Ch. 2: Physical and Electrical Properties of Cells in the Nervous System Flashcards
On a neuron:
What is the cell body called?
Soma
On a neuron:
What is the “reciving” antenna called?
Dendrite
On a neuron:
Where are new action potentials generated?
Axon Hilock
On a neuron:
What is the “transmitting antenna?”
Axon
On a neuron:
Where do parts of two neourns come together?
Synapse
On a neuron:
What is the end of an axon called when it connects with the next neuron?
Presynaptic Terminal
On a neuron:
What is the space called where chemical signaling occurs?
Synaptic Cleft
On a neuron:
What is the dendrite called that recieves chemical signals?
Postsynaptic membrane
What are the 4 general functions of nerve cells?
- Reception: receive signals
- Integration: gather many inputs and boil down to a majority opinion.
- Transmission: Transmit new signals electrically and chemically to other cells
- Transfer: transfer messages to other neurons across the synapse
What is the name of this neuron?
Bipolar
What is the name of this neuron?
Pseudo-Unipolar
(sensory neurons of the peripheral nervous system)
What is the name of this neuron?
Multipolar
(motor)
Transmission of info ALONG one neuron is _______
electrical
(within)
Transmission of info BETWEEN neurons _______
Chemical and electrical
(between)
What is a Nongated channel?
- structural gate that it always open
- Always leaking ions depending on relative concentrations or charge gradient
What is a Modality-Gated channel:
- Touch or temperature
- Primary modalities that cause them to open
- @ distal end of sensory neurons
What is a Ligand-Gated channel?
- “Protein”
- Ligands that open these channels are neurotransmitters
- On dendrites & bodies of nerve cells
What is a Voltage-Gated channel?
- Responds to charge in membrane voltage
- When -70mV changes it allows these gates to open
- @ axon hilock of multipolar celss (most often) & near distal end of puedo-unipolar cells
What must exsit across cell membranes to create an “excitable” cell?
Potential Difference
(difference in charge)
What factors maintain “resting potential” across a membrane?
- Na+/K+ (3 Na+ out for every 2 K+ in)
- Large negative molecules trapped in soma
- Passive diffusion through non-gated channels
What is Depolarization?
Cell becomes:
- Less negative
- More excited
- More likely to create action potential
What is Hyperpolarization?
Cell becomes
- More negative
- More Inhibited
- Less likely to create an action potential
What characterizes a local (change in) potential?
- Modality and Ligand-Gated channels
- “Receptor” and “Synaptic”
- Small changes in polarity
- Graded (can sum)
- Larger stimulus or more transmitter equals bigger change in polarity
- Depolarizing or hyperpolarizing
- “Passive” propagation
- Travel short distances
- “Do I want to send a message or not?”
What characterizes an action potential?
- Voltage-Gated channels
- “Action”
- Large changes in polarity
- All or none (can’t sum)
- Larger stimulus or more transmitter equals more frequent action potentials
- Depolarizing
- “Passive” and “Active” propagation
- Travel long distances
- Message is sent
