Introduction to the ANS Flashcards
What are drug targets?
Receptors Proteins Hormone receptors Growth factor receptors Transcription factor receptors Neurotransmitter receptors Ion channels Enzymes Transport proteins Glycoproteins Structural proteins DNA
What are the types of receptor modulators?
Full agonist- complete mimicry
Partial agonist- only partial
Neutral antagonist
Inverse agonist (also called antagonist) - block constitutive activity.
Responses of effector organs to ANS impulses
see slide 7, table in DSA also, be familiar with table.
What is the sym receptor in the heart?
B1 mainly but also B2
What is the parasym receptor in the heart?
M2 mainly but also M3
What is the parasym neurotransmittor?
receptors?
Ach
nAChR, mAChR
What is the sym neurotransmittor?
receptors?
NE, Epi (DA) Ach/
alpha, beta (D), nAChR, mAChR
All preganglionic autonomic fibers are what type?
Cholenergic
What is cholinergic transmission?
a) Cholinergic neurotransmission refers to any neurotransmission in which ACh is released in vesicles; neurons that release ACh are called cholinergic neurons
Where are NNAChR found?
Where are mAChR found?
Within the ANS, NNAChRs are found in all ganglia (sympathetic and parasympathetic) and the adrenal medulla (sympathetic) while mAChRs are found in smooth and cardiac muscle, gland cells, and nerve terminals (sympathetic and parasympathetic)
What is adrenergic neurotransmission?
Adrenergic neurotransmission refers to neurotransmission in which catecholamines (NE, Epi, and DA) are released upon stimulation by an action potential (neurons that release catecholamines are called adrenergic neurons)
What are the catecholemines that we learned?
Precursor?
Norepinephrine, epinephrine (both adrenergic) and Dopamine (precursor to previous 2)
Tyrosine is precursor to all
What is the major NT of the Sym nervous system
Norepinephrine ( vast majority of postganglionic sym fibers)
Where does dopamine act?
CNS and renal vascular smooth muscle.
Talk about Cholinergic NT.
Axonal conduction
Junctional transmission (cholinergic) Synthesis of acetylcholine (ACh) Storage of ACh Release of ACh Destruction of ACh
ACh signaling
End organ effects
Describe nAChR?
Located in the CNS/Autonomic ganglia(Nn) (para) and adrenal medula (sym)
Excitatory (para) and release of catecholamines (sym)
Agonists- Ach and nicotine
Describe mAChR?
Located in CNS/autonomic ganglia; effector organs (cardiac and smooth muscle, gland cells, nerve terminals) (para)
Sweat glands ( sym)
Excitatory and inhibitory (para); sweat secretion (sym)
Agonists- Ach and muscarine.
Focus on M2 and M3
Slide 13
What are the two types of Ion channels?
What are the different drugs that inhibit
Voltage gated- local anesthetics
Ligand gated- neurotransmittor blockers
What are the steps in adrenergic neurotransmission?
Axonal conduction
Junctional transmission (adrenergic) Synthesis of catecholamines Storage Release Destruction (reuptake)
ACh signaling
End organ effects
Tyrosine> DOPA> Dopamine> NE> EPI; where do these occur?
First 2 in nerve cytoplasm last 3 in vesicle (last 2 mainly in adrenal medulla)
What are the transporters of adrenergic transmission?
What do they do?
Na+-dependent tyrosine transporter
Transports tyrosine into the nerve terminal
Vesicular monoamine transporter (VMAT-2)
Transports NE, Epi, DA, and serotonin into vesicles (promiscuous)
Release upon action potential and Ca2+ influx
NE transporter (NET) Imports NE into the nerve terminal Dopamine uptake occurs via a separate transporter (DAT)
What is the mechanism of re uptake?
Major mechanism that terminates the actions of catecholamines
NET (norepinephrine transporter) and DAT (dopamine transporter)
After reuptake, catecholamines are stored in vesicles by the VMAT-2
Focus on A1,2 and B1,2
Slide 22
