Pharmacology 6 and 7 - Autonomic Pharmacology Flashcards
Afferent?
Towards the CNS
Efferent?
Away from the CNS
4 branches of the PNS?
Somatic effent Autonomic (ANS)EntericSomatic and visceral afferent
What are the 2 division of the ANS?
SympatheticParasympathetic
What is the purpose of the ANS?
To carry output from the CNS to the whole body with the exception of skeletal muscle
What allows a degree of copious control of some ANS functions?
Training e.g. urination, defecation
What does the parasympathetic ANS coordinate?
the bodies basic homeostatic functions
What does the sympathetic ANS coordinate?
The body’s response to stress, associated with fight, flight and fright reactions
What 2 neurones is a sympathetic/ parasympathetic branch made up of?
Preganglionic neuronePostganglionic neurone
What is the transmitter in the preganglionc neurone of the sympathetic ANS?
Acetylcholine (ACh)
What is the transmitter in the preganglionic neurone in the parasympathetic ANS?
Acetylcholine (ACh)
What is the transmitter in the post-ganglionic neurone in the parasympathetic division?
Acetylcholine (ACh)
What is the transmitter in the postganglionic neurone in the sympathetic division?
Usually Noradrenaline (NA)
What is the word used to describe neurones that use ACh?
Cholinergic
What is the word used to describe neurones that use NA?
Adrenergic
Where can sympathetic signals synapse?
In the sympathetic chainIn the prevertebral ganglia
What organs sympathetic supply tends to synapse in the sympathetic chain?
signals going to the eye, heart and lungs (above diaphragm)
What organs sympathetic supply tends to synapse in pre-vertebral ganglia?
Signals going to the liver, gallbladder, stomach, pancreas, spleen, kidney, intestines and genitourinary tract (below diaphragm)
What tissues sympathetic supply doesn’t synapse?
Adrenal gland (nerve supply only consists of a preganglionic neurone - transmitter released is ACh)
What branch of the ANS has thoracolumbar outflow?
Sympathetic
What branch of the ANS has craniosacral outflow?
Parasympathetic
Where does the parasympathetic axons leave the CNS?
Via cranial nerves III, VII, IX, and XVia sacral spinal nerves
What organs does the parasympathetic outflow supply?
Parasympathetic ganglia in head = Lacrimal gland and salivary glandsVagus nerve = organs of the neck, chest and abdomen as far as the midgutSacral spinal nerves “carry” parasympathetic axons to the hind-gut, pelvis and perineum
Where are parasympathetic ganglia?
Usually in the target organs (discrete ganglia exist in the head and beck)
What does sympathetic stimulation at heart cause? (2)
Increases heart rateIncreases force of contraction
What does parasympathetic stimulation of the heart cause?(1)
Decreases heart rate
What does sympathetic stimulation of the lungs cause? (2)
Relaxes bronchi Decreases mucus production (decreasing airway resistance)
What does parasympathetic stimulation of the lungs cause? (2)
Constricts bronchiStimulates mucus production
How does sympathetic nervous system cause the relaxation of bronchi?
Via release of adrenaline
Effect of sympathetic stimulation on the GI tract? (2)
Reduces motilityConstricts sphincters
Effect of parasympathetic stimulation on the GI tract? (2)
Increases motilityRelaxes sphoncters
Effect of sympathetic stimulation on the arterioles?
Constricts in most locations although relaxes at muscles
Effect of parasympathetic stimulation on arterioles?
Largely no effect
Effect of sympathetic stimulation on adrenal gland?
Release of adrenaline
Effect of parasympathetic stimulation on adrenal gland?
No effect
Effect of sympathetic stimulation on penis?
Ejaculation
Effect of parasympathetic stimulation on penis?
Erection
What are the steps of neurochemical transmission?
1) Uptake of precursor2) Synthesis of transmitter3) storage of transmitter4) depolarisation by action potential5) Ca2+ influx through voltage-activated Ca2+ channels6) Ca2+ induced release of transmitter (exocytosis)7) receptor activation8) enzyme mediated inactivation of transmitter OR9) reuptake of transmitter