Neural Communication Flashcards
Action potential transmits signal from neuron cell body to the axon terminals.
Electrical communication
Neurotransmitters travel across the synapse and bind to post synaptic receptors.
Chemical Communication
Pituitary gland releases corticoptropin releasing hormone to signal to the adrenal glands to release cortisol
Hormonal communication
Communication begins with neuronal transmission from one part of the cell to another part of the same cell via their axons which is
electrical
Communication between neurons at synapses is
chemical
Neurons communicate with?
other neurons, end organs, and external sensory receptors (brain/afferent neurons)
What happens at the neuron?
- neurotransmitters bind with receptors on the neuron at the dendritic spines 2. Chemical changes inside the spine that are communicated via the dendrite to the cell body 3. if accumulation of signals is sufficiently large cell communicates down the axon to the axon terminals. 4. At the axon terminals cell-specific neurotransmitter released
How does the neuron signal the axon terminals to release neurotransmitter?
Signals come in at the dendrites and are accumulated by the cell body, if accumulation is sub threshold, cell is hyperpolarized and inhibited from signaling, if accumulation is at or above threshold the cell body sends a signal to the axon terminals to release neurotransmitter
What are action potentials?
An electrochemical process that is directly related to the structure of the cell wall and the concentrations of important ions on both sides of the wall
What are the most important voltage sensitive ion channels?
sodium and potassium
At rest voltage sensitive ion channels are?
closed
Identify the normal concentration of sodium and potassium ions.
Sodium is greater on the outside and potassium is greater on the inside of the cells
What happens when a cell depolarizes?
The cell opens and sodium ions rush in, to maintain homeostasis the potassium channels open and potassium ions pour out. The sodium channels close, then the potassium channels close. Then the sodium/potassium pump works to return ion concentrations back to homeostasis. Overall outcome is a wave of signal moving downstream.
What is absolute refractory period?
No signal can cause the neuron to fire both sodium and potassium channels are open
What is relative refractory period?
A larger than normal signal can cause the neuron to fire. Sodium ions begin to close but potassium channels still open.
What happens when the action potential arrives at an axon terminal?
It turns from electric to chemical. A calcium channel opens and calcium motivates vesicles to move toward cell walls. Vesicles bind with the cell wall. Exocytosis of contents of the vesicles, calcium channels close and neuron returns to its resting state.
Communication within a neuron is?
electrical
Communication between neurons is?
chemical
What are circiuts
the networks that coordinate behavior
What are pathways?
Projections or groups of neurons that project between structures that use the same neurotransmitter.
What are the three criteria for being a neurotransmitter?
must be stored in the presynaptic neuron, must be released with depolarization induced by the influx of calcium (in the presynaptic neuron), and it must bind with a specific receptor on the postsynaptic neuron.
What four amino acid neurotransmitters are there?
Glutamate, aspartate, GABA, and Glycine
What are the two subcategories of monoamines?
Catecholamines and Idoleamines
What are the three types of catecholamine neurotransmitters are there?
Dopamine, epinephrine, and norepinephrine