Neuron Flashcards
Functional unit of the nervous system
Neuron
Cell body of neuron — contains organelles
Soma
Extensions that receive signals
Dendrites
Long extensions that transmit signals
Axons
Cells around neuron that produce the myelin sheath
Schwann cells
Insulation along the axon; quickens conduction of signals
Myelin sheath
Gaps between myelin sheath
Nodes of Ranvier
Where action potential can be reached
Axon hillock
Ending of axon
Axon terminal
Gap between one neuron and another neuron, gland, or muscle cells
Synapse
Presynaptic cell _________ signal
Transmits
Postsynaptic cell ________ signal
Receives
Chemical messages released from vesticles in the synaptic terminals into synapse
Neurotransmitters
Dopamine and serotonin are examples of
Neurotransmitters
Transmit information from sensory receptors to the brain
Sensory neurons
Connect sensory and motor neurons to make local connections in brain and spinal cord
Interneuron
Transmit signals to effectors
Motor neuron
Difference in electrical charge across a cell
Membrane potential
“All or none” response to depolarization of the membrane
Action potential
Causes depolarization; moves membrane potential closer to threshold
Excitatory neurotransmitters
Causes hypopolarization; moves membrane potential away from threshold
Inhibitory neurotransmitters
Nerve impulses jump between the nodes of Ranvier
Saltatory conduction
Transmission of information from neurons to other cells occur at synapses
Neuron communication
Complex network of nervous tissue that carries signals throughout the body
The nervous system
Simple autonomic response to stimulus
Reflex
Response pathway
Ensure input —> integration —> motor input
Consists of bundled axons
White matter
Supporting cells in nervous systems
Glial cells
Line ventricles of the brain — have cilia to promote circulation of spinal fluid
Ependymal cells
Star shaped cells — facilitate transfer, promotion of blood flow to neurons
Astrocytes
Myelinate axons in the CNS
Oligodendrocytes
Mylinate axons in the PNS
Schwann cells
Immune cells in the CNS
Microglia
Brain and spinal cord
CNS
Transmits information to and from the CNS
Peripheral nervous system
Carries signals to skeletal muscles
Somatic nervous system
Regulates smooth and cardiac muscles
Autonomic nervous system
Increases heart rate
Sympathetic nervous system
Decreases heart rate
Parasympathetic nervous system
Exerts direct and partially
Enteric nervous system
Responsible for breathing, swallowing and digestion — conducts sensory and moto signals between spinal cord and higher brain regions
Brainstem
Coordinates movement and balance
Cerebellum
Main center for which sensory and motor information passes to and from cerebrum
Thalamus
Regulates homeostasis & information processing
Hypothalamus
