4.AUTONOMICNERVUSSYSTEMANS

8/11/2019 4.AUTONOMICNERVUSSYSTEMANS

1/42

AUTONOMIC NERVUS

SYSTEM (ANS)

Zahreni HamzahRahardyan Parnaad j iLab. Fis io logi Bag Biom edik FKG Univ. Jember


2/42

9/3/2014 Free Template from www.brainybetty.com 2

How is the organizat ion of

the autonom ic nervous

sys tem (ANS) d i f feren t fromthat of the somat ic nervous

sys tem (SNS)?


3/42


Autonomic Nervous System(ANS)

Operates without conscious instruction

Coordinates systems functions:

cardiovascular respiratory

digestive

urinary

reproductive


4/42

Sistem ini merupakan sistem saraf eferen

(motorik) yang mempersarafi organ-

organ dalam seperti otot-otot polos, otot

jantung, dan berbagai kelenjar.

Sistem ini juga melakukan fungsi kontrol,

semisal: kontrol tekanan darah, sekresi

gastrointestinal,pengosongan kandungkemih, proses berkeringat, suhu tubuh,

dan beberapafungsi lain.

Karakteristik utama SSO:

kemampuan mempengaruhi yang sangat

cepat (misal: dalam beberapa detik

denyut jantung dapat meningkat,

perubahan tekanan darah, berkeringat).


5/42

Keterlibatan dengan SSP:

Medulla spinalis bertanggung jawab

untuk persarafan otonom yangmemengaruhi sistem kardiovaskular dan

respirasi

Hipotalamus berfungsi :

Mengintegrasikanpersarafan otonom,

somatik, dan hormonal (endokrin) dan

emosi serta tingkah laku

Misal: seseorang yang marahmeningkatkan denyut jantung,tekanan

darah, dan laju respirasi.


6/42


ANS in the Nervous System


7/42

Refleks visceral, sama seperti

refleks somatik lainnya, terdiri atas

komponen reseptor, integrasi, danefektor.

Pembeda refleks visceral dengan

refleks somatik:Informasi reseptor refleks visceral

diterima secara bawah-sadar

(subconsc ious).

Misal: Pembuluh darah melebar(kulit yang kemerahan).

Pupil mata melebar.


8/42

PERJALANAN SSO DIMULAI DARIPERSARAFAN SSP:

Neuron (orde pertama) berada di SSP (sisi lateralmedullaspinalis dan di batang otak) >preganglionicfiber.

Serabut ini bersinaps dengan badan sel neuron ordekedua yang terletak di dalam ganglion.

Serabut pascaganglion menangkap sinyal dariserabut preganglion melalui neurotransmiter yangdilepaskan oleh serabut preganglion.

(Ganglion: kumpulan badan sel yang terletak di luarSSP).

Akson neuron orde kedua (postganglionic fiber)menuju organ yang akan diinervasi.

Organ efektor menerima impuls melalui pelepasanneurotransmiter oleh serabut pascaganglion.


9/429/3/2014 Free Template from www.brainybetty.com 9

Comparison of Somatic and Autonomic

Nervous Systems



Organization Similarities

of SNS and ANS

Are efferent divisions

Carry motor commands:

SNS controls skeletal muscles

ANS controls visceral effectors

Motor neurons synapse on visceral motor

neurons in autonomic ganglia

Ganglionic neurons control visceral

effectors



rgan za on m ar esof SNS and ANS



Neurotransmitters and Receptors

Acetylcholine (ACh) and norepinephrine (NE)

are the two major neurotransmitters of the ANS

ACh is released by all preganglionic axons and

all parasympathetic postganglionic axons Cholinergic fibersACh-releasing fibers

Adrenergic fiberssympathetic postganglionic

axons that release NE Neurotransmitter effects can be excitatory or

inhibitory depending upon the receptor type


13/42

Serabut preganglion parasimpatismelepaskan neurotransmitter asetilkolin

(ACh) yang ditangkap oleh reseptor

kolinergik nikotinik badan sel

pascaganglion.

Efek dari penangkapan ACh oleh reseptor

nikotinik menyebabkan pembukaan kanal

ion nonspesifik, menyebabkan influxterutama ion Na+


Pelepasan Neurotransmitter


14/42

Setelah itu, serabut pascaganglion

parasimpatis juga menghasilan

asetilkolin yang ditangkap olehreseptor kolinergik muskarinik yang

terdapat di semua organ efektor

parasimpatis. Penempelan Ach dapat menginhibisi

atau mengeksitasi organ efektor.



15/42

Serabut preganglion simpatis melepaskanneurotransmitter ACh yang ditangkap oleh

reseptor nikotinik yang berada di badan sel

neuronpascaganglion.

Serabut pascaganglion melepaskannoradrenalin (atau norepinefrin) dan ditangkap

oleh reseptor adrenergik.


Pelepasan Neurotransmitter



Differences between SANS and PANS



What are the divis ions and

funct ions of the ANS?



Sympathetic Division :

Kicks in only during exertion, stress, oremergency

Parasympathetic Division :

Controls during resting conditions

2 divisions may work independently:

some structures innervated by only 1 division

2 divisions may work together: each controlling one stage of a complex

process


19/42

Divisi parasimpatis cenderung mengatur

organ efektor dalam keadaan rest-and-

digest, yakni ketika tubuh berada dalam

keadaan tenang,relaks, kondisi yang

tidak mengancam, atau dalam keadaan

pembersihan dan pemulihan tubuh( general housekeeping).



22/42


23/42



24/42


Visceral Reflexes


25/42

What are the mechanisms

o f neuro transm itterrelease in the sympathet ic

d iv is ion?


26/42


SANS


27/42


Sympathetic Receptors

Sympathetic ReceptorsAlpha receptors

Beta receptors

Norepinephrinestimulates alpha receptorsto greater degree than beta receptors

Epinephrinestimulates both classes ofreceptors.

Sympathetic postganglionic Fibers

Mostly adrenergic (release NE)

A few cholinergic (release ACh)


28/42


Alpha () Receptors

(activated by enzymes on inside of cell membrane)

Reseptor -1

More common type of

alpha receptor

Releases intracellularcalcium ions from

reserves in

endoplasmic

reticulum

Has excitatory effect

on target cell

Reseptor -2

Lowers cAMP levels

in cytoplasm

Has inhibitory effecton the cell

Helps coordinate

sympathetic andparasympathetic

activities


29/42


Beta (

) Receptors Affect membranes in many organs (skeletal muscles,

lungs, heart, and liver) Trigger metabolic changes in target cell

Changes occur indirectly

Each is a G protein

Stimulation increases intracellular cAMP levels Beta-1 (1) - Increases metabolic activity

Beta-2 (2) Causes inhibition

Triggers relaxation of smooth muscles along respiratory tract

Beta-3 (3) Is found in adipose tissue

Leads to lipolysis, the breakdown of triglycerides in adipocytes

Releases fatty acids into circulation


30/42


Adrenal Medulla

Preganglionic fibers entering adrenal

gland proceed to center (adrenal medulla)

Modified sympathetic ganglion Preganglionic fibers synapse on

neuroendocrine cells

Specialized neurons secrete hormonesinto bloodstream


31/42


32/42

What are the s tructu res

and funct ions o f the

parasympathet ic div is ionof the autonom ic nervous

system?


33/42



34/42


35/42


Rest and Repose

Parasympathetic division stimulates

visceral activity

Conserves energy and promotes

sedentary activities


36/42


Parasympathetic Activation

Centers on relaxation, food processing,

and energy absorption

Localized effects, last a few seconds at

most


37/42


Parasympathetic Receptors

Action of Nicotinic Receptors Exposure to ACh causes excitation of

ganglionic neuron or muscle fiber

Open chemically gated channels inpostsynaptic membrane

Action of Muscarinic Receptors

Can be excitatory or inhibitory Effects are longer lasting than nicotinic

receptors


38/42


10 Effects of Parasympathetic Activation

1. Constriction of pupils:

restricts light entering eyes

2. Secretion by digestive glands:

exocrine and endocrine

3. Secretion of hormones

4. Changes in blood flow and glandular activity:

associated with sexual arousal5. Increases smooth muscle activity:

along digestive tract


39/42


10 Effects of Parasympathetic Activation

6. Defecation:

stimulation and coordination

7. Contraction of urinary bladder:

during urination

8. Constriction of respiratory passageways

9. Reduction in heart rate:

and force of contraction10.Sexual arousal:

stimulation of sexual glands


40/42


Parasympathetic division

The parasympathetic division release ACh

Body wall and skeletal muscles are not

innervated by parasympathetic division

Both NE and ACh needed to regulate

visceral functions

Sympathetic and Parasympathetic


41/42


Sympathetic and Parasympathetic

ResponsesStructure Sympathetic Stimulation Parasympathetic

StimulationIris (eye

muscle)

Pupil dilation Pupil constriction

Salivary

Glands

Saliva production

reduced

Saliva production

increased

Heart Heart rate and force

increased

Heart rate and force

decreased

Lung Bronchial muscle relaxed Bronchial muscle

contracted

Stomach Peristalsis reduced Gastric juice secreted;motility increased

Kidney Decreased urine

secretion

Increased urine

secretion

Bladder Wall relaxed

Sphincter closed

Wall contracted

Sphincter relaxed


42/42

See in the next subject

4.AUTONOMICNERVUSSYSTEMANS

Documents