chapter 37 Flashcards
what are neurons
nerve cells that transfer information, collection signals then transfers it
what is a cell body
the inner part of the neuron; most of the organelles are located here
what are dendrites
highly branched extensions that receive signals from other neurons, shorter in length, collects and stores all incoming information from axon terminals
what are axons
the largest part of the cell, longer in length, less branching,
what is depolarization
most cells are negative inside relative to their surroundings, there is an electrical shift causing the inside of the cell becomes positive ; open gated ion channels trigger depolarization a reduction in magnitude of membrane potential
what is a synapse
the branched ends of the axons transmit signals to other cells at a junctions, which hold chemical messages called neurotransmitters
what are neurotransmitters
pass information from the transmitting neuron to the receiving cells
what are the three stages of the nervous system prodcesses
1) sensory imput 2) integration 3) output
what are sensory neurons
transmit information detect external and internal stimuli, neurons collecting information (eye, ear, mouth)
what are interneurons
information is sent to the brain where interneurons integrate the information and collect neurons
what are motor neurons
transmit signals to the muscle cells, respond to stimuli
what is the central nervous system
the brain and spinal cord and has much smaller in connections
what is the peripheral nervous system
neurons that carry information in and out of the CNS
PNS neurons bundle together forming nerves that hold neurons creating a tube/collection of the neurons, highways for neurons to go to the same direction
what is membrane potential
the difference in inside the cell (-) and the outside being (+)
what is resting potential
membrane potential of a neuron not sending signals, the cell is getting ready to build up that energy to release
what are the two ions that cannot travel across the membrane on its own
K+ and Na+
what ion is being moved out of the cell
Na+, sodium
what ion is being moved into the cell
K+, potassium
what is a sodium potassium pump
uses the energy of ATP to maintain the K+ and Na+ gradients across the plasma membrane
what are gated ion channels
changes in membrane potential occurs because nervous contain gated ion channels, that open or close in response to stimuli
what is action potential
if depolarization shifts the membrane potential sufficiently, it results in a membrane voltage, occurs when a depolarization increases the membrane potential to a particular value called the threshold
what are the stages that trigger action potential
1) resting potential 2) rising phase 3) falling phase 4) undershoot
what is the rising phase
the threshold is crossed and the membrane potential increases as all gates Na+ channels are open, peak of action potential;
some gated Na+ channels are opened at first and Na+ flows into the cells
what is the falling phase
voltage gates Na+ channels become inactivated and voltage gates K+ open, K+ flows out of the cell closing Na+ channels making the inside of the cell (-) until it goes back into rest
