Download autonomic nervous system

AUTONOMIC NERVOUS
SYSTEM
DR. PETER REONISTO
MOORPARK COLLEGE
CNS
PNS
Cranial nerves
and spinal nerves
Motor (efferent)
division
Sensory (afferent)
division
Somatic sensory
Visceral sensory
General: Touch,
General: Stretch,
Pain, pressure,
Pain,temperature,
Vibration, temp.,
Chemical changes,
And proprioception
Irritation in viscera;
In skin, body wall,
Nausea and hunger
And limbs
Special: Hearing,
Equilibrium, vision,
Special: taste
smell
•
•
Somatic-outer tube
Visceral-inner tube
Somatic Motor
General: Motor
Innervation of all
skeletal muscles
General-widespread
Special-localized
Visceral Motor
General: Motor
Innervation of
Smooth muscle,
Cardiac muscle, and
Glands; equivalents
To ANS
Parasympatheitc
division
Sympathetic
Division
MOTOR NEURONS
• ANS includes a chain of 2 motor neurons:
1) Pre-ganglionic neuron – cell body lies within the
spinal cord or brain.
a) Preganglionic axon- synapses with the
ganglionic neuron
2) Ganglionic neuron- cell body lies in the peripheral
location.
a) Postganglionic axon- extends to the visceral
organs
DIVISIONS OF THE ANS
1) Sympathetic- “fight, flight, or fright
response”
2) Parasympathetic- body at rest, conserving
body energy; directs vital “housekeeping
activities” (digestion , urination); “rest and
digest”
Both divisions have chains of motor neurons
that mostly innervate the same visceral
organ, but they cause opposite effects.
Anatomical and biochemical
difference:
SYMPATHETIC
• originate at the thoracolumbar
region of the spinal cord.
• Long postganglionic fibers.
• Sympathetic fibers branch
profusely.
• Neurotransmitter released at
postganglionic axons are
Norepinephrine mostly.
PARASYMPATHETIC
• originate from the cranial
(brain) and sacral (spinal
cord) outflow
• Short postganglionic fibers
• Parasympathetic fibers not
profusely branched.
• Neurotransmitter released
are Acetylcholine
The preganglionic axon terminals of both divisions release acetylcholine
Refer to Table 15.1, page 434
PARASYMPATHETIC NERVOUS SYSTEM
CRANIAL OUTFLOW
- comes from the brain.
- Innervate the head,
neck, thorax, and most
of the abdomen.
- Preganglionic fibers
come from CNIII, VII,
IX, X.
SACRAL OUTFLOW
- comes from the sacral
sinal cord
- Supplies the rest of
abdominal organs and
the pelvic organs
Cranial
outflow
Sacral
outflow
SYMPATHETIC NERVOUS SYSTEM
• Paravertebral ganglion
located along both sides
of the vertebral column.
• Connected to the ventral
rami of nearby spinal
nerves
Prevertebral ganglia:
-occur only in the abdomen
1) Celiac
2) Superior mesenteric
3) Inferior mesenteric
4) Inferior hypogastric
Cranial
outflow
Paravertebral ganglion
Sacral
outflow
SYMPATHETIC NERVOUS SYSTEM AND ADRENAL
MEDULLA
The adrenal gland is divided into the:
1) Adrenal cortex
2) Adrenal medulla
SYMPATHETIC NERVOUS SYSTEM AND ADRENAL
MEDULLA
Adrenal Medulla
- Cells secretes the hormone norepinehrine and
epinephrine
- Innervated only by the sympathetic nervous
system
- Considered to be part of the sympathetic nervous
system; modified ganglionic cells that lack nerve
processes.
- Hormones have a excitatory effect of the “flight,
fight, or fright response”
CENTRAL CONTROL OF THE ANS
SUMMARY OF NEURONS CONNECTED TO THE SPINAL CORD
SUMMARY OF ANS
FUNCTIONS
EFFECTOR
ORGAN
HEART
SYMPATHETIC STIMULI
PARASYMPATHEITIC
STIMULI
Rate
Contractility
Increase
Decrease
SA NODE
Conduction velocity
Increase
Decrease
AV NODE
Conduction velocity
Increase
Decrease
VENTRICLES
Conduction velocity
Increase
------
LUNGS
Bronchial smooth muscle
Relaxation smooth
Muscle B2
Contraction smooth
Muscle A1
ARTERIOLES
Skin, resistance vessels
Skin surface vessels
Constriction(direct A1)
Dilation(circ Epi at B2)
Both dilation (circ
AcH at M2) (minor)
Constriction (direct A1)
------
Mucosa
SUMMARY OF ANS
FUNCTIONS
EFFECTOR
ORGAN
ARTERIOLES
SYMPATHETIC STIMULI
Abdominal viscera
PARASYMPATHEITIC
STIMULI
Constriction (direct A1)
------
Dilation (circ Epi at B2)
Dilation (circ AcH at M2)
Dilation (circ Epi at B2)
Dilation (circ AcH at M2)
Constriction (direct at A1)
Dilation (circ AcH at M2)
Constriction (direct at A1)
------
Decrease
Increased
Contraction
Relaxation
Skeletal muscles
Coronary
Glands
VEINS
(SYSTEMIC)
GIT
Motility and tone
Sphincter contraction
SUMMARY OF ANS
FUNCTIONS
EFFECTOR
ORGAN
SKIN
SYMPATHETIC STIMULI
Pilomotor muscle
PARASYMPATHEITIC
STIMULI
Piloerection
------
Secretion
------
Contraction
------
Contraction (mydriasis)
------
------
Contraction (miosis)
Relaxation (far vision)
Contraction (near vision)
Inhibition of secretion
Secretion
Sweat glands
SPLEEN
CAPSULE
EYE
Radial muscle of iris
Sphincter muscle of th iris
Ciliary muscle
GLANDS
Gastrointestinal
SUMMARY OF ANS
FUNCTIONS
EFFECTOR
ORGAN
GLANDS
SYMPATHETIC STIMULI
Lacrimal
Nasopharyngeal
Respiratory
Salivary
PARASYMPATHEITIC
STIMULI
------
Secretion
-------
Secretion
Inhibition of secretion
Secretion
Thick secretion
Thin secretion
CENTRAL CONTROL OF THE ANS
Cerebral Cortex
(Frontal lobe)
Limbic Lobe
(emotional input)
Hypothalamus
Overall integration of the
ANS
Reticular formation of the
brainstem
Regulation of pupil size,
Respiration, heart, BP,
Swallowing etc.
Spinal cord
Urination, defecation,
Erection, and ejaculation
reflexes
OVERVIEW OF THE
SENSORY ORGANS
Vision
Your eyes
gather
visual
information
, which is
sent to your
brain to be
processed
and
understood.
Vision (retina)
Vision: Retina
• Rods sense
brightness
• Cones sense color
The retina, in the back
of your eye, has cells
that are sensitive to
light. They connect
directly to your
brain.
Hearing
Sound waves
make your
eardrum
vibrate.
Then, the
small bones
in your ear
vibrate, and
the
vibrations
go through
the snaillike cochlea,
which turns
them into
nerve
impulses to
your brain.
Taste
• 10,000 taste buds
in your mouth
• Sweet and salty
are least
sensitive
• Bitter ones are
most sensitive
Your tongue picks
up four types of
taste: sweet,
sour, bitter, and
salty.
Taste
Buds
• You have
10,000 taste
buds in
your mouth.
Tastebuds closeup
Molecules
of food
stimulat
e the
taste
cells to
send
messages
to your
brain.
The
sweet
and salty
buds are
the least
sensitive
and the
bitter
ones are
the most
sensitive.
SMELL
Odor particles
drift into
your nose
and cause
your smell
receptors to
send
messages to
your brain.
OLFACTORY BULB
(SMELL)
The smell
part of the
brain is in
the limbic
region, and
is
connected
to feeling
and
memory.
TOUCH
There are at least six types of touch
receptors in your skin. One for hot,
one for cold, one for pain, one for
pressure, one for touch, and one for
fine touch.
END
PLEASE READ THE SENSORY
SYSTEM AND THE ENDOCRINE
SYSTEM