Topic 8B : The Brain, Behavour & Disease Flashcards
what is the largest part of the brain
cerebrum
what makes up the cerebrum
left and right cerebral hemispheres
cerebral cortex
the thin outer layer of the cerebrum
cortex has a large surface area so its highly folded to fir into the skull
in what is the cerebrum involved
vision, learning, thinking, emotions and movement
what part of the cerebrum is involved in vision
back of the cortex
what part of the cerebrum is involved in thinking
front of cortex
where is hypothalamus located
beneath the middle part of the brain
what is the role of the hypothalamus
maintenance of body temp at normal level as well as producing hormones that control the pituitary gland.
where is the medulla oblongata located
at the base of the brain, at the top of the spinal cord
what is the role of medulla oblongata
controls breathing and heart rate
where is the cerebellum located
underneath the cerebrum and it also has a folders cortex
what is the role of the cerebellum
coordinates movement and balance
what are the different types of brain scanners
computed tomography
magnetic resonance imaging
functional magnetic resonance imaging
positron emission tomography
how are CT scans used to investigate brain structure and function
the scan shows major structures in the brain but it doesn’t show the function.
if the scan shows a diseased or damaged brain structure and the patient has lost some function, the function of that prt of the brain can be worked out
how are CT scans used to diagnose medical probelms
they can show damaged or diseased areas of the brain
why are CT scans dangerous
they use x-rays which can cause mutations in DNA leading to cancer
however, the risk of developing cancer is very low
how are MRI scans used to investigate brain structure and function
they give higher quality images for soft tissue types and better resolution between tissue types for an overall better resolution final picture.
they allow you to clearly see the difference between normal and abnormal brain tissue.
brain function can only be worked out by looking at damaged areas.
how are MRI scans used for medical diagnosis
they show damaged or diseased areas
what do MRI scans use
strong magnetic fields and radio waves to produce cross-section images
how are fMRI scans used to investigate brain structure and function
they give detailed, high resolution picture of the brains structure but also used to research the function of the brain.
they show changes in brain activity as they happen.
how are fMRI scans used for medical diagnosis
they show damaged or diseased areas of the brain and allow you to study conditions caused by abnormal activity in the brain
how are PET scans used to investigate brain structure and function
a radioactive tracer is introduced into the body and is absorbed into the tissues.
the scanner detects the radioactivity of the tracer.
the scan produces very detailed pictures that can be used to investigate both structure and function at the same time.
how are PET scans used for medical diagnosis
they show areas in the brain that are unusually inactive or active so they are useful for studying conditions that change the brains activity.
habituation
the reduced response to an unimportant stimulus after repeated exposure over time
what is the purpose of habituation
so animals don’t waste energy responding to unimportant stimuli and can spend more time doing other activities for their survival
describe habituation in terms of electrical impulses
repeated exposure to stimuli decreases the amount of calcium ions entering the presynaptic neurone due to calcium channels being less responsive.
the decrease in influx of calcium ions means less neurotransmitters are released from vesicles into synaptic cleft so fewer neurotransmitters can bund to receptors in postsynaptic membrane.
fewer sodium ion channels on postsynaptic membrane open so theres a reduced chance of threshold for an action potential being reached on the postsynaptic membrane.
fewer signals are sent to the effector to carry out the response.
visual cortex
an area of the cerebral cortex at the back of the brain
what is the role of the visual cortex
to receive and process visual information from either left or right eye.
ocular dominance columns
neurones grouped together in columns
right ocular dominance columns
when neurones receive information from the right eye
left ocular dominance columns
when neurones receive information from the left eye
who discovered the structure of the visual cortex
hubel and wiesel