Lecture 5: Autonomic System Flashcards
E.g homeostasis
Heart
Sympathetic: increase rate and strength of contractions, inhibits effect of parasympathetic system to allow blood vessels to dilate
Parasympathetic: decrease rate and strength of contractions, constricts coronary vessels in accordance with decreased demand
E.g of homeostasis
Eye
Parasympathetic: constrict pupil, contract ciliary muscles to allow lens to thicken for near vision
Sympathetic: dilate pupil
E.g homeostasis
Genital organs
Sympathetic: ejaculation and constriction causing remission of erection
Parasympathetic: produces engorgement of erectile tissue
Autonomic nerves
All sympathetic and parasympathetic nerves contain BOTH general visceral sensory and general visceral motor fibres
General visceral sensory (afferent)
Usually parasympathetic
Visceral reflexes (gag reflex)
Organic sensation
Pain only accompany sympathetic nerves e.g heart attack
Sympathetic comes from what region?
Thoracolumbar region
Parasympathetic comes from what region?
Craniosacral region
Sympathetic ganglia are located where?
Close to spinal cord in a chain
Parasympathetic ganglia are located where?
Close to target organ
Sympathetic post ganglionic fibres are what length in general?
Long
Parasympathetic post ganglionic fibres are what length in general?
Short
Sympathetic branching?
Lots of branching so that more than one organ can be targeted at once
Parasympathetic branching?
Not much branching
Sympathetic nerve system pre-synaptic fibres are located where?
in lateral horn of grey matter of T1-L2.
Para vertebral ganglia of sympathetic system are located where?
sympathetic trunk
Prevertebral ganglia sympathetic nerve system are located where?
plexuses on abdominal aorta.