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NERVOUS SYSTEM
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FROM
THE GROUP VI(SIX)
HUSNUL KHATIMAH
MUTMAINNAH BASRI
GORGIUS PATILAGA NAEM
JAINUDDIN
SUSILAWATI MA’RUF
STIKPER
GUNUNG SARI MAKASSAR
T.A
2013
NERVOUS
SYSTEM
CHAPTER I
DISCUSSION
A. DEFINITION
The nervous system is a complex system, a
sophisticated set up and coordinate the activities of the body
Brain (English: encephalon) is a central nervous
system (English: central nervous system, CNS) in vertebrates and many other
invertebrates.
The human brain is the central structure has a volume
setting 1.350cc and comprises approximately 100 million nerve cells or neurons.
Brain organize and coordinated most, movement, behavior and homeostatic body
functions such as heart rate, blood pressure, body fluid balance and body
temperature. The human brain is responsible for setting the whole body and the
human mind. Therefore there is a strong link between the brain and thinking.
Brain and nerve cells in it is believed to affect human cognition. Knowledge of
the brain affects the development of cognitive psychology. The brain is also
responsible for functions such as recognition, emotion. memory, motor learning
and all other forms of learning.
The majority
of the nervous system is a network consisting of two classes of cells: neurons
and neuroglia.
· Neurons.
Neurons, also known as nerve cells, communicate within the body by transmitting
electrochemical signals. Neurons look quite different from other cells in the
body due to the many long cellular processes that extend from their central
cell body. The cell body is the roughly round part of a neuron that contains
the nucleus, mitochondria, and most of the cellular organelles. Small tree-like
structures called dendrites extend from the cell body to pick up stimuli from
the environment, other neurons, or sensory receptor cells. Long transmitting
processes called axons extend from the cell body to send signals onward to
other neurons or effector cells in the body.
There are 3 basic classes of neurons: afferent neurons, efferent neurons, and interneurons.
There are 3 basic classes of neurons: afferent neurons, efferent neurons, and interneurons.
1.
Afferent
neurons.
Also known as sensory neurons, afferent neurons transmit sensory signals to the
central nervous system from receptors in the body.
2.
Efferent
neurons.
Also known as motor neurons, efferent neurons transmit signals from the central
nervous system to effectors in the body such as muscles and glands.
3.
Interneurons.
Interneurons form complex networks within the central nervous system to
integrate the information received from afferent neurons and to direct the
function of the body through efferent neurons.
· Neuroglia.
Neuroglia, also known as glial cells, act as the “helper” cells of the nervous
system. Each neuron in the body is surrounded by anywhere from 6 to 60
neuroglia that protect, feed, and insulate the neuron. Because neurons are
extremely specialized cells that are essential to body function and almost
never reproduce, neuroglia are vital to maintaining a functional nervous
system.
B. Nerves
Nerves are bundles of axons in the peripheral nervous system (PNS) that act as information highways to carry signals between the brain and spinal cord and the rest of the body. Each axon is wrapped in a connective tissue sheath called the endoneurium. Individual axons of the nerve are bundled into groups of axons called fascicles, wrapped in a sheath of connective tissue called the perineurium. Finally, many fascicles are wrapped together in another layer of connective tissue called the epineurium to form a whole nerve.
Nerves are bundles of axons in the peripheral nervous system (PNS) that act as information highways to carry signals between the brain and spinal cord and the rest of the body. Each axon is wrapped in a connective tissue sheath called the endoneurium. Individual axons of the nerve are bundled into groups of axons called fascicles, wrapped in a sheath of connective tissue called the perineurium. Finally, many fascicles are wrapped together in another layer of connective tissue called the epineurium to form a whole nerve.
The wrapping of nerves with connective tissue
helps to protect the axons and to increase the speed of their communication
within the body.
· Afferent,
Efferent, and Mixed Nerves.
Some of the nerves in the body are specialized
for carrying information in only one direction, similar to a one-way street.
Nerves that carry information from sensory receptors to the central nervous
system only are called afferent nerves. Other neurons, known as efferent
nerves, carry signals only from the central nervous system to effectors such as
muscles and glands. Finally, some nerves are mixed nerves that contain both
afferent and efferent axons. Mixed nerves function like 2-way streets where
afferent axons act as lanes heading toward the central nervous system and
efferent axons act as lanes heading away from the central nervous system.
· Cranial
Nerves.
Extending from the inferior side of the brain
are 12 pairs of cranial nerves. Each cranial nerve pair is identified by a
Roman numeral 1 to 12 based upon its location along the anterior-posterior axis
of the brain. Each nerve also has a descriptive name (e.g. olfactory, optic,
etc.) that identifies its function or location. The cranial nerves provide a
direct connection to the brain for the special sense organs, muscles of the head,
neck, and shoulders, the heart, and the GI tract.
· Spinal
Nerves.
Extending from the left and right sides of the
spinal cord are 31 pairs of spinal nerves. The spinal nerves are
mixed nerves that carry both sensory and motor signals between the spinal cord
and specific regions of the body. The 31 spinal nerves are split into 5 groups
named for the 5 regions of the vertebral column. Thus, there are 8 pairs of
cervical nerves, 12 pairs of thoracic nerves, 5
pairs of lumbar nerves, 5
pairs of sacral nerves, and
1 pair of coccygeal nerves. Each spinal nerve exits from the spinal cord
through the intervertebral foramen between a pair of vertebrae or between
the C1 vertebra
and the occipital bone of
the skull.
C. Functions
of the Nervous System
The nervous system has 3 main functions: sensory, integration, and motor.
The nervous system has 3 main functions: sensory, integration, and motor.
· Sensory.
The
sensory function of the nervous system involves collecting information from
sensory receptors that monitor the body’s internal and external conditions.
These signals are then passed on to the central nervous system (CNS) for
further processing by afferent neurons (and nerves).
· Integration. The
process of integration is the processing of the many sensory signals that are
passed into the CNS at any given time. These signals are evaluated, compared,
used for decision making, discarded or committed to memory as deemed
appropriate. Integration takes place in the gray matter of the brain and spinal
cord and is performed by interneurons. Many interneurons work together to form
complex networks that provide this processing power.
· Motor. Once
the networks of interneurons in the CNS evaluate sensory information and decide
on an action, they stimulate efferent neurons. Efferent neurons (also called
motor neurons) carry signals from the gray matter of the CNS through the nerves
of the peripheral nervous system to effector cells. The effector may be smooth,
cardiac, or skeletal muscle tissue or glandular tissue. The effector then
releases a hormone or moves a part of the body to respond to the stimulus.
D.Divisions
of the Nervous System
Central
Nervous System
The brain and spinal cord together form the central nervous system, or CNS. The CNS acts as the control center of the body by providing its processing, memory, and regulation systems. The CNS takes in all of the conscious and subconscious sensory information from the body’s sensory receptors to stay aware of the body’s internal and external conditions. Using this sensory information, it makes decisions about both conscious and subconscious actions to take to maintain the body’s homeostasis and ensure its survival. The CNS is also responsible for the higher functions of the nervous system such as language, creativity, expression, emotions, and personality. The brain is the seat of consciousness and determines who we are as individuals.
The brain and spinal cord together form the central nervous system, or CNS. The CNS acts as the control center of the body by providing its processing, memory, and regulation systems. The CNS takes in all of the conscious and subconscious sensory information from the body’s sensory receptors to stay aware of the body’s internal and external conditions. Using this sensory information, it makes decisions about both conscious and subconscious actions to take to maintain the body’s homeostasis and ensure its survival. The CNS is also responsible for the higher functions of the nervous system such as language, creativity, expression, emotions, and personality. The brain is the seat of consciousness and determines who we are as individuals.
1.
Peripheral
Nervous System
The peripheral nervous system (PNS) includes all of the parts of the nervous system outside of the brain and spinal cord. These parts include all of the cranial and spinal nerves, ganglia, and sensory receptors.
The peripheral nervous system (PNS) includes all of the parts of the nervous system outside of the brain and spinal cord. These parts include all of the cranial and spinal nerves, ganglia, and sensory receptors.
2.
Somatic
Nervous System
The somatic nervous system (SNS) is a division of the PNS that includes all of the voluntary efferent neurons. The SNS is the only consciously controlled part of the PNS and is responsible for stimulating skeletal muscles in the body.
The somatic nervous system (SNS) is a division of the PNS that includes all of the voluntary efferent neurons. The SNS is the only consciously controlled part of the PNS and is responsible for stimulating skeletal muscles in the body.
3.
Autonomic
Nervous System
The autonomic nervous system (ANS) is a division of the PNS that includes all of the involuntary efferent neurons. The ANS controls subconscious effectors such as visceral muscle tissue, cardiac muscle tissue, and glandular tissue.
The autonomic nervous system (ANS) is a division of the PNS that includes all of the involuntary efferent neurons. The ANS controls subconscious effectors such as visceral muscle tissue, cardiac muscle tissue, and glandular tissue.
There are 2 divisions of
the autonomic nervous system in the body: the sympathetic and parasympathetic
divisions.
· Sympathetic.
The sympathetic division forms the body’s
“fight or flight” response to stress, danger, excitement, exercise, emotions,
and embarrassment. The sympathetic division increases respiration and heart
rate, releases adrenaline and other stress hormones, and decreases digestion to
cope with these situations.
· Parasympathetic.
The
parasympathetic division forms the body’s “rest and digest” response when the
body is relaxed, resting, or feeding. The parasympathetic works to undo the
work of the sympathetic division after a stressful situation. Among other
functions, the parasympathetic division works to decrease respiration and heart
rate, increase digestion, and permit the elimination of wastes.
D.
Cranial Nerves
Cranial nerve ( Latin : nervii craniales) is 12 pairs of nerves in man sticking out
of the brain ,
as opposed to the spinal
nerves are sticking out from the spinal cord . Cranial nerves are part of the nervous system is conscious .
12 pairs of nerves, 3 pairs have the kind of sensory (nerve I, II, VIII), 5
pairs of motor types (nerve III, IV, VI, XI, XII) and 4 pairs of composite
types (nerve V, VII, IX, X) . Couple these nerves are numbered in order from
front to rear, typically using roman numerals
Nerves are connected primarily with existing
structures in the head
and neck human like eyes , nose , ears , mouth and tongue . Couples I
and II sticking out of the brain , while others are sticking out of the brain stem .
Cranial Nerves
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Number
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Name
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Type
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Function
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I
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Sensory
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II
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Sensory
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Receive
stimuli from the eye and deliver them to the brain for processing the visual
perception
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III
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Motor
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IV
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Motor
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V
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Combination
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VI
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Motor
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Abduction of eye
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VII
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Combination
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Sensory: Receive stimuli from the anterior part of
the tongue to be processed in the brain as a taste sensation
Motor: Controlling facial muscles to create facial expressions |
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VIII
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Sensory
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Sensory vestibular
system : Controls the balance
Cochlear sensory: Receiving stimuli to be processed in the brain as sound |
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IX
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Combination
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Sensory:
Receive stimuli from the posterior part of the tongue to be processed in the
brain as a taste sensation
Motor: Controlling the internal organs |
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X
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Combination
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Sensory:
Receive stimuli from the internal organs
Motor: Controlling the internal organs |
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XI
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Motor
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Controlling
the movement of the head
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XII
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Motor
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Controlling
the movement of the tongue
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Peripheral nervous system consists of the nervous
system and nervous system realize unconscious (autonomic nervous system).
Conscious nervous system controls the activity regulated by the brain works,
whereas autonomic nerves that control the activity of the brain unmanageable
including heart rate, movement of the digestive tract, and sweat secretion.
Cranial Nerves
Cranial nerves are nerves that straight out of the
brain, other spinal nerves exit the spinal cord segments. In humans, there are
twelve pairs of cranial nerves. Only the first and second pair of nerve coming
out of the brain (cerebrum), the remaining 10 pairs of cranial nerves exit the
brain stem.
1.
Cranial nerve I - olfactory nerve
Is a sensory nerve, derived from telensefalon the
anterior olfactory nucleus in the nucleus. Its function is to receive
excitatory odor; located olfaktorii foramina in the ethmoid bone kribriform
plate.
2.
Cranial nerves II - the optic nerve
Sensory nerves from diensefalon the core retinal
ganglion cells. Serves to deliver visual information to the brain; located in
the optical channel.
3.
Cranial nerve III - Nerve Okulomotorius
Primarily motor, derived from the midbrain to the
nucleus in okulomotorius nucleus, the nucleus of Edinger-Westpal. Its function
is to supply the superior palpebral levator muscle, superior rectus, medial
rectus, inferior rectus, and inferior oblique, which generally supplies the eye
movement; Also supplying the pupil spincter muscles, and the muscles of the
body siliar. Located in superior orbital fissure.
4. IV cranial nerves - nerves trokhlearis
Primarily motor, derived from the midbrain. Troklearis
nerve supplies the superior oblique muscle, which moves the eye down, or turned
sideways (the optical axis), and intorts eyeball; superior orbital fissure is
located at.
5. V cranial nerve - the trigeminal nerve
Is the sensory and motor nerves. Derived from the
Pons. Trigeminal sensory nuclei in the nucleus, spinal trigeminal nucleus, the
trigeminal nucleus mesensefalik, trigeminal motor nucleus. Its function is to
receive stimuli from the face and the muscles of mastication; superior orbital
fissure located (nerve oftalmikus - V1), foramen rotundum (nerve maxillaris -
V2) and foramen ovale (mandibular nerve - V3)
6. VI cranial nerves - nerves Abdusen
Primarily motor. Derived from the posterior margin of
the core premises Pons abdusen nucleus. Abdusen nerve supplying the lateral
rectus muscle, whose function is to abduct the eyeball; superior orbital
fissure located.
7. Cranial nerve VII - facial nerve
Is the sensory and motor nerves. Derived from the Pons
(serebelopontin corner) on the olive. Core in facial nucleus, the nucleus
solitarius, nucleus salivarius superior. Facial nerve supplies the muscles of
facial expression, posterior belly digastrik muscles and stapedius muscles.
Sensory nerves receive excitatory taste of 2/3 anterior tongue, and supplies
the salivary glands (except parotid) glands and lakrimalis; located in the
internal acoustic canal, extending into the facial canal and foramen
stilomastoideus out.
8. Cranial nerve VIII - Vestibulokokhlearis nerve (or the
vestibulo-auditory nerve or nerve statoakustikus)
Primarily sensory. Located on the lateral facial nerve
(serebelopontin corner). The vestibular nuclei, and kokhlear. Receive
excitatory sound, rotation and gravity (for balance and body movement). More
specifically, the branch of the vestibular carry impulses for hearing; located
in the internal acoustic canal.
9. Cranial nerves IX - Nerve Glossofaringeus
Is the motor and sensory nerves. Derived from the
medulla. Nucleus ambiguus, inferior salivarius core, nucleus solitarius.
Glossofaringeus receive excitatory nerve taste of 1/3 back of the tongue,
supplying the parotid gland, and supplies the stilofaringeus movement. Some
sensation is also relayed to the brain from the palatine tonsil. Sensation in
the relay to the opposite side of the thalamus and some hypothalamic nuclei. located
in the jugular foramen.
10.
Cranial nerve X - Vagus Nerve
Is the sensory and motor nerves. Out of the sulcus
posterolateral medulla. Nucleus ambiguus, the motor dorsal vagal nucleus, the
nucleus solitarius. Brakhiomotorik vagus supplies the movement for almost all
pharyngeal muscles and laringeral (except stafilofaringeus muscles, which are
innervated by the nerve glossofaringeus); vagus nerve as well as the
parasympathetic fibers to nearly all organs of the chest and abdominal viscera
down to flexure splenikus, and vagus nerve also received a special taste
sensation of the epiglottis. The main functions: to control muscles and
resonant voice. Symptoms of damage: dysphagia (swallowing problems),
insufficiency velofaringeal. Located in jugular foramen.
11.
Cranial nerve XI - Asesorius nerve (or cranial nerves
or nerve asesorius asesorius cord)
Primarily motor. Derived from the root of the cranial
and spinal. Nucleus ambiguus, nucleus asesorium cord. Nerve function is to
control and trapezius muscles sternokleidomastoideus, along with the function
of the vagus. Examples of symptoms: ketidakmampuah shrug, weak head movement; located
in the jugular foramen.
12.
Cranial nerve XII - Nerve Hipoglosus
It is a motor nerve. Derived from the medulla.
hypoglossal nucleus. movement of the muscles of the tongue (except
palatoglossus the innervated muscles of the vagus) and other glossal muscles.
Important for swallowing (bolus formation) and the articulation of language.
located in the hypoglossal canal.
E.
Definition
of spinal cord
Spinal cord is a part of the composition of CNS. Stretching under conu terminalis nerve fibers is not known phylum terminale which is connective tissue.
There are 31 pairs of spinal nerves: 8 pairs of nerve cervical, 12 thoracic nerve Plug, 5 Place the lumbar nerves, 5 Place 1 pair of nerves and nerve Sacred koksigeal. Lumbar and sacral nerve roots collected called the cauda equina. Each pair nerves exit through the intervertebral foramina. Spinal nerves are protected by the vertebrae and ligaments as well as the spinal meninges and CSF.
Spinal cord is a part of the composition of CNS. Stretching under conu terminalis nerve fibers is not known phylum terminale which is connective tissue.
There are 31 pairs of spinal nerves: 8 pairs of nerve cervical, 12 thoracic nerve Plug, 5 Place the lumbar nerves, 5 Place 1 pair of nerves and nerve Sacred koksigeal. Lumbar and sacral nerve roots collected called the cauda equina. Each pair nerves exit through the intervertebral foramina. Spinal nerves are protected by the vertebrae and ligaments as well as the spinal meninges and CSF.
G. spinal meninges
Spinal meninges consist of three layers, namely: dura mater, arachnoid and piamater. Dura which is a layer of strong, fibrous membrane, Unite the phylum terminale. Piamater form a thin layer, rich in blood vessels, connects with the spinal cord. The cavity between the dura periosteum which is called the epidural area that contains many blood vessels and fat. The cavity between the dura mater is called the subdural arachnoid. Sub dural not contain CSF. The cavity between the arachnoid and Piamater called Subarachnoid. In this cavity there Cerebral Spinal Fluid, Blood Vessels and nerve roots
Spinal meninges consist of three layers, namely: dura mater, arachnoid and piamater. Dura which is a layer of strong, fibrous membrane, Unite the phylum terminale. Piamater form a thin layer, rich in blood vessels, connects with the spinal cord. The cavity between the dura periosteum which is called the epidural area that contains many blood vessels and fat. The cavity between the dura mater is called the subdural arachnoid. Sub dural not contain CSF. The cavity between the arachnoid and Piamater called Subarachnoid. In this cavity there Cerebral Spinal Fluid, Blood Vessels and nerve roots
Meninges
The meninges are the protective coverings of the central nervous system (CNS). They consist of three layers: the dura mater, arachnoid mater, and pia mater.
The meninges are the protective coverings of the central nervous system (CNS). They consist of three layers: the dura mater, arachnoid mater, and pia mater.
·
Dura
mater.
The dura mater,
which means “tough mother,” is the thickest, toughest, and most superficial
layer of meninges. Made of dense irregular connective tissue, it contains many
tough collagen fibers and blood vessels. Dura mater protects the CNS from
external damage, contains the cerebrospinal fluid that surrounds the CNS, and
provides blood to the nervous tissue of the CNS.
· Arachnoid
mater.
The arachnoid mater,
which means “spider-like mother,” is much thinner and more delicate than the
dura mater. It lines the inside of the dura mater and contains many thin fibers
that connect it to the underlying pia mater. These fibers cross a fluid-filled
space called the subarachnoid space between the arachnoid mater and the pia
mater.
· Pia
mater.
The pia mater,
which means “tender mother,” is a thin and delicate layer of tissue that rests
on the outside of the brain and spinal cord. Containing many blood vessels that
feed the nervous tissue of the CNS, the pia mater penetrates into the valleys
of the sulci and fissures of the brain as it covers the entire surface of the
CNS.
Cairan Serebro Spinal merupakan Cairan bening hasil
ultrafiltrasi dari pembuluh darah di kapiler otak. Cairan ini selalu
dipertahankan dalam keadaan seimbangan antara produksi dan reabsorpsi oleh
pembuluh darah. CSF mengandung air, protein dalam jumlah kecil, oksigen dan
karbondioksida, Na,K,Ca,Mg,Cl, glukosa, Sel darah putih dalamjumlah kecil, dan
material organic lainnya.
F. Serebro Spinal Fluid
Serebro Spinal fluid is a clear fluid ultrafiltration result of capillary blood vessels in the brain. This fluid is constantly maintained in a state of balance between production and reabsorption of the blood vessels. CSF contains water, protein, small amounts of oxygen and carbon dioxide, Na, K, Ca, Mg, Cl, glucose, the highest number of small white blood cells, and other organic material.
Serebro Spinal fluid is a clear fluid ultrafiltration result of capillary blood vessels in the brain. This fluid is constantly maintained in a state of balance between production and reabsorption of the blood vessels. CSF contains water, protein, small amounts of oxygen and carbon dioxide, Na, K, Ca, Mg, Cl, glucose, the highest number of small white blood cells, and other organic material.
Cerebrospinal
Fluid
The space surrounding the organs of the CNS is filled with a clear fluid known as cerebrospinal fluid (CSF). CSF is formed from blood plasma by special structures calledchoroid plexuses. The choroid plexuses contain many capillaries lined with epithelial tissue that filters blood plasma and allows the filtered fluid to enter the space around the brain.
The space surrounding the organs of the CNS is filled with a clear fluid known as cerebrospinal fluid (CSF). CSF is formed from blood plasma by special structures calledchoroid plexuses. The choroid plexuses contain many capillaries lined with epithelial tissue that filters blood plasma and allows the filtered fluid to enter the space around the brain.
Newly created CSF flows
through the inside of the brain in hollow spaces called ventricles and through
a small cavity in the middle of the spinal cord called the central canal. CSF
also flows through the subarachnoid space around the outside of the brain and
spinal cord. CSF is constantly produced at the choroid plexuses and is reabsorbed
into the bloodstream at structures called arachnoid villi.
Cerebrospinal
fluid provides several vital functions to the central nervous system:
1.
CSF
absorbs shocks between the brain and skull and between the spinal cord and
vertebrae. This shock absorption protects the CNS from blows or sudden changes
in velocity, such as during a car accident.
2.
The
brain and spinal cord float within the CSF, reducing their apparent weight
through buoyancy. The brain is a very large but soft organ that requires a high
volume of blood to function effectively. The reduced weight in cerebrospinal
fluid allows the blood vessels of the brain to remain open and helps protect
the nervous tissue from becoming crushed under its own weight.
3.
CSF
helps to maintain chemical homeostasis within the central nervous system. It
contains ions, nutrients, oxygen, and albumins that support the chemical and
osmotic balance of nervous tissue. CSF also removes waste products that form as
byproducts of cellular metabolism within nervous tissue.
some disorders of the nervous system?
The nervous system is
vulnerable to various disorders. It can be damaged by the following:
· trauma
· infections
· degeneration
· structural defects
· tumors
· blood flow disruption
· autoimmune disorders
Disorders of the nervous system:
Disorders of the nervous
system may involve the following:
· vascular disorders - such as stroke, transient ischemic attack
(TIA), subarachnoid hemorrhage, subdural hemorrhage and hematoma, and
extradural hemorrhage
· infections - such as meningitis, encephalitis, polio, and
epidural abscess
· structural disorders - such as brain or spinal cord injury,
Bell's palsy, cervical spondylosis, carpal tunnel syndrome, brain or spinal
cord tumors, peripheral neuropathy, and Guillain-Barré syndrome
· functional disorders - such as headache, epilepsy, dizziness,
and neuralgia
· degeneration - such as Parkinson's disease, multiple
sclerosis, amyotrophic lateral sclerosis (ALS), Huntington's chorea, and
Alzheimer's disease
Signs and symptoms of nervous system disorders:
The following are the most
common general signs and symptoms of a nervous system disorder. However, each
individual may experience symptoms differently. Symptoms may include:
· persistent or sudden onset of a headache
· a headache that changes or is different
· loss of feeling or tingling
· weakness or loss of muscle strength
· sudden loss of sight or double vision
· memory loss
· impaired mental ability
· lack of coordination
· muscle rigidity
· tremors and seizures
· back pain which radiates to the feet, toes, or other parts of the body
· muscle wasting and slurred speech
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