- basic building block of nervous system

- body cells specialized for transmitting information or messages in the form of electrical impulses

(consists of soma, axon, dendrites)

- cell body

- main body of cell. houses cell nucleus which contains cell's genetic materials and carries out metabolic (life-sustaining) functions of cell.

- long cable that projects trunklike from soma and conducts outgoing messages to other neurons.

- carries neural message

- located at the ends of axon branches

- knoblike swellings

- chemicals called neurotransmitters are stored and released

- rootlike structures that project from the soma

- have receptor sites (docking stations) that enable them to recieve neurotransmitters

- transmit info about outside world to spinal cord and brain

- first registers with sensory organs

-example: someone touches your hand. sensory receptors in skin transmit message through sensory neurons to spinal cord and brain where info is processed. Result: feeling of touch

-also carry info from muscles and inner organs to spinal cord and brain.

- convey messages from brain and spinal cord to muscles that control movement.

- also convey messages to glands, which then release hormones (chemical substances that help regulate body processes)

- most common neuron.

- connects neurons to neurons.

- in spinal cord, connect sensory neurons to motor neurons

- in brain, form complex assemblages of interconnected nerve cells that process info from sensory organs and that control higher mental functions : planning, thinking

- bundle of axons from different neurons

- an individual nerve can consist of millions+ axons

- act as glue to hold neurons together.

- nourish neurons, remove their waste, and assist them in communication

- amplify pain signals

- also form myelin sheath

a fatty layer of cells that acts as a protective sheild for axons

- helps speed transmission of neural impulses, allowing more efficient smooth movement

electrically charged atoms and molecules located inside and outside neuron

- have either positive or negative charge

- movements of ions across cell wall cause electrochemical changes in cell that generate an electrical signal to travel down axon in neural impulse

(neural impulse)

-resting neuron stimulated : opens sodium gates : positively charged sodium ions rush in : cell shifts from negative to positive charge

- one it passes, gates close and cell pumps out positive ions

- restores resting state.

a temporary state in which a neuron is unable to fire in response to continued stimulation

- after action potential, neurons pump out + ions, which restores it to negative state.

then, it restores electrochemical balance by pumping out some sodium ions and drawing in some potassium

- because neurons dont touch and impulses cant jump the synapse, they must be carried by neurotransmitters, which are released in tiny vesicles (sacs)

- each neurotransmitter has a particular chemical structure and will only fit into one type of receptor site. when they arrive, they lock into place and cause chemical changes.

-changes have either excitatory (makes action potential more likely) or inhibitory (makes it less likely) effect

natures recycling

neurotransmitters are sometimes re-absorbed by transmitting neuron (vesicle) to be used again

released by terminal buttons

chemicals that increase or decrease the sensitivity of receiving neuron to neurotransmitters

drugs or chemicals that block actions of neurotransmitters by occupying receptor sites in which they normally dock

- prevent transmittion of messages carried by neurotransmitters

Agonists

(opposite of antagonists)

- enhance activity of neurotransmitters

- either increase availiability or effecitiveness of neurotransm. or binding to their receptor sites and mimicking their actions

agonists that increase availability of dopamine in brain by blocking re-uptake

- increased amounts of dopamine accounts for "high" because dopamine is a key neurotrans. in neural pathways in the brain that regulate states of pleasure

gamma-aminobutyric (GABA)

- regulates nervous system by preventing neurons from overly exciting neighbors.

- drugs with GABA have calm or relaxing effect

consists of brain and spinal cord

column of nerves that transmit info between brain and peripheral n.s.

- recieves incoming from sensory organs and other peripheral body parts

- carries outgoing from brain to muscles, glands, and organs

- encased in Spine (protective bony column)

-controls some spinal reflexted (knee jerk)

- allows us to respond almost instantly and with efficiency to particular stimuli.

-connects spinal cord and brain with sensory organs, glands, and muscles

somatic and automatic

-transmits info between central n.s. and your sensory organs and muscles.

- also controls voluntary movements.

- regulates subtle movements

-maintains posture and balance

- composed of sensory and motor neurons

speeds up bodily processes and draws energy from stored reserves. accelerates heart rare and provides more energy for body by released glucose (sugar) to liver

- activated by vigorous physical activity or strong emotions

fosters bodily processes, such as digestion

- helps conserve energy by slowing other processes

- relaxing and digesting

4 components to hindbrain

MCPT

-medulla

-cerebellum

-pons

-thalamus

involved with basic life-support functions, closest to spinal cord

contains nerve pathways that connect forebrain to hindbrain

- reticular info: weblike network of neurons rises from hindbrain and passes through thalamus to forebrain; plays key role in regulating states of attention, alertness, and arousal; screens visual and auditory info, filtering out irrelevant info while allowing inmportant info to reach higher processing centers

relay station near middle of brain. route info from sense receptors for touch, vision, hearing, taste (not smell) to processing centers in cerebral cortex

1. sorts through sensory info

2. transmit info to appropriate parts of cerebral cortex for processing

pea sized structure that helps regulate vital body functions such as hunger and thirst, fluid concentrations, body temp, reproductive processes, emotional states, aggressive behavior, and stress response

- part of the endocrine system. triggers release of hormones through body

group of interconnected structures that includes the amydgala, hippocampus, parts of thalamus, hypothalamus, and others.

important in memory and emotional processing

thinking, calculating, organizing, and creativity

- forms thin, outer layer of largest part of forebrain called cereburm, which consists of right and left hemisphered.

- contains corpus callosum

- controls voluntary movement, states of motivation, and emotional arousing, and processing of sensory info

occipital, parietal, frontal, and temporal

black of head, processes visual info.

sides of brain. in front of these lies a strip of nerve cells called somatosensory cortex which processes info on touch and pressure on skin as well as the position of the parts of our bodies we move about

- brain devotes more of its capabilities to parts that require greater sensitivity or control *hands

"executive center" higher role in mental functions

- access memories, mull things over, have self- awareness

- solve problems, make decisions, plan actions, weigh evidence, and carry out coordinated actions

-processing emotional states such as happiness and sadness

recieive and process sensory info from ears, producing experience of hearing

- great majority of cortex consists of association areas, found in each lobe, responsible for performing higher mental functions

left : language abilities, tasks requiiring logical analaysis

right : nonverbal processing, understanding relationships, puzzles, recognizing faces, interpreting gextures, emotions, music sounds, etc.

area of frontal lobe that lies in front of the motor cortex

-weighs consequences of our actions, makes plans for future, solves problems, makes decisions, and constrains impulsive behavior

-seat of intelligence

-moral judgements or decisions