Psych Chapter 2

neuron-- functional unit of the NS responsible for receiving and transmitting electrochemical information

the basic building block of the NS

each one sends and receives signals

dendrites: branches that stem out from cell body and receive messages

axon: signal is sent down here to next neuron

cell body: has a semi-permeable membrane, nucleus, and mitochondria

myelin sheath: fatty substance that allows rapid transmission of messages

axon terminal branches: smaller branches coming off of the axon

Axon terminal buds: cap the branches

vesicles: inside the buttons and have NT that can be released

Neurotransmitter: cross the synapse, land on receptor sites of dendrites of next neuron

receptor sites

• electrical and chemical language
• neurons transmit info--electrical messages received by the dendrites and cell body
• messages are passed along the axon in the form of a neuron impulse or action potential

outside of the membrane is positive and inside is negative

sucks the positive ions in, depolarizing the membrane

special gates that the positive ions go into

making the inside more positive

action potential either happens or doesnt

after AP, neuron rests before next AP

action potential reaches end of axon--> branches--> enters buds and pushes vesicles downward, causing release of NT into the synapse

At the membrane of the postsynaptic cell, NTs attach to proteins called receptors in a key into lock type of format--> post-synaptic potential

• 1) actions of muscles and glands
• 2) sleep or stimulate mental/physical alertness
• 3) affect learning, memory, motivation, emotions, and psychological disorders

• mood (big part in disorder= depression)
• low levels lead to depression

responsible for allowing memories to be processed

• low levels: Alzheimers
• also for muscle contraction

pleasure enter [addiction caused by dopamine] (reward system)

schizo and parkinson's

• number one inhibitory NT (relaxed)
• you have anxiety if you lack it

natural pain killers

coping mechanisms

CNS: brain and spinal cord; critical for ability to live; limited in plasticity; not a great ability to repair selves; reflexes

PNS: somatinc and autonomic; all neurons connecting the CNS to rest of body; carries messages from sensory--> CNS--> motor

somatic: takes in info from senses and sends to brain to let it be processed and perform action

divided into sensory (afferent) and motor (efferent)

• sensory takes in info
• motor allows action to be performed

controls involuntary functions

Subdivided into sympathetic (fight or flight) and parasympathetic (rest and digest)

fight or flight: body is sped up: increased HR, breathing, blood flow

parasympathetic calms: when one up, one down

medulla: breathing; HR; automatic (damage leads to no breathing or HR)



cerebellum: finely coordinated movement and balance; smooth precise movements  (alcohol affects this)

largest

thalamus: sensory relay system; receives all sensory info except smell

hypothalamus: hunger, thirst, sex, aggression

limbic system: hippocampus--> short term memory/ amygdala: emotional memory and memory of others and self

cerebral cortex (next page)

two hemispheres

four types lobes (two of each): temporal, parietal, frontal, occipital

structure: wrinkled convolutions; biggest portion

high complex functioning and thinking

• skin/ tactile senses
• pain, pressure, temp, and touch location

hearing

vision

specialization of the left and right hemishperes of the brain for particular operations

left: logical, analytical

right: emotion, risk-taking, creativity, etc.

down syndrome

schizophrenia

alzheimer's Disease

1) inside cell body are positive and negative ions with positive being pumped out, leaving inside slightly negative (polarized/ resting state)

2) A force (electrochemical potential) pulls the positive ions back inside through special channels called gates

3) Depolarized once positive is back inside

4) Actional potential fires an all-or-none response (either fires or not)

5) refractory period (taking a rest)