Drugs and the nervous system

Question 1

General anaesthetics
act mainly in the _______ _______ _______
may be given by ________ or __________

Answer 1

act mainly in the Central Nervous System

may be given by inhalation or intravenously

Question 2

Why use anaesthetics?

Answer 2

To promote:
Analgesia
Unconsciousness
Amnesia
Loss of reflexes
But, too much → adverse effects → DEATH!

Question 3

How do anaesthetics work?

Answer 3

act on CNS to promote insensitivity
usually fat soluble – can cross blood-brain barrier
may act on membrane receptors to reduce excitability of neurones
may affect ion channels

Question 4

Side effects of anaesthetics are…

Answer 4

Nausea / vomiting 
Breathing swallow/ rapid
Decrease in blood pressure 
Decreased kidney perfusion
Crosses the placenta 
Loss of temperature control

Question 5

What are the stages of anaesthesia’s?

Answer 5

Stage 1 – analgesia
Stage 2 – excitement
Stage 3 – surgical anaesthesia → skeletal muscle relaxation/ loss of reflexes
Stage 4 – medullary paralysis → loss of respiratory/ vasomotor control

Question 6

What are the types of general anaesthetics?

Answer 6

Non -Barbiturates
Barbiturates
Gases
Volatile liquids