Please enable JavaScript.
Coggle requires JavaScript to display documents.
NERVOUS SYSTEM (ACTION POTENTIAL (How does NT release lead to an AP? (EPSP…
NERVOUS SYSTEM
ACTION POTENTIAL
-
- AP reaches axon terminal & DEPOLARIZES it, voltage gated Ca++ enters neuron triggering exocytosis of vesicles containing NT
- NT is released & travels across the synapse binding w receptor on post synaptic neuron initiating a response
- Voltage gated ion channels (Na+) opens
- EPSP's continue to charge summates (spatially or temporally) until potential @ axon hillock becomes -55mV
- EPSP begins (mem. potential :arrow_up: bc of Na+)
- excitatory n.t. (glutamate) binds to receptors on post synaptic neuron. Ligand gated channel opens and Na+ enters
- post synaptic neuron @ rest (-70 mV)
-
-
CNS
microglia immune cells of the CNS (phagocytize debris) small, found in cerebral spinal fluid (CSF)
astrocyte provide neurons w/ nutrients (glucose,) form part of the blood brain barrier, regulate ion conc. in extracellular space. Neurotransmitter uptake & release. (v important)
BBB- composed of capillaries (selectively permeable due to tight junctions) It regulates the substances that can enter the brain.
Ependymal cells- epithelial cells that the ventricles in the brain and the central canal of the spinal cord. Have cilia that beat to move the cerebral spinal fluid (CSF) around.
types of polarization
-
-
Polarization membrane has a charge associated with it (+ outside, - inside)
Hyperpolarization neuron becomes more (-) inside than it was at a resting mem. potential. Gains (-) charge or Loses (+) charge
Types of Neurons
Interneurons Primarily in CNS, link neurons together
-
Sensory (afferent neurons) respond to sensory stim (temp, touch) bring info from PNS to CNS
NEUROTRANSMITTERS
Neurotransmitter Release
- Ca++ triggers exocytosis of vesicles containing nt
- NT is released and travels across synapse
- Voltage gated Ca++ channels open and Ca++ enters the neuron
- NT binds w/ receptor on post synaptic neuron and initiates response
- Action potential reaches axon terminal and depolarizes it
-
Common N.T.'s
-
Acetylcholine (ACh)
released onto muscles --> muscle contraction synthesized by choline + acetyl coA. Broken down by AChE.
-
-
-
-
-
-
-
