PSYC 2 Midterm

sensations

fundamental, elementary components of experience (sight, smell, touch, hearing, taste)

perceptions

process used to arrive at a meaningful interpretation of sensations

1. reception (sensory receptors)


2. transduction (changing stimulus energy into electrochemical neuronal change)
3. coding (correspondence between stimulus and neuronal activity)

what three processes happen prior to our senses taking action?

after having a spike enter the frontal lobe we learned there was mental changes after damage to his brain

what did we learn through Phineas Gage?

dualism

mind and body are separate entities

parallelism

nonphysical mind is parallel to physical brain/body (DO NOT INTERACT WITH EACH OTHER)

interactionism (Rene Descartes)

believes mind and brain are working together through pineal gland

monism

mind and brain/body are the same thing

1. materialism
2. mentalism
3. emergent property position
4. identity position

what are the four concepts that navigate the no mind? no matter possibility to the mind body/brain debate?

materialism

everything is material, everything is physical (mind is considered a physical entity)

mentalism

everything’s mental, nothing is material. (only the mind exists: everything is a figment of our minds)

emergent property position

mind emerges from some brain activity

identity position

mind is brain activity (mind unequal to brain)

bones, stomach, or heart

historically what part of the body was believed to control behavior?

cardiac hypothesis (aristotle)

heart is involved in controlling behavior because it is warm

brain hypothesis (hippocrates, plato, galen)

brain is involved in behavior; elaborated on by galen who was a physician for gladiators and saw a lot of brain trauma

cerebral spinal fluid

brain controlled behavior by interacting with or moving fluid in the ventricles

what REALLY controls behavior

electrical impulses

how does the brain control behavior?

consciousness

awareness of one’s desires

plasticity

brain has some aspect of interacting with changing environment, it is malleable

cerebellum is a posterior inferior part of the brain

in terms of location/direction where is the cerebellum

neural net hypothesis (reticular theory)

nerve system is a continuous mass of tissue based on cardiovascular system

golgi stains

what helped created the cell hypothesis?

cell hypothesis

neurons are individual cells with actual gaps

neurons

cells that form the basic unit of the nervous system

neurons and glia (non-neural cells)

what are the two main types of cell within the brain?

nucleus

main factory for DNA replication

mitochondria

powerhouse of the cell (ATP)

golgi body

transporting system (packaging and moving)

endoplasmic reticulum (smooth ER and rough ER)

protein and fat synthesis

lysosomes

breaking down stuff and removing anything we don’t want in a cell there

cell membrane

two layers of phospholipids (lipid bi-layer)

phospholipid head = hydrophilic (loves water)

lipid tail = hydrophobic (hates water)

middle of cell membrane = hydrophobic

how does the cell membrane look on the inside and out in terms of its lipids?

transmembrane protein

able to travel within the entire scope of the cell membrane

cell channel

group of proteins coming together going from outside to in forming a pore through the membrane

ion channels

ions using protein membranes to travel

neurons

neuroglia

what are the types of neural cells in the nervous system?

neuroglia

for support, regulation, and protection of neurons

\-epithelia cell

\-connective tissue cell

\-pukinje cell

\-business factor

how do you identify a neuron?

\-dendrites

\-soma

\-axon

\-axon terminal

what are neurons identifiable characteristics?

dendrites

branchlike structures that receive information from other neurons

soma (cell body)

where information is submitted

axon

carries information away from neuron

myelin sheath

fatty tissue that helps speed up the information going through an axon

motor neuron (cell body in spinal cord)

what is the biggest neuron?

afferent axon (sensory)

admission into spinal cord

efferent axon (motor)

exit the spinal cord

axon terminal

has synapses which releases neurotransmitters to spinal cord or brain depending on neuron

multipolar

bipolar

pseudounipolar

what are the classifications of neurons based on form?

anaxonic neurons

no anatomical clues to determine axons from dendrites

multipolar neuron

multiple dendrites to single axon

*most common type*

bipolar neuron

two processes coming off cell body with one dendrite and one axon

*only found in eye, ear, and nose*

unipolar (pseudounipolar) neuron

single processes coming off cell body, giving rise to dendrites and axon

sensory (afferent) neurons

transmit sensory information from receptors of PNS towards the CNS (usually unipolar, few bipolar)

motor (efferent) neurons

transmit motor info from CNS to effectors (muscles/glands) in the periphery of the body ALL ARE MULTIPOLAR

association (interneuron)

transmit information between neurons within the CNS; analyze inputs, coordinate outputs ALL ARE MULTIPOLAR

amyotrophic lateral sclerosis

when we can’t send messages to muscles properly or as effectively motor neurons degenerate because they are not receiving that electrical signal

astrocytes

wrap synaptic terminal to help communication and increase in number after brain injury

radial glia

helpful during fetal development and is associated with blood brain barrier

microglia

help when neurons die by chomping up dead neural debris to create efficient synaptic communication

oligodendrocytes and schwann cells

create neurilemma and myelin sheaths around most axons on peripheral nervous system

satellite cells

support groups of cell bodies of neurons with ganglia

Na, K, Ca (sodium, potassium, calcium)

what ions within neurons are positive?

when transmembrane proteins group together (4-6 at a time) they create pores called ion channels that are selective to specific ions

how can ions cross the membrane?

1. diffusion (concentration gradient): wanting to go from high concentration to low to maintain homeostasis
2. electrostatic (electrical gradient): when a side of membrane is positive, negative ion will attract to it

what forces will push an ion across an open ion channel?

\-65 (-70) mV

\-unequal distribution of ions

what is the resting membrane potential? why do we have it?

sodium since it is the only one that wants to come into the neuron during both diffusion and electrostatic interactions

what forces are acting on ions?

due to the permeability of cell membrane

\-sodium is semi-permeable

\-potassium and chlorine is permeable

why is there an unequal distribution of ions?

Na+/K+ pump

pumps out 3 Na+, pumps 2 K+

depolarization

make inside of cell less negative (go up toward 0) meaning more cations entering the cell and anions leaving the cell

hyperpolarization

inside of the cell becomes more negative with cations leaving the cell and anions entering the cell

axon hillock

lead up of the soma to the axon

\-60 millivolts

what is the threshold of excitation in millivolts?

repolarization

going back down to resting potential which leads to a portion of hyperpolarization

voltage gated Na+ channels open up and Na+ enters the cell

in the meantime voltage gated K+ channels open, K+ leaves cell repolarizing it

what happens during action potential?

action potential would not occur, no neuron would fire (e.g. drugs used for surgeries so no pain perception)

what would happen if we were given drugs that block sodium channel?

one neuron would not be able to fire again (e.g. muscles contract but don’t relax = cramps)

what would happen if we were given drugs that block potassium channels?

refractory period

no matter what type/strength of stimulus you cannot induce another action potential

relative refractory period

possible to induce another action potential WITH BIGGER STIMULUS

NO. axon that has never had myelin can work no matter what; axon that loses its myelin results in multiple sclerosis

is an axon without myelin the same as an axon that lost myelin?

multiple sclerosis

slows or stops action potential causing poor motor coordination and cognitive disability

temporal summation

several impulses from one neuron over time

EPSP/IPSP (excitatory/inhibitory post synaptic potential)

loses its strength as it travels, contributes eventually to an action potential occurring at the axon hillock

spatial summation

impulses from same several neurons at a time

ESPSs and IPSPs

what helps us conclude the probability of action potential firing?

synaptic cleft

presynaptic neuron

postsynaptic neuron

what are the three properties of synapses

chemical

are messages within the brain chemical or electrical?

neurotransmitters

chemicals that send messages

synthesis

packaging

release

receptor action

inactivation

IN ORDER what is the chemical synapses process to release neurotransmitters?

synthesis

classical neurotransmitters: synthesized in terminal button

peptide neurotransmitters: synthesized in soma will help of ribosomes

packaging

classical neurotransmitters: packaged into vesicles with phospholipid bilayer

peptide neurotransmitters: packaged in secretory granules

release

release from presynaptic neuron docking with other proteins

active zone

has docking proteins and calcium ion channels

calcium ion channels

causes vesicles to fuse with cell membrane and enters the presynaptic neuron

exocytosis

as synaptic membrane fuses to cell membrane, neurotransmitter gets pushed out into synaptic cleft

receptor activation

neurotransmitter binds to receptor like key and lock

ionic receptors

fast, short-lived, gated ion channels

neurotransmitter → finds receptor → opens ion channel

metabotropic receptor

slow longer lasting process that uses a second gate process of G-protein

*helpful for bigger effects*

1. amplify the signal
2. have longer lasting effects
3. can affect cellular processes far from the receptor
4. coordinate many different types of cellular responses

what are the advantages of metabotropic receptors?

myasthenia gravis

what disease is caused by blockage of postsynaptic receptors?