Chapter 3 Flashcards
what is the most complex thing in the universe?
the brain, 1.36kg, gelatinous
what kind of psychologists deal with the brain?
neuroscientists
Neuroscientists study the nervous system. What is the nervous system?
a communication network consisting of nerve cells, both inside and outside the brain and spinal cord.
Definition of Neurons
a bundle of nerve cells specialized for communication. There are tens of thousands of connections.
Definition of Dendrites
Part of the neuron that are extensions for receiving receptor sites.
Definition for Nucleus/ Cell Body
Part of the neuron that renews and manufactures proteins; receptor sites
What are glial cells comprised of?
Astrocytes
What make up the Blood Brain Barrier?
Astrocytes
What is the Blood Brain Barrier?
coat of blood vessels
protects brain against disease and bacterial infections.
What causes neuronal communication in neurons?
ion channels causing change in charge.
Change in charge causes a potential difference
(the flow of Na and K ions)
potential difference
charge difference between the inside and outside of the neuron
What does potential difference cause?
Resting Potential
What is resting potential?
electrical charge difference across neuronal membrane.
What is the charge difference in resting potential?
-60mV
The inside and outside of the neuronal membrane is described as…
polarized (inside more negative than the outside)
What is Action Potential?
abrupt electrical change
- charge becomes depolarized
What does action potential result in?
The release of neurotransmitters
Electrical charges travel down the……?
axons.
Action Potential is described as an “all or….”
all or none – always full strength
where does action potential occur?
trigger zone (near cell body) and continues along axons.
when the membrane because depolarized, what is crossed?
the treshold potential.
What is the absolute refractory period?
the brief interval which makes impossible to fire another AP
rate of fire for neurons
over 100x a second.
What limits the maximal firing rate of neurons?
ARP (absolute refractory period)
What add together to cancel out charges?
EPSP or IPSP
What does EPSP do to the cell?
bring cell closer to threshold to fire AP
IPSP
moves cell farther from treshold to fire AP
What is the myelin sheath comprised of?
glial cells insulate axons to and aids in speed up signal transmissions
What is the node of ranvier?
gaps in myelin sheath – allows AP to jump.
how does the myelin sheath connect to MS?
in multiple sclerosis, own cells are attacking myelin.
Neurotransmission process
- NT synthesis
- NT storage in vesicles
- NT release into synapse
- NT bind to receptor sites on dendrite
- removal of NT from synapse (degradation or recycling)
different neurotransmitters have different effects on the nervous system…
they can excite or inhibit
what do neurons use to send information?
electrical activity
Electroencephalogram
measures brain generated electrical activity
- electrodes on face
Neuroimaging is either one of two main categories..
brain structure or brain function
two neuroimaging techniques to see brain structure
MRI and CT scan
two neuroimaging techniques to see brain function
fMRI
PET
MEG
TMS
CT scan
big rotating machine around head, 3D X Ray of brain
MRI
whole body, magnetic field study,
measures energy released by hydrogen atoms
PET - Positron Emission Tomography
red, white, green, and blue pictures
how is brain changing in response to different emotions or activities
-
what does the PET measures?
consumption of glucose after being injected with radioactive glucose
- has a 4-6 second delay
fMRI -functional magnetic resonance imaging
measures changes in blood oxygen level
- better time than PET
plasticity over development steps
- growth of dendrites
- synaptogenesis
- pruning
- myelination
what is pruning?
death/retraction of axons (70%), meant to streamline communication
- can cause infantile autism because too many are killed off.
how does being exposed to rich environments support the theory of neural plasticity?
think about the mice. Changes occur as we learn, synapses perform better with new stimuli
stem cells
potential to differentiate into variety of specialized cells
neurogenesis
creation of new neurons in the adult brain
