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Презентация на тему Efferent peripheral NS: the autonomic votor divisions

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Autonomic nervous system: A part of the nervous system that regulates key involuntary functions of the body, including the activity of the heart muscle; the smooth muscles, including the muscles of the intestinal tract; and the
Efferent Peripheral NS: The Autonomic Motor Divisions Autonomic nervous system: A part of the nervous system that regulates key Review (again) Autonomic Nervous System Responsible for control of involuntary or visceral bodily functions Overview: The Parts of a Reflex Autonomic TargetsSmooth MuscleCardiac MuscleExocrine GlandsSome Endocrine glandsLymphoid TissueAdipose Divisions of ANSSympathetic ParasympatheticMetasympathetic Sympathetic and parasympathetic divisions typically function in opposition to each other. But ANS2 divisions:Sympathetic “Fight or flight”“E” divisionExercise, excitement, emergency, and embarrassmentParasympathetic “Rest and 1. The autonomic nervous system (ANS) is an involuntary motor (efferent) system.2. Autonomic pathway: Two Efferent Neurons in SeriesPreganglionic neuron cell body in CNSSynapse 3. Although “involuntary”, the autonomic nervous system is regulated by higher centers. 4. The autonomic nervous system consists of two divisions:a) the sympathetic (or Sympathetic  “Fight or flight” “E” division Exercise, excitement, emergency, and embarrassment = Thoracolumbar  division (T1 to L2) Preganglionic neurons (N1)from thoracolumbar region Sympathetic (preganglionic ):1. The cell bodies giving rise to preganglionic neurons (N1) Sympathetic (postganglionic ):1. The cell bodies giving rise to postganglionic neurons (N2) Sympathetic ganglia Sympathetic chain ganglia (paravertebral ganglia) – preganglionic fibers of the Sympathetic Trunk GangliaLocated on both sides of the vertebral columnLinked by short Prevertebral GangliaUnpaired, not segmentally arrangedOccur only in abdomen and pelvisLie anterior to The Organization of the Sympathetic Division of the ANS CopyrightSympathetic Pathways to PeripheryFigure 15.9 Rejoin spinal nerves and reach their destination by way of the dorsal CopyrightSympathetic Pathways to Thoracic Organs Sympathetic innervation via preganglionic fibers that synapse within collateral gangliaSplanchic nerves – Celiac ganglionInnervates stomach, liver, gall bladder, pancreas, spleenSuperior mesenteric ganglionInnervates small intestine CopyrightSympathetic Pathways to the Abdominal Organs CopyrightSympathetic Pathways to the Pelvic Organs Other important considerations:ganglion cells are usually located at some distance from the Sympathetic DivisionA single sympathetic preganglionic fiber has many axon collaterals and may Sympathetic Variosities Effects of Sympathetic Divisioncardiac output increasesSA node: heart rate (chronotropic) β1, : THE STRESS REACTIONA stressful situation activates three major communication systems in the THE STRESS REACTION	When stress occurs, the sympathetic nervous system is triggered. Norepinephrine The two divisions of the autonomic nervous system are not Homeostasis and the Autonomic DivisionBP, HR, Resp., H2O balance, Temp. . . Other important considerations:ganglion cells are usually located at some distance from The terminations of most, but not all, sympathetic postganglionic fibers release a The effects elicited by the action of the sympathetic division of the Parasympathetic  “Rest and digest” “D” division Digestion, defecation, and diuresis Parasympathetic: Craniosacral or rest and digest Center of parasympathetic division the ANS The Organization of the Parasympathetic Division of the ANS The Distribution of Parasympathetic Innervation = Craniosacral Division Long preganglionic axons from brain & S2- S4 Intramural Parasympathetic: Craniosacral or rest and digest Center of parasympathetic division the ANS The ganglion cells of the parasympathetic system are located in or on Most postganglionic parasympathetic fibers release acetylcholine at their terminations. These fibers are, Summary: Pre- & Postganglionic Parasympathetic Neurons Release AChmuscarinicnicotinicReceptorsN1N2 All parasympathetic fibers release AChShort-lived response as ACH is broken down by Parasympathetic (muscarinic)cardiac output M2: decreases SA nodeSA node: heart rate (chronotropic) M2: Effects produced by the parasympathetic division relaxationfood processingenergy absorptionParasympathetic activation The parasympathetic division controls body process during ordinary situations. Generally, it conserves Most Common Autonomic NTs:Acetylcholine (ACh)ACh neurons & ACh receptors are called cholinergic NTs of Autonomic NSCompare to Fig 11-7α and βN1N1N2N2 Neuroeffector Junction= Synapse between postganglionic cell and targetMost are different from model Summary: Pre- & Postganglionic Parasympathetic Neurons Release AChmuscarinicnicotinicReceptorsN1N2 Two Types of Cholinergic Receptors: Nicotinic and MuscarinicNicotine = agonistIn autonomic ganglia When the neurotransmitter, acetylcholine, attaches to the portion of the nicotinic receptor 2) Muscarinic Muscarinic ACh are G-protein Mediated Receptor Mechanism of Sweat Glands:Also some 2nd messenger mechanisms Note on G-Proteins: Many functions of the nervous system (e.g., memory) require Adrenergic  ReceptorsFound in neuroeffector junctions of sympathetic branchG protein linked, with NE Action Sympathetic Receptorsα Receptors: NT is NE (most common) ⇒ Excitation [Ca2+] In↑ β − Receptors Clinically more important β1 ⇒ Excitation heart ([E] = Termination of NT ActivityACh:ACh esteraseCatecholamine reuptakerepackagingdegradation (MAO)Blocked by cocaineFig 11-9Fig 8-22 Somatic Motor DivisionPathway consists of single neuron from CNS to targetNeuromuscular junction: Myasthenia gravisMG: Antibodies block, alter, or destroy the receptors for acetylcholine at the neuromuscular junction Direct (Ant)agonist = mimic or block the NT receptor (Ant)agonist = mimic Strychnos Toxifera (Curare) from Koehler's Medicinal-Plants 1887 Direct AntagonistsAtropine → muscarinicCurare → Indirect (Ant)agonistsBotulinum toxin → inhibits ACh releaseParathion, malathionorganophosphate insecticides → inhibit AChE Important physiological and functional differences existComparison of the two divisions Table 11-4Overview: The ANS Overview: The ANS Compare the somatic motor pathway to the parasympathetic and sympathetic motor pathways A Comparison of Somatic and Autonomic Function Summary of Efferent NS Activity in the ANS is controlled by centers in the brainstem that Levels of Autonomic ControlExample of higher-level of autonomic function would be increased ccLimbic systemГИПОТАЛАМУСCraniosacral anteriornucleusposteriornucleusThoracolumbar Levels of Autonomic ControlExample of higher-level of autonomic function would be increased Visceral Afferents and Referred Pain
Слайды презентации

Слайд 2
Autonomic nervous system: A part of the nervous

Autonomic nervous system: A part of the nervous system that regulates

system that regulates key involuntary functions of the body,

including the activity of the heart muscle; the smooth muscles, including the muscles of the intestinal tract; and the glands.

Слайд 3 Review (again)

Review (again)

Слайд 4 Autonomic Nervous System
Responsible for control of involuntary

Autonomic Nervous System Responsible for control of involuntary or visceral bodily

or visceral bodily functions
cardiovascular cardiovascular „
respiratory respiratory

„
digestive digestive „
urinary urinary „
reproductive functions
Key role in the bodies response to stress


Слайд 6 Overview: The Parts of a Reflex

Overview: The Parts of a Reflex

Слайд 7 Autonomic Targets
Smooth Muscle
Cardiac Muscle
Exocrine Glands
Some Endocrine glands
Lymphoid Tissue
Adipose

Autonomic TargetsSmooth MuscleCardiac MuscleExocrine GlandsSome Endocrine glandsLymphoid TissueAdipose

Слайд 8 Divisions of ANS
Sympathetic
Parasympathetic
Metasympathetic

Divisions of ANSSympathetic ParasympatheticMetasympathetic

Слайд 9
Sympathetic and parasympathetic divisions typically function in opposition

Sympathetic and parasympathetic divisions typically function in opposition to each other.

to each other. But this opposition is better termed

complementary in nature rather than antagonistic. For an analogy, one may think of the sympathetic division as the accelerator and the parasympathetic division as the brake.
The sympathetic division typically functions in actions requiring quick responses.
The parasympathetic division functions with actions that do not require immediate reaction. Consider sympathetic as "fight or flight" and parasympathetic as "rest and digest".


Слайд 10 ANS
2 divisions:
Sympathetic
“Fight or flight”
“E” division
Exercise, excitement, emergency,

ANS2 divisions:Sympathetic “Fight or flight”“E” divisionExercise, excitement, emergency, and embarrassmentParasympathetic “Rest

and embarrassment
Parasympathetic
“Rest and digest”
“D” division
Digestion, defecation, and diuresis


Слайд 11
1. The autonomic nervous system (ANS) is an

1. The autonomic nervous system (ANS) is an involuntary motor (efferent)

involuntary motor (efferent) system.

2. Autonomic nerves are typically composed

of a two-neuron chain. One neuron has its cell body in the central nervous system while the other is outside the CNS.

Слайд 12 Autonomic pathway: Two Efferent Neurons in Series
Preganglionic neuron

Autonomic pathway: Two Efferent Neurons in SeriesPreganglionic neuron cell body in

cell body in CNS
Synapse in autonomic ganglion outside CNS

(often divergence!)
Postganglionic neurons
target cells





N1

N2


Слайд 14
3. Although “involuntary”, the autonomic nervous system is

3. Although “involuntary”, the autonomic nervous system is regulated by higher

regulated by higher centers. The best known of these

centers is the hypothalamus which has descending projections to cell bodies of the preganglionic neurons. Other areas of the central nervous system affect the activities of the hypothalamus.

Слайд 15
4. The autonomic nervous system consists of two

4. The autonomic nervous system consists of two divisions:a) the sympathetic

divisions:
a) the sympathetic (or thoracolumbar) division in which the

preganglionic cells are located in the thoracic and first two lumbar segments of the spinal cord.
b) the parasympathetic (or craniosacral) division in which the preganglionic neurons are located in the brain stem and in sacral (S2 - S4) segments of the spinal cord.


Слайд 16 Sympathetic “Fight or flight” “E” division Exercise, excitement, emergency, and

Sympathetic “Fight or flight” “E” division Exercise, excitement, emergency, and embarrassment

embarrassment


Слайд 17 = Thoracolumbar
division (T1 to L2)

= Thoracolumbar  division (T1 to L2) Preganglionic neurons (N1)from thoracolumbar


Preganglionic neurons (N1)from thoracolumbar region of spinal cord

Pre and paravertebral ganglia
Long postganglionic neurins (N2) secrete NE onto adrenergic receptors

Слайд 18 Sympathetic (preganglionic ):
1. The cell bodies giving rise

Sympathetic (preganglionic ):1. The cell bodies giving rise to preganglionic neurons

to preganglionic neurons (N1) are located in the intermediolateral

column (lateral horn) of the gray matter in spinal cord segments T1 through L2.
2. Preganglionic fibers leave the spinal cord with the ventral roots of spinal nerves arising from cord segments T1 - L2.

Слайд 19 Sympathetic (postganglionic ):
1. The cell bodies giving rise

Sympathetic (postganglionic ):1. The cell bodies giving rise to postganglionic neurons

to postganglionic neurons (N2) are located in the paravertebral

ganglia (sympathetic trunk (vertebral chain)).
2. Prevertebral (collateral) ganglia: celiac, superior mesenteric, inferior mesenteric, aorticorenal and renal.
.

Слайд 20 Sympathetic ganglia
Sympathetic chain ganglia (paravertebral ganglia) –

Sympathetic ganglia Sympathetic chain ganglia (paravertebral ganglia) – preganglionic fibers of

preganglionic fibers of the sympathetic NS that carry motor

impulses to the body wall or thoracic cavity synapses in chain ganglia
Collateral ganglia (prevertebral ganglia) – group of second order neurons that innervate organs in the abdominopelvic region

Слайд 21 Sympathetic Trunk Ganglia
Located on both sides of the

Sympathetic Trunk GangliaLocated on both sides of the vertebral columnLinked by

vertebral column
Linked by short nerves into sympathetic trunks
Joined to

ventral rami by white and gray rami communicantes

Right and left sympathetic trunks extend from the base of the skull to the region of the coccyx; at their distal ends, the right and left trunks are fused.



Слайд 22 Prevertebral Ganglia
Unpaired, not segmentally arranged
Occur only in abdomen

Prevertebral GangliaUnpaired, not segmentally arrangedOccur only in abdomen and pelvisLie anterior

and pelvis
Lie anterior to the vertebral column
Main ganglia
Celiac, superior

mesenteric, inferior mesenteric, inferior hypogastric ganglia


Слайд 23

The Organization of the Sympathetic Division of the

The Organization of the Sympathetic Division of the ANS

ANS


Слайд 24 Copyright
Sympathetic Pathways to Periphery
Figure 15.9

CopyrightSympathetic Pathways to PeripheryFigure 15.9

Слайд 25 Rejoin spinal nerves and reach their destination by

Rejoin spinal nerves and reach their destination by way of the

way of the dorsal and ventral rami
Those targeting structures

in the thoracic cavity form sympathetic nerves
Go directly to their destination

Postganglionic fibers


Слайд 26 Copyright
Sympathetic Pathways to Thoracic Organs

CopyrightSympathetic Pathways to Thoracic Organs

Слайд 27 Sympathetic innervation via preganglionic fibers that synapse within

Sympathetic innervation via preganglionic fibers that synapse within collateral gangliaSplanchic nerves

collateral ganglia
Splanchic nerves – carry fibers that synapse in

collatheral ganglia

Abdominopelvic viscera


Слайд 28 Celiac ganglion
Innervates stomach, liver, gall bladder, pancreas, spleen
Superior

Celiac ganglionInnervates stomach, liver, gall bladder, pancreas, spleenSuperior mesenteric ganglionInnervates small

mesenteric ganglion
Innervates small intestine and initial portion of large

intestine
Inferior mesenteric ganglion
Innervates kidney, urinary bladder, sex organs, and final portion of large intestine

Abdominopelvic viscera


Слайд 29 Copyright
Sympathetic Pathways to the Abdominal Organs

CopyrightSympathetic Pathways to the Abdominal Organs

Слайд 30 Copyright
Sympathetic Pathways to the Pelvic Organs

CopyrightSympathetic Pathways to the Pelvic Organs

Слайд 31 Other important considerations:
ganglion cells are usually located at

Other important considerations:ganglion cells are usually located at some distance from

some distance from the effectors. Accordingly, postganglionic sympathetic fibers

are usually long fibers.

Acetylcholine (Ach) - pre-ganglionic ganglionic Neurotransmitter
Norepinephrine (NE) - post-ganglionic ganglionic Neurotransmitter


Слайд 32 Sympathetic Division
A single sympathetic preganglionic fiber has many

Sympathetic DivisionA single sympathetic preganglionic fiber has many axon collaterals and

axon collaterals and may synapse with 20 or more

postganglionic neurons.

The postganglionic axons typically terminate in several visceral effectors and therefore the effects of sympathetic stimulation are more widespread than the effects of parasympathetic stimulation.


Слайд 33 Sympathetic Variosities

Sympathetic Variosities

Слайд 34 Effects of Sympathetic Division
cardiac output increases
SA node: heart

Effects of Sympathetic Divisioncardiac output increasesSA node: heart rate (chronotropic) β1,

rate (chronotropic) β1, : ↑cardiac muscle: contractility (inotropic) β1

↑conduction at AV node β1 : increases
vascular smooth muscle: α = contracts; β2 = relaxes
smooth muscles of bronchioles β2: relaxes;
pupil of eye α1: relaxes
ciliary muscle β2 : relaxes
smooth muscles of GI tractα, β2: relaxes
sphincters of GI tract α1: contracts
glands of GI tract inhibits


Слайд 35 THE STRESS REACTION
A stressful situation activates three major

THE STRESS REACTIONA stressful situation activates three major communication systems in

communication systems in the brain that regulate bodily functions.


The first of these systems is the voluntary nervous system, which sends messages to muscles so that we may respond to sensory information.
The second communication system is the autonomic nervous system.
The brain’s third major communication process is the neuroendocrine system, which also maintains the body’s internal functioning.


Слайд 36 THE STRESS REACTION
When stress occurs, the sympathetic nervous

THE STRESS REACTION	When stress occurs, the sympathetic nervous system is triggered.

system is triggered. Norepinephrine is released by nerves; epinephrine

and norepinephrine is secreted by the adrenal glands. By activating receptors in blood vessels and other structures, these substances ready the heart and working muscles for action.
Acetylcholine is released in the parasympathetic nervous system, producing calming effects. The digestive tract is stimulated to digest a meal, the heart rate slows, and the pupils of the eyes become smaller. The neuroendocrine system also maintains the body’s normal internal functioning.


Слайд 38
The two divisions of the autonomic

The two divisions of the autonomic nervous system are not

nervous system are not infrequently said to be antagonists

in the sense of their having opposite effects

Слайд 39 Homeostasis and the Autonomic Division
BP, HR, Resp., H2O

Homeostasis and the Autonomic DivisionBP, HR, Resp., H2O balance, Temp. .

balance, Temp. . .
Mostly dual reciprocal innervation
i.e., agonist/antagonist

or excitatory/inhibitory
Sympathetic:
AKA Thoracolumbar
flight-or-fight
Parasympathetic:
AKA Craniosacral
rest and digest

Слайд 40 Other important considerations:
ganglion cells are usually located

Other important considerations:ganglion cells are usually located at some distance

at some distance from the effectors. Accordingly, postganglionic sympathetic

fibers are usually long fibers.

Слайд 41
The terminations of most, but not all, sympathetic

The terminations of most, but not all, sympathetic postganglionic fibers release

postganglionic fibers release a substance (norepinephrine). Such postganglionic fibers

are commonly called adrenergic fibers.

Слайд 43
The effects elicited by the action of the

The effects elicited by the action of the sympathetic division of

sympathetic division of the ANS are typically effects useful

in “fight or flight”. These include dilation of the pupil, increase in heart rate, elevation of blood pressure, diversion of blood from the alimentary tract to skeletal muscles, etc.

Слайд 44 Parasympathetic “Rest and digest” “D” division Digestion, defecation, and diuresis


Parasympathetic “Rest and digest” “D” division Digestion, defecation, and diuresis

Слайд 45 Parasympathetic: Craniosacral or rest and digest Center of parasympathetic

Parasympathetic: Craniosacral or rest and digest Center of parasympathetic division the

division the ANS
Has preganglionic cell bodies (N2) in

the midbrain and brainstem and in sacral segments 2, 3 and 4 of the spinal cord.

The fibers of cells in the midbrain and brainstem are in the oculomotor (III), facial (VII), glossopharyngeal (IX), and vagus (X) nerves. They innervate smooth muscles of the eye (III), lacrimal and salivary glands (VII and IX), and smooth muscles of the thoracic and abdominal viscera (X).


Слайд 46


The Organization of the Parasympathetic Division of the

The Organization of the Parasympathetic Division of the ANS

Слайд 47


The Distribution of Parasympathetic Innervation

The Distribution of Parasympathetic Innervation

Слайд 49 = Craniosacral Division
Long preganglionic axons from brain

= Craniosacral Division Long preganglionic axons from brain & S2- S4

& S2- S4
Intramural ganglia
Postganglionic (nonmyelinated) neurons

secrete ACh onto cholinergic muscarinic receptors

Слайд 50 Parasympathetic: Craniosacral or rest and digest Center of parasympathetic

Parasympathetic: Craniosacral or rest and digest Center of parasympathetic division the

division the ANS
The cell bodies giving rise to

postganglionic neurons (N2) are located in the Intramural ganglia.

Слайд 51
The ganglion cells of the parasympathetic system are

The ganglion cells of the parasympathetic system are located in or

located in or on the wall of the organs

supplied or in specific ganglia located near the organs supplied. Hence the postganglionic fibers are short.

Except for the vagus nerves, the area of distribution of parasympathetic nerves is somewhat limited. The number of synaptic connections is smaller than in the sympathetic division. Accordingly, the effects of the parasympathetic division tend to be local rather than widespread.


Слайд 53
Most postganglionic parasympathetic fibers release acetylcholine at their

Most postganglionic parasympathetic fibers release acetylcholine at their terminations. These fibers

terminations. These fibers are, hence, often called cholinergic fibers.

They may also release a variety of peptides that influence smooth muscle activity.

Слайд 54 Summary: Pre- & Postganglionic Parasympathetic Neurons Release ACh
muscarinic
nicotinic
Receptors
N1
N2

Summary: Pre- & Postganglionic Parasympathetic Neurons Release AChmuscarinicnicotinicReceptorsN1N2

Слайд 55 All parasympathetic fibers release ACh
Short-lived response as ACH

All parasympathetic fibers release AChShort-lived response as ACH is broken down

is broken down by AChE and tissue cholinesterase


Neurotransmitters and

parasympathetic functions

Слайд 56 Parasympathetic (muscarinic)
cardiac output M2: decreases
SA nodeSA node:

Parasympathetic (muscarinic)cardiac output M2: decreases SA nodeSA node: heart rate (chronotropic)

heart rate (chronotropic) M2: decreases
cardiac musclecardiac muscle: contractility

(inotropiccardiac muscle: contractility (inotropic) M2: decreases (atria only)
conduction at AV node M2: decreases
smooth musclessmooth muscles of bronchioles M3: contracts
pupilpupil of eye M3: contracts
ciliary muscle M3: contracts
salivary glands: secretions stimulates watery secretions
GI tract motility M1, M3: increases
smooth musclessmooth muscles of GI tract M3: contracts
sphincterssphincters of GI tract M3: relaxes
glandsglands of GI tract M3: secretes


Слайд 57 Effects produced by the parasympathetic division
relaxation
food processing
energy

Effects produced by the parasympathetic division relaxationfood processingenergy absorptionParasympathetic activation

absorption
Parasympathetic activation


Слайд 58
The parasympathetic division controls body process during ordinary

The parasympathetic division controls body process during ordinary situations. Generally, it

situations. Generally, it conserves and restores. It slows the

heart rate and decreases blood pressure. It stimulates the digestive tract to process food and eliminate wastes. Energy from the processed food is used to restore and build tissues.

Слайд 59 Most Common Autonomic NTs:
Acetylcholine (ACh)
ACh neurons & ACh

Most Common Autonomic NTs:Acetylcholine (ACh)ACh neurons & ACh receptors are called

receptors are called cholinergic (nicotinic or muscarinic). Located at

autonomic preganglionic & para-sympathetic postganglionic synapses
Norepinephrine (NE)
NE neurons & receptors are called (nor) adrenergic (α and β). Located at sympathetic postganglionic synapses

Fig 11-7


Слайд 60 NTs of Autonomic NS
Compare to Fig 11-7
α and

NTs of Autonomic NSCompare to Fig 11-7α and βN1N1N2N2

β

N1
N1
N2
N2


Слайд 61 Neuroeffector Junction
= Synapse between postganglionic cell and target
Most

Neuroeffector Junction= Synapse between postganglionic cell and targetMost are different from

are different from model synapse (compare to Fig 8-20,

p. 270)
ANS synapse: axon has varicosities containing neurotransmitter
May supply many cells, resulting in less specific communication
Synthesis of NT is in the varicosity


Fig 11-8


Слайд 62 Summary: Pre- & Postganglionic Parasympathetic Neurons Release ACh
muscarinic
nicotinic
Receptors
N1
N2

Summary: Pre- & Postganglionic Parasympathetic Neurons Release AChmuscarinicnicotinicReceptorsN1N2

Слайд 63 Two Types of Cholinergic Receptors: Nicotinic and Muscarinic
Nicotine

Two Types of Cholinergic Receptors: Nicotinic and MuscarinicNicotine = agonistIn autonomic

= agonist
In autonomic ganglia & somatic NS
Directly opens a

Na+ & K+ channel: ⇒ ?
Curare = antagonist

1) Nicotinic cholinergic receptor


Слайд 64
When the neurotransmitter, acetylcholine, attaches to the portion

When the neurotransmitter, acetylcholine, attaches to the portion of the nicotinic

of the nicotinic receptor outside of the cell wall,

it induces a conformational change that selectively opens up the channel to sodium ions. The resulting influx of positively charged sodium then triggers membrane depolarization.

Слайд 65 2) Muscarinic

2) Muscarinic       cholinergic receptor Muscarine

cholinergic receptor
Muscarine

= agonist
Found in neuro-effector junctions of parasympathetic branch
G-protein coupled mechanisms
Atropine = antagonist


Amanita muscarina

N1

N2


Слайд 66 Muscarinic ACh are G-protein Mediated Receptor Mechanism of

Muscarinic ACh are G-protein Mediated Receptor Mechanism of Sweat Glands:Also some 2nd messenger mechanisms

Sweat Glands:
Also some 2nd messenger mechanisms


Слайд 67 Note on G-Proteins:
Many functions of the nervous

Note on G-Proteins: Many functions of the nervous system (e.g., memory)

system (e.g., memory) require prolonged changes in neurons after

the initial neurotransmitter is gone. Ligand-gated channels (such as those found in nicotinic receptors) are not suitable for this because the channels close in milliseconds. Prolonged changes can be achieved, however by activating G-proteins inside the post-synaptic neuron. It is then the G-proteins that trigger the prolonged effects.

Слайд 68 Adrenergic Receptors
Found in neuroeffector junctions of sympathetic branch
G

Adrenergic ReceptorsFound in neuroeffector junctions of sympathetic branchG protein linked, with

protein linked, with various 2nd mess. Mech
NT is NE
α-

and β- Receptors




Слайд 69 NE Action

NE Action

Слайд 70 Sympathetic Receptors

α Receptors:
NT is NE
(most common)

Sympathetic Receptorsα Receptors: NT is NE (most common) ⇒ Excitation [Ca2+]

⇒ Excitation [Ca2+] In↑ ⇒ muscle contraction or secretion

by exocytosis.
⇒ Inhibition of GI tract and pancreas

Слайд 71
β − Receptors Clinically more important
β1 ⇒

β − Receptors Clinically more important β1 ⇒ Excitation heart ([E]

Excitation heart ([E] = [NE])
“β - blockers” = Antagonists

(e.g.: Propranolol)
β2 usually inhibitory: smooth muscle relaxation of some blood vessels and bronchioles ([E] > [NE])
β3 Adipose; [NE]>[E]
“β -blockers” = Antagonists (e.g.: Propranolol)

Слайд 72 Termination of NT Activity
ACh:
ACh esterase
Catecholamine reuptake
repackaging
degradation (MAO)
Blocked by

Termination of NT ActivityACh:ACh esteraseCatecholamine reuptakerepackagingdegradation (MAO)Blocked by cocaineFig 11-9Fig 8-22

cocaine

Fig 11-9
Fig 8-22


Слайд 73 Somatic Motor Division
Pathway consists of single neuron from

Somatic Motor DivisionPathway consists of single neuron from CNS to targetNeuromuscular

CNS to target
Neuromuscular junction: nicotinic cholinergic receptors
Similar to

synapse; post – synaptic membrant called Motor End Plate
Recall Motor Unit
Always excitatory ⇒ muscle contracts
All Ach mediated
Degraded by Ach esterase

Fig 11-13


Слайд 74




Myasthenia gravis

MG: Antibodies block, alter, or destroy the

Myasthenia gravisMG: Antibodies block, alter, or destroy the receptors for acetylcholine at the neuromuscular junction

receptors for acetylcholine at the neuromuscular junction


Слайд 75 Direct (Ant)agonist = mimic or block the NT

Direct (Ant)agonist = mimic or block the NT receptor (Ant)agonist =

receptor (Ant)agonist = mimic or block secretion, reuptake or degradation

of NT

Слайд 76 Strychnos Toxifera (Curare) from Koehler's Medicinal-Plants 1887
Direct

Strychnos Toxifera (Curare) from Koehler's Medicinal-Plants 1887 Direct AntagonistsAtropine → muscarinicCurare

Antagonists
Atropine → muscarinic
Curare → nicotinic
Propranolol → β1 and β2
Metoprolol

→ β1

Слайд 77 Indirect (Ant)agonists
Botulinum toxin
→ inhibits ACh release
Parathion, malathion
organophosphate

Indirect (Ant)agonistsBotulinum toxin → inhibits ACh releaseParathion, malathionorganophosphate insecticides → inhibit

insecticides → inhibit AChE (anticholinesterases)
Cocaine
→ prevents NE reuptake
Amphetamines

→ stimulates NE release

Слайд 78 Important physiological and functional differences exist
Comparison of the

Important physiological and functional differences existComparison of the two divisions

two divisions


Слайд 79 Table 11-4
Overview: The ANS

Table 11-4Overview: The ANS

Слайд 80 Overview: The ANS
Compare the somatic motor pathway

Overview: The ANS Compare the somatic motor pathway to the parasympathetic and sympathetic motor pathways

to the parasympathetic and sympathetic motor pathways


Слайд 81


A Comparison of Somatic and Autonomic Function

A Comparison of Somatic and Autonomic Function

Слайд 82 Summary of Efferent NS

Summary of Efferent NS

Слайд 84 Activity in the ANS is controlled by centers

Activity in the ANS is controlled by centers in the brainstem

in the brainstem that deal with visceral functioning
Higher levels

of autonomic control

Слайд 85 Levels of Autonomic Control

Example of higher-level of autonomic

Levels of Autonomic ControlExample of higher-level of autonomic function would be

function would be increased heart rate when you see

a person that you dislike.

Слайд 86 cc
Limbic system
ГИПОТАЛАМУС
Craniosacral
anterior
nucleus
posterior
nucleus
Thoracolumbar

ccLimbic systemГИПОТАЛАМУСCraniosacral anteriornucleusposteriornucleusThoracolumbar

Слайд 88 Levels of Autonomic Control

Example of higher-level of autonomic

Levels of Autonomic ControlExample of higher-level of autonomic function would be

function would be increased heart rate when you see

a person that you dislike.

Слайд 89 Visceral Afferents and Referred Pain

Visceral Afferents and Referred Pain

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