The Autonomic Nervous System

Front 1

What two categories can the nervous system be broadly divided into?

Back 1

Central nervous system and the peripheral nervous system

Front 2

What is the autonomic nervous system (ANS) responsible for?

Back 2

For carrying output from the CNS to the whole of the body with the exception of the skeletal muscle

Front 3

Give some functions of the ANS

Back 3

1) regulates visceral functions that are largely involuntary and which do not require concious effort

eg heartbeat, exocrine and some endocrine secretions, contraction of vascular and visceral smooth muscle, apects of metabolism

Training allows a degree of control of some ANS functions

Front 4

What is the ANS subdivided into?

Back 4

sympathetic and parasympathetic divisions

Front 5

How do the two subdivisions work?

Back 5

Work in an opposing fashion to maintain homeostasis:

Parasympathitic ANS- coordinates the bodies basic homeostatic functions

Sympathetic ANS- coordinates the bodys response to stress associated with fight, flight and fright reactions

Front 6

What is the Autonomicganglion?

Back 6

An autonomic ganglion is a cluster of nerve cell bodies (a ganglion) in the autonomic nervous system. The two types are sympathetic ganglion and parasympatheticganglion.

Front 7

What is the trasmitter in the preganglionic neurons of the sympathetic and parasympathetic ANS?

Back 7

ALWAYS acetylcholine

Front 8

What is the trasmitter in the postganglionic neurons of the sympathetic and parasympathetic ANS?

Back 8

different, usually noradrenaline

Front 9

What is the difference in distance of the preganglonic and post ganglionic in the symapthetic vs the parasymathetic

Back 9

Front 10

Show the sympathetic outflow

Back 10

Front 11

Where are the parasympathetic ganglia usually located?

Back 11

in the target organs (discrete ganglia in head and neck)

Front 12

give some examples of the activities of the ANS with sympathetic function vs parasympathetic function

Back 12

Front 13

What is the process of chemical transmission in the ANS in the sympathetic division

Back 13

1) action potential originates in the CNS

2) travels to the presynaptic terminal of the preganglionic neuron triggering Ca2+entry and the release of ACh

3) ACh opens ligand-gated ion channels (nicotinic receptors) in the postganglionic neuron, causing depolarization and the generation of action potentials that travel to the presynaptic terminal of the neurone triggering Ca2+ entry and the release of noradrenaline

4) This activated G-protein coupled adrenoceptors in the target cell membrane causing a cellular response.

Front 14

What is the process of chemical transmission in the ANS in the parasympathetic division

Back 14

Theprocess is identical to that described for the sympathetic division, with theexception that:

1) ACh is always the transmitter used by postganglionic neurons

2) ACh activates G-protein-coupledmuscarinicacetylcholinereceptors in the targetcell membrane to cause a cellular response

Front 15

Give examples of 3 G-protein coupled muscarinic ACh receptor subtypes

Back 15

1) M1 (Muscarinic AChReceptor) to Gq (G-protein)

2) M2 to Gi

3) M3 to Gq

Front 16

What is the funtion of M1 to Gq?

Back 16

Stimulation of phospholipase in the stomach resulting in increased acid secretion

Front 17

What is the function of M2 to Gi?

Back 17

Inihibition of adenylyl cyclase: opening of K+ channels in the heart leading to decreased heart rate

Front 18

What is the function of M3 to Gq?

Back 18

stimulation of phospholopase C in the salivary glands leading to increased secretion... and in the lungs leading to increased contraction of visceral smooth muscle

vascular muscle is indirectly relaxed by M3 receptor activation

Front 19

Give the functions of someG-ProteinCoupled Adrenoceptor Subtypes at Sympathetic NeuroeffectorJunctions.

Back 19