Autonomic Nervous System Flashcards
Neurotransmitter and receptors of somatic system?
- acetylcholine
- Nicotinic muscular receptors (Nm)
- one neuron system
Neurotransmitter and receptors of parasympathetic system?
- pre ganglionic (long) neurons release acetylcholine to Nicotinic neural (Nn)
- post ganglionic release acetylcholine
- Muscarinic receptors 1-5
Neurotransmitters and receptors of sympathetic system?
- pre ganglionic (short) release acetylcholine to Nicotinic neural (Nn)
- post ganglionic release Norepinephrine
- Adrenergic receptors (alpha, beta)
- sweat glands= acetylcholine release at M3, M5
- renal smooth muscle= NE to alpha, Dopamine to D1
Neurotransmitters and receptors of adrenal medulla?
- stimulated by acetylcholine at Nicotinic neural (Nn)
- release catecholamines (NE, epinephrine, dopamine)
Hemicholinemiums?
inhibits choline transporter from transporting choline into the presynaptic neuron for acetylcholine synthesis
Vesamicol?
- inhibits Ash vesicle transporter
- results in less ACh in vesicles
Botulinum toxin?
-inhibits fusion of ACh vesicles to neuron membrane
Neostigmine?
- inhibts acetylcholinesterase
- allows ACh to remain in synaptic cleft to continue stimulating
Monoamine oxidase (MAO)?
- located in mitochondria of nerve cells
- degrade NE
Catecholamine O-methyltransferase (COMT)?
metabolizes NE that diffuses out of the synaptic cleft
Metyrosine?
- inhibits tyrosine hydroxylase (rate limiting step)
- no Dopa is made from Tyrosine for Dopamine synthesis
Reserpine?
- inhibits Vesicular Monoamine Transporter (VMAT)
- limits the amount of Dopamine into the vesicles so limits amount of NE synthesized
Bretylium and Guanethidine?
-inhibit fusion of NE vesicles with cell membrane for NE release
Cocaine and tricyclic anti depressants?
- inhibit NET (NE transporter) and NE autoreceptor
- no NE is reuptaken into the cell, stays in synaptic cleft
Tyramine and Amphetamine?
- taken up by NET and deplete vesicle of NE
- causes NE to leak out in synaptic cleft to stimulate receptors
Tranylcypromine?
- inhibits MAO within mitochondria of neuron
- decreases the amount of NE metabolized and increases NE taken into vesicles
Nicotinic neural (Nn) receptors location?
- postganglionic neuron cell bodies
- depolarize neuron as a result of Na and K channels opening
Nicotinic muscle (Nm) receptors location?
- skeletal muscle at neuronal end plate
- depolarize due to Na and K channels opening
Muscarinic 2 (M2) receptors?
- ACh activated
- in the heart
- slow HR by reducing Calcium
Muscarinic 3 (M3) receptors?
- ACh activated
- located in smooth muscle of GI, iris, lungs
- located in exocrine glands, blood vessels
-mechanism is to increase calcium for increased muscle contractions
- actions:
- constricts bronchi and pupils
- increases GI motility
- increases exocrine secretions
- circulating ACh is metabolized into nitric oxide to dilate blood vessels
Muscarinic 5 (M5) receptors?
- activated by ACh
- located in blood vessels of cerebrum
- circulating ACh is metabolized into nitric oxide to dilate blood vessels
Alpha 1 receptors?
- NE and Epi activated
- located in smooth muscle
- increases Calcium for smooth muscle contractions
- vasoconstriction of blood vessels
- mydriasis (pupil dilation, iris constriction)
- sphincter constriction of bladder
- lower affinity than beta 2 receptors for NE
Alpha 2 receptors?
- NE and Epi activated
- located in presynaptic adrenergic cells
- control and regulates NE release
- reduce insulin secretion
Beta 1 receptors?
- NE and Epi activated
- located in heart and kidney juxtaglomerular apparatus of renal tubules
- increase cAMP and Calcium
- increases HR and force of contraction
- increases release of Renin to increase BP
Beta 2 receptors?
- NE and Epi activated
- located in smooth muscle
- increases cAMP, causing inhibition of myosin LC kinase, to relax smooth muscle
- bronchodilation
- vasodilation
- uterine dilation
- glycogenolysis
- higher affinity than alpha 1 receptors
Beta 3 receptors?
- NE and Epi activated
- located in fat cells
- increases oxidation of fat for energy
