SISTEM SARAF (NERVOUS SYSTEM) - Portal

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 • • • •

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 • • • • • • •

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 • • •

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).