Introduction to

Nervous SystemPRESENTED BY : WAJEEHA.

Introduction to Nervous System

1. What is Nervous System...?

2. Structural Classification of Nervous System

3. Brain

a) Location & Functional Division

b) Brain Structures & their Functions

c) Brain Lateralization

4. Spinal cord

a) Peripheral Nervous System

b) Somatic Nervous system

c) Autonomic Nervous System

5. Basic Functions of the Nervous

System

a) Integrative Function

b) Sensory Function

c) Motor Function

6. Neuron

7. Synapse

8. Memory….

9. Learning & Memory

10. Can I Improve My Memory?

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What is Nervous System...?

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What is Nervous System...?

It is the master controlling and communicating

system of the body.

The NERVOUS SYSTEM controls and coordinates

all essential functions of Human Body.

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What is Nervous System...?

System of specialized cells (NEURONS or NERVE CELLS) that conduct

stimuli from SENSORY RECEPTOR through a “neuron network” to the

site (e.g ; a gland or muscle) where the response occurs.

A system of NEURONS, NEUROCHEMICALS and ALLIED STRUCTURES

involved in receiving sensory information, generating and

coordinating responses and controlling bodily activities.

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Structural Classification of Nervous

System

a) Central Nervous System (CNS)

It consists of BRAIN and SPINAL CORD which act as integrating

and command centers of nervous system.

b) Peripheral Nervous System (PNS)

They link all parts of the body by carrying impulses from sensory

receptors to CNS and from CNS to the effectors.

In consists of nerves extending from brain and spinal cord,

CRANIAL and SPINAL NERVES.

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CNS:

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Brain 8

Location & Functional Division It is located within the cranial cavity of the skull and consists of

Divisions of the Brain

Major Division Subdivision Structures

Telencephalon Neocortex; Basal Ganglia; Amygdala;

Hippocampus; Lateral Ventricles Prosencephalon

(Forebrain)

Diencephalon Thalamus; Hypothalamus;

Epithalamus; Third Ventricle

Mesencephalon

(Midbrain) Mesencephalon

Tectum; Tegmentum; Cerebral

Aqueduct

Metencephalon Cerebellum; Pons; Fourth Ventricle Rhombencephalon

(Hindbrain)

Myelencephalon Medulla Oblongata; Fourth Ventricle

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Brain Structures & their Functions 10

Cerebral Cortex Brain stem

Functions:

Thought

Voluntary movement

Language

Reasoning

Perception

CerebellumFunctions:

Movement

Balance

Posture

Functions:

Breathing

Heart Rate

Blood Pressure

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Spinal Cord

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Spinal Cord

It is a reflex center and a conduction pathway which is found within

the vertebral canal.

It extends from the foramen magnum up to the level of L1 Or L2 .

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Classification14

Peripheral Nervous System

It has two divisions

Sensory or Afferent Division:

Consists of nerve fibers that transmit information from sensory

receptors to the CNS. It is further divided into SOMATIC SENSORY &

VISCERAL SENSORY nerve fibers.

Motor or Efferent Division:

Consists of nerve fibers that transmit information from CNS to the

effector organs. It is also divided into SOMATIC & AUTONOMIC

nervous system.

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Somatic Nervous system

The somatic nervous system is responsible for coordinating the body

movements, and also for receiving external stimuli.

It is the system that regulates activities that are under conscious control.

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Autonomic Nervous System

The autonomic system is for regulating involuntary body functions,

such as blood flow, heartbeat, digestion and breathing.

This system is further divided into two branches:

1. the sympathetic system regulates the flight-or-fight responses,

2. the parasympathetic system helps maintain normal body functions and

conserves physical resources.

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Basic Functions of the Nervous

System

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Basic Functions of the Nervous

System

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Sensory Function

Nervous system uses its millions of sensory receptors to monitor

changes occurring both inside and outside the body

These changes are called STIMULI, and the gathered information is

called SENSORY INPUT

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Integrative Function

The nervous system processes and interprets the sensory input and

makes decision about what should be done at each moment, a

process called INTEGRATION.

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Motor Function

The nervous system then sends information to MUSCLES or GLANDS

so that they can respond correctly, such as muscular contraction and glandular secretions.

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NeuronTHE STRUCTURAL AND FUNCTIONAL UNIT OF NERVOUS SYSTEM

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Structure

Dendrites:

Carry impulses towards the cell body.

Receive stimuli from receptors or

synapses.

Cell Body:

contains nucleus and Nissel’s bodies, a

form of rough endoplasmic reticulum.

Axon:

Carry nerve impulses away from cell

body.

It interacts with glands, muscles or

other neurons.

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Types of Neurons

On the basis of structure,

a) Unipolar Neurons

b) Bipolar Neurons

c) Multipolar Neurons

d) Pseudounipolar Neurons

On the basis of function,

a) Sensory Neurons

b) Motor Neurons

c) Interneurons

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Function Of Neuron

Sensory neurons:

These neurons tell the rest of the brain about the external and internal

environment.

Motor (and other output) neurons:

Motor neurons contract muscles and mediate behavior, and other

output neurons stimulate glands and organs.

Interneurons:

Communication neurons transmit signals from one brain area to

another.

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Function of Neuron 27

Synapse

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Synapse

In the nervous system, a synapse is

a structure that permits a

neuron (or nerve cell) to pass an

electrical or chemical signal to

another cell (neural or otherwise).

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Features

It is the junction point between one neuron and the next.

It determines the direction through which the nerve impulse will

spread through the nervous system.

Some synapses transmit signals with ease while others don’t.

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Memory….

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Memory….

Storage

Information

Memory is the process in

which information is

encoded, stored, and

retrieved.

Encoding allows

information that is from the

outside world to reach our

senses in the forms of chemical and physical

stimuli.

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It is just Neurons and some good

chemicals…..

Memory is, at its simplest, a set of encoded neural connections in

the brain.

It is the re-creation or reconstruction of past experiences by the synchronous firing of neurons that were involved in the original

experience.

Our memories are not stored in our brains like books on library

shelves, but are actually on-the-fly reconstructions from elements

scattered throughout various areas of our brains.

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Can I Improve My Memory? 35

Yes!!!!

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How???

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The following techniques take

advantage of brain’s storage and

retrieval mechanism:

Concentrate

Minimize interference

Break down large amount of information into

smaller topic

Rephrase material in your own words

Test yourself

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That’s all…

Presented By: Wajeeha.

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