SOS-304-OL009
WA 2
1b. List and describe briefly the major structures of the brain, as presented in your textbook, including the function of those elements that are most related to psychoactive drug reaction.
The first layer of the brain is the cortex which covers the top and sides of the brain. This area controls reasoning and language, and this area will be less active when under sedative drugs. The basal ganglia are located underneath the cortex and it is made up of by the striatum. The striatum controls muscle tone and is part of the dopamine pathway which is a potential transport highway for psychoactive drugs. The hypothalamus is at the base of the brain and serves as liaison between the brain and pituitary gland. The pituitary hormonal output is involved in behaviors such as feeding and temperature regulation. The limbic system affects emotion, location memory, and physical activity. Along the brain stem are the medulla, midbrain, and pons from which contain the bulk of neurons that create dopamine, norepinephrine, and serotonin. The lower brain stem controls vomiting and respiratory functions. If affected, the respiratory function can be suppressed by drugs.
1c. Describe the life cycle of a typical neurotransmitter.
A cell membrane with the uptake of a particular precursor absorbs amino acids to create a neurotransmitter. The amino acids undergo synthesis with a reaction with enzymes to become a neurotransmitter. Once created, the neurotransmitters are stored in vesicles until they are released into the synapse. Once released, the neurotransmitters will attempt to attach to the membrane of neurons. If the neurotransmitter does not make it to the neuron, then it will either absorb in the originating cell or be metabolized within the synapse.
2b. Differentiate between drug disposition tolerance, behavioral tolerance, and pharmacodynamics tolerance, and provide reasons why these concepts should be taken into account when determining