Structure and Function of the Nervous System

dendrites

receivers on the large end of the neuron

cell body

the middle/bulk of the big part of the neuron, receives the messages after the dendrites

contains the nucleus

also has the cell membrane

action potential - negatively and positively charged sodium and potassium ions

axon

the string part of the neuron

myelin sheath

fatty tissue that protects the axon

made of glial cells

glial cells

nurture/support neurons

make up the blood brain barrier

cover capillaries

axon terminal

the small strings at the small end of the neuron

synapse

the empty space between neurons

resting potential

when the neuron is at rest

inside the cell body: negative charge

outside the cell body: positive charge

action potential

“all or nothing” response

happens when an excitatory neural message comes in

the thing with the exchange of the ions

depolarization happens

then hyperpolarization also happens

brain stem

oldest part of the brain

responsible for basic life functions

relays sensory information to the cerebrum

pons

coordinates voluntary movement along with the cerebellum

regulates consciousness

medulla oblongata

regulates heart rate and breathing

you die if this doesn’t work

reticular formation

network of neurons that connects the spinal cord to the thalamus

filters incoming sensory stimuli

responsible for habituation

helps regulate sleep and alertness

thalamus

relay center for all sensory information except for smell

part of the limbic system

hypothalamus

regulates hunger, thirst, body temp, and sexual behavior

in charge of the endocrine system

relays neurohormones to the pituitary gland

pituitary gland

master endocrine gland

sends messages to all other glands to excrete hormones

amygdala

processes emotions

regulates aggression and fear

hippocampus

part of temporal lobe

responsible for encoding memories

encoding: short term memories get stored as long term memories

cerebellum

“little brain”

coordinates voluntary muscle movement

stores procedural memories

cerebrum

main portion of the brain

cerebral cortex

outer layer of gray matter of the cerebrum

responsible for higher brain function (sensation, voluntary muscle movement, thought, reasoning, memory

basal ganglia

bundle of nerves that connects the thalamus to the cerebrum and cerebellum

regulates movement, balance, eye movement, posture

sulcus

fold in the brain

also called fissures

separates the areas of the cortex

olfactory bulb

relays sense of smell to the olfactory cortex

smell does not go through the thalamus

frontal lobe

enables judgement and planning (prefrontal cortex)

damage to this area can alter personality

motor cortex

part of the frontal lobe

sends messages to the muscles and glands to move

broca’s area

speech articulation

damage to this area results in broca’s aphasia - slurred speech

parietal lobe

mathematical and spatial reasoning

somato-sensory cortex

part of the parietal lobe

receives sensory information relating to touch, pain, temperature (somatosensation)

angular gyrus

part of the parietal lobe

responsible for reading

partially in the temporal lobe as well

damage can cause difficulty in math as well

supramarginal gyrus

part of the parietal lobe

reading comprehension

occipital lobe

contains the visual cortex

where vision is processed

has lots of cortical space

temporal lobe

where hearing/audition is processed

contains the auditory cortex, hipp

wernicke’s area

part of the temporal lobe

speech comprehension

damage will result in wernicke’s aphasia - incomprehensible speech + inability to understand speech

fusiform gyrus

part of temporal lobe

facial recognition

corpus callosum

bundle of nerve fibers that connects the two hemispheres of the brain

cerebral lateralization

each half of the brain controls certain functions

contralaterality

right half of the brain controls left half of the body and vice versa

spinal cord

information highway

connects brain to the peripheral nervous system

somatic nervous system

skeletal nervous system

enables voluntary muscle control

autonomic nervous system

controls glands and internal muscles

sympathetic nervous system

fight or flight

raised heart rate, blood pressure, blood sugar

pupils dilate

digestion slows

bladder muscles contract

you sweat

parasympathetic nervous system

returns body to homeostasis after sympathetic ns activation