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Title: Peripheral%20Nervous%20System%20(PNS)%20Autonomic%20Nervous%20System%20(ANS)

Peripheral Nervous System (PNS) Autonomic Nervous
System (ANS)
Nervous System Classification-1
  • Somatic Nervous System
  • Motor nerves to skeletal muscle (somatic motor
  • Upper and lower motor neurons
  • Skeletal Muscle Reflexes
  • Sensory, interneurons, lower motor neurons
  • Visceral (organ) Reflexes
  • Sensory nerves (somatosensory neurons)
  • Peripheral Nervous System
  • Whatever neurons are outside of CNS
  • Autonomic Nervous System
  • Motor nerves to smooth and cardiac muscle
    (visceral motor neurons)
  • Sympathetic
  • Parasympathetic

Todays lectures are the red topics
Nervous System Classification-2
  • Efferent Nervous System
  • Somatic Nervous System
  • Upper and lower motor neurons to skeletal muscle
    (somatic motor neurons)
  • Visceral (Autonomic) Nervous System
  • Motor nerves to smooth and cardiac muscle
    (visceral motor neurons)
  • Sympathetic
  • Parasympathetic
  • Afferent Nervous System
  • Sensory nerves (somatosensory neurons)
  • Reflexes

I did not organize the lectures by this method of
  • A visceral motor nerve innervates involuntary
    effectors (smooth muscles in organs or cardiac
    muscle). This is part of the ANS.
  • A somatic motor nerve innervates voluntary
    effectors (skeletal muscle). It is not part of
    the ANS.
  • (dont confuse this with a somatic sensory nerve
    for the sense of touch sensory nerves are not
    part of the ANS either)

  • Internal organs also have sensory nerves that
    tell you when you have eaten enough or your
    bladder is full. These are not part of the ANS
    because they are sensory.
  • Not all organs have sensory nerves, for instance,
    you cant feel when you have high blood pressure.
  • You can also have visceral reflexes, which
    trigger the parasympathetic system to contract
    the bladder when full, etc.
  • Reflexes are hard to localize.

Nervous System Classification-1
  • Somatic Nervous System
  • Motor nerves to skeletal muscle (somatic motor
  • Upper and lower motor neurons
  • Skeletal Muscle Reflexes
  • Sensory, interneurons, lower motor neurons
  • Visceral (organ) Reflexes
  • Sensory nerves (somatosensory neurons)
  • Peripheral Nervous System
  • Whatever neurons are outside of CNS
  • Autonomic Nervous System
  • Motor nerves to smooth and cardiac muscle
    (visceral motor neurons)
  • Sympathetic
  • Parasympathetic

Todays lectures are the red topics
Somatosensory Neurons
  • The somatosensory system is made up of a number
    of different neurons with various receptors,
    including thermoreceptors (action potential is
    triggered by heat or cold), photoreceptors
    (triggered by light), mechanoreceptors (triggered
    by movement) and chemoreceptors (triggered by
    chemicals), proprioception (position of the
    body), and nociception (pain).
  • Each somatosensory neuron specializes in
    conducting one type of sensation.
  • The sensory receptors cover the skin, skeletal
    muscles, bones and joints, internal organs, and
    the cardiovascular system.

Somatic Senses
  • Pain
  • Haptic perception
  • Deep Pressure
  • Light Touch
  • Vibration
  • Thermoception (Hot/Cold)
  • Two-point discrimination
  • Proprioception
  • Special senses

These are routinely tested by doctors in a
physical exam, especially for people with
diabetes and lupus.
Sense of Touch
  • Touch is a laymans term. It is not specific in
    what it describes.
  • Touch includes mechanoreception (deep pressure,
    light touch, vibration and proprioception), pain
    (nociception) and heat (thermoception). Since
    each of these are different neurons, each of
    these has to be tested separately.

Sense of Pain
  • A nociceptor is a receptor of a sensory neuron
    (nerve cell) that responds to potentially
    damaging stimuli by sending signals to the spinal
    cord and brain.
  • This process, called nociception, usually causes
    the perception of pain.
  • They travel in the dorsal column pathway in the
    spinal cord, ascend to the thalamus in the brain,
    and go to the cerebral cortex.

Referred Pain
  • Pain in an organ may not be where the organ is.
  • Heart pain usually manifests in the left side of
    chest, the left shoulder, arm, but not the heart.
  • This is REFERRED PAIN.
  • Pain in the lungs usually shows up as neck pain.
  • Hip pain often presents as the appearance of a
    groin injury.
  • These areas of referred pain are important to
    know, but not for this class.

A Map of Referred Pain
Complex regional pain syndrome (CRPS)
  • Formerly called Reflex Sympathetic Dystrophy
  • Chronic progressive disease characterized by
    severe pain, swelling, and changes in the skin.
  • It often affects an arm or a leg and may spread
    to another part of the body and is associated
    with dysregulation of the autonomic nervous
    system resulting in multiple functional loss,
    impairment, and disability.
  • Symptoms include burning and shooting pains and
    edema that occur more often during times of
  • Treatment is often unsatisfactory. Early
    multimodal therapy can cause dramatic improvement
    or remission of the syndrome in some patients.
  • http//

Treatment for Pain
  • Somatosensory Rehabilitation of Pain is a method
    whose aim is to treat conditions of a reduced
    sense of touch or sensation (hypoesthesia) in
    order to decrease neuropathic pain.
  • Neuropathic pain, with a prevalence of 7 of the
    general population, represents an important
    public health problem.

Treatment for Pain
  • Examples of pain syndromes include
  • Carpal Tunnel Syndrome (CTS) concerns 3 of the
    general population.
  • Complex Regional Pain Syndrome (CRPS) concerns
  • Patients with chronic pain might use
    transcutaneous electrical nerve stimulation (TENS
    unit) and other physical therapy modalities,
    which bring substantial pain relief to large
    numbers of people.

Haptic perception(Sense of Touch)
  • Deep Pressure
  • Light Touch

  • While touch (also called tactile perception) is
    considered one of the five traditional senses,
    the impression of touch is formed from several
    modalities including pressure, skin stretch,
    vibration and temperature.
  • There are separate neurons for each of those
    sensations, and each group of neurons must be
    evaluated during a physical exam.
  • In medicine, the colloquial term "touch" is
    usually replaced with "somatic senses" to better
    reflect the variety of mechanisms involved.

Haptic perception
  • Haptic perception is the process of recognizing
    objects through touch. It involves a combination
    of somatosensory perception of patterns (e.g.,
    edges, curvature, and texture) on the skin
    surface and proprioception of hand position and
    conformation (what position do my finger go into
    while tracing the surface of the object?).

Haptic perception
  • People can rapidly and accurately identify
    three-dimensional objects by touch.They do so
    through the use of exploratory procedures, such
    as moving the fingers over the outer surface of
    the object or holding the entire object in the

  • Haptic perception is active exploration, whether
    with a body part or a tool, such as feeling the
    contours of something by using a stick to touch
  • Haptic perception allows the creation of
    "virtual", illusory haptic shapes with different
    perceived qualities.
  • Loss of the sense of touch is a catastrophic
    deficit that can impair walking and other skilled
    actions such as holding objects or using tools.

Disorder of Sense of Touch
  • One disorder of the sense of touch
  • Allochiria

  • Allochiria (from the Greek meaning "other hand")
    is a neurological disorder in which the patient
    responds to stimuli presented to one side of
    their body as if the stimuli had been presented
    at the opposite side.
  • It is associated with spatial transpositions,
    usually symmetrical, of stimuli from one side of
    the body (or of the space) to the opposite one.
    Thus a touch to the left arm will be reported as
    a touch to the right arm
  • If the auditory or visual senses are affected,
    sounds (a person's voice for instance) will be
    reported as being heard on the opposite side to
    that on which they occur and objects presented
    visually will be reported as having been
    presented on the opposite side.
  • Commonly from damage to the right parietal lobe.

  • Allochiria can also occur to other senses.
  • Motor Allochiria
  • Reflex Allochiria
  • Audio Allochiria
  • Visual Allochiria
  • Gustatory Allochiria

Sense of Vibration
  • Pallesthesia refers to the sensation of
    mechanical vibration on or near the body.
  • Vibration sense may be lost as a result of a
    number of lesions to the nervous system, often in
    conjunction with other deficits.
  • The word "pallesthesia" is derived from the Greek
    pallein, meaning "to shake."
  • Pallesthesia may be tested for using a vibrating
    mechanical tuning fork, placed on a bony

Thermoception(Sense of Hot/Cold)
  • Thermoception is the sense of heat and the
    absence of heat (cold) by the skin.
  • There are specialized receptors for cold
    (declining temperature) and for heat.
  • Cold receptors help an animals sense of smell,
    telling wind direction. Heat receptors help
    animals that can use radiation to detect prey,
    such as snakes.
  • The information travels up the spinothalamic
    tract in the spinal cord and ascends to the
  • The thermoceptors in the skin are quite different
    from the homeostatic thermoceptors in the brain
    (hypothalamus), which provide feedback on
    internal body temperature.

Two-point discrimination
  • Two-point discrimination is the ability to
    discern that two nearby objects touching the skin
    are truly two distinct points, not one.
  • It is often tested with two sharp points during a
    neurological examination and is assumed to
    reflect how finely innervated an area of skin is
    and diagnosing tactile agnosia (dont know what
    is touching me).

Two-point discrimination
  • The therapist randomly alternates between
    touching the patient with one point or with two
    points on the area being tested (e.g. finger,
    arm, leg, toe).
  • The patient is asked to report whether one or two
    points was felt. The smallest distance between
    two points that still results in the perception
    of two distinct stimuli is recorded as the
    patient's two-point threshold.

Two-point discrimination
  • Performance on the two extremities can be
    compared for discrepancies.

  • There are sensors within the muscles and joints
    that measure the amount of force, movement, and
  • Proprioception neurons travel up the
    spinocerebellar tract. The brain can then
    interpret whether you are off balance, then send
    a command to the muscles to contract and
    straighten yourself up so you dont fall.
  • Note that this sense of balance is NOT the same
    as the sense of balance from equilibrium in the
    ears. Proprioception neurons are located within
    the muscles and joints.
  • During a physical exam, a doctor will test the
    patients proprioception ability by telling them
    to close their eyes and place their finger on
    their nose. This may indicate a lesion in the
    cerebellum. Who else may ask you to do this test?
    Alcohol disrupts the cerebellum.

Muscle spindles
  • Muscle spindles are sensory receptors within the
    belly of a muscle that primarily detect changes
    in the length of this muscle. The brain can then
    determine the position of body parts.
  • Muscle spindle responses also play an important
    role in regulating the contraction of muscles, by
    activating motor neurons via the stretch reflex
    to resist muscle stretch.

  • Sensory receptors that report on internal events
    in your muscles and joints.
  • They report on muscle stretch and joint position.
  • They generate electrical impulses that will
    travel up neurons to the CNS.
  • A muscle spindle is one type of proprioceptor.

Proprioception Disorders
  • Not enough vitamin B1 (memory problems)
  • Too much vitamin B6 (balance problems)
  • Damage to proprioceptors can occur from consuming
    excess vitamin B6 (pyridoxine).
  • Patients cannot tell where their body parts are
    unless they look at them.
  • They have difficulty with all motor tasks
    including walking, eating, dressing, etc.
  • They must use their vision to watch each body
    part to make it move in the right direction.

  • Proprioception is often tested by having the
    patient close their eyes and saying if their
    thumb is up or down.
  • Proprioceptors send information to the
    cerebellum. Thats how you know your legs are
    crossed before you stand up.
  • Somatic senses and proprioception are NOT
    considered special senses.

Somatic Senses
  • Pain
  • Haptic perception
  • Deep Pressure
  • Light Touch
  • Vibration
  • Thermoception (Hot/Cold)
  • Two-point discrimination
  • Proprioception
  • Special senses (these are not somatic)

Special senses
  • The special senses are those that have
    specialized organs devoted to them
  • vision (the eye)
  • hearing and balance (the ear)
  • smell (the nose)
  • taste (the tongue)

These will be discussed in a separate lecture.
  • Somatic sense information goes into the spinal
    cord, travels up a tract and into the primary
    somatosensory area in the parietal lobe of the
    cerebral cortex.
  • The mapping of the body surfaces in the brain is
    called a homunculus and plays a fundamental role
    in the creation of body image. Loss of an arm may
    cause phantom limb syndrome.

This brain-surface ("cortical") map is not
immutable, however. Dramatic shifts can occur in
response to stroke or injury.
  • These come out of the spinal cord and go to
    specific regions of skin on the body.
  • For example, nerve C4 innervates the skin region
    C4 of the DERMATOME MAP.
  • Its important to know these dermatome map
    regions (not for this class), especially physical
    therapists and nurses.

Dermatome Map
  • If a patient has a shooting pain down the
    anterior shin, what nerve is pinched? L5.
  • Numbness in pinky and ring finger is what nerve?
  • If a workmans comp patient comes in saying his
    whole hand is numb, no other symptoms, you know
    hes lying because the nerves dont run that way.

  • If a person has a spinal cord injury in their
    cervical region, they could have
    quadriplegia/tetraplegia (arms and legs
  • If a person has a spinal cord injury in their
    thoracic region, they could have paraplegia (just
    legs are paralyzed).

Disruption of Blood Supply
  • When a body part falls asleep, the region has
    become ischemic (lack of blood flow), impairing
    the action potential of the nerves.
  • Unlike the CNS, when blood is restored to the
    PNS, the nerves recover.
  • Damage to the CNS tends to be permanent, but
    damage to the PNS tends to heal.

Cut nerves
  • If a small nerve is cut, it will regenerate
    because where are the cell bodies? In the
    posterior root ganglion (sensory) or anterior
    horn (motor).
  • Since the cell body is about a meter away, axons
    can regrow.
  • Large nerves are harder to regrow, but you can
    still stitch the ends together at the epineurium
    and perineurium, and you may get healing.

Doctors trying to fix damaged nerves
  • http//
  • Nerve disease and injuries are tough to treat,
    largely because there's no way to regenerate many
    damaged nerve cells. Neurologist Joseph Corey is
    trying to change that.
  • Corey and a team of scientists used tiny polymer
    fibers as a scaffold. They coaxed an
    oligodendrocyte to form a myelin sheath around
    the fiber. The artificial fiber mimicked an axon.
  • Myelin provides the pathways along which some
    nerve cells regenerate after an injury. When a
    person has MS or cerebral palsy, the
    oligodendrocytes are damaged and don't function
    properly and the myelin sheaths start to break

Rat Brain in a Dish Flies Plane
  • An electrode grid was placed at the bottom of a
    glass dish and then covered with rat neurons that
    gradually formed a neural network -- a brain.
  • They then used the brain to control an F-22
    fighter jet flight simulator.
  • The research could lead to tiny, brain-controlled
    prosthetic devices and unmanned airplanes flown
    by living computers.

Exoskeleton Helps Paralyzed Patients Walk
  • Exoskeletons have been designed for military use
    and boosting strength. But the same technology
    that makes people able to lift heavier loads
    might also one day allow those with spinal
    injuries to walk.
  • Ekso Bionics, a California company, developed the
    Human Universal Load Carrier, or HULC for the
    military, and another one called the Ekso, for
    people who need either physical therapy or

Tens unit
  • Transcutaneous electrical nerve stimulation

TENS is usually applied at high frequency with an
intensity below motor contraction. It just blocks
pain impulses. This is a different machine than
a muscle stimulator, but they look the
same. TENS is available without a Rx.
Corydalis powder for pain
  • http//

Put ½ teaspoon into one cup of hot fluid (tea,
etc) and drink it. Alleviates chronic pain in
about 20 minutes!
Pinched nerves
  • When a nerve gets pinched (e.g. herniated disc),
    it damages the nerve by interfering with its
    action potential, causing weakness, pain, or

Nervous System Classification-1
  • Somatic Nervous System
  • Motor nerves to skeletal muscle (somatic motor
  • Upper and lower motor neurons
  • Skeletal Muscle Reflexes
  • Sensory, interneurons, lower motor neurons
  • Visceral (organ) Reflexes
  • Sensory nerves (somatosensory neurons)
  • Peripheral Nervous System
  • Whatever neurons are outside of CNS
  • Autonomic Nervous System
  • Motor nerves to smooth and cardiac muscle
    (visceral motor neurons)
  • Sympathetic
  • Parasympathetic

Todays lectures are the red topics
Spinal Nerves Posterior View
Peripheral Nerves are motor nerves that have left
the spinal cord or sensory nerves that have not
yet entered the spinal cord.
  • Note an epidural nerve block during child birth
    will numb the mother from her navel to her knees.
  • PUDENDAL NERVE this is the nerve that can be
    anesthetized during childbirth as an alternative
    to an epidural (a pudendal nerve block is also
    called a saddle block because the numb areas are
    where you would be touching a saddle).
  • PHRENIC NERVE allows the diaphragm to contract.
    If it gets severed, the person can no longer
    breathe without assistance.

Nerve Plexus
  • A PLEXUS is a network of nerves that primarily
    serves the limbs. There are four major plexi
    cervical, brachial, lumbar, and sacral.
  • 1. CERVICAL PLEXUS comes out of the neck and are
    cutaneous nerves (sensory input of the skin) of
    the neck and back of the head. The phrenic nerve
    (supplies the diaphragm) is also in this plexus.

Cervical Plexus
  • This is the major group of nerves that supply the
    upper limbs. It runs through the axilla.
  • If a person leans their armpits on their
    crutches, they can damage this plexus and lose
    the use of their arms (crutch paralysis).
  • The nerves in the brachial plexus change names as
    they go to different regions in the arm.

The Brachial Plexus
Major Nerves of the Upper Extremity
Axillary Nerve
  • Deltoid

Musculocutaneus Nerve
  • Supplies anterior muscles of the arm

Instead of radial and ulnar nerve, we have median
and ulnar nerve.Median Nerve
  • Supplies no muscles of the arm
  • Supplies anterior forearm (except flexor carpi
  • Damage can cause
  • Hand of benediction
  • Ape Hand
  • Carpal Tunnel Syndrome

Patient trying to make a fist
  • This is the nerve that gets cut when people try
    to slit their wrists.
  • The arteries are so small in the wrist people
    rarely die from this type of suicide attempt.
  • However, they live with a lot of tissue damage.
  • They are not able to move the thumb towards the
    little finger, so it is hard to pick up small
  • This is called ape hand.

(No Transcript)
Carpel Tunnel Syndrome
Median NerveCarpel Tunnel Syndrome
  • The median nerve travels under the transverse
    carpal ligament.
  • The nerve is pinched in carpal tunnel syndrome.

Carpel Tunnel Syndrome
Patient Case
  • George has been a computer programmer for 20
    years. He has numbness in his right hand on the
    thumb, index finger, and middle finger.
  • Tapping on the carpal tunnel causes parathesias
    (tingling) in the median nerve distribution
    (positive Tinels sign).
  • Placing his wrist in sustain flexion for one
    minute also causes the parathesias (positive
    Phalens test).

Patient Case
  • Diagnosis is carpal tunnel syndrome. Treatment
    began with splinting the wrist in neutral
    position and patient education for proper
    ergonomics (how to use your body at work without
    injury). George was told to use a wrist pad while

Ulnar Nerve
  • Supplies flexor carpi ulnaris
  • Funny Bone
  • Damage can cause claw hand cannot adduct or
    abduct fingers

Radial Nerve
  • Supplies muscles on the posterior arm and forearm
  • Triceps brachii
  • Extensor carpi radialis
  • Extensor digitorum
  • Damage can cause wrist drop
  • Also called waiters hand

Carpel Tunnel Syndrome
Ape Hand
Axillary, Musculocutaneus, Ulnar, Median, Radial,
Figure 14.4
Brachial Plexus
  • Damage to Brachial Plexus
  • Congenital (brachial plexus damaged during birth
    the baby comes out arm first and someone pulls
  • Klumpkes paralysis
  • Acquired Brachial Plexus injuries
  • Crutch paralysis (total upper extremity
  • Claw Hand
  • Carpal Tunnel Syndrome, Ape hand, Hand of
  • Wrist Drop (Waiters Hand)

  • FEMORAL NERVE is the main nerve to the anterior

Lumbo-Sacral Plexus
  • Lumbar
  • Femoral nerve
  • Sacral
  • Sciatic nerve

The Lumbar Plexus
Figure 14.15
Sacral Plexus
  • 4. SACRAL PLEXUS are spinal nerves from L4-S5
  • Some of the fibers from the lumbar plexus mix
    with the sacral plexus, so these are often
    referred to together as the lumbosacral plexus.
  • SCIATIC NERVE is the largest branch of the sacral
    plexus and the largest nerve in the body it is
    about the size of your pinky finger. It leaves
    the pelvis through the greater sciatic notch.
  • A short, thick muscle (Piriformis muscle) covers
    the greater sciatic notch, and when it contracts,
    it can pinch the sciatic nerve, causing a type of
    sciatica (sciatic nerve irritation) known as
    piriformis syndrome.
  • This can be alleviated by stretching exercises
    (lay on back and move knee to opposite shoulder).
    However, sciatica can also be caused if there is
    a herniated lumbar disc, in which case stretching
    exercises make it worse.

The Sacral Plexus
Figure 14.16a, c
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  • Sciatica tremors video

Spinal steroid shots may have little effect on
  •  http//
  • For the back pain component of sciatica, the
    researchers found that the injections didn't seem
    to make a difference over short or long periods
    of time.
  • When it came to leg pain, there was no difference
    a year or so after the injection, but there was a
    statistically significant drop in pain scores
    over the short term - about 2 weeks to 3 months.

(No Transcript)
Nerves of the Lower Extremity
The sciatic nerve supplies the back of the thigh,
then branches out into the TIBIAL and FIBULAR
(peroneal) nerves, which supply the leg and
foot. The fibular nerve branches into superficial
and deep.
Lower Extremity Nerves
  • Obturator Nerve
  • Supplies adductor muscles
  • Femoral Nerve
  • Supplies anterior Thigh
  • Sciatic Nerve
  • Supplies posterior thigh
  • Tibial Nerve
  • Supplies posterior leg and foot
  • Common Fibular Nerve
  • Superficial branch
  • Supplies lateral side of leg
  • Deep branch
  • Supplies anterior leg
  • Injury causes Foot Drop

Tibial Nerve
  • Sometimes a small branch of the tibial nerve in
    the foot gets pinched between the metatarsal
    heads, and the irritation causes nerve swelling
    and pain.
  • It is called a neuroma (nerve tumor) and
    manifests as pain in the ball of the foot, made
    worse with high heels.

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Nervous System Classification-1
  • Somatic Nervous System
  • Motor nerves to skeletal muscle (somatic motor
  • Upper and lower motor neurons
  • Skeletal Muscle Reflexes
  • Sensory, interneurons, lower motor neurons
  • Visceral (organ) Reflexes
  • Sensory nerves (somatosensory neurons)
  • Peripheral Nervous System
  • Whatever neurons are outside of CNS
  • Autonomic Nervous System
  • Motor nerves to smooth and cardiac muscle
    (visceral motor neurons)
  • Sympathetic
  • Parasympathetic

Efferent Nervous System
Somatic Division
Visceral (Autonomic) Division
Smooth muscle, cardiac muscle, and glands
Blood vessel
  • We dont have voluntary control over these
  • They are involved digestion, blood flow,
    urination, defecation, glandular secretion.
  • Therefore, the ANS supplies the glands, smooth
    muscle, and cardiac muscle, but NOT the skeletal
  • For this reason, the ANS is also called the
    general visceral motor system.

Sympathetic Division of the ANS
  • All of the neurons of the ANS are motor neurons
    (there are no sensory neurons in the ANS).
  • The ANS motor neurons differ from the somatic
    motor neurons (for skeletal muscle) because the
    ANS has two lower motor neurons in the periphery
    (the cell body of one is in the spinal cord and
    the cell body of the other is in the periphery),
    whereas the somatic motor neurons have one lower
    motor neuron, and its cell body is within the
    spinal cord, not in the periphery.

ANS has TWO lower motor neurons
Post-ganglionic neuron
Preganglionic neuron
Ganglion (where the cell bodies of the
post-ganglionic neurons are)
Somatic system has just one lower motor neuron
  • The ANS lower motor neuron comes from the spinal
    cord and synapses on the cell body of another
    neuron, which then synapses on the target (gland,
    blood vessel or organ).

  • The area where the two neurons come together is
  • The first neuron is the PRE-GANGLIONIC NEURON.
  • The second neuron is the POST-GANGLIONIC NEURON.

  • The ANS motor unit is characterized by having
    more than one lower motor neuron, the axons are
    usually unmyelinated (since they are only going
    to organs), conduction is slow, and the axons are
    thin (which also slows conduction like a freeway
    with only one lane).
  • The ANS has two divisions sympathetic and

SYMPATHETIC DIVISION(has nothing to do with
  • ?heart rate and blood pressure,
  • ?metabolic activity (increased blood glucose),
  • decreased peristalsis (decreased food digestion)
  • dilation of bronchioles
  • constricts blood flow to the skin
  • sweating

Sympathetic Division
  • E.g. when running, ?heart rate sympathetic.
  • When hot ? sweat sympathetic.
  • The term Fight or Flight is inaccurate it
    refers to the ? heart rate, etc, but the
    sympathetic division is also active when relaxing
    on a nice beach with a cool drink on a hot day,
    because whenever youre sweating, thats the
    sympathetic division.
  • Sympathetic NS and sympathy are opposites. They
    should call it the ANTI-sympathetic system.

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  • The sympathetic neurons exit the spinal cord at
    the thorax and lumbar regions.
  • The axons of most pre-ganglionic neurons in the
    sympathetic division are fairly short, and they
    synapse quickly on a ganglia.
  • All these ganglia are lined up along the
    vertebral column and are called the SYMPATHETIC
  • Therefore, the postganglionic cell bodies of the
    sympathetic nervous system are in the chain
  • There are also nerves that connect the ganglia to
    each other.

Sympathetic Trunk Ganglia
Sympathetic Division
In Sympathetic division, preganglionic axons are
SHORT because they terminate in ganglia that are
close to the spinal cord
That means the post-ganglionic axons are LONG,
because they have to reach all the way to the
target muscle.
Sympathetic Division
  • The axons of POST-GANGLIONIC NERVES are very
    long, and go to the target organs.
  • Some pre-ganglionic neurons go into to the
  • They create a group of ganglia in the abdomen
    called the SOLAR PLEXUS (sun).
  • When you get punched in the abdomen, you are
    punched in the solar plexus, and get the wind
    knocked out of you. It causes the diaphragm to go
    into spasm.

  • Unlike the sympathetic division, the axons of the
    preganglionic neurons of the parasympathetic
    division are long, and the axons of the
    postganglionic neurons are short.
  • The nerve cell bodies (peripheral ganglia) of the
    parasympathetic division are closer to the organs
    being innervated than in the sympathetic
  • In fact, the cell bodies are either next to or
    inside of the target organs. Therefore, they have
    short post-ganglionic fibers.

Parasympathetic Division
In the Parasympathetic division, preganglionic
axons are LONG because they terminate in ganglia
that are close to the target organ
That means the post-ganglionic axons are SHORT
  • Rest and Digest
  • Involved in vegetative activities, such as
    digestion, voluntary urination and defecation
  • Has postganglionic cell bodies in terminal
    ganglia, located either near or within target
  • Has both preganglionic and postganglionic neurons
    that secrete acetylcholine
  • Has preganglionic cell bodies located in the
    cervical (Vagus nerve) and sacral areas.

Parasympathetic Division
  • The function of this division is often
    antagonistic (opposite) of the sympathetic, but
    actually, they work together.
  • The parasympathetic division inhibits cardiac
    contraction, so there is ?heart rate, constricts
    bronchioles, activates digestive system, and
    causes salivation, urination, and defecation.
  • When you are lounging on the beach, the heart
    rate decreases (parasympathetic), but the sweat
    increases (sympathetic).

Vagus Nerve
  • The parasympathetic neurons come out of either
    the brain or the sacral region of the spinal
  • The majority of the parasympathetic outflow from
    the head is by the vagus nerve.
  • One thing the Vagus nerve does is cause
    vasodilation of blood vessels to lower the blood
    pressure when baroreceptors tell the brain that
    blood pressure is too high.

Vasovagal Syncope (Fainting)
  • The most common type of fainting.
  • After a stressful trigger where your blood
    pressure goes up, the brain senses this and tells
    the Vagus nerve to get to work. The Vagus nerve
    tells all the blood vessels in the body to open
    up to lower the blood pressure.
  • The heart rate speeds up at first.
  • Then Vagus nerve kicks in and the blood pressure
    drops too much.
  • Unconsciousness results.
  • Treatment elevate the legs above the heart for a
    few minutes, and make sure the airway remains
  • A cold, wet cloth on the forehead and back of the
    neck may make the person feel better as they

Path of the Vagus Nerve
Reynaud's Phenomenon
  • Autonomic nervous system (sympathetic division)
    is hyperactive in the ANS neurons that innervate
    the walls of blood vessels.
  • It causes spasms of peripheral blood vessels,
    cuts off some blood supply, and causes the
    fingers and toes to be white or blue.
  • Emotional stress and being cold tend to trigger
    the discoloration.

Other things that can cause vasoconstriction
  • With frequent use, tolerance to many of the
    effects of caffeine will develop. Caffeine causes
    vasoconstriction. In doses of 600 milligrams
    (about six cups of coffee) or more daily,
    caffeine can cause nervousness, sweating,
    tenseness, upset stomach, anxiety, and insomnia.
    It can also prevent clear thinking and increase
    the side effects of certain medications. This
    level of caffeine intake represents a significant
    health risk.

  • Caffeine can be mildly addictive. Even when
    moderate amounts of caffeine are withdrawn for 18
    to 24 hours, one may feel symptoms such as
    headache, fatigue, irritability, depression, and
    poor concentration. The symptoms peak within 24
    to 48 hours and progressively decrease over the
    course of a week. To minimize withdrawal
    symptoms, experts recommend reducing caffeine
    intake gradually.

  • At levels over 200 milligrams per day, caffeine
    may delay conception and doubles the risk of
    miscarriages and low birth weight babies.
  • Black tea and green tea are also dangerous,
    despite what you see on the market today. Herbal
    tea is ok. Caffeine and tannin in tea decreases
    iron and protein absorption, and is especially
    dangerous during pregnancy. Black tea during
    pregnancy causes birth defects.
  • Caffeine taken during pregnancy is thought to
    increase the probability of a child contracting
  • Because children have developing nervous systems,
    it is important to moderate their caffeine

Caffeine, per cup
  • Ammo 1140 mg
  • Redline Power Rush 946 mg
  • Expresso 500 mg
  • Jolt Energy 300 mg
  • Rockstar Energy 160 mg
  • Coffee 100 mg
  • Red Bull 80 mg
  • Mountain Dew 60 mg
  • Green tea 50 mg
  • Tea 50 mg
  • Coke 37 mg
  • Dark Chocolate (1.5 oz) 20 mg
  • Milk Chocolate (1.5 oz) 9 mg
  • Hot Chocolate 5 mg
  • Root Beer, Ginger ale, Lemon-Lime 0 mg

The Ammo and Redline manufacturers recommend
users dilute the concentrated energy drink prior
to consumption. They also claim that drinkers
should not just drink the shot straight out of
the bottle due to the extreme potency!
Symptoms of Excess Caffeine
  • nervousness                  headache   
              increased heart rate
  •  anxiety                           upset
    stomach      irregular heartbeat
  •  irritability                       GI
    irritation           elevated BP
  •  agitation                        
    heartburn              increased cholesterol
  •  tremors                         
    diarrhea                nutritional deficiencies
  •  insomnia                       
    fatigue                  poor concentration
  • depression                     
    dizziness              bed wetting

Caffeine Withdrawal Symptoms
  • headache                       constipation       
       runny nose
  • craving                           
    anxiety                 nausea
  • irritability                        
    nervousness         vomiting
  • insomnia                        
    shakiness              cramps
  • fatigue                            
    dizziness              ears ringing
  • depression                     
    drowsiness           hot and cold
  •  apathy                            inability to
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