The Nervous System

By : Group 1 –

Bio a

The Nervous System

Introduction

Process

New discovered

technologies

Cool Facts and

Trivias

Parts and Functions

Diseases

• What are you thinking at this very moment?! Is your mind preoccupied with so many things?

Introduction

• The nervous system is the body’s communication network. In fact, It controls all of your daily functions. It is the most complex and highly developed system in the body.

• Have you ever felt nervous, excited, or afraid? Well, there is one body system that controls every movement and action of your body..

Introduction

• YES ! It’s the NERVOUS SYSTEM !

• The nervous system is similar to a telephone network. It consists of interconnecting nerves taking the place of wires and a brain functioning as a highly complex central control station.

Functions

The nervous system is the major controlling, regulatory, and

communicating system in the body. It is the center of all mental activity including thought, learning, and

memory. 

Coordination and integration of many activities of the body through the conduction of impulses from the

receptors to the effectors.

It is the body’s communication network.

The Human Brain

• How do you remember the way to your friend's house?

• Why do your eyes blink without you ever thinking about it?

• Where do dreams come from?

-Your brain is in charge of these things and a lot more.- In fact, your brain is the boss of your body. It runs the show and controls just about everything you do, even when you're asleep. Not bad for something that looks like a big, wrinkly, gray sponge.

• The Three Parts of the Brain* The Brain has three main parts…

1. The Cerebrum 2. The Cerebellum3. The Brain Stem

Lobes, the Cerebral Cortex, and Cortical Regions of the Brain

…

The Biggest Part: the Cerebrum

Cerebrum -The largest division of the brain. It is divided into two hemispheres, each of which is divided into four lobes.

CerebrumCerebrum

Cerebellum

- The biggest part of the brain is the cerebrum. - The cerebrum makes up 85% of the brain's weight, and it's easy to see why. - The cerebrum is the thinking part of the brain and it controls your voluntary muscles

Cerebral Cortex

Cerebral Cortex

Cerebral Cortex - The outermost layer of gray matter making up the superficial aspect of the cerebrum.

Cerebral Features:

• Sulci – Small grooves dividing the gyri

– Central Sulcus – Divides the Frontal Lobe from the Parietal Lobe

• Fissures – Deep grooves, generally dividing large regions/lobes of the brain

– Longitudinal Fissure – Divides the two Cerebral Hemispheres

– Transverse Fissure – Separates the Cerebrum from the Cerebellum

– Sylvian/Lateral Fissure – Divides the Temporal Lobe from the Frontal and Parietal Lobes

• Gyri – Elevated ridges “winding” around the brain.

Gyri (ridge)

Fissure

(deep groove)

Sulci (groove)

Longitudinal Fissure

Transverse Fissure

Sylvian/Lateral Fissure

Central Sulcus

Specific Sulci/Fissures:

Lobes of the Brain (4)

• Frontal• Parietal• Occipital• Temporal

* Note: Occasionally, the Insula is considered the fifth lobe. It is located deep to the Temporal Lobe.

Lobes of the Brain - Frontal• The Frontal Lobe of the brain is located deep to the

Frontal Bone of the skull.

(Investigation: Phineas Gage)

• It plays an integral role in the following functions/actions:

- Memory Formation

- Emotions

- Decision Making/Reasoning

- Personality

Investigation (Phineas Gage)

Primary Motor Cortex/ Precentral Gyrus

Broca’s Area

Orbitofrontal Cortex

Olfactory Bulb

Regions

Investigation (Phineas Gage)

Lobes of the Brain - Parietal Lobe

• The Parietal Lobe of the brain is located deep to the Parietal Bone of the skull.

• It plays a major role in the following functions/actions:

- Senses and integrates sensation(s)

- Spatial awareness and perception(Proprioception - Awareness of body/ body parts in space and in relation to each other)

Primary Somatosensory Cortex/ Postcentral Gyrus

Primary Gustatory Cortex

Somatosensory Association Cortex

Regions

Lobes of the Brain – Occipital Lobe

• The Occipital Lobe of the Brain is located deep to the Occipital Bone of the Skull.

• Its primary function is the processing, integration, interpretation, etc. of VISION and visual stimuli.

Primary Visual Cortex

Visual Association Area

Regions

Lobes of the Brain – Temporal Lobe

• The Temporal Lobes are located on the sides of the brain, deep to the Temporal Bones of the skull.

• They play an integral role in the following functions:

- Hearing

- Information Retrieval (Memory and Memory Formation)

Lobes, the Cerebral Cortex, and Cortical Regions of the Brain

…

The Cerebellum's Balancing Act

Next up is the cerebellum. The cerebellum is at the back of the brain, below the cerebrum. It's a lot smaller than the cerebrum at only 1/8 of its size. But it's a very important part of the brain. It controls balance, movement, and coordination (how your muscles work together). Because of your cerebellum, you can stand upright, keep your balance, and move around. Think about a surfer riding the waves on his board. What does he need most to stay balanced? The best surfboard? The coolest wetsuit? Nope — he needs his cerebellum!

…………………………>>>>>>!

Lobes, the Cerebral Cortex, and Cortical Regions of the Brain

…

Brain Stem Keeps You Breathing — and More

Another brain part that's small but mighty is the brain stem. The brain stem sits beneath the cerebrum and in front of the cerebellum. It connects the rest of the brain to the spinal cord, which runs down your neck and back. The brain stem is in charge of all the functions your body needs to stay alive, like breathing air, digesting food, and circulating blood.Part of the brain stem's job is to control your involuntary muscles — the ones that work automatically, without you even thinking about it. There are involuntary muscles in the heart and stomach, and it's the brain stem that tells your heart to pump more blood when you're biking or your stomach to start digesting your lunch. The brain stem also sorts through the millions of messages that the brain and the rest of the body send back and forth. Whew! It's a big job being the brain's secretary!

The Anatomy of the Nervous System

The Central Nervous System

• efficiently the centre of the nervous system

• it processes the information received from the peripheral nervous system

• it consists of the brain and a spinal cord

• responsible for the interpretation of signals coming from the peripheral nervous system, thus, also sends signals to it, and vice versa

The Peripheral Nervous System

• consists of the nerves and ganglia outside the brain and the spinal cord

• its main function is to connect the central nervous system ( CNS ) to limbs and organs in the body

• this is divided to two divisions:• SOMATIC Nervous System,• and the AUTONOMIC Nervous

System.

The Nerve Cell

• this body system consists of millions of millions of millions of nerve cells or also called as neurons ( or neurones ) as seen in the diagram below.

The Nerve Cell ( cont. )

•Parts of a nerve

cell…

DENTRITES : • are the branched projections of the

neuron ( nerve cell )

CELL BODY : • contains the nucleus of the neuron

NUCLEUS :• found at the soma ( cell body)• composed of nucleolus and

chromosomes

AXON : • a slender projection in the neuron• serves as a conductor of electrical

impulses away from the body cell

NEUROLEMMA : • is the outermost nucleated cytoplasmic

layer of Schwann cells that surrounds the axon

MYELIN SHEATH :• is layer of phospholipids that increases

the conductivity of the electrical messages that are sent through the cell

NODE OF RANVIER:• are the gaps formed between the

myelin sheaths generated by different cells

AXON TERMINALS : • branches of the axon, or its ends

The Nerve Cell ( cont. )Neurons, as we all know, conducts

messages/ impulses. It involves chemical and electrical charges.

There are three ( 3 ) kinds of neurons accordingly, namely:

• Sensory neurons : conducts impulses from receptors to or toward the central nervous system

• Motor neurons : conducts impulses from the central nervous system to various effectors

• Interneurons : located in the brain and nerve cord which join the sensory and motor neurons

  Sensory neuron Interneuron Motor Neuron

Length of Fibers Long dendrites and short axon

Short dendrites and short or long anxon

Short dendrites and long axons

Location

Cell body and dendrite are outside of the spinal cord; the

cell body is located in a dorsal root ganglion

Entirely within the spinal cord or CNS

Dendrites and the cell body are located in the spinal cord;

the axon is outside of the spinal cord

Function Conduct impulse to the spinal cord

Interconnect the sensory neuron with appropriate motor

neuron

Conduct impulse to an effector (muscle or gland)

TYPES OF NEURONS

Motor Neuron (Efferent)

TYPES OF NEURONS

Sensory Neuron (Afferent)

How does the nervous

system works?!

How is a signal or “message” sent?

FIRST

Second

Third

Lastly

the receptor cells of the same organ receive the

information.

the message is transferred to the motor nerves and to the specific body part that

gives the response.

it then goes to the brain, which gives the

interpretation.

the information received is changed to an impulse or signal and travels through

the sensory nerve.

Reflex Action

• Is an involuntary response of a muscle or gland to a sensory stimulus.

• This action is done immediately with or without thinking.

eg. When an ant bites you, you shoo it right away. When you accidentally prick your finger with a safety pin,

you remove it fast.

• The knee jerk reflex is a test done by a doctor. He hits the knee at a point just below the knee cap and the leg kicks out.

• The knee jerk reflex is also called a monosynaptic reflex because there is only one synapse in the circuit needed to complete the reflex.

• The knee jerk takes about 50 milliseconds between the tap below the knee causes the thigh muscle to stretch. Information is then sent to the spinal cord. Once it reaches the spinal cord, the information is sent back out to the muscle.

Reflex Action (Cont.)

Reflex Action

Action Potential…• an action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory.

Action Potential…

• The synapse is a small gap (called a cleft) separating a nerve terminal and a dendrite.

• Information flows from one neuron to another across a synapse.

• Neurotransmitters leave the axon terminal of one neuron and across the synapse to the dendrite of another neuron.

Synapse…..

Synapse…..

Diseases&

Disorders

Broca’s Aphasia• Aphasia is defined by

Websters Dictionary as a "loss or impairment of the power to use or comprehend words usually resulting from brain damage.“

• Persons with a Broca aphasia can usually understand what words mean, but have trouble performing the motor or output aspects of speech.  Thus, other names for this disorder are 'expressive' and 'motor' aphasia.

Treatment• Have a neurologist evaluate the

exact location, nature and extent of the brain injury that initially caused the patient to develop Broca's aphasia

• Keep in mind that there are currently no surgeries or medical treatments available that will cure Broca's aphasia. 

• Hold out hope.

Stroke• Stroke is a general

term for a sudden neurological event which results in the new onset of neurological symptoms.

• Stroke referring to something that occurs suddenly and without warning.

• This commonly used term can refer to more than one nervous system disease.

• Stroke is a medical emergency. If you think you are having a stroke or a person with you is having a stroke, immediately call 911 for an ambulance and transport to a hospital's emergency department.

• Self-Care at Home

Treatment

Brain Tumor• A brain tumor is an

abnormal growth that involves the brain itself or its surrounding structures.

• In addition, pineal region tumors, originating from the area of the pineal gland, while technically part of the brain are often considered separately. Tumors vary in location as well as other characteristics such as their typical presenting symptoms, their speed of growth and aggressiveness (whether they are benign or malignant) and their typical locations.

• Brain tumors are treated with surgery, radiation therapy and chemotherapy.

• Surgery is the usual treatment for most brain tumors. To remove a brain tumor, a neurosurgeon makes an opening in the skull. This operation is called a craniotomy.

• Chemotherapy is the use of drugs to kill cancer cells. The doctor may use just one drug or a combination, usually giving the drugs orally or by injection into a blood vessel or muscle. 

Treatment

Hydrocephalus• Hydrocephalus is an

abnormality of the normal dynamics of the cerebrospinal fluid (CSF).

• The CSF is a water-like fluid that surrounds the brain and spinal cord. Normally, it is produced, flows throughout the open spaces in and around the central nervous system (the ventricles and subarachnoid space) and is then re-absorbed.

• The most common treatment for hydrocephalus is the surgical insertion of a drainage system, called a shunt. It consists of a long, flexible tube with a valve that keeps fluid from the brain flowing in the right direction and at the proper rate. 

Treatment

Epilepsy• Epilepsy is a condition

characterized by recurring seizures in an individual. 

• The effects of seizures depend on their location in the brain and their extent. 

• convulsions in a patient is a common manifestation of seizures but not all types of seizures include convulsions.

• In general, any injury to the brain can lead to seizures, including trauma, tumors, vascular lesions, hemorrhage and developmental anomalies.

• Drug Therapy• Surgery for Epilepsy

Treatment

Spinal Disease• Spinal disease is any

pathology which affects the spinal column and/or the spinal cord and spinal nerves which are contained therein. 

• Spine disease is a large area of study because of the large number of diseases which can affect the spinal system, from purely skeletal disorders to primary nervous system disorders. 

• Spine disease is very common, with many people undergoing spinal surgery every day.

• Neurointervention is a word used to describe a treatment approach to conditions that occur within the vessels of the brain or within the spinal cavity.

Treatment

Multiple Sclerosis• Multiple Sclerosis (MS)

is a disease of the central nervous system which leads to recurring attacks of neurological symptoms. 

• The deterioration in function is related to something termed "demyelination".

• In MS, the myelin sheath around some axons in the central nervous system becomes damaged.

Traumatic brain injury (TBI)

•Traumatic brain injury (TBI) is one of the most common causes of death and disability in the world.

• Brain trauma can lead to a number of different consequences. It can result from both blunt trauma, as in the case of a motor vehicle accident, and penetrating trauma, such as in the case of gun-shot or stab wounds.

• Anyone with moderate or severe TBI should receive medical attention as soon as possible.

•  Primary concerns include insuring proper oxygen supply to the brain and the rest of the body, maintaining adequate blood flow, and controlling blood pressure. Imaging tests help in determining the diagnosis and prognosis of a TBI patient.

Treatment

Amnesia• is a condition in which

one's memory is lost.• Sometimes the memory loss

associated with amnesia includes everything from a person's past, and other times just bits and pieces are missing.

• There are several different types of amnesia, including:

• Anterograde amnesia - Inability to remember ongoing events after the incidence of trauma or the onset of the disease that caused the amnesia

Amnesia (cont.)• Retrograde amnesia - Inability to

remember events that occurred before the incidence of trauma or the onset of the disease that caused the amnesia

• Emotional/hysterical amnesia - Memory loss caused by psychological trauma; usually a temporary condition

• Lacunar amnesia - Inability to remember a specific event

• Korsakoff syndrome - Memory loss caused by chronic alcoholism

Amnesia (cont.)• Posthypnotic amnesia - Memory loss

sustained from a hypnotic state; can include inability to recall events that occurred during hypnosis or information stored in long-term memory

• Transient global amnesia - Spontaneous memory loss that can last from minutes to several hours; usually seen in middle-aged to elderly people

• Surgical Treatment• Medical Treatment

Treatment

• Is an inherited disease that destroys nerve cells in the brain, which causes uncontrollable movements and mental deterioration. This disease of the nervous system is a progressive one. As it progresses, destruction of the nerve cells in the brain leads to mental deterioration and gradual incapitation.

Huntington’s Disease (HD)

• There is no drug to cure HD. Also, there is no treatment that can slow its rate of progression. However, there are certain medicines that may reduce some of the symptoms. Death usually occurs 15-20 years after a person has been diagnosed with HD.

Treatment

DID YOU KNOW?!(Cool facts and trivias about

the nervous system)

Did you know about this?

• The first brain cell transplant was performed by a team of doctors from the University of Pittsburgh Medical Center, Pennysylvania, USA on January 23, 1998.

• The purpose of the operation was to reverse the damage that had been caused by a stroke to Alma Cerasini.

• The brain has no sense of touch or pain. It cannot feel the surgeon’s cutting scalpels or laser beams. On the other hand, the brain coverings or meninges are very sensitive.

• The great mathematician and physicist Albert Einstein died on April 18 1955 at the age of 76. His body was cremated, but Dr. Thomas S. Harvey, a pathologist, removed his brain and cut it into 240 pieces. He protected the brain parts and kept them in jars at his residence. In his last years, he gave several pieces of Einstein’s brain to different researchers. What became of Einstein’s brain is something of a mystery….

Did you know about this?

Dr. Thomas Harvey

• According to the history, early people with mental disorders were regarded as being “possessed” by devils or divinely inspired. It was believed there was a link between mental illness and creativity link in the case of the genius artist Vincent van Gogh.

• Most of the 200 canvases van Gogh painted in 1888-1890 were extraordinarily original and these made him famous. They claimed that during that time, he was either clinically insane or very near to it, and his condition played a big role in pushing him to a creative level that he would not otherwise have achieved.

Did you know about this?

Vincent van Gogh

• Archeologists were able to unearth lots of skulls with healed holes. During olden times, drilling holes through the skull was ancient people’s way of treating terrible headaches.

Did you know about this?

TECHNOLOGIES USED IN

NERVOUS SYSTEM

POSITRON EMISSION TOMOGRAPHY(PET)

It is a diagnostic imaging technique used to

evaluate the body organs, especially the brain. It

involves the acquisition of physiologic images based

on the detection of radiation from the

emission of positrons. It is used to diagnose brain tumors, stroke, mental

illness and how the brain processes words that are

read or spoken.

What are positrons? They are subatomic

particle emitted from a radioactive

substance.

Haptic technology,

or haptics, is a tactile feedback technology that

takes advantage of a user's sense of touch by

applying forces, vibrations, or motions to the

user. This mechanical stimulation may be used

to assist in the creation of virtual objects (objects

existing only in a computer simulation), the

control of such virtual objects, and the

enhancement of the remote control for

machines and devices (teleoperators)

What is tactile feedback?

composed of the receptors and

processing centres to produce the sensory

modalities

Electroencephalography (EEG) is the

recording of electrical activity along the scalp. EEG

measures voltage fluctuations

resulting from ionic current flows within

the neurons of the brain.

It is a test to detect problems in the

electrical activity of the brain.

It is also called as ….THE

BRAIN WAVE TEST

The Electroencephalography

The Nervous System…

-end-