Transcript Week 3: Nervous - Balance Massage Therapy

Class 3
The Nervous System
and
Somatic and Special Senses
Peripheral Nervous System
Cranial Nerves and Spinal Nerves
Cranial Nerves
•12 Pairs of nerves that
originate on the brain.
I - Olfactory
II - Optic
III - Oculomotor
IV - Trochlear
V - Trigeminal
VI - Abducens
VII - Facial
VIII - Auditory
IX - Glossopharyngeal
X - Vagus
XI - Accessory
XII - Hypoglossal
Spinal Nerves
• 31 pairs of spinal
nerves (mixed nerves)
–
8 cervical (C1 – C8) C1
between skull and atlas
– others exiting at
intervertebral
foramen
– 12 thoracic (T1 – T12)
–
5 lumbar (L1 – L5)
–
5 sacral (S1 – S5)
–
1 coccygeal (Co)
Spinal cord
Anterior median fissure
Pia mater
Denticulate
ligaments
Dorsal root
Ventral root, formed by
several “rootlets” from
one cervical segment
Arachnoid mater
(reflected)
Dura mater (reflected)
Spinal blood vessel
Stimulus
Reflex Arc
Skin
1 Receptor
Interneuron
2 Sensory neuron
3 Integration center
4 Motor neuron
5 Effector
Spinal cord
(in cross section)
Patellar Reflex
Withdrawal Reflex
Nerve Plexus
• Where 2 or more
nerves come
together, are resorted, and form a
new nerve
• Include:
– Cervical
– Brachial
– Lumbosacral
Cervical Plexus
C1 – C4
Brachial Plexus
C5 – T1
Lumbosacral
Plexus
L1 – L4
&
L4 – S3
Peripheral Nerves
Phrenic Nerve
Axillary Nerve
Median Nerve**
Ulnar Nerve
Radial Nerve
Musculocutaneous
Nerve
Sciatic Nerve**
Femoral Nerve**
Obturator Nerve
Cervical plexus
diaphragm
armpit
associated with carpal tunnel syndrome
medial forearm
posterior arm, lateral forearm, posterior
hand
muscles and skin of arm
posterior thigh to bottom of foot to big toe;
splits into Tibial and Fibular at knee; largest
and longest nerve in the body; can often
been impinged by the piriformis muscle
anterior and lateral thigh
pelvis
Brachial plexus
Lumbosacral plexus
Dermatomes
C2C3
NV
C2C3
C2
C3
• A dermatome is
a region of the
skin supplied by
a single spinal
nerve.
T2
C6
L1
L2
C8
C7
T1
L3
L4
L5
C4
C5
T1
T2
T3
T4
T5
T6
T7
T8
T9
T10
T11
T12
S2
C3
T2
T3
T4
T5
T6
T7
T8
T9
T10
T11
T12
L1
L2
L4 L3
L5
C4
C5
T2
C6
T1
C7
SS
4 3
L1
S1 L5
S5
C8
L2 S2
L3
S1
L4
ANTERIOR
POSTERIOR
Shingles
Autonomic Nervous System
Parasympathetic and Sympathetic
Sympathetic Division
“Fight or Flight”
Thoracolumbar division
it’s branches come from the
T₁ – L₂ or L₃
Effects
heart rate, breathing rate,
sweating, pupil size, blood
vessel size to skeletal muscle,
adrenal gland secretions
intestinal function and
saliva
Parasympathetic Division
“Rest and Digest”
CranioSacral Division
it’s branches come from
the CNs III, VII, IX, X and
S₂, S₃, and S₄
Effects:
•Increase Intestinal Activity and
saliva
•Decrease Heart Rate
•Slower, deeper breathing
•Constricts pupils
Role of Massage Therapy in Autonomic Nervous System Function
Stimulates a
Parasympathetic
response
Relaxation!
Relaxation!
Relaxation!
Exception:
Pre-event Massage/Sports Massage – which is
designed to “stimulate” the body to
prepare it for the event about to take
place
Somatic and Special Senses
5 Types of Receptors:
Chemoreceptors
Detect chemical concentrations in an aqueous solutions
ex) taste buds and receptors of the nose
Pain Receptors
Detect damage to tissue
ex) free nerve endings throughout body
Thermoreceptors
Detect changes in temperature
ex) receptors found throughout skin and more
Mechanoreceptors
Detect changes in pressure or movement
ex) receptors found in skin, inner ear and more
Photoreceptors
Detect light energy
ex) rods and cones – the visual receptors
Sensations
•All impulses (information) entering
the CNS are virtually the same.
• The brain sends the signals to
specific areas of the brain for
interpretation.
•All sensation is subjective.
•Sensation is projected back to the
site of the original stimulus, which
makes us think we sense it at that
point.
•Many senses will adapt, impulses
rates will decrease.
Somatic Senses
Touch, Pressure and Vibration
Temperature Sensation
2 categories of Thermoreceptors:
Hot and Cold receptors.
• Cold receptors
– Most stimulated between 77º F and 41º F. Below that and area goes numb.
• Hot receptors
– Perceive hot sensations above 86º F and are most stimulated at 113º F.
• Free Nerve Endings: Detect as burning sensation when temp
is above 113⁰ or detect as numbing when temp is below 41⁰.
• Thermoreceptors are found all over the body, with highest concentration
found in the face and ears (hence why your nose and ears always get
colder faster than the rest of your body on a chilly winter day).
Pain Sensation
• Acute Fibers (A-Delta
fibers)
– sharp, myelinated,
remove stimulus & pain
goes away
• Chronic Fibers (C fibers)
– dull, unmyelinated,
remove stimulus & pain
stays
Visceral Pain and Referred Pain
Regulation of Pain Impulses
Endorphins and Enkephalins
Our Natural Pain Killers – special chemicals that when
released slow down the pain fiber impulses hence
lessening pain.
Muscle and Tendon Proprioception
Muscle Spindles
Golgi Tendon Organs
Special Senses
Sense of Smell
Olfaction
Sense of Taste
Gustation
Sense of Sight
• Hyperopia (farsightedness) –
difficulty focusing on objects near
the face.
• Myopia (nearsightedness) –
difficulty focusing on distant
objects.
• Astigmatism - An irregular shaped
cornea or lens prevents light from
focusing properly on the retina.
Images focus at multiple points on
retina
Sense of Hearing/Equilibrium
Hearing
Cochlea of the Inner Ear
Organ of Corti – hearing receptor
Static Equilibrium
• As the head
moves, the thick
fluid above the
receptor cells,
weighted with
otoliths, pulls on
the cilia of the
cells, generating a
nerve impulse
Dynamic Equilibrium
• As the body
spins or moves
in different
directions, the
cilia bend as the
head changes
position,
generating
nerve impulses.
EXAM REVIEW
This…….is….…Jeopardy
Nervous
System
Peripheral
Nervous System
Neurons
The Brain
Senses
100
100
100
100
100
200
200
200
200
200
300
300
300
300
300
400
400
400
400
400
Thank goodness!!!