Autonomic Nervous System Flashcards
What does the autonomic nervous system innervate
smooth muscle, cardiac muscle, glands
What carries the visceral nerves
afferent neurons
What are the two divisions of the autonomic nervous system
sympathetic, parasympathetic
What is the sympathetic system associated with
fight or flight
What does the sympathetic system increase
HR, BP, cardiac contractility, ventilation, blood glucose, ATP production
Where are the ganglia found in the sympathetic nervous system
close to spinal cord
What does the sympathetic system act to decrease
salivation
Describe increased sympathetic activity on the muscles
vasodilation and re-direction of blood to skeletal, cardiac muscle,
Describe the effect of the sympathetic system on pupilss
pupils dilate
What is the parasympathetic system associated with
rest and digest
What does the parasympathetic system promote/increase
digestion, absorption, secretion, increased mobility of GI tract
What does the parasympathetic system decrease
HR, BP
Describe the effect of the parasympathetic system on the pupils
constrict
Where are ganglia found in the parasympathetic system
far away from the spine
Where does the parasympathetic system originate
crainosacral - base of brain, tailbone in spinal cord
Describe the control of the sympathetic and parasympathetic nervous systems
antagonistic control
Give some examples of the antagonistic control of the autonomic nervous system
Heart rate
Describe the antagonistic control of Heart Rate
post-ganglionic neuron innervates heart directly, sympathetic increase HR, parasympathetic decreases HR
What are the exceptions to antagonistic control
male sexual function, sweat glands, hair follicles, blood vessels
What are blood vessels, smooth muscle and adrenal medulla innervated by
sympathetic nerve fibres
What are hair follicles innervated by
sympathetic system
What are sweat glands innervated by
sympathetic nervous system only
What are the roles of each system in male sexual function
parasympathetic stimulates an erection, sympathetic stimulates ejaculation
TRUE or FALSE - sympathetic and parasympathetic have the same organisation
TRUE
What is the exception to the same organisation of the ANS
adrenal medulla
Describe the organisation of the adrenal medulla
post-ganglionic forms synapse with effector
Describe the pre-ganglionic nerve fibres
Always myelinated, always cholinergic
What do pre-ganglionic fibres release as their primary neurotransmitter
ACh
What is the ligand in pre-ganglionic fibres
ACh
What is the receptor subtype for pre-ganglionic fibres
N2 receptor subtype
What receptor does ACh activate on the post ganglionic neuron
nicotinic ACh receptors
Describe the pre-ganglionic neurons in the sympathetic nervous system
short, cholinergic
Describe the post-ganglionic neurons in the sympathetic nervous system
long, adrenergic - release mainly noradrenaline
what do target tissues of the sympathetic nervous system express
alpha and beta adrenergic receptors
What cells release adrenaline in the adrenal medulla
chromaffin cells
Describe the fibres of the sweat glands
both pre and post ganglionic are cholinergic
What are the receptors for sweat glands
muscarinic ACh receptors - GPCRs
Describe the pre-ganglionic neuron of the parasympathetic system
long, cholinergic
Describe the post-ganglionic neuron of the parasympathetic system
short, cholinergic
What receptors do tissues of the parasympathetic system express
muscarinic ACh receptors
What controls the emotional inputs of the ANS
limbic lobe
What integrates an co-ordinates ANS function
hypothalamus
What mediates autonomic reflexes
spinal cord
Where are regulatory centres for ANS located
brainstem nuclei
TRUE or FALSE - descending cortical input control autonomic output
TRUE
