chapter 3 Flashcards
Do we use only 10% of our brain?
false every part of the brain has a function
The nervous system is primarily made up of
neurons, glial cells
neurons
nerve cells specialized for communications
glial cells
provide support and nutrients for neurons
what do glial cells do?
form myelin, form the blood brain barrier
Blood-brain barrier
prevents harmful substances from entering the brain, alcohol effects the brain
why do we care about glial cells?
we care because einstein’s brain had more glia than average (made him smarter)
what does the brain contain?
it contains 100 billion neurons that form 160 trillion connections
collectively neurons
monitor our internal and external environments, control our behavior and create our mental experiences
myelin sheath
glial cells that help speed signal transmission it helps with a quick movement to brain, react quicker
cell body
central region of cell (called soma)
axon
deliver signals to other cells
dendrites
receive outside signals
axon terminals
end of axon where signal is released
communication between neurons (two parts)
electrical signal propagation within neuron, chemical communication between neurons
action potential
all or none electrical impulse that neurons use to propagate signal ex: like a wave in a crowd, can’t stop in between
absolute refractory period
recovery time when another AP is not possible
communication between neurons
chemical signal from 1 neuron to the next
synapse
junction between two communicating neurons
neurotransmitter
chemical signal
synaptic cleft
space between two neurons where neurotransmitter is released
receptor sites
lock and key mechanisms that take us neurotransmitters
sensory neurons
sense information and respond to tactile stimuli and can activate motor neurons in order to achieve muscle contraction
interneurons
help to do processing, pass on signal to others
motor neurons
travel from the brain to body to tell you what to do
the nervous system?
how the brain communicates with the body composed of peripheral nervous system
the central nervous system
brain and spinal cord
peripheral nervous system
consists of nerves that connect muscles, organs and glands to the central ns composed somatic and autonomic ns
somatic ns
carries signals between the CNS and muscles in the body that control movement
autonomic ns
carries signals between the CNS and organs/glands that regulate involuntary actions and the body’s internal state
sympathetic ns
readies the body for action, increases heart rate, dilates pupils, inhibits digestion, “fight or flight”
parasympathetic ns
active during rest, slows heart and breathing rates, stimulates digestion “rest and digest”
ex: parachute dropping
spinal cord
carries sensory information to the brain, and motor control commands back to the body. manages simple reflexes and movements
serves to increase speed of important reflexes
brainstem
consists of medulla, pons and midbrain
medulla
helps regulate heart rate and breathing
pons
involved in maintaining balance, and walking (motion)
midbrain
involved in modulation of motor activity (substantia mibra)
thalamus
relay station of the brain directs signals passing between the body and the brain ex: old telephone operator
cerebellum
important for balance, coordination and preplanned actions, learning motor skills
ex: triple axel in ice skating can’t stop in between
basal ganglia
responsible for executing planned actions (implicated in parkinson’s disease)
hypothalamus
regulates the internal environment of the body by controlling the autonomic ns
hypothalamus controls
hormone levels and drive states (hunger, thirst)
amygdala
involved in emotion regulation and fear
hippocampus
important for memory, especially forming new memories, and spatial memory
