3.1.1 CNS Flashcards
(19 cards)
What is the CNS?
The nervous system coordinates the voluntary and involuntary actions of the body by transmitting signals from the brain to the other body parts.
What 3 major parts is a neuron made up of?
A cell body, the dendrite, the axon
What does a cell body in a neuron do?
Contains the nucleus of the cell and that keeps the cell alive.
What does the dendrite in a neuron do?
Collects information from other cells and sends the information to the cell body.
What does the axon do in a neuron?
Transmits information away from the cell body toward other neurons, muscles or glands.
What is the Myelin sheath?
Layers of fatty deposit that provide an insulating layer to the axon and help to speed up the rate of message transmission.
What are the nodes of Ranvier?
Breaks in the axon, the electrical impulse jumps to each section of axon.
What are the terminal buttons?
These bulb shaped structures contain tiny vesicles that store neurotransmitters ready for the next stage of neural transmission.
What are the axon terminals?
They form terminals with other cells passing nerve impulses from the cell body to parts of the body they control or activate- this could be another neuron or a muscle or a gland.
What is the role of a neuron?
Send messages electrochemically.
What is an action potential?
An action potential occurs when a neuron sends information down an axon, away from the cell body. It is an explosion of electrical activity that is created by a depolarizing current.
How does dopamine influence behaviour?
Dopamine is linked to feelings of pleasure and seems to play a part in addiction. It is linked to the reward pathway, which influences motivation, pleasure and attention. Increased dopamine is associated with increased aggression
How does serotonin influence behaviour?
Serotonin is the neurotransmitter for happiness and moods. In it’s normal levels inhibits aggression by preventing stimulation of the amygdala.
What will happen if you have low levels of serotonin?
the amygdala will be more active when stimulated by external events, causing the person to act of their impulsive emotions.
What did Mann find/ do?
Gave participants the drug dexfenfluramine, which depletes levels of serotonin in the brain, to participants. The researchers then used a questionnaire to assess hostility and aggression levels, which were raised after taking dexfenfluramine in males but not in females.
What did Gorkal do/ find?
Used fMRI scans to study activity between the prefrontal cortex and amygdala. Participants who had taken alcohol showed less brain activity. Alcohol interferes with the brains ability to pass on serotonin messages.
What did Dee Higley do/ find?
Studied rhesus monkeys living wild on an island. The researchers used behavioural observations of the monkeys fighting and leaping from trees.
What did Lavine find/ do?
Found that an increase in dopamine levels through the use of amphetamines was associated with an increase in aggressive behaviour, suggesting that higher levels of dopamine correlate with higher levels of aggression.
What did Ferrari et al find/ do?
They allowed a rat to fight every day for 10 days at approximately the same time. This was done by introducing an “intruder rat” into the test rat’s cage. On the 11th day, no intruder rat was introduced. The researchers measured the levels of serotonin and dopamine in the test rat’s brain. The test rat’s dopamine levels had increased and serotonin levels decreased, because it was anticipating a fight. The rats brain chemistry altered to prepare for an aggressive act.
