Biology Psychology 3/6/14

nervous system - starts with an individual never cell called a neuron.
parts of a neuron:
cell body - center and support cell life.
dendrites - transmits message to cells (other cells/recieve)
axon - passage messages away from cell body to other parts.
myelin sheath - covers the axon and helps speed up neural impluses.
terminal branches of the axon - forms junctions with other cells.
neurotransmitters - chemicals help inn the terminal buttons that travel through synapse.
synapse - a structure that permits a neuron to pass a chemical or electrical signal to other cell.

how does a neuron fire?
resting potential - slightly negative charge reach the threshold when enough neurotransmitters reach dendrites.
it is an electrochemical process.

• electrical inside the neuron
• chem. outside the neuron ( in the synapse in the form of a neurotransmitter)

 firing is called action potential.
the all-or-none response.

• idea that either the neuron fires or doesn't. no part way firing. 

ex. like a gun

acetylcholine (ACH)

• deals with motor movements and memory
• lack of ACH has been linked to Alzheimer's disease.

dopamine

• deals with motor movement and alertness
• lack linked to parkinson's disease
•  too much linked with schizophrenia

serotonin

• mood control
• lack linked with clinical depression

endorphins

• pain control
• many of our most addictive drugs deal with endorphins

drugs can be...

• agonist: make neurons fire
• antagonist: stop neural firing

sensory neuron (afferent neurons): takes info from senses to the brain
inter neuron (relay neuron): takes messages from sensory neuron to the other parts of the brain or to the motor neuron.
motor(efferent neuron): takes info from brain to the rest of the body.

central nervous system - brain and spinal cord.
peripheral nervous system - all nerves that are not encased by bone. everything but brain and spine.
divided into 2, somatic and autonomic.

somatic nervous system - controls voluntary muscles movement. uses motor/efferent neurons.
autonomic nervous system - controls automatic functions of the body. divided into 2 categories sympathetic and parasympathetic.

sympathetic nervous system - fight or flight response, automatically accelerates heart rate, breathing, dilated pupils, slows down digestion.

parasympathetic nervous system - automatically slows the body down after stressful event. heart rate and breathing slows down, pupils constrict and digestion speeds up.

reflex - normally, sensory (afferent) neurons take into up through spine to brain. some reactions occur when sensory neurons reach touch the spinal cord.

lesions - cutting into the brain and looking for change. less invasive way to study brain.

brain structure - brain divided into 3 parts. hindbrain, midbrain, and forebrain.

hindbrain:
medulla oblongata - heart rate , breathing, and blood pressure.
pon - connects hindbrain, midbrain, and forebrain together. involved in facial expression.
cerebellum - located in the back of the head. means "little brain"

mid brain: coodinates simple movements with sensory information. contains reticular formation: arousal and ability to focus attention.

thalamus: in fore brain, receives sensory   information and sends them to appropriate areas of the forebrain like a switchboard.

limbic system: emotional control center of brain made of hypothalamus, amygdala, and hippocamppus.

hypoothalamus: pea sized. but plays big role. body temp., hunger, thirst, and sexual arousal (libido)

hippcampus & amygdala:
hippocampus - memory processing
amygdala - vital for our basic emotions.

cerebral cortex: top layer of our brain. wrinkles called fissures. fissures increase surface area of brain. laid out about the sized of a large pizza.

hemispheres : divided into left and right. contra lateral controlled - left controls right of body and vice versa.
brain lateralization
lefties are btter at spatial and creative task
righties are better at logic

splt brain patients: corpus callosum attaches the two hemispheres of cerebral cortex. when removed you have split brain.

cerebral cortex contains 4 lobes

• frontal
• temperal
• occipital
• parietal

frontal lobe: abstract thought and emotions.
motor cortex: sends sinals to body controlling muscle movements.
brocas's area: responsible for controlling muscles that produce speech.
damage to area is called broca's aphasia: unable to make movements to talk.
motor cortex: left hemisphere control right side.

parietal lobe: contains sensory cortex. receives incoming touch sensations from rest of the body.
most of parietal love are made up of association areas.
assocaition areas: any area not associated with recieving sensory information or coordinatinng muscles movements.

occipital lobe: deals with vision. contains visual cortex. interprets message from our eyes into images we can understand.

temperal lobe: source sensed by our ears. contains wernicke's area: interprets written and spoken speech.
wernicke's aphasia: unable to understand langauge: the syntax and grammar jumbled.