Uploaded by FREMA BAGUHIN

THE NERVOUS SYSTEM PPT

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THE NERVOUS SYSTEM
The nervous system and endocrine system work together
to control and coordinate the workings of the components
of the body. All actions and thoughts are coordinated by a
complex group of organs and nerves that enable man to
receive stimuli. The nervous system is like a
communication network that transmits information by
electrical signals called nerve cells or neurons.
The Nerve and Nerve Cell
• The basic cell of the nervous system is the neuron. It carries nerve
impulses, or action potential, from one part of the body to another.
• A typical neuron has three parts: a cell body, which controls the growth
of the nerve cell; dendrites, which are short-branched fibers that carry
impulses or messages toward the cell body; and the axon, which is
typically long, thin fibers that carries messages away from the cell
body.
• The axon is also known as nerve fibers. The fibers are made up of
connective tissue bundles.
Parts and Functions of the
Nervous System
A. The Central Nervous System
The Central Nervous System (CNS) consists of the brain and the spinal cord. It
is where the interneurons receive and pass on messages. The brain is the
control center of the CNS while the spinal cord relays sensory and motor
information to and from the brain and other parts of the body.
The Brain
It is a moist and spongy organ with an average of 3 pounds in
weight. It consists of 10 billion neurons that control everything a person does,
such as thoughts, movements, memory, and sense. The brain produces waves
of electrical impulses that differ in length and frequency, depending upon the
type of activity performed by the body. Every person has a different brain wave
pattern, just as every person has a unique set of fingerprints and footprints.
1. The Brain
The skull protects the brain. Beneath the skull are three distinct
layers of membranes that cover the entire brain. The entirety of these
membranes of these membranes is call meninges. The cerebrospinal fluid
substance is located between the middle and inner meninges and in some
spaces within the brain. This fluid helps cushion and protect the brain
and the spinal cord. The brain is divided into three parts: the cerebrum,
cerebellum, and the brain stem.
• Brain Stem – located below the cerebellum at the base of the skull,
which serves as the body’s life support system. It controls the
heartbeat, breathing, and blood pressure.
1. The Brain
• Cerebellum – located beneath the back part of the cerebrum. It
coordinates muscle movement. It has an outer layer of gray matter and
white matter in the brain’s interior. The cerebellum produces signals
that stimulate reactions in other parts of the nervous system.
• Cerebrum – the large upper region of the brain. It consists of deep
folds, which are divided into many ridges and depressions just like the
surface of a walnut.
1. The Brain
• Corpus callosum – a broad band of nerve fibers joining the two
hemispheres of the brain.
• Hippocampus – a small organ located within the brain’s medial
temporal lobe, which is associated mainly with the memory, in
particular long-term memory.
• Hypothalamus - regulates the body’s temperature, use of water,
blood pressure, and release of regulatory chemicals.
• Medulla – controls breathing, heart rate, and swallowing.
1. The Brain
• Midbrain - also linked to vision and controls the movement of the
eye and constriction and dilation of the pupil.
• Pituitary gland – a pea-sized structure located at the base of the
brain. It is part of endocrine system that produces critical
hormones that control various body functions.
• Pons – regulates breathing and helps control eye movement.
• Thalamus – one of the smaller parts of the brain, which serves a
relay station for senses. It is responsible in processing the
information from the sense organs.
Spinal Cord
• The spinal cord is a rod of brain tissue that extends
about two-thirds of the way down the back, just below
the ribs. It is covered with three meninges and
cerebrospinal fluid. The spinal cord is protected by a
spinal column, which allows the trunk to bend.
The Peripheral Nervous System
• The Peripheral Nervous System (PNS) is made up of
cranial and spinal nerves. There are 12 pairs of cranial
nerves in the body that emerge from the brain that
connect with the eyes, ears, and nose.
• The cranial nerves contain mostly sensory nerve fibers.
• Some cranial nerves are made up of sensory and motor
nerve fibers.
The PNS is divided into two:
• The Somatic Nervous System (SNS) is responsible for actions
that a person can control such as skeletal muscles and sensory
neurons of the skin. This is under conscious voluntary control.
• The Autonomic Nervous System (ANS) controls autonomic
functions that do not require a person to think. For example,
involuntary muscles help digest food, heartbeat, and breathing.
The ANS is important in maintaining homeostasis, just like the
endocrine system.
• There are two subdivisions of the autonomic nervous system –
the sympathetic nervous system that prepares the body for action
and stress, and the parasympathetic nervous system that helps
the body to conserve energy.
Common Diseases of the Nervous System
• Meningitis is an inflammation of the meninges of the brain or
spinal cord caused by bacterial infection or a virus. The infection
occurs most often in children and young adults. Those who have
weakened immune system and long-term health problems are at
risk to this disease. Meningitis can be deadly if not treated
immediately.
Symptoms: Stiff and painful neck, fever, headache, vomiting,
seizures, trouble breathing, and slight headache
Treatment: Treated with antibiotics
• Cerebral Palsy is a disorder resulting in a lack of full control of
physical movement and muscle tightness that affect almost all
parts of the body. Some people have little or no control over their
arms and legs or other parts of their body. For example, they
cannot control the movement of their mouth and tongue, which
can cause problems with eating and speaking.
• Symptoms : Seizures, intellectual disability, slight limp, and
difficulty in walking
• Treatment: Surgery
• Parkinson’s disease is a disorder of the nervous system that
affects the movement of a person. It develops gradually and
tremors start in the hands. In early stages, the face shows little or
no expression. The arms do not swing when one walks.
• Symptoms: Tremors, slow movement, impaired posture and
balance, penmanship changes, speech changes, emotional
changes and depression, difficulty swallowing, sleep disorder,
blood pressure changes, inability to smell, and constipation.
• Treatment: Cannot be cured, but symptoms can be improved
through surgery to regulate the region of the brain.
• Brain Tumor
an adult brain tumor is called meningeal tumor. The
tumor is formed in the meninges that cover the brain and the spinal
cord. Another type is the metastatic brain tumor. It develops cancerous
cells from another tumor is called metastasis. Not all brain tumors are
cancerous. The term cancer is for a malignant tumor, while a benign
tumor is less serious.
• Cancer refers to any disease that is characterized by the uncontrolled
growth and spread of useless abnormal cells. Cancer cells form a mass
of tissue called a malignant tumor. The tumor has no sheath or
membrane enclosing it; thus, the cancer cells invade the surrounding
tissue. On the other hand, a benign tumor is a mass of tissue formed
from non-cancerous cells. It is enclosed within a sheath so that it does
not spread nearby tissues. This occurs as the cancer cells grow out
into the neighboring tissues and are carried elsewhere in the body.
• Symptoms: Trouble walking and change of
mental status.
• Treatment: Surgery, radiation therapy, and
chemotherapy.
• Epilepsy is a brain disorder in which clusters of nerve
cells or neurons act abnormally. The action potential
activity becomes disturbed causing strange sensation
and emotions, convulsions, and muscle spasms.
• Symptoms: Loss of muscle tone, jerking movements,
brief loss of consciousness, muscle stiffness
• Treatment: Epileptic seizures are controlled through
drug therapy and anticonvulsant drugs
Keeping the Nervous System Healthy
• Ensure adequate intake of healthy fats such as oil and vegetable oil.
Adequate vitamin d and vitamin B-12 is essential to maintain optimal myelin
in the neurons.
• Exercise the nervous system on daily basis by stretching the arms and
reading in order for the motor and sensory pathways to be used. This type of
exercise plays a role in regulating blood circulation through your brain and
also reduces the risk of many diseases.
• Spend a minimum of 15 minutes per day writing on paper as legibly as you
can.
• Engage yourself in social activities to keep your brain active. Socialization
helps to reduce stress and promote emotional health.
Reporters:
Baguhin, Frema M.
Napala, Gwyn Berry D.
Raniel, Nina
Dominique B.
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