ANS Anatomy And Phys Flashcards
What 3 forms can an extracellular signal take form?
Chemical
Electrical
Mechanical
What are the 3 categories of membrane bound receptors?
Ion channel
G-protein couple receptor (GPCR)
Enzyme linked receptor
What are the two ways a GPCR works?
Opens/closes a channel
Activates/inactivates an enzyme inside the cell
Where are intracellular receptors located?
In the cytoplasm or nucleoplasm
(Steroids)
What are the 3 subunits in a g-protein receptor?
Alpha, beta, and gamma
What do Gs and Gq proteins do?
STIMULATE (turn ON am effector)
What do Gi proteins do?
INHIBIT (turn OFF an effector)
What are the main second messengers?
cAMP
cGMP
IP3
DAG
Calcium
What is the receptor, signal transduction, effector and second messenger for alpha 1?
Signal transduction: Gq
Effector: ^ phospholipase C
Second messenger: ^ IP3, DAG, Ca
What is the receptor, signal transduction, effector and second messenger for alpha 2?
Signal transduction: Gi
Effector: decreased adenylate cyclase
Second messenger: decrease cAMp
What is the receptor, signal transduction, effector and second messenger for Beta 1?
Signal transduction: Gs
Effector: ^ Adenylate Cyclase
Second messenger: ^ cAMP
What is the receptor, signal transduction, effector and second messenger for Beta 2?
Signal transduction: Gs
Effector: ^ adenylate cyclase
Second messenger: cAMP
What is the receptor, signal transduction, effector and second messenger for beta 3?
Signal transduction: Gs
Effector: ^ adenylate cyclase
Second messenger: ^cAMP
What is the receptor, signal transduction, effector and second messenger for nicotinic (ANS, NMJ, CNS)?
Ion channels
What is the receptor, signal transduction, effector and second messenger for M1, M3, and M5?
Signal transduction: Gq
Effector: ^ Phospholipase C
Second messenger: ^ IP3, DAG, Ca
What is the receptor, signal transduction, effector and second messenger for M2 and M4?
Signal transduction: Gi
Effector: decreased adenylate cyclase
Second messenger: decreased cAMP
What is the receptor, signal transduction, effector and second messenger for dopamine 1?
Signal transduction: Gs
Effector: ^ adenylate cyclase
Second messenger: ^ cAMP
What is the receptor, signal transduction, effector and second messenger for dopamine 2
Signal transduction: Gi
Effector: decreased adenylate cyclase
Second messenger: decrease cAMP
What is the receptor, signal transduction, effector and second messenger for vasopressin 1
Signal transduction: Gq
Effector: ^ phospholipase C
Second messenger: ^ IP3, DAG, Ca
What is the receptor, signal transduction, effector and second messenger for vasopressin 2?
Signal transduction: Gs
Effector: ^ adenylate cyclase
Second messenger: ^ cAMP
What is the receptor, signal transduction, effector and second messenger for histamine 1?
Signal transduction: Gq
Effector: ^ phospholipase C
Second messenger: ^ IP3, DAG, Ca
What is the receptor, signal transduction, effector and second messenger for histamine 2?
Signal transduction: Gs
Effector: ^ adenylate cyclase
Second messenger: ^ cAMP
What does Beta 1 affect the heart?
> Positive Inotrope
positive chronotropy
positive dromotropy
What does Beta 2 do to the lungs?
Bronchodilation
What does a1 do to the GI tract?
Vasoconstriction sphincter contraction
What does alpha 1 do to the glands?
> Increased sweating
decreased pancreatic activity
What does a1 and Beta 2 do to the urinary tract?
Bladder sphincter contraction
^ renin secretion (I’m almost positive this is actually Beta 1 stimulation)
What does alpha 1 do to the skin?
Vasoconstriction
What does beta 2 do the skeletal muscle?
Vasodilation
What does alpha 1 cause in the pupils?
Dilation
What does M2 do in the heart?
> negative inotropy
negative chronotropy
negative dromotropy
What does M3 do in the lungs?
Bronchoconstriction
Increased gland secretions
What does M3 do in the GI system?
> increased motility
sphincter relaxation
increased gland secretion
What does M1 and M3 do to the glands?
> ^ salivation
^ lacrimination
^ pancreatic activity
What does M3 do to the urinary tract?
Bladder sphincter relaxation
What does M3 do to the pupils?
Constriction
How does alpha 2 affect beta cells?
Decrease insulin release
How does Beta 2 affect the uterus?
Relaxes uterus
How does the SNS system affect the pupil?
SNS activity > alpha 1 stimulation > radial muscle contraction > MYDRIASIS (pupil dilation)
How does the PNS system affect the pupil?
PNS activity > muscarinic stimulation > sphincter muscle contraction > MIOSIS (pupil constriction)
Where is the alpha 2 receptor present?
Presynaptic in the CNS and peripheral nervous system (this is a negative feedback mechanism that reduces NE release)
Post synaptic: smooth muscle and several organs
Nonsynaptic: platelets
How does alpha 2 affect the nervous system?
Decreases SNS tone
Increases PNS tone
Sedation
Analgesia
Anti-shivering
How does alpha 2 affect the vasculature?
Vasoconstriction
How does alpha 2 affect the renal tubules?
Inhibits ADH (diuresis)
How does alpha 2 affect the pancreas?
Decreased insulin release
How does alpha 2 affect the platelets?
Increases platelet aggregation
How does alpha 2 affect the salivary glands and GI tract?
Salivary glands: dry mouth
GI tract: decreased gut motility
How does rapid administration of precedex cause vasoconstriction and hypertension?
Stimulates postsynaptic alpha 2 receptors in the arterial and venous circulations.
How many moles of ATP can be produced with 1 mole of glucose?
38!
What metabolizes cAMP to AMP?
Phosphodiesterase 3 (PDE 3)
What is one of the main PDE 3 Inhibitors?
MILRINONE!! ~ it’s an inodilator.
What are PDE 3 inhibitors useful in?
Beta blocker myocardial depression
Acute heart failure
Unresponsiveness to IV catecholamines
Any time a combo of increased inotropy and decreased SVR would be desirable!
What is the prototype nonselective phosphodiesterase inhibitor?
Theophylline
In vascular smooth muscle, what does cAMP inhibit?
Myosin light chain kinase
What is the primary neurotransmitter of the SNS?
NE
What are the 3 ways catecholamines are removed from the synaptic cleft?
Reuptake (main)
Diffusion
MAO and COMT
Which local anesthetic blocks reuptake of NE at the synapse?
Cocaine
What is the end-product of catacholamine metabolism?
Vanillylmandelic acid
What is the primary transmitter in the parasympathetic nervous system?
Ach
Where are Type N cholinergic receptors located?
PNS ganglia
SNS ganglia
Central nervous system
Where are Type M cholinergic (nicotinic) receptors located?
Neuromuscular junction
Where are muscarinic receptors (cholinergic) located?
Post ganglionic PNS effector organs
CNS
What is an antagonist of Ca at the presynaptic nerve terminal?
Magnesium!
What is the primary mechanism for ACh removal?
Metabolism by Acetylcholinesterase
What is the rate-limiting factor for ACh synthesis?
The availability of substrates, choline, and acetyl-CoA
What are the two locations for neurotrasmitter release in the ANS?
Ganglia and effectors (organs)