PHARMACOLOGY - Basics Flashcards
inositol triphosphate is activated by what? what is its pathway?
activated by alpha one adrenoceptors. Binds to endoplasmic reticulum membrane, increases concentration of intracellular calcium –> smooth muscle contraction –> ++ exocrine secretion and force/rate of cardiac contractions
What are the actions of the parasympathetic pathway? (2)
- Ciliary muscle contaction –> accomodation
- Sphincter muscle constriction –> constriction
What are the actions of the sympathetic pathway?
- Ciliary muscle relaxation
- Sphincter pupillae action –> pupil miosis
- Upper lid retraction (Dalrymple sign)
Where are Beta-2 receptors found? (3)
Lungs, GI tract, vascular smooth muscle
What is the systemic effect of leukotrienes? (3)
- Bronchoconstriction
- Vasoconstriction
- Increase vascular permeability
–> involved in allergic reactions and inflammation
What is Fick’s Law?
Movement of particles from high to low concentration (diffusive flux) is directly proportional to the particle’s concentration gradient
rate of diffusion = diffusion coefficient x (concentration gradient / membrane thickness)
Which drug can cause xanthopsia (yellow-blue discoloration), photopsia and pain on eye movements?
digoxin
Accomodation occurs with parasympathetic or sympathetic control?
parasympathetic control
What effects happen with beta-2 blockers?
- Bronchoconstriction
- Peripheral arterial constriction
- Reduced aqeous production from ciliary epithelium
What are the general ocular actions of adrenergic agonists (4)
- Increase aqueous outflow
- Ciliary muscle relaxation
- Contraction of Muller’s muscle –> reversal ptosis
- Conjunctival vessel constriction
What are some examples of G-protein receptors? What are some examples of ligand gated ion channels?
G-protein
Muscarinic Receptors
Adrenergic Receptors
Ligand gated ion channels
5HT3 receptors
GABA receptors
What are the main neurotransmitters in the parasympathetic nervous system? (1)
Acetylcholine
What receptors does ACh act on?
- Muscarinic (G-protein coupled) usually post-ganglionic acting at effect organs
- Nicotinic (ligand-gated) usually at synapses and neuromuscular junction
What are the main neurotransmitters in the sympathetic nervous system? (3)
- ACh (autonomic ganglia)
- Adrenaline
- Noradrenaline
How are adrenaline and noradrenalin signals terminated?
Terminated by
1. presynaptic reuptake
2. degradation by COMT and monoamine oxidases