Physiology + pharmacology of the ANS Flashcards
(20 cards)
Describe the synthesis of noradrenaline.
Tyrosine is converted to dopa by tyrosine hydroxylase.
Dopa is converted to dopamine by dopa decarboxylase.
Dopamine is taken up into vesicles and converted to noradrenaline by dopamine beta-hydroxylase.
During the synthesis of noradrenaline, tyrosine is converted into what?
Which enzyme catalyses this?
Dopa
Tyrosine hydroxylase
During the synthesis of noradrenaline, dopa is converted into what?
Which enzyme catalyses this?
Dopamine
Dopa decarboxylase
During the synthesis of noradrenaline, dopamine is converted into what?
Which enzyme catalyses this?
Noradrenaline
Dopamine beta-hydroxylase
What type of receptors are beta-1 and beta-2 adrenergic receptors?
Which mechanism is activated when noradrenaline binds?
G protein coupled receptors
Adenylyl cyclase
What type of receptors are alpha-1 adrenergic receptors?
Which mechanism is activated when noradrenaline binds?
G protein coupled receptors
Phospholipase C
Describe the phospholipase C mechanism.
Phospholipase C breaks down PIP2 into DAG and IP3.
DAG activates protein kinase C.
IP3 stimulates Ca2+ release from intracellular stores.
Describe the adenylyl cyclase mechanism.
Adenylyl cyclase converts ATP to cAMP.
cAMP activates protein kinase A.
What type of receptors are alpha-2 adrenergic receptors?
Which mechanism is activated when noradrenaline binds?
G protein coupled receptors
Inhibitory G protein complex - adenylyl cyclase is inhibited
Which kind of adrenergic receptor predominates in the heart?
B1 adrenergic receptors
What is positive chronotropy?
Increase in heart rate
What is positive ionotropy?
Increase in force of contraction
Which kind of adrenergic receptor predominates in skeletal muscle blood vessels?
B2 adrenergic receptors
Do B2 adrenergic receptors dilate or constrict arterioles?
Dilate arterioles
Which kind of adrenergic receptor predominates in the lungs?
B2 adrenergic receptors
Acetylcholine is formed from which 2 molecules?
Choline
Acetyl CoA
What type of receptors are M1, M3 and M5 muscarinic receptors?
Which mechanism is activated when acetylcholine binds?
G protein coupled receptors
Phospholipase C
What type of receptors are M2 and M4 muscarinic receptors?
Which mechanism is activated when acetylcholine binds?
G protein coupled receptors
Inhibitory G protein complex - adenylyl cyclase is inhibited
Which kind of muscarinic receptor predominates in the heart?
M2 muscarinic receptor
Which kind of muscarinic receptor predominates in the lungs?
M3 muscarinic receptor
