1What are the major divisions of the human nervous system?
The central nervous system and peripheral nervous system
2What makes up the CNS
Brain + spinal cord
3What makes up the PNS
Afferant and Efferant neurons
4How do afferant and efferant neurons compare?
Afferant neurons are out to in (cns), efferant neurons are in (cns) to out
5What are the major trends in brain and nervous system evolution
Nervous systems get bigger and more complex, concentration of sensory structures at head, and more complex behaviors arise
6What are emergent properties?
Behaviors or functions that cannot be explained purely through the sum of their parts (neurons)
7What is a hallmark of neurological disorders?
Disorganization of either thoughts, words or movements. Loss of proper control + functionings
8What is required to see that there are gaps between synapses?
Electron microscope, the gap is only a few nm across
9What is the golgi method?
Soaking nervous tissue with potassium dichromate + SILVER NITRATE, con is that it only stains a small percentage of neurons
10What were Cajal's major findings?
The neuron doctrine aka the nervous system is made by discrete neurons wired in circuits which communicate over synaptic gaps
11How are neurons and glia similar?
Both are cells (nucleus + organelles), both process information and respond, both make synapses
12What do glia do that neurons do not?
Insulate neurons, remove waste from neurons, are able to divide, feed neurons
13What do neurons do that glia do not?
Command body responses (muscular for example), process information and communicate that info to other neurons
14What types of glia are there
Three major: Schwann cells (insulate PNS), Oligodendrocytes (insulate CNS) and Astrocytes (maintain extracellular space =ion balance, most numerous, CNS) Three minor: microglia, ependymal (CNS) + Satellite cells (PNS)
15What is the space between myleniating glia called?
The node of Ranvier
16What is resting potential?
The base electrical charge when a neuron is not firing or recovering from doing so, resting potential must be maintained, -70 mV
17What does membrane potential refer to?
The voltage across the neuronal membrane
18What ions are involved in maintaining resting potential?
Potassium inside (banana, positive), sodium, calcium and chlorine (outside, negative except for potassium)
19What is responsible for maintaining resting potential on the membrane?
Leak channels (always open, usually for K+) and pump proteins (Na-K pumps and calcium pumps)
20What is the nernst equation?
The equation for equilibirum membrane potential which is Eion = (gas constant x temperature)/(charge of ion x farraday constant) x log of (ion out / ion in) requires no knowledge of permeability
21What is the goldman equation?
A permuation of the nernst equation: (gass constant x temperature)/Faraday constant x log of (permeability for K x K out + perm of NA x out)/(permeability for K x K ion + perm of NA x in)
22What ion is particularly impactful to membrane potential?
K+
23What is an example of a disease of membrane potential?
Hypokalemia, not enough K+, everything takes a LOT more to fire, slow everything (bad!)
24What are some ways that K+ is regulated in the brain?
The BBB (blood brain barrier) and astrocyte glial cells
25What ion tends to trigger action potentials and how?
Na+ and by coming into the cell from outside from sodium channels
26What term means tending towards and action potential?
Depolarization
27What are the four phases of an action potential?
Rising (depolarizing), Overshoot (inside becomes positive and AP is triggered), Falling (repolarization), Overshoot (Cell is briefly hypoerpolarized and returns to RP)
28What limits the frequency of action potentials?
Refractory period
29What is different about a graded potential in comparison to an action potential?
Graded potentials do not cross the threshold to trigger an AP and can de or hyper polarize, they spread passively and are short range
30Where does the rising period of an AP come from?
Voltage gated Na+ channels opening
31Where does the falling period of an AP come from?
Voltage gated Na+ channels close and K+ voltage gated channels open
32what is the physical mechanism behind refractory periods?
Na+ channels are temporarily inactive and cannot open
33Where do graded potentials occur?
The dendrites and soma (relatively few NA+ channels)
34Where do action potentials occur?
The axon and axon hillcock, many Na+ channels here
35Why does information only flow in one direction on an axon?
voltage gated sodium channels open, close, are forced to stay closed for some time and then reopen
36What is the ball and chain model?
As the sodium channel opens the "ball" is pulled and forcefully closes the channel for a milisecond
37What refreshes the signal on nodes of ranvier?
There are many sodium channels and there is no mylein
38What are the neurotransmirrer catagories
Atcetylcholine, Amino acids, Peptides, Biogenic amines, and Gaseous signalling
39What ways can neurotransmitters be made?
synthesis in the soma (peptides), or synthesis at the synapse (enzyme travels from soma and is used at synapse)
40What are the types of transmitters?
Ionotropic and metabotropic
41How do ionotropic transmitters work?
A neurotransmitters binds to a channel and lets ions in or out
42How do metabotropic transmitters work?
A neurotransmitter comes onto the protein, the g protein attached intracellularly detaches and travels over to another channel and creates changes
43How do amanita/muscarine mushrooms kill?
Acetylcholine binds G protein coupled receptor for this molecule, the K+ channels open and the heart is hyperpolarized
44How do many neurotoxins kill?
They have higher affinity to the receptor than natural transmitters and cannot be removed
45What are catecholamine transmitters involved in?
movement, mood, stress, attention and autonomic motor system function
46What effects does serotonin have on the brain?
regulates mood, emotional behavior and sleep. ssri's and maoi's help increase levels
47GABA and glycine gated channels, what do they do?
Gaba mediates most syanptic inhibition,and Glycine usually does what Glycine doesnt