The nervous system is a complex network of nerves and cells that carry messages to and from the brain and spinal cord to various parts of the body.

1. NERVOUS
SYSTEM
Presented by
ARSHA P BABU
2nd M pharm (pharmacology)
Jkkm college of pharmacy
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2. BASIC FUNTCIONS :
• SENSATION
monitor changes /events occurring in and outside the body .
Such changes are known as stimuli and the cells that monitor
them are Receptors.
• INTEGRATION
The parallel processing and interpretation of sensory
information to determine the appropriate response.
• REACTION
Motor output
The activation of muscles or glands (typically via the release of
neurotransmitters(NTs)

3. THE NERVOUS SYSTEM
• A network of billions of nerve cells linked together in a
highly organized fashion to form the rapid control
centre of the body .
• Functions include:
Integrating centre for homeostasis , movement , and
almost all other body functions.
The mysterious source of those traits that we think
of as setting human apart from animals

4. MOTOR EFFERENT DIVISION
• Can be divide further :
• Somatic nervous system
• VOLUNTARY
• Somatic nerve fiber that conduct impulse from the CNS to skeletal muscles
• Autonomic nervous system
• INVOLUNTARY
• Conduct impulse from the the CNS to smooth muscle, cardiac muscle and glands.

5. ORGANISATION OF THE NERVOUS SYSTEM
• 2 main division :
1 Central nervous system
The brain +the spinal cord = the centre of integration and control
2 Peripheral nervous system
The nervous system outside of the brain and spinal cord
Consists of :
31 spinal nerves
Carry info to and from the spinal cord
12 cranial nerves
Carry info to and from the brain

6. PERIPHERAL NERVOUS SYSTEM
• Responsible for communication between the CNS and the rest of the body.
• Can be divided into ;
- Sensory Division
Afferent division
- conducts impulses from receptors to the CNS.
- informs the CNS of the state of the body interior and exterior
- sensory nerves fiber can be somatic (from skin , skeletal muscle or joints ) or
visceral (from organs with the ventral body cavity)
-Motor Division
Efferent Division
- conducts impulses from CNS to effectors (muscles/glands)
- motor nerve fibers

7. NERVOUS TISSUE
• 2 TYPES ;
1. Neurons
*functional, signal conducting cells.
2. Neuroglia
*supporting cells

8. AUTONOMIC NERVOUS SYSTEM
• Can be divided into ;
-sympathetic nervous system
“Fight or Flight”
-parasympathetic nervous system
“Rest and Digest”
* These 2 system are antagonistic.
* Typically ,we balance these 2 to keep ourselves in a state of
dynamic balance.

9. NEUROGLIA
• 6 types of supporting cells -4 are found in the CNS.
1. Astrocytes
1. Star-shaped ,fine branching process lie – mucopolysaccharide ground
substance .
2. At free end of some processes there are small swelling c/a foot process
3. Abundant , and versatile found adjacent to blood vessels with foot
processes forming sleeve around them .
4. Involved in the formation of the blood brain barrier .
5. It help maintain the chemical environment for nerve impulse generation
i.e K+
6. Function in nutrient transfer .
2. Oligodendrocytes
1. These are cells that coat axons in the central nervous system (CNS) with
their cell membrane ,

10. Forming a specialized membrane differential called myelin .
2. The myline sheath which provides the electrical insulation for certain
neuron in the CNS .
3. Ependymal cells
cuboidal –columnar cells that lines the ventricles of the brain and the
central canal of the spinal cord
Some are ciliated which facilitates the movement of cerebrospinal fluid
they also form the blood –CSF fluid barrier.
4. Microglia
 Specialized immune cells that act as the macrophage of the CNS .
 Derived from monocyte that migrate from blood into NS before birth .
 They remove cellular debris formed during normal development of NS .
 Phagocytize m.o and damaged nervous tissue .

11. • 2 types of glia in the PNS
1 . Satellite cells
 Flat cells surrounds cell bodies in the PNS
 Regulate the exchange of material between neuronal cell bodies and
interstitial fluid .
2. Schwann cells
 Form myelin sheaths around the PNS axon .
 Vital to neuronal regeneration
 A single Schwann cells can also enclose as many as 20 or more
unmyelinated axons.

12. NEURONS
• The functional and structural unit of the nervous system .
• Specialized to conduct information from one part of the body to
another .
• There are many different types of neurons but most have certain
structural and functional characteristics in common .
- cell body (soma )
- one or more specialized ,slender process (axons/dendrites )
- an input region (dendrites/soma)
- a conducting component (axon )
- a secretory ( output ) region (axon terminal)
Neurones cannot divide
they need continuous supply of oxygen & glucose

14. SOMA
• Contains nucleus plus most normal organelles (mitochondria
,lysosomes, Golgi complex )
• Biosynthetic center of the neuron
• Contains free ribosome’s & rough endoplasmic reticulum
SOMATA
 cluster of somata in the CNS are known as nuclei .
Clusters of somata in the PNS are known as ganglia

15. • AXON
• Most neurons have a single axon process designed to convey info
away from the cell body
• Originates from a special region of the cell body called the axon
hillock .
• Transmit action potentials from soma toward the end of the axon
where they cause Neuro transmitter release .
• DENTRITES
• They are thin , branched processes whose main function is to
receive incoming signals ,
• They effectively increase the surface area of a neuron to increase
the ability to communicate with other neurons .
• Their cytoplasm contain mitochondria ,Nissl bodies & other
organelles .
• In motor neurons they form part of synapses , & in sensory
neurons they form
the sensory receptors that respond to stimuli .

16. Thank