Nervous System I Chapter 14 Flashcards
Consists of the brain and spinal cord
Central Nervous System
Consists of nerves that lie outside the CNS
Peripheral Nervous System
The nervous System receives sensory input. Sensory receptors in the skin and other organs generate nerve signals that travel by the way of the _______ and the _________
PNS and CNS
The ______ performs information processing and integration. It reviews and stores the information, and creates the appropriate motor responses.
CNS
The ____ generates motor output. Nerve signals from the CNS go by the way of the ____ to muscles, glands and organs
CNS
PNS
What are the three types of neurons
sensory
interneuron
motor
Take nerve signals from the sensory receptor to the CNS
sensory
Lie in the CNS where they sum up information from the sensory neurons and communicate with motor neurons
Interneuron
Take nerve impulses away from CNS to effectors
motor
Receive signals from sensory receptors or other neurons
Dendrites
Contains the nucleus and other organelles
Cell body
Conducts signal down neuron
Axon
End of the neuron where signals is relayed
Axon terminal
Occurs when a Neuron is not conducting a nerve impulse during an action potential
Resting Potential
What is happening to Na+ and K+ at rest?
Na+ gathers around the outside of plasma membrane
K+ diffuses out of cell to join sodium ions
Inside of cell becomes negative
Stimulus causes the axon to reach its threshold; the axon potential increases from ______ to _______. The action potential has begun
-70
-55
Adding + ions causes inside of axon to become + compared to outside
depoloration
Na+ moves to inside axon
depolarization
K+ moves to outside axon
repolarization
Action potential ends: repolarization occurs when ___ gates open and ___ moves to outside the axon. The _______ ______ pump returns the ions to their resting positions
K+
K+
sodium-potassium
Resets for next action potential
refractory period
If axon is unmyelinated, action potential at one locale stimulates an adjacent part of axon membrane to produce an action potential. Much slower because needs to stimulate each section of axon
Signal Propagation
When an action potential at one node of ranvier causes an action potential at the next node, jumping over the entire myelin-coated portion of the axon
Saltatory Conduction
Action potential stimulates release of ________ from axon terminal into _____ cleft
neurotransmitter
synaptic
Stored in synaptic vesicles in axon terminals. Transmits signals between nerves
Neurotransmitters
Neurotransmitter must be _______ to stop the signal
eliminated
