AP Psychology Unit 3

dendrites

-input fibers that carry electrical signals into a neuron from connected cells.

soma (cell body)

-control center of neuron
-integrates inputs from all dendrites
-determines whether neuron should fire or not

axon

-output fiber carries electrical signal from a neuron to a neighboring cell.
-neurons have one each
-larger than dendrites
-divide into branches at end called terminals

myelin sheath

-a layer of fatty tissue that covers around the axon
-enables greater transmission speed of neural impulses as impulses jump from node to node
-composed of glial cells (glove), support, nourish, protect neurons.

synapse

-the junction between the axon tip and the dendrite of the receiving neuron.
-called the synaptic gap or cleft as well

resting state

-a neuron has a slightly negative charge
-negative ions mostly inside cell, positive ones outside.

level of excitation

-level of stimulation needed for electrochemical communication to occur.

action potential

-brief charge that travels down the axon as it becomes depolarized.
-travels down to terminal where it causes neuro transmitters that bind to specific receptor sites on receiving neurons to fire.

refractory phase

-return to state of resting slightly negative charge (polarization)
-no amount of stimulation can cause the neurons to fire again in this stage.
-absolute refractory phase is followed by relative refractory phase in which neuron needs more stimulation to

excitatory neurotransmitter

-excite the cell into firing

inhibitory neurotransmitter

-inhibit the nerve cell from firing

serotonin

-regulates mood, eating, sleeping, and arousal
-prozac and ecstasy work by boosting its effects

dopamine

-regulates movement and posture
-particularly in basal ganglia
-lack= Parkinson's or catatonic
-overabundance, associated with Tourrete's and schizophrenia

acetylcholine

-regulates cognitive functioning and memory
-Alzheimer's associated with loss of it in neurons that connect with hippocampus
-nicotine is an agonist (mimics it), thats why cigarettes boost arousal and concentration

norepinephrine (noradrenalin)

-regulates alertness and wakefulness
-too much=mania, too little=depression
-puts the body on "red alert" during stressful or exciting situations
-coke and amphetamines boost levels

gaba

(agamma amniobutyric acid)
-inhibits the action of target cells
-low levels: implicated in anxiety and epilepsy
-alcohol and barbiturates raise levels

endorphins

-"morphine within"
-natural opiate-like neurotransmitter linked to pain control and pleasure
-exercise linked to raising endorphin level

glutamate

-most abundant excitatory n.t.
-plays significant role in learning and memory

afferent neurons (sensory neurons)

-takes info from senses to brain

interneuron

-once info reaches brain, it takes message and sends it along

efferent neurons (motor neurons)

-takes instructions back to muscles

Central Nervous System (CNS)

-made up of two major components: brain and spine
-receives, processes, interprets, and stores incoming sensory info.
-sends out messages for muscles, glands, and internal organs.

Peripheral Nervous System (PNS)

-consists of nerves/tissue outside brain and spinal cord
-two categories: somatic and autonomic nervous systems.

somatic

(skeletal)
-consists of nerves that are connected to sensory receptors and to skeletal muscles that permit voluntary action
-muscles, joints, skin
-associated with all body movement

autonomic

-controls autonomic functions of the body
- controls fight or flight response

Autonomic: sympathetic

-mobilizes body to respond to stress
-accelerates some functions (heart, b.p.) but conserves resources (digestion slows)

Autonomic: parasympathetic

-responsible for slowing down body after stress response

Wilder Penfield

-stimulated brain with electrical probes while patients underwent surgery for epilepsy
-created maps of sensory and motor cortices

localization

-major parts of brain perform different (though sometimes overlapping) tasks

plasticity

-in cases of injury certain structures can take on new tasks

hindbrain

-consists of structures in the top part of the spinal cord
-controls basic biological functions that keep us alive
-primitive part of brain

medulla oblongata

(hindbrain)
-regulates heart rate, b.p., breathing, etc.

pons

(hindbrain)
-connects the hindbrain with the mid and fore brains.
-involved in control of facial expressions

cerebellum

(hindbrain) "little brain"
-coordinates voluntary movement and balance
-damaged in people with autism

midbrain

-located just above the spinal cord, and hindbrain, below forebrain
-small in humans
-coordinates simple movements with sensory info.
-contains reticual formation: nerve network in brain stem
-plays role in controlling arousal
-if damaged, coma results

basal ganglia

(midbrain)
-body movements and speech
-overactive: Tourrette's, under-active= Parkinson's

nucleus acumbens

(midbrain)
-plays central role in rewards, laughter, sexuality, etc.
-high concentration of serotonin and dopamine pathways

thalamus

(forebrain)
-located on top of brain stem
-responsible for receiving sensory signals and sending them to appropriate ares in the forebrain.
-all senses except smell

hypothalamus

(forebrain)
-small structure below thalamus
-controls metabolic functions: body temp., hunger, thirst, endocrine system, libido

amygdala

(forebrain)
-almond shaped near the front of brain
-involved in the arousal and regulation of emotion and initial reaction to sensory info

hippocampus

(forebrain)
-involved in storage of new info, memories

limbic system

-made up of thalamus, hypothalamus, amygdala, and hippocampus
-deals with emotions and memory

cerebral cortex/cerebrum

-grey, wrinkled surface that is densely packed with neurons
-located in upper forebrain
-connections between neurons grow as we learn and develop
-surface is wrinkled to increase surface area (convolutions)

left hemisphere

-logic and reasoning (detail oriented)
-number manipulation, arithmetic
-language (grammar skills)
-right handed touch, movement.

right hemisphere

-spatial construction, non-verbal imagery
-face recognition
-more "big picture" oriented (initiative)

frontal lobe

-large area, 1/2 of brain
-goal oriented behavior, future planning
-believed responsible for abstract thought and emotional control
-contains Broca's area: controls muscles involved in speech
-thin,vertical strip at back of cortex, motor cortex: sends sig

parietal lobe

-located behind frontal lobe
-contains somato-sensory cortex: thin, vertical strip, receives incoming touch sensations
-both the motor and somato-sensory cortices are organized similarly: top receives sensations from bottom of body; and vice-versa.
-invol

occipital lobe

-located at the very back of brain, farthest from eyes
-however, one major function is to interpret messages from eyes into visual cortex.
-impulses from right half of each retina are processed in the visual cortex of the left side, and vice-versa.

temporal lobe

-processes sound sensed by ears
-sound waves processed, turned into neural impulses and interpreted in auditory cortex.

endocrine system

-system of glands that secrete hormones that affect many different biological functions in body
-controlled by hypothalamus

adrenal gland

-produces adrenaline

melatonin

-regulates biological rhythm, i.e. sleep
-controlled by pineal gland
-inhibited by light, increased by dark

monozygotic

-identical twins

dizygotic

-fraternal twins

Thomas Bouchard

-studied 100 identical twins, who were raised separately.