Autonomic Nervous Systen Flashcards
“Flight or Fight” system
Sympathetic system
Sympathomimetic
Anticholinergic
Sympathetic nerves are adrenergic nerves that release norepinephrine (NE) which interacts with alpha and beta receptors
“Right & Digest”
Parasympathetic system
Parasympathomimetic
Cholinergic
Parasympathetic nerves are cholinergic nerves. They release acetylcholine (ACh) which interacts with muscarinuc receptors
Norepinephrine on eyes
Dilate
Facilitating clear vision
Norepinephrine on heart
Increased heart rate
Norepinephrine on trachea and bronchioles
Dilates
Increased respirations
Norepinephrine on liver
Stimulates the conversion of glycogen into glucose
Facilitating energy
Norepinephrine on blood flow
Shunts blood away from skin and viscera to the skeletal muscles, brain and heart
Causing cold sweats
Norepinephrine on Gastrointestinal tract
Inhibits peristalsis
Norepinephrine on bladder and rectum
Inhibits contraction
Sphincter muscles contract
Detrusor muscles relax
Norepinephrine on blood vessels
Vasoconstriction
Increased blood pressure
Norepinephrine on kidneys
Release of renin
Norepinephrine on adrenal gland
Release of adrenaline
Norepinephrine on sweat glands
Sweating
Norepinephrine on skeletal muscles
Increased muscle activity
Tremors
Norepinephrine on tear ducts
Decreased lacrimation
Dry eyes
Norepinephrine on salivary glands
Decreased salivation
Dry mouth
Norepinephrine on penis
Ejaculation
Norepinephrine on uterus
Relaxation
Steps of Adrenergic Synapse
1) Synthesis of norepinephrine
2) Storage of NE in vesicles
3) Release of NE
4) Action of NE
5) Inactivation by presynpatic reuptake transporters
Adrenergic Agonists are subdivided into 3 classes of drugs:
Direct-acting
Indirecting-acting
Dual-acting
Direct-acting agonist
These bind to and activate a1, a2, b1, b2 and b3.
Naturally occurring molecules which bind to these receptors are norepinephrine and epinephrine.
Dopamine can also bind to a1 and b1 which stimulates heart rate.
Indirect-acting adrenergic (i.e., amphetamines and cocaine)
Stimulates the release of NE and prevents its reuptake. By preventing the NE inactivation, they linger in the adrenergic synapses.
ALPHA 1 RECEPTORS LOCATED
Blood vessels
AGONIST - Vasoconstriction
(Treat Hypotension)
ANTAGONIST - Vasodilation (Treat Hypertension)
ALPHA 2 RECEPTORS LOCATED
Blood vessels
AGONIST - Vasoconstriction
(Hypotension)
ANTAGONIST - Vasodilation
(Hyertension)
Pre-synpatic membranes in adrenergic nerves (inhibits NE release)
