Week 8 Flashcards
What is the blood brain barrier?
A physiological barrier that protects the brain
- prevents many drugs from crossing unless they have significant lipid solubility
- Alteration in the integrity of BBB such as inflammation can allow drugs such as penicillin to be used to treat bacterial meningitis.
What is the red nucleus?
A checkpoint to determine if stimulus is detrimental to body, then convey message to various parts of the body (reflex example)
What is the main inhibitory neurotransmitter?
GABA
What is the main excitatory neurotransmitter?
Glutamate
What are two ways in which negative feedback can work?
Turning off excitatory nerves or turn on inhibitory neurons
What are two ways in which negative feedback can work?
Turning off excitatory neurons or turn on inhibitory neurons
Explain plasticity of the brain?
Long term potentiation (LTP) and long term depression (LTD) can facilitate changes in neurological signaling and adaption.
Basically the more you do something the more neuronal connections are created around it. The less you do something the more neuronal connections you lose…
Learning, memory, dementia
What do general anaesthetics do?
Used to render patients unaware of, or unresponsive to, painful stimulation during surgical procedures
- Alters consciousness
What are the main types of general anaesthetics?
- inhalational
- intravenous
What are the 3 main components of The Anaesthetic State?
- Loss of consciousness
- Analgesia
- Muscle relation
What are the 3 main phases of general anaesthesia?
- Induction
- Maintenance
- Recovery
What do mosr anaesthetics do to the CNS inhibitory transmitter GABA and CNS excitatory receptors glutamate and nACHR’s?
- Enhance GABA activity
- inhibit excitatory receptors
What are 3 anaesthetics and their characteristics?
Thiopentone - rapid onset but slower recovery and can cause laryngospasm
Propofol - fast onset and recovery but higher incidence of hypotension and injection pain
Midazolam - least effective but has amnesic effects
What are inhalational anaesthetics typically used for?
the maintenance of anaesthesia.
The rate of induction and recovery from inhilational anaesthetics is dependant on what?
the lipid solubility of the compound
Inhalational anaesthetics effects are directly proportional to what?
the partial pressure of the drug in the brain
What factors cause faster induction time for inhalational anaesthetics
- high inspired concentration
- increased ventilation
- low blood gas solubility
- increased alveolar-to-capillary pressure difference
WHat happens with inhalational anaesthetics when increased alveolar ventilations occurs?
Rate of recovery increases.
What is Minimum alveolar concentration inversely related with?
potency
WHat are issues with Nitrous oxide as an inhalational anaesthetic?
Low potency (must be combined with other agents) but rapid induction and recovery
WHat are issues with Halothane as an inhalational anaesthetic?
potent and widely used but can cause dysrythmias and lover damahe
WHat are issues with Isoflurane as an inhalational anaesthetic?
less toxicity than halothane but irritates respiratory tract and can cause myocardial ischaemia
Normal cellular homeostasis and equilibrium results in an electrochemical potential difference between what?
ECF and ICF
If GABA acts on a receptor it is it more or less likey to reach AP?
Less
