Chapter 2 Psych

nervous system

network of all cells that carries info to and from all parts of the body

neuron (what's its charge)

a cell that sends messages

• charged at -70 mV (at rest)

  • the inside of the cell is 70mV more negative than the outside

dendrite

• RECIEVES messages from other cells

• attached to the soma

soma

neuron’s cell body that contains the nucleus and keeps entire cell alive

axon

• CARRIES messages to other cells

• branches into axon terminals

axon terminals

communicate with other nerve cells

Label each part of the neuron

myelin

• layer of fatty substances

glial cells

• also a significant cell in the brain (other than neurons)

• homeostasis in the nervous system

• partner cells with neurons

oligodendrocyte

• type of glial cell

• produces myelin for neurons in the brain and spinal cord

schwann cells

• type of glial cell

• produce myelin for the neurons of the body (peripheral nervous system)

• damaged nerve cells can reconnect and repair themselves with the myelin being produced in these types of cells (can’t in oligodendrocytes)

tracts

myelinated axons in the central nervous system

nerves

bundle of myelinated axons in the peripheral nervous system

myelin

• serves as insulation and protection of the neuron

• speeds up the process of neural messages traveling down the axon

nodes

• spaces not covered by myelin

• electrical impulses are regenerated at each node and jumps to node to node

  • only need to send impulses here

    • completely skip over myelin

electrical potential

• outside positive ions are trying to come inside but can’t because of semi permeability

• inside ions are negative and want to leave and push against the cell membrane

• then there is an attraction between the outside positive ions and negative inside ones pulling together

action potential

• electrical potential is not in rest anymore but action

• when the positive ions (sodium) come rushing in and the neuron becomes more positively charged and do depolarization (become more positive)

  • small positive ions (potassium) leave to try and remove some positivity and do repolarization (return to normal state)

• impulse is sent down once those channels open

• SEQUENCE of ion channels closing and resetting

• this reversal happens at the axon hillock

axon hillock

• closest to the stoma

• where the first ion channel will open

hyperpolarization

• there is more negative ions inside the neuron than when started

  • too much potassium leaves and makes it negative

• goes beyond original resting potential

neurotransmitters

a chemical suspended in a synaptic vessel

(neuro - inside a neuron, transmitters - will be transporting a message)

• merge into cell wall to be released from the axon terminals

synapse

• fluid filled gap

• composed of dendrite, gap, and axon terminal

presynaptic membrance

vessels at the end of the axon

postsynaptic membrane

surface of dendrite next to axon

excitatory synapse

turning cells on (by the effect of the neurotransmitter that is going onto the receptor site)

• the cell becomes more positive inside and then it is more likely to fire

inhibitatory synapse

turning cells off (by the effect of the neurotransmitter that is going onto the receptor site)

• opens ion channels that let potassium out, making the inside more negative and causing hyperpolarization

antagonist

blocks/reduces effects of neurotransmitter

agonist

mimics of enhances the effects of a neurotransmitter

acteylcholine

• first neurotransmitter

• helps contract heart muscle

• if blocked then acts like curare

glutamate

NS’s major excitatory neurotransmitter

endorphins

pain controlling neurotransmitter

reuptake

neurotransmitters are taken back into the presynaptic synapse

SSRI

• keep the serotonin in the synapse longer (inhibit the reuptake process and from the serotonin from going back up)

experimental control

control group, nothing is manipulated

more negative or positive in a RESTING neuron?

more negative :)

random SAMPLING

prior to experiment you are choosing people

random assignment

choosing randomly WITHIN your group

standard normal distribution

• if make random groups they will normally distribute themselves and the groups will be no different

ethic principles

a. beneficence and nonmaleficence (we shouldn’t hurt people, try to benefit those we are working with)

b. fidelity and responsibility (trying to have a good relationship)

c. integrity (be as truthful as possible)

d. justice (everyone should be able to have access to the study, not just for the wealthy)

e. respect for people’s rights and dignity

f. deception = if it is justified by significant science then you can deceive people.

How is intensity conveyed?

• speed of firing

• # of neurons firing

presynaptic vessel

• the neurotransmitters that are still in their vessels inside the axon terminal that have not yet merged with the cell membrane

serotonin

• sleep, impulsivity, aggression, mood, appetite

dopamine

• learning, attention, movement

• too little

  • parkinson’s

• too much

  • schizophrenia

• controls involuntary movement