Nervous system Flashcards
Central Nervous System (CNS)
Comprises the brain and spinal cord.
Peripheral Nervous System (PNS)
Nerves throughout the body communicating with CNS.
Neuron
Specialized cell transmitting electrical impulses.
Electrical Impulse
Fast signal carried by neurons.
Nerve
Bundle of neurons transmitting information.
Cell Body
Contains the nucleus of the neuron.
Dendrites
Branches receiving messages from other neurons.
Axon
Nerve fiber sending impulses away from cell body.
Axon Terminal
Passes messages to the next neuron’s dendrite.
Myelin Sheath
Fatty layer insulating axon, speeding impulses.
Synapse
Gap between neurons for communication.
Neurotransmitter
Chemical signal transmitting across synapse.
Sensory Neurons
Carry messages from sense organs to CNS.
Interneurons
Connect sensory and motor neurons in CNS.
Motor Neurons
Transmit information away from CNS to muscles.
Role of Dendrite
Receives signals from other neurons.
Role of Axon
Sends impulses away from neuron.
Role of Myelin Sheath
Insulates axon, increasing transmission speed.
Role of Axon Terminal
Transfers signals to next neuron’s dendrite.
Somatic nervous system
Controls voluntary skeletal muscle movements
Autonomic nervous system
Controls involuntary actions such as breathing and heartbeat
Sympathetic nervous system
Speeds up the functions of the body - fight or flight
Parasympathetic nervous system
Slows everything down - in control when the body is resting
