THE NERVOUS SYSTEM (HK24CY005 2.1)

The nervous system co-ordinates all body movement and activities, voluntary and involuntary

actions. Neurology is the study of the Nervous System.

Throughout the whole of the body is a vast network of nerve fibres creating the ultimate

communication and messaging service. Rather like the Network Signalling System where the

brain is the main controller (not the Fat Controller!), or computer, and the spinal column is

the main line. The spinal nerves are branch lines with junctions at ganglions leading to the

stations – the organs and glands! However, there is more than just an understanding of

neurons for the Complementary Health Practitioner to appreciate about this amazing system.

Many clients seek the help of a Reflexologist for pain, and pain is indeed all in the brain, as

will become clear.

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When working on the feet, the Reflexologist has the opportunity to access over 7,500 nerve

endings all capable of responding to signals initiated by an effective thumb and finger

walking technique.

The Nervous System is split into two main parts: the Central Nervous System (CNS) and

the Peripheral Nervous System (PNS).

The Central Nervous System consists of the Brain (the Main Computer/Controller) and the

Spinal Cord (the main central line), all incoming and outgoing signals are routed through the

Central Nervous System.

The Peripheral Nervous System includes all of the branch lines (the spinal and cranial

nerves) and nerves in the rest of the system that cover actions we are not even aware of

taking place, such as the dilation and constriction of the pupils in the eye (Autonomic

Nervous System) as well as relaying nerve impulses to move skeletal muscle that we can

control (Somatic Nervous System).

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Nervous System Outline:

Central Nervous System Peripheral Nervous System

(CNS) (PNS)

Brain and Spinal Cord Cranial Nerves from Brain

Co-ordinates body functions. Spinal Nerves from Spinal Cord

Reflex actions

Autonomic Nervous System

Supplies muscles of internal organs and

glands (no voluntary control)

Somatic Nervous System

Supplies muscles of

The Skeletal System Parasympathetic nerves Sympathetic Nerves

(voluntary control) Slow down activity Speed up activity

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THE CENTRAL NERVOUS SYSTEM

The brain connects to the spinal cord which, together, makes up the Central

Nervous System (CNS), running from the neck to the hip area. The spinal cord

carries nerve messages between the brain and the body.

Protection

The cells of the nervous system are quite fragile and need extensive protection

from being crushed and/or infected by disease organisms. The brain and spinal

cord are protected by layers of connective tissue called the Meninges. The

outermost layer is a tough, translucent membrane, called the Dura Mater

(meaning tough mother). The middle layer is the Arachnoid (spider-like as it

resembles a spiders web) and the innermost layer is the Pia Mater (Pia =

delicate, as it is a thin transparent covering).

Cerebrospinal fluid (CSF) is a clear, watery liquid that surrounds the brain and spinal cord,

and is also found throughout the ventricle (brain cavities and tunnels). CSF cushions the

brain and spinal cord from jolts.

The cranium (the top of the skull) surrounds and protects the brain, whereas, the spinal cord

is surrounded by vertebrae (hollow spinal bones). Some muscles also serve to pad and support

the spine.

More subtly, blood flowing into the brain is filtered, so that many harmful chemicals cannot

enter the brain. This is called the blood-brain barrier, and it protects the brain from

chemical intrusion from the rest of the body.

Functions of the Brain

The human brain is a complex organ that allows us to think, move, feel, see, hear, taste, and

smell. It controls the body, receives, analyses and stores information (our memories). The

brain produces electrical signals which, together with chemical reactions, let the various

parts of the body communicate. Nerves send these signals throughout the body. For example,

a child touches a hot object and burns its fingers. The heat and pain are detected by sensory

nerves in the skin and this information is passed to the child’s brain. The brain stores this

information in its memory, so that when the child sees the hot object again, it will remember

the heat and pain associated with it. The brain will send out messages to the appropriate

muscles in the child’s body to move it away from the hot object.

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Size of the Human Brain

The average human brain weighs about 3 pounds (1.3kg). At birth, the human brain

weighs less than a pound (0.78-0.88 pounds or 350-400g). As a child grows, the

number of cells, within the brain, remains relatively stable, but the cells grow in size, and the

number of connections increases. The human brain reaches its full size at about 6 years of

age and constitutes about one-fiftieth of the total body weight.

Nourishment of the Brain

Although the brain is only 2% of the body's weight, it uses 20% of the oxygen supply and

gets 20% of the blood flow. Blood vessels (arteries, capillaries, and veins), supply the brain

with oxygen and nourishment, and take away wastes. If brain cells do not get oxygen for 3 to

5 minutes, they begin to die. Cerebrospinal fluid (CSF) surrounds the brain.

Composition of the Brain

The brain is located at the top of the spinal cord and fills the cranial

cavity of the skull. The surface of the brain is folded and looks a bit

like a walnut. The folds give the brain a larger surface area for

absorbing nutrients from the blood vessels on its surface. The brain

consists of 100 billion neurones (nerve cells) and 1000 billion neuroglia

(nerve tissue cells). The brain is not solid but has cavities inside it

called ventricles. These are filled with the nutrient, liquid, cerebrospinal fluid, which also

removes waste from the brain, helping to maintain the shape of the brain by providing

pressure from within (a bit like the water in a hot water bottle makes it more solid).

The brain is composed of both grey matter (40%) and white matter

(60%). Grey matter includes neuron cell bodies, dendrites (meaning

little trees – the receiving input portion of a neuron), axon terminals

(an axon is the long thin process that the nerve impulses travel along),

bundles of unmyelinated axons, and neuroglia. White matter consists

of myelinated processes of many neurons, myelin is white.

Structure of the Brain

The brain has four main regions: the Brain Stem, the

Cerebellum, the Diencephalon and the Cerebrum.

The Brain Stem – this is continuous to the spine and

consists of the:

Medulla Oblongata (known as the Medulla)

Pons Varolii (‘Pons’ means ‘bridge’ - the bridge between the spinal cord and brain)

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Midbrain (mesencephalon) - reflex centres for body movement.

The Brain Stem is essential to life, with the Medulla regulating heartbeat, breathing,

swallowing, coughing, hiccupping, vomiting, posture and balance. Ten, of the twelve pairs of

cranial nerves, originate in the brain stem, with the remaining two originating in the brain

itself. If the Medulla ceases to function, for whatever reason, then the person dies or

remains on a life support machine.

The Reticular Formation is a mass of grey matter that extends the entire length of the

brain stem. It is responsible for the motor control of visceral organs and muscle tone, as well

as consciousness and awakening from sleep.

The Cerebellum is the cauliflower-shaped region at the back of the head behind the brain

stem. Its main functions are regulating posture and balance, and co-ordinating and smoothing

complex sequences of skeletal muscular contraction.

The Diencephalon lies above the brain stem and includes the:

Epithalamus – containing the pineal gland

Thalamus – the main relay station for sensory

impulses of hearing, vision, taste, touch,

pressure, vibration, heat, cold and pain. It is

also involved in emotions and memory, cognition,

voluntary motor actions and arousal.

Hypothalamus – the main regulator of

homeostasis. Controls the pituitary gland,

synthesises oxytocin and antidiuretic hormones (see Endocrine system handout). It

regulates emotional behaviour, hunger, fullness and thirst, controls body temperature

and regulates sleep patterns.

The Cerebrum appears as a cap over the Diencephalon and fills most of the cranium. It is

divided into two halves; the right and left cerebral hemispheres. Each hemisphere of the

cerebrum is divided into four lobes that take their names from the sections of the cranium

under which they lie:

Frontal

Parietal

Temporal

Occipital

The functions of the Cerebrum include:

1. Mental activities involved in memory, language, intelligence, sense of responsibility,

thinking, reasoning, moral sense and learning.

2. Sensory perception, including perception of pain, temperature, touch, sight, hearing,

taste and smell.

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3. Initiation and control of skeletal muscle contraction.

4. It is the seat of emotions.

5. It controls consciousness.

The folded, outer layer of the cerebrum is called the Cerebral Cortex and is responsible for

integrating the sensory information into meaningful pictures, smells, tastes and sounds,

together with co-ordinating the response to these.

The Limbic System is often called the “emotional brain” because it controls the emotional

and voluntary aspects of behaviour. It is the area associated with pain, pleasure, anger, rage,

fear, sorrow, sexual feelings, affection, and memory.

Basal Ganglia are found in the cerebral hemispheres and receive information, and provide

output to the cerebral cortex, thalamus and hypothalamus. They control large automatic

movements of the skeletal muscles and help regulate muscle tone.

The Spinal Cord is continuous with the medulla oblongata and is located within the

protective “tubing” of the vertebral column. The cord passes through an outlet in the skull

and travels for approximately 42cm down the vertebral column. It is half an inch thick and

ends just above the second lumbar vertebra in a tail like structure. For protection, the cord

is bathed in cerebro-spinal fluid, and when a specimen of CSF is needed, it is taken from the

point below the end of the undivided cord, ie below the level of the second lumbar vertebra.

The spinal cord is protected by the Spinal Meninges (see protection of the brain section).

Nerve impulses are transported to and from the brain via the spinal cord. Also the spinal

cord receives and integrates information, and produces reflex actions in response to specific

changes in the environment.

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PERIPHERAL NERVOUS SYSTEM

The Peripheral Nervous System (PNS) has three main types of nerve: Cranial Nerves, Spinal

Nerves and the Autonomic Nerves. There are two types of nerve cells: neurons and neuroglia.

Neuroglia, or glial cells, perform the function of connective tissue - they support and protect

the neurons, and maintain homeostasis of the fluid that surrounds them. Neuroglia are

smaller and more numerous than neurons.

Neurons

Throughout the nervous system, information is conveyed as tiny electrical signals called

nerve impulses, or action potentials. These impulses are the same all over the body – about

100 millivolts (0.1 volts) in strength and lasting just 1 millisecond.

The information carried depends on their position in the nervous system, and frequency.

When a nerve receives enough impulses from another nerve, it fires an impulse of its own.

These impulses jump from one nerve to another at junctions known as synapses. Imagine a

firework display, with the spark from one firework igniting the touch paper of the next

firework.

These cells of the nervous system, called nerve cells or neurons (sometimes spelt with an “e”

on the end (neurone)), are specialised to carry "messages" through an electrochemical

process. The human brain has about 100 billion neurons. Neurons become excitable when

stimulated - they undergo chemical changes that produce travelling waves of electricity.

Because conduction of nerve impulses is active, energy is required, and expended by the

neurons. Therefore, thinking consumes calories!

Neurons carry messages.

Neurons come in many different shapes and sizes for example:

Multipolar (several dendrites and one axon).

Bipolar (one dendrite and one axon).

Unipolar (the axon and dendrite are fused).

Neurons are similar to other cells in the body because they:

are surrounded by a cell membrane.

have a nucleus that contains genes.

contain cytoplasm, mitochondria and other organelles

carry out basic cellular processes, such as protein synthesis and energy production.

However, neurons differ from other cells in the body because they:

have specialised extensions, called dendrites and axons. Dendrites bring information

to the cell body, and axons take information away from the cell body.

communicate with each other through an electrochemical process.

contain some specialised structures (for example, synapses) and chemicals (for

example, neurotransmitters).

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There are three main types of neurons (nerves):

Motor (Efferent) neurons - carry impulses from the brain and spinal cord to muscles,

producing movement, and to glands stimulating secretion.

Sensory (or Afferent) neurons - convey impulses that give the sensation of touch, taste and

smell etc, from the body to the brain, which then translates it into meaningful pictures,

tastes, sounds etc.

Mixed neurons - carry both of the above but, are only present in the spinal nerves.

Interneurons (or Association) neurons - carry nerve impulses from one neuron to another.

These make up the vast majority of neurons.

A Typical Neuron

Axon - the long extension of a neuron that carries nerve impulses away from the body of the

cell.

Axon terminals - the hair-like ends of the axon.

Cell body - of the neuron; it contains the nucleus (also called the soma).

Dendrites - the branching structure of a neuron that receives messages (attached to the

cell body).

Myelin sheath - the fatty substance that surrounds and protects some nerve fibres. It is

whitish in colour, giving “white matter” its name, and acts as protection for the nerve fibre

by insulating the axon, and increasing the speed of impulse transmission. If a neuron is

unmyelinated (ie, with no myelin sheath), transmission of impulses is slower - the grey matter

of the nervous system contains unmyelinated axons.

Node of Ranvier - one of the many gaps in the myelin sheath, it also increases the speed of

impulse transmission along the axon. The impulse jumps across the nodes as in the firework

analogy used earlier.

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Nucleus - the organelle, in the cell body of the neuron, which contains the genetic material

of the cell.

Schwann's cells – are cells that produce myelin in the peripheral nervous system. They are

located within the myelin sheath and are a form of neuroglia. Myelin sheaths in the Central

Nervous System are produced by oligodendrocytes, another form of neuroglia.

The Synapse (from the Greek word ‘synaptein’, to ‘join’ - pronounced

sin.aps)

Messages are passed from neuron to neuron via the synapse. Some

electrical synapses pass signals very quickly, such as in the central

nervous system, smooth muscle, viscera and cardiac muscles. They allow

for two way transmission and can synchronize the activity of a group of

neurons or muscle fibres. The other type of synapse is called a chemical

synapse, these are slower with mostly only one-way communication.

Synapses are essential for homeostasis because they allow information to be filtered and

integrated. By the time you finish this course many of your synapses will have been modified!

Some diseases and psychiatric disorders result from disruptions of synaptic communication.

Synapses are also the sites of action for many therapeutic and addictive chemicals.

When an electrical impulse arrives at a synapse it triggers the release of chemicals called

neurotransmitters. Examples of neurotransmitters include:

Acetylcholine, Dopamine and Noradrenaline (norepinephrine) – this is both a

neurotransmitter and a hormone.

They cross the gap (the synaptic cleft) between the membranes of the presynaptic (sending)

and postsynaptic (receiving) neurons, and either trigger a new impulse, or actively inhibit it

from firing. Once it has completed its action the neurotransmitter is then quickly removed

by diffusion, enzyme degradation, or it is transported back into the cells where it is

recycled. At a neuromuscular synapse, the motor end plate of the muscle fibre receives the

neurotransmitter.

The Myotatic Reflex (Reflex Action)

One of the most familiar reflexes is the

stretch reflex, also known as the knee-

jerk reflex, and the myotatic reflex. In

its simplest form it is a two-neuron loop,

one afferent neuron and one efferent

neuron.

The afferent neuron is connected to a

muscle spindle, which detects stretch in

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the muscle. The efferent neuron is the motor neuron, which causes the muscle to twitch.

This reflex can also be used to describe the action of touching something that causes pain,

for example, and withdrawing your hand before you have even thought about it. It is a reflex

that does not involve the brain and is called an Arc Reflex.

Nerve Injury and Regeneration

Peripheral nerves that have been damaged may regenerate slowly if the cell body remains

undamaged. The damaged section of fibre loses its nourishment and degenerates, leaving the

myelin sheath hollow. In the meantime, the healthy remaining fibre begins to grow along the

empty sheath at a rate of 1-2mm per day.

Natural regeneration is unlikely in the nerve fibres of the spinal cord and brain, they are too

specialised to recreate their highly developed functions. So, spinal cord injuries may lead to

paralysis, depending on the location and extent of the damage. Monoplegia is paralysis of one

limb only; diplegia – two limbs; paraplegia – both lower limbs; hemiplegia is paralysis of one

upper limb, trunk and one lower limb on the same side of the body; and quadriplegia is

paralysis of all four limbs.

Spinal shock is an immediate response to spinal injury, and includes loss of reflex action, low

blood pressure, paralysis of skeletal muscle, loss of somatic sensations and urinary bladder

dysfunction. The patient has an improved outcome if an anti-inflammatory corticosteroid

drug is administered within eight hours. Spinal shock can last from several minutes to several

months, after which reflex activity gradually returns. Recovery from a traumatic brain

injury may be quick or slow; it may be complete, partial or absent. Scientists still don’t know

how the brain heals itself.

Cranial Nerves

The cranial nerves from the brain, and the spinal nerves from the spinal cord, are the first

part of the Peripheral Nervous System to be studied.

There are twelve pairs of cranial nerves, which arise from the under-surface of the brain.

They are numbered according to where they arise in the brain, in order, from anterior to

posterior. They are named according to their distribution or function and supply the head,

neck and major organs of the body as summarised below:

1) OLFACTORY sensory nerve for smell

2) OPTIC sensory nerve for sight

3) OCULOMOTOR )

4) TROCHLEAR ) motor nerves for muscles of the eye

5) TRIGEMINAL mixed nerve, (sensory and motor) for teeth, head

and facial skin

6) ABDUCENT motor nerve for eye

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7) FACIAL mixed nerve for facial expression

8) AUDITORY sensory nerve for hearing

9) GLOSSO-PHARYNGEAL mixed nerve for taste, muscles of pharynx

10) VAGUS mixed nerve for larynx, pharynx, heart, oesophagus,

spleen, lungs, liver, kidneys, stomach, pancreas, colon

and small intestines

11) SPINAL ACCESSORY motor nerve for trapezius and sterno-mastoid

muscles

12) HYPOGLOSSAL motor nerve for muscles of the tongue

NB: “Mixed nerves” refer to motor/sensory.

Spinal Nerves

There are 31 pairs of Spinal Nerves:

Cervical region of spine = 8 pairs of nerves C1-7 the first two are counted as 1

Thoracic region of spine = 12 pairs of nerves T1-T12

Lumbar region of spine = 5 pairs of nerves L1-L5

Sacral region of spine = 5 pairs of nerves S1-5

Coccygeal region of spine = 1 pair of nerves Coccygeal nerves

31 pairs in total

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Although there are only 7 cervical vertebrae,

there are 8 pairs of cervical spinal nerves. This

is because the 1st pair of nerves leaves the spinal

cord between the base of the skull and the 1st

cervical vertebra. The 8th cervical spinal nerve

leaves below the 7th cervical vertebra. In

reflexology, we call the 1st and 2nd cervical spinal

nerves C1 (or 1C on some charts), because this is

the cervical vertebra closest to both these nerves.

Each spinal nerve contains a mixture of motor nerves, supplying the skeletal muscles of the

trunk and limbs, and sensory nerves supplying the skin and muscles. A skin area innervated by

the sensory fibres of a single nerve root is known as a dermatome (derma = skin, tome = thin

segment), and a group of muscles primarily innervated by the motor fibres of a single nerve

root is known as a myotome.

Motor nerves leave the spinal cord via the ventral (front) root of the spinal nerve. If this

interior root of a motor nerve is injured, the result would be loss of power in the part

supplied by that particular nerve, but sensation would remain. However, if the posterior root

is damaged, the power of movement remains, but the sensation would be lost, since the

sensory nerve enters the spinal cord via the posterior root.

So each muscle in the body is supplied by a particular level or segment of the spinal cord and

by its corresponding spinal nerve. The muscle and its nerve make up a myotome. For example:

C6 bends the wrist back, C7 straightens the elbow, C8 bends the fingers, T1 spreads the

fingers and so on. So, a myotome is the relationship between the spinal nerve and muscle and

a dermatome is the relationship between the spinal nerve and the skin.

A Spinal Nerve

As nerve impulses travel up, or down, the spine

to the brain, they cross over. Sensory

messages from the right hand, end up in the

sensory area of the left cerebral hemisphere

of the forebrain. Also, motor impulses from

the motor areas in the left cerebral

hemisphere would exit the brain via spinal

nerves that emerge on the right-hand side of

the body. This explains why people who have

had a stroke, which has damaged the left

cerebral hemisphere, are paralysed down the

right side of their body. Cranial nerves do not

cross over as they exit the brain, so the same

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left-sided stroke would paralyse the left side of the face. Speech would also be impaired

since this function is controlled by a region within the left cerebral hemisphere. As a

reflexologist working with a stroke victim, it is important to work on the big toe, on the

opposite side of the body to where the stroke damage has manifested.

The innervation of each part of the body occurs in an organised manner. For instance, the

nerve which leaves the spine at the level of T10 innervates the kidneys and covers the

dermatome at the level of the naval. In the case of shingles, where one or two nerve roots

are infected by the herpes zoster virus, a characteristic rash forms along a well demarcated

dermatome on the skin; it can also be very painful along the nerve. Conversely, the loss of

sensation in a particular area of the skin, can lead to the relevant nerve - remember how it

feels to have an anaesthetic for dental work. Knowing the dermatomes can help locate the

nerve or nerves affected and assist the Reflexologist in deciding how to treat the client

more proactively. For the Reflexologist, an understanding of dermatomes, myotomes, and

particularly all nerve innervations is essential, as clients may present with pain, loss of

sensation or imbalances in any location in the body that can be helped by working the spine

and brain effectively. Tenderness found on the feet in the spine may indeed be an organ or

gland in need of balancing, not necessarily a problem with the spine.

Dermatome Chart

Detailed Dermatome Chart of Hands and Arms

Dermatome organisation of the limbs is more complex due to embryological development

when the limb buds “pull out” the dermatomes.

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Plexuses

When a spinal nerve leaves the intervertebral foramen (the opening in the vertebra) it

divides into several branches. These branches are known as rami. The anterior or ventral

rami of spinal nerves (except for thoracic nerves T2-T12) do not go directly to the body

structures they supply. Instead, they form networks on both the left and right sides of the

body by joining with various numbers of nerve fibres from anterior rami (branches) of

adjacent nerves. Such a network of nerves is known as a plexus (braid).

The main plexuses are:

The Cervical Plexus (C1-C4)

Motor Nerves: form the Phrenic nerve that innervates the diaphragm. It innervates muscles

that turn, flex and extend the head and open the jaw, and shares the innervation of the

trapezius.

Sensory: Innervates the skin on the back of the head, the neck and shoulders.

The Brachial Plexus (C5-T1)

Motor Nerves: Innervates muscles of the shoulder girdle, upper chest wall, arm and hands.

Sensory: Innervates skin, bone and muscle of the shoulders, arms and hands.

The Lumbar Plexus (L1-L4): Supplies the front and side abdominal wall, external genitals and

some of the lower extremities.

The Sacral Plexus: innervates the buttocks and perineum. The sciatic nerve, the longest

nerve in the body arises from the sacral plexus.

Emerging from the plexuses, are nerves with names describing the regions of the body they

serve, or travel through. It is important for a reflexologist to appreciate that a painful

reflex may be the nerve plexus serving that area of the body, or an imbalance in the part of

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the body showing up in that nerve plexus. For example, the Solar Plexus is a network of

nerves that is located behind the stomach. It supplies nerves to the abdominal organs below

the diaphragm and regulates the functions of these organs. When emotionally stressed or

shocked, the solar plexus may give rise to a feeling of nausea stemming from the stomach,

together with a feeling of tenderness for the reflexology client.

In some Anatomy and Physiology books there is another system within the Peripheral

Nervous System and that is the Enteric Nervous System (ENS - enter = intestines). The

ENS is the “brain” of the gut and its operation is involuntary. The ENS consists of

approximately 100 million neurons in enteric plexuses that extend the entire length of the

gastrointestinal tract. It is not included in the PNS because many of the neurons function

independently of the ANS and CNS to some extent, although they also communicate with the

CNS via sympathetic and parasympathetic neurons. Sensory neurons within the GI tract

monitor chemical changes and the stretching of its walls. Enteric motor neurons govern

contraction of GI tract smooth muscle, secretions of the GI tract organs such as stomach

acid, and activity of the GI tract endocrine cells.

Spinal Reference Chart

There are many charts showing the nerve innervations (where the spinal nerves go to in the

body) and, below is a good general chart with some of the symptoms that a person might

experience if the nerve impulses are blocked to a particular organ or gland.

As a reflexologist it is vital to understand the importance of working the spine as it impacts

on every part of the body.

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The Peripheral Nervous System is also subdivided into the:

Sensory-Somatic Nervous System; and the

Autonomic Nervous System

SENSORY-SOMATIC NERVOUS SYSTEM

The Somatic (‘somat’ meaning ‘body’) Nervous System consists of sensory neurons that

convey information from receptors in the head, body wall and limbs to the Central Nervous

System (Brain and Spinal Cord). Also, the Somatic Nervous System includes motor neurons

sending signals from the Central Nervous System to skeletal muscles. Because these motor

responses can be consciously controlled, this part of the Peripheral Nervous System is

voluntary.

PERIPHERAL NERVOUS SYSTEM

Autonomic Nervous System - (‘auto’ meaning ‘self’, and ‘nomos’ meaning ‘law’, ie it runs by

itself)

The Autonomic Nervous System (ANS) consists of sensory neurons and motor neurons that

run between the Central Nervous System (especially the hypothalamus and medulla

oblongata) and various internal organs such as the:

heart

lungs

viscera

glands (both exocrine and endocrine)

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The ANS is responsible for monitoring conditions in the internal environment and bringing

about appropriate changes in them. The contraction of both smooth muscle and cardiac

muscle is controlled by motor neurons of the Autonomic System.

The actions of the Autonomic Nervous System are largely involuntary (in contrast to those

of the Sensory-Somatic System).

The Autonomic Nervous System has two subdivisions, the

Sympathetic Nervous System and the

Parasympathetic Nervous System.

The Sympathetic Nervous System

stimulates heartbeat

raises blood pressure

dilates the pupils

dilates the trachea and bronchi

stimulates the conversion of liver glycogen into glucose

shunts blood away from the skin and viscera to the skeletal muscles, brain, and heart

inhibits peristalsis in the gastrointestinal (GI) tract

inhibits contraction of the bladder and rectum

In short, stimulation of the Sympathetic branch of the Autonomic Nervous System prepares

the body for emergencies: for "fight or flight". If the body is continuously in a state of

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“fight or flight” due to on-going stress then the long term effects may result in serious

illness as the chart below demonstrates.

The Parasympathetic Nervous System

slows down the heartbeat

lowers blood pressure

constricts the pupils

increases blood flow to the skin and viscera

increases peristalsis of the GI tract

In short, the Parasympathetic System returns the body functions to normal, after they have

been altered by Sympathetic stimulation. In times of danger, the Sympathetic System

prepares the body for violent activity, whereas, the Parasympathetic System reverses these

changes when the danger is over.

If you imagine a ‘Para’chute coming down from the sky, you will remember that the

‘Para’sympathetic slows everything down, which in turn helps you to remember that the

Sympathetic nervous system has the opposing effect.

Although the Autonomic Nervous System is considered to be involuntary, this is not entirely

true. A certain amount of conscious control can be exerted over it, as has long been

demonstrated by practitioners of Yoga and Zen Buddhism. During their periods of

meditation, these people are clearly able to alter a number of autonomic functions, including

heart rate and the rate of oxygen consumption. These changes are not simply a reflection of

decreased physical activity, because they exceed the amount of change occurring naturally

during sleep or hypnosis.

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Ganglia

A ganglion is a collection of neuronal cell bodies outside the Central Nervous System. All

autonomic motor pathways consist of two motor neurons, one following the other. The first

neuron has its cell body in the central nervous system, and its myelinated axon extends from

the CNS to an autonomic ganglion. The cell body of the second neuron is also in that

autonomic ganglion, but its unmyelinated axon extends directly from the ganglion to the

effector (smooth muscle, cardiac muscle or gland). There are ganglions for each part of the

body. Sympathetic neurons use the chain of ganglia to reach all parts of the body. So, a

chain of ganglia are switching centres, where one neuron switches to another. In the railway

analogy, it is a junction where you can change routes.

SUMMARY

The Nervous System senses changes

in the external and internal

environments, analyses these changes,

decides how to respond and then

responds.

Nerve cells that transmit nerve

impulses are called neurons.

Sensory (afferent) neurons transmit

information received from the sensory

organs to the Central Nervous

System.

The Central Nervous System consists

of the brain and spinal cord. It

analyses sensory information and responds with nerve impulses; the motor (efferent)

neurons tell the muscles or glands how to respond.

The Peripheral Nervous System consists of everything in the nervous system except

the brain and spinal cord.

The Autonomic Nervous System is the part of the Peripheral Nervous System that

deals with the body’s many involuntary or automatic responses to stimuli.

The Autonomic Nervous System consists of the Sympathetic and Parasympathetic

Nervous Systems, which generate opposite responses.

The Sympathetic Nervous System increases the heart rate, respiratory rate and

blood pressure, but slows digestion.

The Parasympathetic Nervous System decreases the heart rate, respiratory rate and

blood pressure, but promotes digestion.

22

References

British National Formulary (2012) 4.3 Antidepressant drugs. Available at:

http://www.medicinescomplete.com/mc/bnf/current/3294.htm (Accessed: 02 May 2012).

Hull, H. (2009) Anatomy & Physiotherapy for beauty and complementary therapies.

Cambridge: The Write Idea.

Kapit, W. and Elson, L. (2001) The Anatomy Colouring Book. San Fransisco: Benjamin

Cummings.

Multiple Sclerosis Society (2011) MS Society Sativex Fact Sheet. [Online] Available at:

http://www.mssociety.org.uk/sites/default/files/Documents/Factsheets/MS%20Society%2

0Sativex%20Fact%20Sheet.pdf (Accessed: 10 May 2012).

NHS Choices (No date) Health A-Z - Conditions and treatments. Available at:

http://www.nhs.uk/Conditions/Pages/hub.aspx (Accessed: 02 May 2012).

Waugh, A. and Grant, A. (2006) Ross and Wilson Anatomy and Physiology in Health and

Illness. 10th Edn. London: Churchill Livingstone.

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REFLEXOLOGY TECHNIQUES – SESSION 5 HK25CY009

Arm / Leg

Finger hook down the lateral edge of the foot, from the shoulder

reflex to the corner of the heel. As this is a line, repeat three

times. As the lateral edge is worked, both the arm and leg are

worked together, as the reflexes overlap.

Place the tip of the thumb on and under the lateral tuberosity,

and rotate over. This is the first of two knee reflexes (this is

also the elbow reflex).

With all fingers, walk across the dorsal aspect of the foot, over

the second knee reflex (also the psoas reflex). Walking with all the

fingers together is known as the ‘Marching Army’ technique. Now

repeat the Marching Army in the opposite direction. Finish the

knee and psoas by thumb walking the area. The psoas and knee have

now been thoroughly worked.

Pelvis and Reproductive

Thumb walk the lateral area of the heel, and lean the foot into the

thumb at the same time to create leverage. This is working the hip

area of the client. Criss-cross all the area under the heel to ensure

good coverage.

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Locate the ovary/testis reflex by placing the left thumb on the

corner of the clients right heel, place the middle finger on the

lateral malleolus, then place the index finger exactly between the

two. The index finger is now successfully on the ovary/testis

reflex. To be sure of exactly the right location, check to see if a

slight hollow can be felt under the index finger. Rotate the reflex

gently, then replace index

finger with ‘energy finger’

(middle finger) and place the

other energy finger in exactly

the opposite location on the

medial edge of the heel. Both finger-tips should now be

pointing at each other, and a technique called ‘Linking’ is

now being applied to the client.

The right middle finger is now over the uterus reflex (if working a female client) or the

prostate (if working a gentleman).

Now it is time to join the ovary up to the uterus, and this is done

by thumb walking along the fallopian reflex, which is found in the v-

notch between the foot and leg. Thumb walk from ovary to uterus

(lateral to medial), pushing the thumb against the tibia and fibula.

When working this area on a gentleman, the vas deferens is being

worked.

Next in the routine, it is time to work the groin lymphatic reflex, which is also found in the

v-notch of the foot. This is going to be worked by using both middle fingers together, and

working from the outside edges of the foot at the same time. When the fingers meet at the

middle, lift one finger up, so the other can slightly overlap the other.

When finger-walking this area, the fingers should be pulling back towards the reflexologist,

onto the talus, to ensure the right area is being worked.

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Now thumb walk the medial aspect of the heel, which is

the internal pelvic area, incorporating the uterus and

prostate. Lever the foot onto the thumb as it is pushed

into the reflex, as was done for the hip reflex.

To work the chronic reflex, rest both thumbs on the plantar aspect of the heel. With the

middle fingers, finger walk up the lateral and medial edge of the foot (at the same time)

from the base of the malleolus, until a comfortable stretch is reached between thumb and

finger.

Now Work the sciatic reflex by placing the tip of the long finger under the lateral malleolus

(have the palm of the hand face up to the ceiling and keep the thumb resting on the heel of

your client). Finger walk up the fibula until you get to a comfortable stretch.

To close this session, sweep across the medial and lateral

edge of the foot with the side of the index finger, starting

at the base of the foot, working slowly upwards. Do this with

both hands together.

The right foot has now been finished, repeat these

techniques on the left foot.

The treatment routine is now finished. A closing relaxation massage can now be applied on

both feet.