Introduction to receptors Flashcards
Define pharmacology.
The study of the effects of chemical substances on the function of living systems in relation to their therapeutic value - it involves aspects of physiology and chemistry.
What are drugs?
Chemical substances of known structure that produce a biological effect in an organism. They can be synthetic, from plants, animals or from genetic engineering.
What are medicines?
Chemical preparations that usually contain drugs but contain other substances to make the drug more convenient to use.
Usually contain one or more drugs
Have an intention of producing a therapeutic effect
What is pharmacokinetics?
How an organism reacts to a drug/processes the drug, absorption, distribution, metabolism and secretion.
What is pharmacodynamics?
How the drug affects the organism.
Who introduced opium and mercury into medicine for the first time?
Paracelsus.
What natural substances were involved in pharmacology before the 19th century?
Quinine (malaria), digitalis (heart failure), atropine (pupils dilate) and ephedrine (active principle of herb ‘ma-huang’).
What are the two main theories of neurotransmission?
The electrical theory and the humoral theory.
What are the main points of the electrical theory?
An electrical current from a large muscle mass may excite a nerve and the effect should be bidirectional. Amplification is required as the current in the nerve is too small. This amplification occurs at the nerve/muscle junction and is achieved chemically.
What are the main points of the humoral (chemical) theory?
Transmission across the gap is uni-directional, and there is a delay in the transmission across the gap as time is taken for the molecules to diffuse across. Fatigue may occur more regularly at the junctions an drugs can act selectively at synapses.
What did Schmiedeberg discover?
Muscarine (found in certain toadstools) can stimulate the vagus nerve of the heart - decreasing heart rate. (vagul stimulation)
What synthetic drugs appeared in the 20th century?
Barbituarates, local anaesthetics, antimicrobial chemotherapy and antibacterials.
What did Paul Ehrlich do?
Studied effect of dyes on bacteria
What did Henry Dale do?
Conducted studies on histamine and acetylcholine.
What did Henry Dale discover?
Noticed Ach was equipotent with muscarine.
Also, that Ach mimicked parasympathetic nerve stimulation and that low doses of Ach were blocked by atropine, but high doses mimicked the effects of nicotine (stimulation of sympathetic ganglionic cells).
