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Autonomic
(Vegetative)
nervous system
Sympathetic division
Parasympathetic division
Metasympathetic division
Control
Autonomic (Vegetative)
nervous system
Autonomic system (involuntary)
takes part in regulation of
activity of an internal organs,
vessels and sweat glands, and
also influences to skeletal
muscles, receptors and nervous
system
Functions of autonomic
nervous system
Regulation of a tonus of vessels
and heart activity
Innervation of smooth muscles
Maintenance of functioning
endocrine and exocrine glands
Metabolism and adaptation of
an organism to environment
(including a thermoregulation)
Maintenance of homeostasis
Autonomic (Vegetative)
nervous system
Sympathetic nervous system
Parasympathetic nervous system
Metasympatheticnervous system
Sympathetic division
(thoracolumbar division)
The central part
The centers – bodies
of the first neurons in lateral
horns of thoracic and lumbar
departments of a spinal cord
(Th1- L3)
Peripheral part
fibers ganglia
The pregan-
glionic
The postgan-
glionicParavertebral Prevertebral
-from
the center
to ganglia
-short
-mediator ACh
-Cholino-
receptors
-body in a
ganglion
-travel to organs
-long
-a mediator NAd
-adreno-
receptors
are located
on both sides
of the spinal
cord and
formed
sympathetic
chains
Interrupt
in ganglia,
form knots
Knots
The cervical
(superior and inferior) The celiac
(Solar plexus) The mesenteric
(superior and inferior)
Functional features of sympathetic
division
Function"Fight or Flight”
TAKES PART IN
FORMATIONACTIVATING INFLUENCE ON
FUNCTIONS OF VARIOUS
ORGANS
aggression
stress
PAIN
REACTIONS
FEATURES
EFFECTS ARE LONG
EXCITATION IN GANGLIA COVERS
SOME VARIOUS ORGANS AT THE SAME TIME,
ESPECIALLY DURING EMOTIONAL
REACTIONS
Sympathetic pathwayBack nucleus of a hypothalamus (the
first neuron of a sympathetic pathway)
|
Lateral horns of a spinal cord (the second neuron of a sympathetic pathway)
|
Preganglionic myelinic fibers from ventral roots of a spinal cord
|
Knots of a sympathetic chain (the third neuron of a sympathetic pathway)
|
Postganglionic the nonmyelinic fibers to organs
|
Sympathetic innervation of an internal
Parasympathetic division
(craniosacral division)
The central part
Centers (body of the first
neurons):
Midbrain
Medulla oblongata, Pons
Sacral levels of the spinal
cord
Peripheral part
ganglia
The pregan-
glionic
The postgan-
glionicNext to organs
Near to pelvises
organs
-from
the center
to ganglia
-long
-mediator ACh
-Cholinore-
ceptors
-body is located
in ganglion
- travel to organs
-short
-a mediator Ach
- Cholinore-
ceptors
-Ciliary – a neck
-Palatal – head
-Submandibular,
-Auricular – a thoracal
and inferior abdominal
cavity (except
sceletal muscles,
blood vessels)
The inferior
abdominal -
organs a
small pelvis (except a uterus)
Ganglia are located
on a surface of organs or inside organs
fibers
Functional features of
parasympathetic division
Function"Rest and Digest"
CAUSES CALMING AND
RELAXING ACTION
“THE ANTISTRESSFUL
FACTOR”
RESTORES AND KEEPS THE
HOMEOSTASIS
FEATURES
EFFECTS OF ACTION UNSTABLE
MAKES THE LIMITED
INFLUENCE WITHIN AN
ORGAN, WHICH IT
INFLUENCES
DOMINATES IN
CALMNESS, PROMOTES
RESTORATION OF PULL
OF ENERGY DURING REST
Parasympathetic
pathway
Forward nucleus of a hypothalamus (the first neuron of a parasympathetic pathway)
|
Nuclei of an midbrain, pons, medulla oblongata and sacral department of the spinal cord (the second neuron of a sympathetic pathway)
|
Preganglionic myelinic fibers from forward roots of a spinal cord
|
Visceral knots (the third neuron of a sympathetic pathway)
|
Postganglionic nonmyelinic fibers to organs
|
Parasympathetic innervation of an internal
Summary
The ganglia of the sympathetic nervous
system lie just outside the spinal cord,
while in the parasympathetic system,
connections to the neuron that innervates
the target organ lie near the target organ.
The transmitters of the postgangionic
neuron are different and the receptors on
the target tissues of the parasympathetic
division are muscarinic Ach receptors, not
nicotinic Ach receptors
Metasympathetic
nervous systemComposition
Complex of microganglionic formations, which
are located in walls of an internal organs that
have motor function
Function
Transfer of the central influences through
sympathetic fibers with a correcting
Influences on organs
Independent
regulation of work
of an internal
Organs
Heart, bronchi, bladder, digestive tube, uterus,
gall bladder, bile ducts
FEATURES
Microganglia are isolated from a surrounding tissue
by dense membranes, have many synapses.
Have properties of automatism – contract without outside
influence under the influence of metabolic changes in the organ
MEDIATORS: АТP, Adenosine
АCh, Аd, Serotonin
Dofaminum, Histamine
Reflex arc
of autonomic (vegetative)
nervous system
Influence
of autonomic nervous
system
Influence
of vegetative nervous system
OrganParasympathetic Response
"Rest and Digest"
Sympathetic Response
"Fight or Flight"
Heart
(baroreceptor
reflex)
Decreased heart rate
Cardiac output decreases
Increased rate and strength of
contraction
Cardiac output increases
Lung
BronchiolesConstriction Dilation
Liver Glykogen No effectGlycogen breakdown
Blood glucose increases
Fat Tissue No effectBreakdown of fat
Blood fatty acids increase
Basal
MetabolismNo effect Increases
Stomach
Increased secretion of HCl &
digestive enzymes
Increased motility
Decreased secretion
Decreased motility
Intestine
Increased secretion of HCl &
digestive enzymes
Increased motility
Decreased secretion
Decreased motility
Urinary blader
Relaxes sphincter
Detrusor muscle contracts
Urination promoted
Constricts sphincter
Relaxes detrusor
Urination inhibited
Rectum
Relaxes sphincter
Contracts wall muscles
Defecation promoted
Constricts sphincter
Relaxes wall muscles
Defecation inhibited
EyeIris constricts
Adjusts for near vision
Iris dilates
Adjusts for far vision
Male Sex Organs Promotes erection Promotes ejaculation
Autonomic Receptors
Autonomic receptors are broadly divided into those for
ACh (cholinergic receptors) and those for catecholamines
such as NE or EPI (adrenergic receptors or adrenoceptors).
Subdivisions of each of these families of receptors are
based on sensitivity to various agonist and antagonist
drugs.
Cholinergic receptors
Cholinergic receptors were originally divided and
named on the basis of sensitivity to alkaloids that
mimicked some, but not all, of the actions of ACh.
These alkaloids are present in the fly agaric
mushroom, Amanita muscaria, and in the tobacco
plant, Nicotiana tabacum. The alkaloids are muscarine
and nicotine, respectively. Thus, cholinergic receptors
are broadly classified as muscarinic (mAChR) or
nicotinic (nAChR).
Cholinergic Receptor System Summary
Autonomic ReceptorsAdrenergic receptors
Adrenergic receptors, also called adrenoceptors, mediate
the actions of epinephrine (Adrenalin) and related
compounds. Adrenergic receptors can be acted upon by a
variety of agonists and antagonists, most of which are related
to beta-phenylethylamine. The classical site of adrenergic
receptors is the sympathetic neuroeffector junction. As in the
case of cholinergic receptors, however, adrenergic receptors
may exist on the cells of effector organs, even in the absence
of sympathetic innervation. In other words, not necessarily all
adrenergic receptors are innervated. Adrenergic drugs mimic
the actions of epinephrine and are also called
sympathomimetics. Direct-acting sympathomimetics act by
direct stimulation of adrenergic receptors.
Adrenergic receptors may be divided into two major
types according to drug (especially antagonist) potency on
the receptors. Alpha receptors, when activated, generally
produce excitatory responses of smooth muscle in which
they are located. Beta receptors, when activated, generally
produce inhibitory responses of smooth muscle in which they
are located.
Adrenergic Receptor System Summary
Autonomic Nervous System
It is also called the visceral nervous system as it controls the functioning of the visceral
(internal) organs.
The autonomic nervous system (ANS) consists of two sets of motor neurons and a collection
of ganglia. The two sets of neurons are:
- Pre-ganglionic Nerve Fibres
They are neurons that emerge from the CNS and enter the ganglions. Their nerve cells are in
the CNS.
- Post-ganglionic Nerve Fibres
They are the neurons that leave the ganglions and reach the smooth muscle/ gland. Their
nerve cells are in the ganglions.
The ANS consists of two divisions:
- Sympathetic nervous system
- Parasympathetic nervous system
Sympathetic Nervous System has the following features:
- It is entirely made up of spinal nerves of the chest (thoracic) and waist (lumbar) region.
- It has ganglia close to the spinal cord.
- The ganglia are linked to each other.
- The pre-ganglionic nerve fiber is shorter than the post-ganglionic nerve fibre.
- Generally it has an accelerating effect which prepares the body for action in emergencies.
Its functions include:
- dilation of pupils - increase rate and force of heart beat
- increase in secretion of sweat - decreases urine output
- releases adrenaline at the effector (gland or muscle) - inhibition of peristalsis
- dilation of blood vessels to brain and skeletal muscle
Parasympathetic Nervous System has the following features:
- It is made up of four pairs of cranial nerves and three pairs of sacral nerves.
- The ganglia are far away from the spinal cord and close to the effectors.
- The ganglia are not linked to each other.
- The pre-ganglionic nerve fibre is longer than the post-ganglionic nerve fibre.
- Generally it has a slowing-down effect which balances the effect of the sympathetic system.
Its functions include:
- constriction of pupils - decrease rate and force of heart beat
- decrease in secretion of sweat - increases urine output
- releases acetylcholine at the effector (gland or muscle) - stimulation of peristalsis
- constriction of blood vessels to brain and skeletal muscle Together, the parasympathetic
and sympathetic nervous systems work to maintain a steady state.
Control
of autonomic nervous
system
The highest level of
control of ANSBY HYPOTHALAMUS (FORWARD AND BACK NUCLEI)
1. Adapts functions of an internal for integrated activity
of an organism
2. Supports constant body temperature, carbohydrate,
fatty, water-salt balance
3. Regulates sexual functions
4. Regulates functions GASTROINTESTINAL TRACT,
endocrine glands
5. Regulates permeability of a wall of blood vessels and
tissue membranes
BY LIMBIC SYSTEM
1. Supports of a constancy of internal medium
of an organism
2. Correction of regulation of vegetative functions
1. Joins somatic and vegetative functions in a whole
system
BY CORTEX OF THE BIG HEMISPHERES
The regulation highest
level of VNS
Research of vegetative
nervous systemCardiovascular reflexes
Oculocardiac reflex of Danini-Ashnera
Decreasing of frequency of heart contractions on 8-10 in a minute at pressing to frontlateral surfaces of an eye during 20-30 seconds
Solar reflex
Decreading of arterial pressure and frequency of heart contractions on 4-12 in a minute at pressing during 20-30 seconds on solar plexus area
Clinicostatic assay
Decreasing of frequency of heart contractions on 10-12 in a minute at changing of posture from vertical to horizontal position
Orthostatic assay
Increasing of frequency of heart contractions on 10-12 in a minute at changing of posture from horizontal to vertical position
Dermal vegetative reflexes
Local reflectory dermographism
Pilomotor reflex
Contraction of a smooth muscule of hair of a skin duringcooling
Several variations of a "smoking shot" have been
used since the 1970's. Most commonly, the shots consist
of anticholinergic medications.
Interest in the use of anticholinergic medications
comes from the presence of Nicotinic Cholinergic
receptors in the Central Nervous System and the
Autonomic Nervous System. Nicotine stimulates the
excitatory pathways of the autonomic nervous system,
mimicking the natural "fight or flight" response. In addition,
nicotine stimulates the Dopamine pathway of the CNS,
which triggers the reward center and leads to addiction. It
was felt that blockade of the nicotinic receptors might ease
withdraw symptoms, and offer an effective treatment for
nicotine addiction.
Literature
Anatomy and physiology. - The
McGraw−Hill, Companies, 2003
www.mhhe.com/seeley6