Day 1.2 Pharm Flashcards
What is the neurotransmitter for the nicotinic receptor?
ACh
What drug is a nicotinic receptor antagonist?
Hexamethonium
What does Hexamethonium block?
Nicotinic receptor antagonist- blocks ACh receptors at ALL autonomic ganglion- both sympathetic and parasympathetic
If hexamethonium blocks both SNS and PNS, how can you determine how it will affect an organ?
How it affects an organ depends on the dominant tone (SNS or PNS) in that organ. e.g. Dominant tone in vessels is SNS, so hexamethonium will act as a symp antagonist to blood vessels- so will decrease BP. (Most organs have dom PNS tone)
What is hexamethonium used for clinically?
Experimental only - to prevent vagal reflex response to changes in BP; prevents reflex bradycardia caused by NE
SNS to sweat glands: Preganglionic neurons go to what kind of receptor? Release which NT?
The sympathetic ganglion have a nicotinic receptor. ACh is the NT. All preganglionic neurons go to Nicotinic receptors.
SNS to sweat glands: Post-ganglionic neurons go to what kind of receptor? Release which NT?
Post-gang neurons go to sweat glands and synapse there with a Muscarinic receptor. ACh is the NT.
SNS to cardiac musc, smooth musc, gland cells, nerve terminals: Preganglionic neurons go to what kind of receptor? Release which NT?
The sympathetic ganglion have a nicotinic receptor. ACh is the NT. All preganglionic neurons go to Nicotinic receptors.
SNS to cardiac musc, smooth musc, gland cells, nerve terminals: Post-ganglionic neurons go to what kind of receptor? Release which NT?
Post-gang neurons go to cardiac musc, smooth musc, gland cells, and nerve terminals and synapse there with a adrenoceptor receptor (alpha or beta). NE is the NT.
SNS to renal vascular smooth musc: Preganglionic neurons go to what kind of receptor? Release which NT?
The sympathetic ganglion have a nicotinic receptor. ACh is the NT. All preganglionic neurons go to Nicotinic receptors.
SNS to renal vascular smooth musc: Post-ganglionic neurons go to what kind of receptor? Release which NT?
Post-gang neurons go to renal vascular smooth muscle and synapse there with a D1 receptor.
SNS to the adrenal medulla: what kind of receptor is at the adrenal medulla? Releases which NT?
There is a Nicotinic receptor at the adrenal medulla. The receptor is ACh. When stimulated, the adrenal medulla itself goes on to release NE and Epi
Somatic system: Nerves to skeletal muscle have what kind of receptor? What is the NT?
Nicotinic receptor; ACh is the NT.
PNS pre-ganglionis neurons go from the medulla all the way to the ganglion located right by the organ they will stimulate. What kind of receptor is in the ganglion? What is the NT?
The parasympathetic ganglion have a nicotinic receptor. ACh is the NT. All preganglionic neurons go to Nicotinic receptors.
PNS post-ganglionic nerves (short) go to cardiac and smooth muscle, gland cells, and nerve terminals. What is there receptor at these locations? What is the NT?
Muscarinic receptor; ACh is the NT.
What are the Nicotinic receptors (what kind of channel/protein)?
Ligand-gated Na+/K+ channels.
Nn for autonomic (SNS, PNS) ganglia
Nm for the NMJ (somatic)
What are the Muscarinic receptors (what kind of channel/protein)?
G-protein-coupled receptors, which act through 2nd messengers.
5 subtypes: M1, M2, M3, M4, M5
Cholinergic Nerve: What kind of NT does it produce?
ACh
ACh goes to a cholinocepor- either a M receptor or N receptor.
Noradrenergic Nerve: What kind of NT does it produce?
NE
Noradrenergic (SNS) goes to an adrenoceptor (alpha or beta receptor)
Cholinergic Nerve: how is ACh produced?
Choline is brought along with Na+ via the Na+ cotransporter. Choline is combined with Acetyl-CoA with the help of ChAT (choline acetyltransferase). Ca2+ helps release of ACh into synaptic cleft.
Cholinergic Nerve: What is the rate-limiting step in ACh synthesis?
Bringing choline in. (Via Na+ cotransporter)
Cholinergic Nerve: what inhibits choline from being brought into the cell?
Hemicholinium
Cholinergic Nerve: What inhibits release of ACh into the cleft?
Botulinum toxin, which causes flaccid paralysis (floppy baby)
Cholinergic Nerve: What toxin stimulates the release of ACh into the cleft?
Black widow spider toxin