What are the 2 types of communication systems?
- uses hormones to influence behaviors and actions
- chemical messenger system
- commanded by hypothalamus
2 components of nervous system?
- central nervous system
- peripheral nervous system
central nervous system
brain and spinal cord
peripheral nervous system includes...
somatic & autonomic nervous systems
neurons that communicate with other neurons
afferent vs efferent nerves
- afferent- carry info to CNS
- efferent- carry info away from CNS
somatic nervous system
- made up of nerves which transmit sensory signals to and from central nervous system
- transmits sensory signals and motor skills between CNS and skin, muscles joints
autonomic nervous system
transmits sensory signals and motor signals between central nervous system & body's glands & internal organs
regulates body's internal environment
two divisions of ANS
sympathetic & parasympathetic
prepares body for fight or flight
returns body to resting state
individual cells in nervous system which receive, integrate & transmit information
how is information passed through neuron?
dendrites receive info, passed along axon via action potential to terminal buttons where neurotransmitters are released to next neuron's dendrites
what is the purpose of the myelin sheath?
to increase speed of transmitters
what are the 4 types of neurons?
receptor, sensory (afferent), motor (efferent), interneurons
what are the 2 ways neurons communicate?
- electrical: within cells
- chemical: between cells
neural impulse which passes along axon
resting membrane potential
electrical charge of neuron when it is not active (negative)
site at which chemical communication occurs between neurons
gap between axon of sending neuron and dendrites of receiving neuron
nodes of Ranvier
small gaps of exposed axon between segments of myelin sheath, where action potentials are transmitted
when does action potential occur?
neuron receives more excitatory signals, potassium flows in, sodium flows out which leads to an excessively positively charged ion (less polarized)
reduces polarization, increases chance of firing
increases polarization, decreases chance of firing
what is the charge of the neuron during: resting state? firing? post firing?
- resting state: negative
- firing: positive
- post-firing: negative
all or nothing principle
neurons fire with the same force each time (either fire or not)
neurons which send signals
neurons which receive signals
what carries the excitatory/inhibitory signal
how do neurotransmitter travel from terminal buttons of presynaptic neuron to dendrites of post synaptic neuron?
carry inhibitory/excitatory signal across synaptic cleft-> bind to receptors on post synaptic neuron
What are the 3 events which can terminate neurotransmitter influence?
- enzyme deactivation
- neurotransmitter is released into synaptic cleft and then returned
- reduce, reuse & reuptake :)
enzyme destroys neurotransmitter in synaptic cleft
receptors on presynaptic neuron (auto receptors) monitor how much neurotransmitter has been released into synaptic cleft and signal for the neuron to stop once excess is detected
drug which enhances actions of neurotransmitters
drug which inhibits actions of neurotransmitters
types of neurotransmitters
acetylcholine, dopamine, norepinephrine, serotonin, glutamate, GABA
- motor control between nerves & muscles
- i.e. Botox
- learning, memory, sleeping, dreaming
- i.e. Alzheimers
- motivation & reward
- i.e. eating when hungary
- motor control & planning
arousal & alertness
- emotional states, impulse control, dreaming
- low levels -> sad, anxious, aggressive
- i.e. Prozac
- primary excitatory transmitter
- aids memory & learning
- primary inhibitory neurotransmitter
- low levels -> epileptic seizures