Cellular Neuroscience-Exam I Flashcards
How many cells are in the human brain?
170 Billion Cells HOW DO THEY KNOW THIS??
What protein structures are used in axoplasmic transport?
MicroTubules and MicroFilaments
Which cell structure accounts for over 90% of the cell surface area for synapses?
Dendrites
What is a common example of an umyenated axon?
A pain receptor, thank god it takes these signals longer eh?
What is an axon branch called?
An axon collateral
What part of the axon contains the N.T. vesicles?
The axon terminal
What determines the action of a neuron? The N.T. or the Receptor? Example??
The receptor determines the action for the neuron.. Ach excitatory in skeletal muscle, but inhibitory in cardiac muscle
Will Negative Ion channels depolarize(excite) or hyperpolarize(inhibit) a neuron?
Hyperpolarize(Inhibit)
Will positive ion channels depolarize (excite) or hyper polarize(inhibit) a cell?
Depolarize (Excite)
Where am I going to find pseudo unipolar neurons? What makes them UNIQUE?
PNS Sensory Afferents…2 AXONS!!
Where am I going to find BiPolar neurons?
Special Sensory. BiPolar people are special :)
What is unique about multipolar neurons?
Large Dentritic Trees, perkunjie fibers
What type of neuron makes up 99% of ALL NEURONS… wow. Where can I find these bad boys?
Interneurons, making connections between the afferent and efferent neurons, processing…ONLY IN CNS
What are two main names for congregations of neuronal cell bodies(gray matter)?
Nuclei and ganglia
What are 4 names to describe groups of axons(white matter)? Ready for some crazy new words?!
Tract, Fasciculus, lemniscus…several tracts=funiculus
What types of glial cells might be excitable?
AstroCytes
What are the main immune-like, and healing functions of Astrocytes?
The Blood Brain Barrier!! and scar formation in CNS
What CNS glial cells line cavities?
EP-EN-DY-MAL cells
What are the macrophages of the CNS?
MicroGlia
What is the function of nonmyleinating schwann cells?
regrowth of motor axons in PNS
What part of the PNS neuron does the Satellite cell surround?
The cell body
What is an astrocytoma that can spread from one side of the brain to the other using the corpus callosum? PLEASE don’t get this wrong!
GlioBlastoma MultiForme
What is the normal resting potential range of a neuron?
-70 to -90 mv
What are the normal Na and K [Gradients]?
More Na outside cell, more K inside cell (Na/K pump-2 K in 3Na out)
At rest which ion is the cell more permeable to Na or K?
K
What is happening when a cells membrane potential only moves a little and gets more positive(like from -70mv to -60mv)?
Excitatory Post Synaptic Potential (E.P.S.P)!!!
What’s it called when a cell potential becomes slightly more negative (like -70mv to -80mv)?
Inhibitory Post Synaptic Potential (I.P.S.P)
What is the A.P. threshold?
-55mv
What are the two ways a nerve or muscle cell can be excited?
Synaptic Input OR Electrical Stimulation
What is the first step after the threshold has been reached? What does the membrane potential reach?
Na channels open. Membrane potential will reach +20mv c/o all the positive Na’s coming in
What are two factors that open a Na channel?
Time and Voltage
What event occurs to REpolarize the cell?
K will rush out naturally (we need to get the Positive charge out!)
What do astrocytes in the CNS do to help maintain resting membrane potentials?
They Eat bananas! I mean potassium.
What causes Myotonia congenita and spasticity?
Plateau Potentials c/o Calcium enrtry
Why is the axon hillock the site of starting the A.P. propagation?
The hillock has the highest density of voltage gated channels
What are the two types of A.P. propagation? Hint: has to do with myelin..
Local Current Flow & Saltatory Conduction
How fast is a myelinated A.P. in mph? How much faster is that then unmyelinated?
360mph!! 50x faster
Which conducts an action potential faster? Larger or smaller axon?
Larger Axons, less RESISTANCE!! I love electricity :)
Which is normal conduction? Orthodromic or Antidromic?
Ortho=normal, Anti=not normal, made in a lab
What type of sandwich are the synaptic transmission signals?
Signals at the synaptic transmission go from an electrical to a chemical, to an electrical sandwich :)
Are synapses in the Soma (axo-somatic) generally E.P.S.P.’s or I.P.S.P.’s? What about ado-dendritic?
axo-somal: IPSP axo-dendritic: EPSP
What type of channels open in the axon terminal to later on release N.T.?
Voltage gated Calcium Channels (Ca then flows down [gradient]
What are the three main ways to end a synaptic transmission?
Diffusion, Enzyme degredation, or reup
What never happens at the synapse of an alpha motor neuron and a motor neuron? What helps a muscle cell relax then?
IPSP.. IPSPs can happen at the dendrite or soma of the alpha motor neuron in the brain (just not at the axon terminal)
What term is used for an axo-axonic synapse that aids another axon to release MORE neurotransmitter? What about the same thing but inhibiting?
Presynaptic Facilitation….vs Presynaptic Inhibition
What are the 5 classy classes of N.T.’s?
1.MonoAmines 2. Cholinergic 3. Amino Acids 4. NeuroPeptides 5.NonTraditional
What are the two classy classes of Receptors? What are their main functions?
Ion-To-Tropic & Metab-O-Tropic (Gprotein)….Iontotopic opens ion channels, metabotropic causes the chain rxn of Gproteins which can be EPSP,IPSP gene signaling YOU NAME IT
What are the subcategories of MonoAmines?
1.Cat-E-Chol-Amines: a)Epi, b)NorEpi, c)Dopamine & 2.Seratonin
What is an example of a Cho-Lin-Ergic N.T.?
Ace-tyl-cho-line
What are three examples of Amino Acid N.T.’s?
a) Gamma-Amino-Butyric-Acid (GABA) b)Glycine c)Glutamate
What are 3 examples of Neruo-peptides?
Endorphins, Calcitonin, Substance P
What are two examples of nontraditional N.T.’s?
NO, and CO2
What are the only two N.T.’s that are not BOTH IontoTropic AND MetaboTropic?
NorEpi & Dopamine
