| Date | November 2019 | Marks available | 3 | Reference code | 19N.3.HL.TZ0.6 |
| Level | Higher level | Paper | Paper 3 | Time zone | TZ0 / no time zone |
| Command term | Describe | Question number | 6 | Adapted from | N/A |
Question
Prior to the 1840s, doctors and dentists did not routinely use anesthesia when operating on patients. However, advances in the knowledge of neurotransmitters have assisted the use of anesthesia.
Define neurotransmitter.
Describe how local anesthetics act on the nervous system.
Describe the main role of slow-acting neurotransmitters in memory and learning.
Markscheme
chemical substance that transmits message across synapses/from one cell to another ✔
OWTTE
Do not accept "connection" instead of "synapse".
a. interfere with neural transmission between areas of sensory perception and the CNS ✔
b. blocks nerve transmission/impulses to pain centres in the CNS ✔
c. inhibit the function of an ion channel «sodium channel» in nerve cells ✔ OWTTE
d. no changes in awareness/consciousness/sense perception in other areas ✔ Accept vice versa
e. suppress excitatory synaptic transmission ✔
f. some increase the intensity of inhibitory synaptic transmission ✔
a. may cause the release of secondary messengers «in post-synaptic neuron» ✔
b. secondary messengers can persist for long time ✔
c. «secondary messengers» may enhance the synaptic connections between neurons OWTTE
OR
«secondary messengers» strengthen neural pathways «involved in memory/learning»
OR
«secondary messengers» increase the number of receptors in the postsynaptic membrane ✔
d. modulate/reduce/increase fast synaptic transmission «in the brain» ✔
