Flashcards in Pharmacology Deck (115)
Stimulation of post-ganglionic cholinergic fibres in the parasympathetic pathway is mediated by ___ Muscarinic Ach Receptors on ASM
What does post-ganglionic stimulation of cholinergic fibres cause?
bronchial smooth muscle contraction
increased mucous secretion
Stimulation of post-ganglionic non-cholinergic fibres causes bronchial smooth muscle contraction - true or false?
false - causes relaxation by Nitric Oxide and Vasoactive intestinal peptide
Peptides involved in parasympathetic non-cholinergic fibres?
Nitric Oxide (NO)
Vasoactive Intestinal Peptide (VIP)
Which nerve provides parasympathetic stimulation to the airway smooth muscle?
Vagus - CN X
There is no sympathetic innervation of bronchial smooth muscle in humans - true or false?
Stimulation of sub-mucosal glands and smooth muscle of blood vessels by post-ganglionic sympathetic fibres causes...(4)
- bronchial smooth relaxation via b2-adrenoceptors
- decreased mucous secretion mediated by b2-adrenoceptors on goblet cells
- increased mucociliary clearance mediated by b2-adrenoceptors on epithelial cells
- vascular smooth muscle contraction mediated by a1-adrenoceptors
contraction stimulated by a1-adrenoceptors
vascular smooth muscle
relaxation stimulated by b2 adrenoceptors
bronchial smooth muscle
Activation of the M3 receptors leads to activation of which G protein?
Gq/11 activates ____ which converts PIP2 to ____ and ____
PLC, IP3, DAG
IP3 stimulates calcium release from the _______ _______ via the ____ receptor
sarcoplasmic reticulum, IP3
Calcium induced calcium release is mediated by which receptor in smooth muscle?
Cellular depolarisation causes the closure of voltage gated calcium channels - true or false?
causes VGCC to open and allow calcium to influx allowing contraction of the smooth muscle
Calcium binds and activates _______, this allows the subsequent activation of _______. Active MLCK allows phosphorylated ______ cross bridge binding to ______ via the breakdown of ATP
Calmodulin, MLCK, myosin, actin
What is calmodulin?
calmodulin is a cytoplasmic Ca receptor which undergoes a conformational change when bound to Ca
In the presence of high IC Ca, the rate of phosphorylation exceeds the rate of dephosphorylation of MLCK by myosin phosphatase - true or false?
How is IC calcium removed from the cell for smooth muscle relaxation?
primary and secondary active transport
Primary Active Transport
utilises energy in the form of ATP to drive a process of moving the ion from a low concentration to a high concentration
Secondary Active Transport
utilises energy from another process where the energy is not required to move another ion i.e. a symporter
In order to counteract the action M3 causing contraction, _______ activates b2 adrenoceptors which activates the G-protein ___.
Activation of the Gs protein stimulates the enzyme...
adenylate cyclase produces _____ which is broken down by _____
What does cAMP activate?
PKA phosphorylates and stimulates MLCK - true or false?
PKA phosphorylates and thus inhibits MLCK
PKA phosphorylates and stimulates...
Overall, activation of PKA causes what?
bronchial smooth muscle relaxation
cAMP is degraded to what by PDE?
What is the incidence of Asthma in industrialised countries?