The Human Nervous System_71911

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Brain and Technology

(Glimpse of Past, Present and Future)

Past:

Electrical Stimulation of the Brain (ESB)

Electrodes



Brain and Technology

(Glimpse of Past, Present and Future)

Past:

Electrical Stimulation of the Brain (ESB)

Jose Delgado confronting a aggressive-charging bull



Present: Pigeons and Behavior Control

Microchips



The Future

1. Wet Wares

Brain Softwares



The Human Nervous

System

By: Mr. Rodel P. Canlas



Why is it that the human

brain is comparable to

aminiature universe?



Introduction

So complex, complicated, or dynamic, just like the

person who possesses this inside his head. Yet

perhaps the best way to understand and learn abouta person and his behavior is through studying his

brain, which is the sheet of all his cognitions,

emotions, and actions.

It is said that the human brain is like a

miniature universe. If the universe is

composed of billions of stars, planets

and other heavenly bodies; so as the

human brain, which is made of billions of

neurons or nerve cells.



Neurons

basic functional unit of the Human NS, w/c transmits

neural impulse (electrochemical in nature).



Basic Parts of a Neuron:



Basic Parts of a Neuron:

Dendrites ± short branch-like structures w/c transmits neural impulsetoward the cellbody

Cell body - (soma/cyton) ± the largest/main part of a neuron

- serve as the center of nourishment.

Nucleus ± the center portion/ control of a neuron

- controls the activities of the neuron, such as metabolism

- if this dies/damage, the entire neuron dies along with it.

Axon ± long elongated structure w/c transmit neural impulse awayfrom the cell body towards the end brush.

Nodes of Ranvier ± gap along the axon membrane.

Synaptic Vesicles ± structures at the tip of the end brush.

- It produce neurotransmitters, w/c transmits neural impulse fromone neuron to another .

Synapse- gap/space between two neurons.



How does Neural Impulse Travel from One

Neuron to Another?




Neuron to Another?



Neurotransmitters

Neurotransmitters: Functions: Imbalance(d):

1. Acetylcholine controls muscle

contraction

In Hippocampus;

formation of memories

Muscle paralysis or convulsions,

death sometimes

Alzheimers diseases

2. Dopamine Pleasure

neurotransmitter

Schizophrenia

Parkinsons Disease

3. Endorphin Pain-relieving effect



Neurotransmitters

Neurotransmitters: Functions: Imbalance(d):

4. GABA

(gamma

aminobutyric acid)

Inhibitory; lowers arousal anxiety

5. Norepinephrine Affects arousal level DepressionHyperactivity

6. Serotonin Plays role in mood

regulation

Difficulty sleeping

Low level - aggression &

depression



Types of Neurons

Afferent (Sensory) Neurons

- nerve cells Approaching the Central Nervous System (i.e. brain and spinalcord).

- carry sensory information from the different parts of the body to the CentralNervous System (CNS).

Efferent (M

otor) Neurons ± nerve cells Exiting the CNS.

- transmit motor commands from the CNS to the our different body parts.

Inter-neurons

± conducts neural impulses from a sensory neuron to a motor neuron.

± carry messages or nerve impulses w/in the brain or CNS.

Glial cells or glia

- serve as supportive structures to neurons

- remove metabolic wastes and dead particles of neurons.

Myelin sheath

- white fatty substance surrounding and protecting neuron.

-for saltatory conduction (jumping movement) of neural impulse

- This speeds up transmissions of neural impulse



Divisions of the Nervous System

Nervous system

Central nervous system Peripheral nervous system

Brain Spinal Cord Autonomic system Somatic system

Sympathetic Parasympathetic



Difference Between the Nerve Cells

in the CNS and PNS

Probably, the major difference between the neuronsin the CNS and the nerves PNS is that neurons in theCNS when damage don¶t regenerate, while nervecells in the PNS have the capacity to regrow or

reattach.

Roughly speaking, the PNS contains schwann cells,which have the capacity to stimulate the regrowth of injured nerve cells.

In contrast, the CNS contains oligodendrocytes andastrocytes, which do not stimulate regrowth of neurons, and even hamper regeneration byproducing inhibitory chemicals.



John Thomas



Christopher Reeve(SUPERMAN)




Central Nervous System (CNS)

Brain

- located within the skull

- floats on a bath of Cerebrospinal Fluid

(CSF)

Spinal Cord

- inside the spine/backbone

- seat of reflex action



The Brain and Spinal Cord

Human Brain Spinal Cord



Methods of Treating

SpineInjury

1. Stem Cells (South Korea)

2. Neural Transplant (Taiwan)



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Four Lobes of the Brain



Parts of the Human Brain

Brain Stem




1. Brain Stem ± Made up of four structures, namely; medulla, pons,midbrain, and interbrain.

1.1 Medulla (Myelencephalon) - the lowest part of the brainstem

- It controls involuntary vital bodily functions such as breathing,heart beat and blood circulation.

1.1.2 Reticular Formation - a formation of neurons found the inmedulla that regulates level of arousal/alertness/awareness,sleeping and waking.

- it also regulates transmission of stimuli through contralateralfashion

1.2 Pons (Metencephalon) - lies above the medulla

- it is involve in the regulation of voluntary movement

- it serve as communication pathway between the motor cortexand cerebellum



Reticular Activating System




Brain Stem



Pons, Cerebellumand Motor Cortex

Somatosensory

Area




1.3 Midbrain (Mesencephalon) ± lies above the pons

- it contains neurons w/c produce dopamine (pleasureneurotransmitter)

1.4 Interbrain (Diencephalon) - uppermost part of the brain stem.

- Subdivided into; thalamus and hypothalamus

1.4.1 Thalamus - serve as the last relay center for all coming sensoryimpulse to the different areas of the brain (i.e. cerebral cortex), withthe exception of the olfactory sense.

1.4.2 Hypothalamus ± controls F4; feeding (eating), feeling(emotions), fluid intake (drinking) and f___ng (sexual behavior)

- part of the brain responsible when you are falling in love




Brain Stem



The Limbic System




1.5 Limbic System - the center of emotions

- appears to exert additional control over some instinctivebehavior

- Some structures of the limbic system are; hypothalamus,hippocampus and amygdala.

1.5.1 Hippocampus ± play a crucial role in memory.

- Responsible for converting short-term memory to long-termmemory.

- Spatial Navigation

1.5.2 Amygdala ± storehouse of emotional memories

- believed to be causing aggressive behavior among animalsand humans as well.




2. Cerebellum ± located at the back of the pons andthe medulla

- it is concerned with the coordination of voluntarymovements (in coordination with the motor cortexand pons)




3. Cerebrum ± uppermost, most expanded and recentlydeveloped structure of the brain.

- seat of consciousness, thinking, judgment,

planning/organization of actions/behavior, problem solvingetc.

- it has two hemispheres (left and right hemisphere), whichhave asymmetries in functions



Two Hemispheres of the

Brain




Peripheral Nervous System (PNS)

includes all neural tissue outside of

the central nervous system. It is responsible for transmitting

information from the brain to the

different parts of the body, and vise

versa.



Two Divisions of the

Peripheral Nervous System

1. Somatic Nervous System (SNS)

interacts with the external environment.

voluntary motor commands, such as movingmuscles to walk or to talk, are controlled by the

SNS.

2.

Autonomic Nervous System (ANS) regulates our internal system

involuntary motor commands, such as digestion

and heart beat, are controlled by the ANS.



Two Divisions of the

Autonomic Nervous System

1. Sympathetic Nervous System

sometimes called the ³fight or flight´ system.

increases alertness, stimulates tissue, andprepares the body for quick responses to

unusual/emergency situations.

2.Parasympathetic Nervous System sometimes called the ³rest and response´

system.

conserves energy and controls sedentary

(inactive) activities, such as digestion.



Functions of the Sympathetic and

Parasympathetic Nervous Systems

The Human Nervous System_71911

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