Autonomic Nervous System

Question 1

Parasympathetic Nervous System Organization

Answer 1

Preganglionic neurone chain rising from brain stem and sacral level of spinal cord. Long.

Synapse onto ganglia close to or within target organ. These postganglionic neurones chain are short.

Question 2

Neurotransmitters of the PNS

Answer 2

Preganglionic neurones release ACh to postganglionic nAChR receptor which releases ACh to mAChR receptors of target organs.

Question 3

Sympathetic Nervous System Organization

Answer 3

Preganglionic neurone chain rises from the thoracic-lumbar region of spine. (short, unbranching)

Synapse onto ganglia close to vertebral column. Postganglionic neurone chains are long and branched.

Question 4

Neurotransmitters of SNS

Answer 4

Preganglionic neuron chain release ACh to postganglionic receptor nAChR which releases noradrenaline to adrenoceptors

Question 5

Co-released NTs

Answer 5

neuropeptides like substance P, VIP, NYP, and

small molecules like 5-HT, ATP, NO

Question 6

nAChRs Drug Targets

Answer 6

Drugs can target nicotinic receptors of ANS without effecting somatic nicotininc receptors

TRIMETHAPAN

Question 7

Sympathetic Nervous System Functions

Answer 7

-Heart rate and BP increase
-Pupil dilation
-Increase respiration
-Diversion of blood to functioning muscle

Question 8

Parasympathetic nervous system functions

Answer 8

-Bradycardia
-Bronchiolar constriction.
-Increased intestinal motility
-Bladder contraction/relaxation
-Penile erection
-Ciliary muscle, iris contraction

Question 9

SNS Adrenal Gland Exception

Answer 9

Preganglionic neurones work directly on adrenal gland. It produces noradrenaline and adrenaline in chromaffin cells pump into blood.

Question 10

SNS Innervation of Sweat Glands and some Blood Vessels

Answer 10

Can use ACh postganglionic neurones on mAChR receptors.

Question 11

Postganglionic Communication to Target Organs

Answer 11

Wider responses.
Volume transmission.
Varicosities along nerve axon allow NT release from multiple points.
Wider receptor engagement.

Question 12

Integratory Site of ANS

Answer 12

Nucleus of the solitary tract (NTS), receives signals from nerves (vagus, heart, lungs) controls outputs from sympathetic and parasympathetic nuclei.

Question 13

Ciliary Ganglia Drug

Answer 13

Tropicamide = prevent constriction of iris causing dilation (anti muscarinic)