Flashcards in Chapter 3 Deck (88)
what are the methods for examining the human brain?
examining autopsy tissue, testing behaviour of patients with damage to certain parts of the brain, recording brain activity through multiple electrodes and through animal studies
what is neuroimaging?
method for studying brain activity and structure by obtaining visual images in awake humans.
what are the three methods of neuroimaging?
CAT or CT scans, MRI and DTI
what are CT scans?
produce clear two dimensional images of brain and other organs, computer combinations of many x rays can produce 3d images that can be virtually sliced.
what is an MRI?
uses a strong magnetic field to produce images of anatomy, Produces 3d images, produce much clearer images than CT scans and does NOT use radiation.
Why are CT scans used?
better at detecting brain diseases or blood vessel abnormalities, detecting many forms of cancer, faster and cost less.
What is DTI?
measures orientation of white matter,
What is an EEG?
examines bran function and allows to visualize na localize it very crudely.
what is a PET?
harmless radioactive substance is injected into a persons blood, radiation detectors are then use to scan the persons brain.
what is an fMRI?
allows for detection in changes of blood flow, does not use radiation and is much faster.
what is the advantage os an MRI over a CT?
less risk and produce better images
what is a neuron?
what is a group of neurons that work together called?
what are glial cells?
cells in addition to neurons that make up the nervous system
what are the categories of glia?
astroglia, oligodendroglia, shwan cells, ependymal cells,, microglia
what do astroglia do?
regulate the flow of blood into different brain regions, absorb or clean up chemicals released by other neurons
what do shwan cells do?
provides a fatty sheath, myelin that insulates axons of neurons
what are ependymal cells?
line the walls ventricles, fluid filled spaces within the brain
what do microglia do?
cleaning up debris and de generating dead neurons
what are the two types of cells in the nervous system?
neurons and glia
what does the central nervous system involve?
motor, sensory, and cognitive information
what is a neurotransmitter?
a chemical released by other neurons
what is action potential?
overal charge inside a neuron differs from the overall charge outside creating a difference in charge across the neuron membrane
what does it mean when a neuron is polarized?
inside of a neuron is negatively charged compared to the outside
what is resting potential?
electrical charge of a neuron at rest
what is selective permeability?
membrane in not equally permeable to all ions
what are sodium potassium pumps?
protein molecules that push out sodium ions and push out potassium ions. (3 sodium, 2 potassium)
what are the two affects of neurotransmitters?
depolarize (inside of neuron becomes less negative) or hyper polarize (inside of neuron becomes more negative)
what is the absolute refractory period?
breif period where a neuron is completely unable to fire again