Physio psych test 1

overt

behavior that can be observed by a viewer

can be quantified

thoughts on the brain fxn 2000 years ago

they believed the brain was a radiator, purpose was to cool down teh temperature of blood

other words for physiological psych

biopsychology, psychobiology, behavioral neuroscience

physiological psych def

branch of psychology that studies the relationship btwn behavior and the body (brain)

neuroscience

multidisciplinary study of nervous system→ all aspects

mind brain problem

what is the relationship btwn the mind and brain? Do they belong to the same world or different worlds?

2 views: Dualism and Monism

Dualism

mind and brain belong to diff worlds

(non physical vs physical world)

mind controls the brain by “interacting” with it

monism

mind and brain belong to same world

subsets

materialism- mind and brain belong to physical world

Idealism- mind and brain belong to the metaphysical world

Rene Descartes

17th century philosopher

proposed the 1st sophisticated model of NS and brain

Dualist

Claimed body is a machine→ want to discover how it works

claimed that mind interacts w body at pineal gland

emphasis on physical explanation of behavior

Descartes Hydraulic model

Descartes Hydraulic model

assumes brain to be like complex plumbing system with pipes under pressure

nerves are hollow tubes where fluid flows

pineal gland pumps fluid through brain and nerves

believe that mind (soul) tilts the pineal gland to direct fluid to specific nerves-> specific muscles inflate (move)

testable model!

galvani

1700s

found that nerves are like wires conducting electricity in frogs→ disproved descartes hydraulic model

helmholtz

1800s

asked why nerve conduction speed is only 90ft /sec

localization - specific brain areas carry out specific fxns

phineas gage

gene

unity of heredity

found on chromosomes

portion of chromosome

paired→ alleles

dominant alleles

produce effects regardless of which allele it is paired with

recessive alleles

produces its effects only when paired with the same recessive allele on the other chromosome

unless X linked→ since y is much shorter and there may not be corresponding allele

codominance

blending of the effects of both alleles, both expressed

effects of gene pairs

characterisitics determined by several gene pairs

neurons

specialized cells that receive info and send it to other cells

86 billion in brain

motor

sensory

interneurons

motor neurons

output

receives info from other neurons and carries info to muscle or gland

CNS to PNS

sensory neuron

input

receive sensory information and carries info to other neurons

PNS to CNS

Unipolar- one projection

bipolar- 2 projections

interneuron

connect one neuron to another in a particular part of the CNS

glial cells

oligodendrocytes and schwann cells

oligodendrocytes

build myelin around axons in CNS

branch to multiple neurons

schwann cells

build myelin sheath around axon in PNS

wrap self around 1 mm segment of 1 axon at a time

channel proteins vs protien pumps

channel proteins- do not involve atp

protein pumps- involve ATP and active transport

polarization

diff in electric charge (voltage) btwn inside and outside the cell

what causes resting potential

unequal distribution of ions on the 2 sides of the membrane

we see more Na on which side of the cell?

outside, more positive

we see more K on which side of the cell?

inside, more negative

why do we have differences in concentration across the Pm?

Na+ channels: closed at rest

K+ channels: leaky at rest

Na-K pump move ions unequally

K ions: concentration and electrical pull

Conc: want to move outside cell→ move from high to low conc of ion

electrical: want to move inside cell to make cell less negative

Na ions: concentration and electrical pull

Conc: want to move inside cell→ move from high to low conc of ion

electrical: want to move inside cell to make cell less negative

depolarization

rapid increase in mem potential→ more positive

Na rushes into cell making inside more positive

repolarization

starts when Na channels close and K channels open letting K go out of cell, making cell more negative

action potential

abrupt depolarization and temporary reversal of the usual polarization of the membrane

allows neuron to send signals over long distances

steps of an AP

1) threshold reached, Na channels open and Na rushes inside cell making it more positive → depolarization

2) Na channels closed and K channels opened letting K rush outside cell, making it more negative → repolarization

3) K channels close, mem potential goes below RMP

4) Na K pump restores membrane to RMP

refractory periods

absolute and relative

absolute refractory period

period of time where Na channels cannot reopen and action potentials cannot be produced

from peak of depolarization to return of RMP

relative refractory period

only stimuli stronger than usual can produce an AP

hyperpolarization below RMP to depolarization back to RMP

rate law

intensity of a stimulus is encoded by the rate of AP

where do AP occur?

axons, axon hillock is integration center

qualities of AP

strength is independent of intensity of stimulus (all or none)

nondecremental- do not decay as they travel

graded potentials

can occur in axon dendrites and soma

stregth depends on intensity

decay as they travel

saltatory conduction

when action potential jumps from node to node btwn myelin sheath

chemical synapses

vesicles carry NTs, empty into synaptic cleft, taken up by mem channels

Ca triggers vesicles to release NTs

exocytosis

receptor sites have lock and key mech that match with NTs

EPSP

partial depolarization of postsynaptic membrane

makes AP more likely to occur in the post synaptic neuron

IPSP

hyperpolarization of postsynaptic mem

makes AP less likely to occur

temporal summation

combines PSPs arriving from the same neuron

spatial summation

combines PSPs occuring simultaneously at diff locations on dendrites and soma

diff neurons w

what happens to Nt left in synaptic cleft?

molecules reabsorbed by transporters in terminal and repackaged into vesicles→ reuptake

some cases they are broken down into simpler components by enzyme→ inactivation

other cases they are 1st absorbed by glial cells

autoreceptors

special proteins in the presynaptic mem that sense the amt of NTs in the cleft→ regulate the amt of NT in cleft

Acetylcholine

transmitter at muscles

involved in learning

monoamines

serotonin

Dopamine

norepinephrine

epinephrine

serotonin

involved in mood, sleep, arousal, aggression, depression, OCD and alcoholism

monoamine

dopamine

contributes to mvmt control

behavior modulation- > reward pathways → addiction

schizophrenia and parkinsons involved in dysregulation

monoamine

norepinephrine

released during stress

inc arousal and attentiveness

dec involved in depression

monoamine

epinephrine

a stress hormone

minor role as nt in brain

monoamine

amino acid nts

glutamate

GABA

glycine

glutamate

pricipal excitory NT in brain and SC.

involved in learning

dysfunction→ schizophrenia

AA

GABA

predominant inhibitory NT

receptors respond to alcohol and benzos

deficiency→ epilepsy

AA

Glycine

inhibitory NT

convulsions and death with introduction of strychnine which affects NT activity

AA

neuropeptides

endorphins

substance P

neuropeptide Y

endorphins

neuromodulators that reduce pain and enhance reinforcement

neurop

substance P

pain

neurop

neuropeptide Y

initiates eating

neuroP

gas nt

nitric oxide

nitric oxide

retrograde

viagra

gas nt

agonist

chemical that mimics or inc the effect of a NT

morphine → mimics endorphins

antagonist

a chemical that blocks the effect of a nt

Curare blocks ACh receptors at the muscles

nerve

bundle of axons in PNS

tract

bundle of axons in CNS

forebrain

cerebral hemispheres

corpus callosum

thalamus- inferior to corpus callosum, posterior to hypothalamus

hypothalamus- anterior to thalamus

gray matter

unmyelinated axons and cell bodies

white matter

myelinated axon pathways

lobes of cerebrum

frontal

parietal

temporal-impt for hearing, dorsal component is suditory cortex

occipital

insula- inner, involved in sense of taste

central sulcus

posterior border of frontal lobe

lateral fissure

separates frontal and parietal lobes from temporal lobe

parietal-occipital sulcus

separates parietal lobe from occipital lobe

midbrain

inferior to thalamus

hindbrain

pons- inferior to midbrain

medulla- inferior to pons

cerebellum- posterior to medulla

neuraxis

an imaginary line drawn through the center of the CNS from the bottom of the spinal cord to that front of the forebrain