Last Modified: 2016-03-08
In a neuron that is polarized, the amount the inside and outside voltage differs (e.g. -70 inside the neuron says that the potential inside the resting neuron is 70 less than that outside the neuron)
Factors- Even distribution of ions
adding or combining a number of individual signals into one overall signal
the summation of graded potentials as a result of stimuli presented from two different presynaptic sites at the same time; best summation results from close stimuli
the summation of two or more graded potentials as a result of two or more stimuli presented with separation in time
the gaps between adjacent myelin segments.
Conduction along the the mylenated sections are the axon are passive, it occurs instantly, and the signal jumps along the axon from node to node.
nodules of various shapes that are located on the surface of many dendrites
synapses at this the site of neurotransmitter release and the sire of neurotransmitter reception are in close proximity
Narrow spaces between adjacent neurons, bridged by fine tubular channels containing cytoplasm
electrical synapses made of protein
Two advantages over chemical synapses because they are so close together:
- Fast communication across junction
- Bidirectional communication (unlike chemical synapses)
Four criteria for identifying neurotransmitters
Chemical must be synthesized or present in neuron
When released chemical must produce response in target cell
Same response must be obtained when chemical is experimentally placed on target
There must be a mechanism for removal after chemical’s work is done
NT is going to cause a depolarization (EPSP) in the synaptic gap and increases the likelihood that a AP will happen
ex Glutamate (amino acid)
NT that is going to cause a hyperpolarization (IPSP) in the synaptic gap and decreases the likelihood that a AP will happen
ex GABA (amino acid)
much bigger than small molecule neurotransmitters
presence of two or more neurotransmitters in same axon terminal
usually different stimuli cause release of diff NTS in different vesicles (big or small)
Synthesis & packaging
Transport to axon terminals
vesicles packaged--> brought down to the axon terminals to be released
When you make a peptide, you need to make it in the cell body where there are rhybosomes you cannot make it in the axon.
Words From Our Students
"StudyBlue is great for studying. I love the study guides, flashcards, and quizzes. So extremely helpful for all of my classes!"
Alice, Arizona State University
"I'm a student using StudyBlue, and I can 100% say that it helps me so much. Study materials for almost every subject in school are available in StudyBlue. It is so helpful for my education!"
Tim, University of Florida
"StudyBlue provides way more features than other studying apps, and thus allows me to learn very quickly! I actually feel much more comfortable taking my exams after I study with this app. It's amazing!"
Jennifer, Rutgers University
"I love flashcards but carrying around physical flashcards is cumbersome and simply outdated. StudyBlue is exactly what I was looking for!"