The brain and neuropsychology Flashcards
What is the nervous system?
It is a complex network of nerve fibres and nerve cells which passes information around the body.
What are the first divisions of the nervous system?
- The Central Nervous system.
- The Peripheral Nervous system.
What is the CNS?
It is the central nervous system, which makes decisions about movement or other activities.
What structures does the CNS consist of?
- The brain.
- The spinal cord.
What is the PNS?
It is the peripheral nervous system, which is the network of nerve fibres connecting the various parts of the body with the central nervous system. It is made up of the SNS and the ANS.
What are the two sections of the PNS?
- The Autonomic nervous system.
- The somatic system.
What is the SNS?
The Somatic nervous system, which is the network of myelinated sensory and motor neurons that carry sensory information to, and instructions for movement from, the central nervous system.
How does the SNS pass information?
It is a network of nerve fibres that run throughout our body, and sense receptors such as those in our skin, muscles and internal organs. The nerve fibres pass information to and from the CNS using sensory and motor neurons, and they are myelinated.
What does myelinated mean?
They are covered with the myelin sheath, a fatty wrapping, which helps the messages to travel quickly.
What is the ANS?
It is the autonomic nervous system, which is a network of un-myelinated nerve fibres running through the body and connecting the senses and internal organs with the central nervous system.
What is different about the ANS in comparison with the SNS?
It transfers information slower because its nerve fibres are not myelinated.
What kind of information does the ANS respond directly to?
Stressful or emotional events.
What is the function of the central nervous system?
It is to coordinate incoming sensory information and to respond to it by sending appropriate instructions to the other parts of the nervous system.
What is sensory information?
It is information that is picked up by the sense organs of the body and passed on to the central nervous system.
Why does the central nervous system contain our store of knowledge, habits and other kinds of learning?
So we can combine our past experiences with what is happening right now and make relevant decisions.
So what are the three main parts of what the central nervous system does?
- Thinking.
- Memory.
- Decision-making.
What are the functions of the SNS?
It collects information, both from the outside world and from our internal organs, and passes it on to the central nervous system. It also receives instructions from the central nervous system, for big movements or small reactions to stimuli. In general, it is what allows us to feel and move.
What are the functions of the ANS?
It acts more slowly, because the neurons are un-myelinated, and because it is concerned with moods and feelings. It deals with the many different emotions that we feel, responds to threats and is also involved in major changes to the body like those which happen during puberty or pregnancy.
What are the two divisions of the ANS?
- The parasympathetic division.
- The sympathetic division.
What is the parasympathetic division responsible for?
It allows the body to store up energy when we are not ‘under threat’.
What is the sympathetic division responsible for?
It sets off arousal, which can be mild like a feeling of anxiety, or extreme like the fight or flight response. It is activated when we are ‘under threat’.
With these two divisions in mind, what part of the nervous system is the ANS?
It is the part of the nervous system that helps us react quickly and strongly in an emergency. It has lots of other functions too: for instance, it controls breathing and digestion, and is the main link between the brain and the endocrine system.
What does the endocrine system comprise of?
A set of glands in the body that releases hormones into the bloodstream.
What does adrenaline do?
It activates the heart, making it ready for action.
What is the first step after the body detects a threat?
You will need all the energy and strength you can manage, so that you can survive. There is no point in keeping reserves of energy, if it means you end up dead, so this is where the ANS steps in.
What does the ANS do when it detects a threat?
- It sends messages all over your body to make you ready for action. This is called the fight or flight response.
- It switches from parasympathetic activity to sympathetic activity during the fight or flight response.
What is the switch from the parasympathetic to sympathetic activity so efficient?
We breathe more deeply, our heart rate increases, and our blood carries more oxygen. We sweat more to cool our muscles, the pupils of our eyes dilate, and our digestive system changes so we metabolise sugar quickly, for instant energy. We also prepare for possible injury: the blood thickens so it clots more quickly, and the brain produces natural painkillers called endorphins.
What other system are these and other changes controlled by?
The endocrine system, which releases adrenaline into the body to keep the aroused state going. It also helps to make us as efficient as possible, so we can fight or escape successfully.
Under normal circumstances, which division is in control of the body?
The parasympathetic division.
But if a threat is detected, what happens to the divisions in the body?
The parasympathetic division switches to the sympathetic division and the body prepares for action.
What happens once a threat has gone away in terms of the divisions?
The ANS switches back to having the parasympathetic division in control.
What part of the nervous system switches between the divisons?
The Autonomic nervous system.
What are some bodily changes that can be observed when the body switches to the sympathetic division?
- Pupil dilates.
- Salivation changes.
- Heart rate increases.
- Lungs expand.
- Stomach contracts.
- Bladder dilates.
- Adrenal glands are stimulated.
What is the James-Lange theory of emotion?
One of the founding fathers of psychology, William James, noticed how the fight or flight reaction happens. He gave the example of tripping as you go downstairs, and saving yourself from falling by grabbing the banister. Your reaction happens very quickly. But afterwards, you feel your heart speeding up, you breathe deeply, you start sweating - in short, arousal kicks in. And it is then, James said, that you begin to feel scared. You experience the changes felt by your body and then interpret these as the emotion.
What did William James believe?
That our emotions are really us perceiving physical changes in the body. The brain makes sense of these changes by concluding that we are feeling certain emotions.
What is the phrase by William James that explains his theory?
‘We do not weep because we feel sorrow: we feel sorrow because we weep.’
What is an evaluation of the James-Lange theory of emotion?
- Not all researchers have not been convinced that the theory is an accurate explanation of how we experience emotional arousal. This is especially the case because for the theory to be correct, there would need to be separate and distinctive patterns of physiological arousal and a different pattern for every different emotion we experience. Researchers have found this is not the case which undermines the James-Lange theory of emotion.
- Schachter and Singer suggested it is not only physiological changes that occur when we perceive a threatening situation, but there was also a cognitive component. The argument is that when we experience stimulation in the ANS, we also interpret the situation we are in. It is these two things that lead to the emotion we then experience. This idea is supported by research evidence which shows physiological change and cognitive interpretations both lead to emotional experiences.
- The James-Lange theory did promote a great deal of research and recognised the importance of the ANS in emotional experiences.
What is emotion?
The moods or feelings that a person experiences.
How does your brain work?
With electricity. Your nervous system is made up of special cells which exchange chemicals to generate small electrical impulses. This is how they pass information around.
What are these special cells called?
Neurons.
What is a neuron?
A specialised nerve cell which generates and transmits an electrical impulse.
What are the three different types of neurons?
- Sensory neurons.
- Motor neurons.
- Relay neurons.
What is a sensory neuron?
A nerve cell that picks up information from sense receptors and carries it to the CNS.
What is an image of a sensory neuron?
What explains the image of a sensory neuron?
They have a cell body with two ‘stems’ on either side. One end receives information from the sense organs, and the other passes it on. Each stem ends in small branches called dendrites which spread out and connect with other cells.
What is a motor neuron?
A nerve cell that takes messages from the CNS (brain) to muscles to cause them to move.
What is an image of a motor neuron?
What explains the image of a motor neuron?
The messages they transfer begin in the spinal cord, and a long axon, or ‘stem’, leads to the muscle, where it divides into a spread-out set of dendrites called the motor end plate, which connects with the muscles.
What is a relay neuron?
It is a nerve cell that passes messages within the CNS.
What is an image of a relay neuron?
What explains the image of the relay neuron?
It has a cell body entirely surrounded by dendrites. These neurons make millions of connections between each other, the sensory neurons, and the motor neurons.
What is an example of an activity that involves all three types neurons?
If you tap a ruler right below your knee. When your knee was tapped, it stimulated sense receptors which generated an electrical impulse. That impulse was picked up by the sensory neurons and carried to the CNS - in this case, to your spinal cord. There, it was passed on to the relay neurons, which in turn stimulated motor neurons, which carried electrical impulses to your leg muscles, causing your leg to kick out. It was an automatic reaction, known as a reflex. the fatty myelin sheath covering the axons helps the electrical impulse to travel fast, so you react quickly.
What is an image that represents the reflex arc?