Nervous System Flashcards
Nerve net
Simple nervous system in invertebrates, diffuse mesh of simple branching nerve cells
Ganglia
Distinct Cluster of cell bodies of neurons
Neurons
Cells that make up nerves
Neuroglia
Nervous tissue cells that structurally and metabolically support neurons, can reproduce
Cell body
Nucleus and cytoplasmic components of cell
Dendrites
Signal input, slender extension from cell body of neuron
Axon
Action potentials, conductors, endings are transmitters
Sensory neurons
Detects stimulus and relays info about it
Motor (effector) neurons
Relays commands from brain or spinal cord to muscle and gland cells
Interneurons
Neuron of brain or spinal cord
Polarization
Sodium on outside, potassium on inside, signals transferred from neuron to neuron through action potential
Threshold
Minimum amount of change in resting membrane potential that will trigger an action potential
Action potential
Abrupt, brief reversal of resting membrane potential of neuron
Hyper polarization
Increase in charge difference of action potential
Sodium potassium pump
positive Sodium outside, negative potassium inside
Refractory period
Interval after an action potential where a patch of neural membrane in insensitive to stimulation
Axon bulb
Endings of axons, transmit signals
Neurotransmitter
Signaling molecules secreted by neurons, acts on cell next to it and then is degraded or recycled
Synaptic integration
Combining of all excitatory or inhibitory signals arriving at a neuron
Synapse
Gap between neurons,
Allows neuron to pass electric or chemical signal to another cell
Acetylcholine
Neurotransmitter in Cns and pns
Epinephrine
Hormone and neurotransmitter, strong emotions
Adrenaline
Norepinephrine
Neurotransmitter, increases heart rate and sugar level
Dopamine
Neurotransmitter, happy calm rewards
Serotonin
Neurotransmitter, sleep
Schwann cells
Neuroglia cell that Wraps around axons like a jelly roll
Myelin sheath
Series of Shwann cells
Nodes of rancher
Breaks in myelin sheath
Salatory conduction
Action potentials jumping from node to node
Central nervous system
Brain and spinal cord
Peripheral nervous system
Nerves and ganglia leading into and out of CNS
Somatic nervous system
Nerves leading from Cns to skeletal muscles
Autonomic nervous system
Nerves going to smooth muscles in organs
Sympathetic nervous system
Autonomic nerves that deal with times of heightened awareness
Parasympathetic nervous system
Autonomic, slows body activities to focus on basic tasks
Afferent
Conveying impulses to Cns
Efferent
Acting out signals from Cns
Cerebrum
Voluntary activities
Sensory information
Largest
Cellebellum
Muscle activity and refinement of movement
Coordination
Hypothalamus
Homeostasis
Secretes hormones
Regulates pituitary gland
Medulla
Involuntary actions
Pons
Connects parts of brain
Contains respiratory center
Midbrain
Visual and auditory reflexes
Thalamus
Sensory relay center for conducting information between spinal cord and cerebrum
Cerebral cortex
Thin surface area of cerebral hemispheres, coordinates responses to sensory info
Corpus callosum
Band of axons linking 2 cerebral hemispheres