Biopsych - Brain and nervous system

Question 1

What are the two components of the CNS?

Answer 1

The Brain and spinal cord

Question 2

Which is the name of the nervous system that connects the CNS to the muscles and organs?

Answer 2

The Peripheral nervous system

Question 3

Which type of nerve sends information from the brain towards the organs and muscles

Answer 3

The motor neuron

Question 4

Name 6 components of a neuron

Answer 4

cell body, dendrites, nucleus, axon, myelin sheath, nodes of ranvier, axon terminal

Question 5

Explain the process of synaptic transmission

Answer 5

Synaptic transmission is the process by which one neuron communicates with another. Information is passed down the axon of the neuron as an electrical impulse known as action potential. Once the action potential reaches the end of the axon it needs to be transferred to another neuron or tissue. It must cross over the synaptic gap between the presynaptic neuron and post-synaptic neuron. At the end of the neuron (in the axon terminal) are the synaptic vesicles, which contain chemical messengers, known as neurotransmitters. When the electrical impulse (action potential) reaches these synaptic vesicles, they release their contents of neurotransmitters. Neurotransmitters then carry the signal across the synaptic gap. They bind to receptor sites on the post-synaptic cell, thereby completing the process of synaptic transmission.

Question 6

What is a neurotransmitter?

Answer 6

A chemical messenger that transmits information from onr neuron to another across a synapse

Question 7

Name the four key lobes of the brain and a function of each

Answer 7

temporal - hearing and recognition, occipital - sight, parietal - touch, frontal - emotions

Question 8

What is the component of the limbic system that is thought to regulate aggression? Which key study can you use to support this?

Answer 8

Amygdala and Charles Whitman (the texas shooter who killed his family and students and was found to have a tumour in his brain pushing against the amygdala

Question 9

What is a PET scan? Name a strength and weakness

Answer 9

A PET scan (positron emission tomography) is used to look at function (it measures activity, like an fMRI scan). It involves injecting a radioactive tracer into the bloodstream with a chemical used by the body, such as glucose or water, to see where most of the blood is flowing

The radioactive particle emissions (positrons) from the tracer give signals which are recorded so levels of activity in different parts of the brain can be detected. Greater levels of brain activity appear on the scan as different colours.

:) able to measure activity in the brain, good spatial and temporal resolution (shows where things are occuring and is quick at responding to changes)
:( invasive - radioactive tracer must be injected into the patient, expensive, takes longer than an FMRI

Question 10

What is an FMRI scan? Name a strength and weakness

Answer 10

Functional magnetic resonance imaging (fMRI) is a brain-scanning technique that measures blood flow in the brain when a person performs a task. fMRI works on the premise that neurons in the brain that are the most active during a task use the most energy.

:) non invasive, good spatial resolution (this means it can pinpoint the exact location where activity is occurring)

:( not good for claustrophobic people, poor temporal resolution (this means it is slow and sometimes there is a timelag in the pictures), also not able to identify causation (we may notice that brain activity is low or high but not know why)

Question 11

What is a CAT scan? Name one strength and one weakness

Answer 11

CAT Scans - Uses X rays. Machine rotates around the body to produce cross sectional images through the body which can be put together to produce a 3D image. CAT scans use X-rays to produce images. Image produced depends on density of tissues. Its uses are: Plan radiotherapy treatment and it can identify diseases in lung tissue, bone, soft tissue blood vessels

:) Shows a range of very different tissue types clearly
3D images can be generated, QUICK CT scan is useful for diagnosing internal injuries in trauma victims - a scan only takes a couple of minutes, and it can find problems quickly and save their lives

:( Uses ionising radiation which can cause cancer - if over exposed, limit to the amount of scans you can have - over exposure is harmful, uses higher dose of radiation compared to an X-ray - CAT scans more harmful