
Stimulus
Polarization
Depolarization
Repolarization
The nerve impulses.
• Italian scientist Luigi Galvani found that
nerve tissue display electrical activity –
nerve impulse – a flow of electrical
charges along the cell membranes of a
neuron.
• Electrical activity is due to movement of
ions ( potassium (K+) and Sodium (Na+)
across the cell membrane.
The nerve impulses….
• The movement of these ions is affected by
their ability to pass through the cell
membrane (Sodium and Potassium Pump)
• The electrical charge different between
inside and outside cell – POTENTIAL.
RESTING POTENTIAL
RESTING POTENTIAL
• As a result of resting potential – the neuron is
said to be POLARIZED.
• A STIMULUS is a change in the environment
that may be insufficient/sufficient strength to
initiate an impulse. (ALL or NONE LAW)
• The ability of a neuron to respond to a stimulus
and convert it into a nerve impulse is known as EXCITABILITY
THE MOVING IMPULSE
REPOLARIZATION
NERVE CONDUCTION
• MYELIN SHEATH.
• WITHOUT MYELIN SHEATH
• One way conduction/propagation
• ALL or NONE Law.
The Synapse
COMMUNICATION BETWEEN
NEURONS – SYNAPTIC CLEFT
BRAIN WAVES
• Brain waves – summation of the electrical
activity of the brain.
• Measured by Electroencephalogram
(EEG)
• 4 basic waves – alpha
- beta
- theta
- delta
EEG graph of Epilepsy
Diseases Related to Lack of
Neurotransmitter
• Dopamine - Parkinson Disease
• Acetylcholine – Dementia (Nyanyuk)
• Gamma Amino Butyric Acid (GABA) Epilepsy
Meninges
• 3 lapisan utama
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i. Dura mater
ii. Arachnoid mater
iii. Pia mater
MENINGITIS
• INFEKSI SELAPUT LAPISAN OTAK
• KETIGA-TIGA LAPISAN TERLIBAT
• JIKA TISU OTAK TERLIBAT MENINGOENCEPHALITIS
Peralatan yang digunakan
• Plain radiography (sinaran x)
• Computerised Tomography Scan (CT
Scan).
• Magnetic Resonance Imaging. (MRI)
• Positron Emission Tomography (PET).
CRANIAL NERVES
Disease of Cranial Nerve
• Bell’s Palsy – 7th Nerve Palsy.
• Commonly due to viral infection.
CEREBELLUM
Fungsi Cerebellum
• Involved in balance and muscle
coordination.
• To compare the intended action with what
is occurring and modify the action to
eliminate the difference.
• If damaged – muscles tone decreases and
fine motor movements become very
clumpsy.
THE SPINAL CORD
SPINAL CORD
• A communication link between the brain
and peripheral nervous system.
• 42 – 45 cm.
• 31 spinal nerves that emerge from the
spinal cord.
• AXONS BUNDLED TOGETHER – NERVE
• Each spinal nerve consists dorsal root and
ventral root
PERIPHERAL NERVOUS
SYSTEM (PNS).
• All the nervous system outside the spinal
cord and brain.
• Can be divided into 2 division:1. Sensory division
2. Motor Division
a. Somatic
b. Autonomic
The Somatic Nervous System
• Regulates activities that are under
concious control – movement of skeletal
muscles.
• Many nerves within this system are part of
reflexes and can act automatically – eg.
Knee reflex
The Spinal Reflex
• Patella Reflex
Autonomic Nervous System
• Regulates activities that are automatic or
involuntary.
• Not under concious control.
• Striking a balance or maintaining
homeostasis of the body.
• Further divided into 2 – sympathetic
(activates) and parasympathetic (retards).