L1 ANS Flashcards
Autonomic Nervous System
– innervates all tissues except skeletal muscle
– operates outside conscious control
– essential role in homeostasis
Sensory Nervous System
– detects stimuli inside and outside the body
– transmits to specific brain regions for processing
– external stimuli – light, sound, smell, touch, taste
– internal stimuli – O2 concentration, pressure, pH
Somatic Nervous System
– skeletal muscle nervous system
– voluntary movement of skeletal muscle
Name the two neurones synapse in specialised autonomic ganglia
- Preganglionic neurone
– neurone with cell body in CNS - Postganglionic neurone
– neurone with cell body in ganglia
- Preganglionic neurone
- Postganglionic neurone
– neurone with cell body in CNS
– CNS origin is the basis of initial classification of sympathetic and parasympathetic divisions
– neurone with cell body in ganglia
– innervates the target tissue
Sympathetic neurotransmitter release simple
CNS→ganglion→ACh→Nicotinic receptors→postganglionic neuron→Noradrenaline in neuroeffector juction→alpha/beta adrenoceptors
Parasympathetic Neurotransmitter release
CNS→preganglionic neuron→ACh→ganglion/nicotinic receptors→ACh→muscarinic receptors
PNS
Heart
↓ rate (bradycardia)
PNS
Lungs
bronchoconstriction, secretion
PNS
GI tract
↑ tone, motility of small & large intestine, ↑ secretion of saliva and gastric acid
PNS
Glands
↑sweating, salivation, lacrimation
PNS
Eye
sphincter muscle contraction, ciliary muscle contraction
PNS
Blood vessels
most blood vessels not innervated vasodilatation in some vessels
How acetylcholine is formed
Choline + acetyl-Co-enzyme A
|
Choline acetyltransferase
↓
Acetylcholine
Cholinergic Synapse routes of ACh
- Diffuse
- (Might cross synapse but don’t hv to) ACh-esterase →choline (+ acetyl-co-A→ACh
- M2 receptors that will decrease production of ACh
- M3 receptors that will cross the synapse and cause contractions in smooth muscle
In chlinergic veins`