Ch. 2 Structure And Function Of Cells Of The Nervous System

Front 1

What are the obstacles for studying the cells of the nervous system?

Back 1

1) Size

2) Nervous tissue/cells are like jello, so we need to harden them to make sections for slides

3) Cells are transparent and need to be stained to be visualized

Front 2

What was the first identified neuron, why, and where do we find them?

Back 2

Pukinje cells because they're huge cerebellum neurons

Front 3

Describe the first identified neuron

Back 3

Purkinje Cells are some of the largest neurons with a long axon and a giant dendritic tree. I'm talking massive **** here.

Front 4

What are the 2 stains used to identify nervous system cells? How do they differ in their staining ability?

Back 4

Nissl staining stains glial cells and cell bodies ONLY

Golgi staining stains all of the neuron, but unfortunately only like 15-20% of cell density

Front 5

What is the benefit of golgi staining?

Back 5

It shows the entire dendritic tree and orientation of the neuron relative to others

Front 6

Who published a paper on silver nitrate staining and believed in the reticular theory of the brain? What is the reticular theory?

Back 6

Camillo Golgi. Reticular theory means all neurons are physically connected in a net as a giant continuous system

Front 7

Who one-upped Golgi's stainng procedure then killed his stupid little reticular thoery? What was proposed instead? How was this theory flawed too?

Back 7

Cajal improved golgi's staining and described nerves as independent elements thus founding the neuron doctrine. He was close, but we described neurons are communicating via contact not continuity.

Front 8

This "Sir" came along after Cajal and Golgi shared their nobel prize in 1906 and finally got it right by proposing the concept of ______ as a place of communication for neurons. Who am I and what did I propose?

Back 8

Sir Charles Sherrington proposed the synapse and walked away with a nobel in medicine in 1932

Front 9

What is the function of the sensory neuron and define nerve.

Back 9

Sensory neurons bring information to the CNS and nerves include blood vessels + bundles of neural axons

Front 10

How can we differentiate between an axon and a dendrite?

Back 10

Axons can branch out at any point whereas dendrites can only branch at their ends

Front 11

What cells are found in the cortex that can communicate with cells above or below, and laterally with other cells?

Back 11

Pyramidal cells thanks to the apical and lateral axons

Front 12

Describe thalamic association cells?

Back 12

Has a ton of dendrites all around it. Kinda looks like a ball of hair?

Front 13

What neurons have some of the largest axons and why?

Back 13

Motor neurons since they go from the spine out to the muscle

Front 14

How do dendrites differ from terminals?

Back 14

Dendrites don't have terminal buttons

Front 15

How can we differentiate unipolar and bipolar neurons?

Back 15

By the number of neurites!
Unipolar cells have a stalk that splits into 2 branches and the soma is not in line with everything else, whereas bipolar cells have 1 axon and 1 dendritic tree with the soma in line with everything else.

Front 16

Sensory neurons are __erent whereas motor neurons are __erent

Back 16

Sensory are afferent whereas motor are efferent

Front 17

Name the 7 important structures of a neurons internal structure

Back 17

1) Nucleus

2) Dendritic Spines

3) Endoplasmic reticulum

4) Ribosomes

5) Mitochondria

6) Golgi Apparatus

7) Microtubules

Front 18

Describe dendritic spines. What is the advantage of dendritic spines?

Back 18

Have a head and neck to a spine. Usually have a synapse. Spines are a way for cells to process diff. inputs

Front 19

Neurofilaments confer ___ to a cell

Back 19

Strength

Front 20

What are the 4 CNS support cells. What is the umbrella term for these cells that provide physical support, control nutrient flow, and are involved in phagocytosis?

Back 20

1) Astrocytes

2) Microglia

3) Oligodendrocyte

4) Schwann Cells

Front 21

What cells are responsible for physical support, debris removal, and nutrient transport to neurons?

Back 21

Astrocytes

Front 22

What cells are involved in phagocytosis and brain immune function?

Back 22

Microglia

Front 23

How do oligodendrocytes differ from Schwann cells?

Back 23

Oligodendrocytes are only found in the CNS and can myelinate multiple cells simultaneously via arm-like extensions of itself. Schwann cells are only in the PNS and the entire cell wraps around the neuron and becomes myelin.

Front 24

What does the BBB separate? Where is the BBB weakest and why?

Back 24

BBB separates blood and the brain by producing cells that line the walls of the brain's capillaries. The BBB is weakest at the area postrema which is in the medulla and acts as a poison detector since it can initiate vomiting.

Front 25

Define and quantify resting membrane potential.

Back 25

Difference in electronic potential between inside and outside of the cell. It's usually -70mV

Front 26

K+ is found in highest concentrations ____ the axon, whereas Cl- and Na+ are found in highest concentrations ____ the axon

Back 26

K+ inside, Cl- and Na+ outside

Front 27

Describe the action of the sodium-potassium pump

Back 27

2 K+ into the cell for every 3 Na+ out of the cell

Front 28

Is a pump is electrogenic, what does that mean?

Back 28

It produces a separation of charge

Front 29

What are 2 properties of passive conduction?

Back 29

It's fast and degrades over distance

Front 30

What are the 6 steps of an action potential?

Back 30

1) Na+ channels open

2) K+ channels open

3) Na+ channels become refractory and close for 2-3ms

4) K+ leaves the cell as membrane potential returns to resting levels

5) K+ channels close and Na+ channels reset

6) Extra K+ outside the neuron diffuses away and we hyperpolarize

Front 31

Define rate law

Back 31

Stronger signals produce higher firing rates at a fixed amplitude

Front 32

How do action potentials differ from local disturbances?

Back 32

Action potentials don't degrade over distance unlike local disturbances

Front 33

Conduction velocity is proportional to what property of a neuron?

Back 33

Axon diameter and myelination

Front 34

Why do we need nodes of ranvier?

Back 34

There is decremental conduction going on under the myelin sheath which is a gradual decrease in the stimuli and response along a pathway of conduction. Nodes of ranvier serve to kick up this signal back to it's full amplitude.

Front 35

What is the function of axonal cisternae? What organelle at these associated with?

Back 35

Cisternae recycle vesicles and are part of the golgi apparatus

Front 36

Define Axosomatic synapse

Back 36

When a terminal of 1 neuron attached to the soma of another

Front 37

Why is the postsynaptic membrane thicker?

Back 37

It's higher concentration of receptors

Front 38

What is the function of an axoaxonal synapse?

Back 38

These are usually inhibitory but serve to regulate amount of neurotransmitter being released

Front 39

How does a vesicle interact with the presynaptic membrane to release NT into the synaptic space?

Back 39

1) Action potential opens voltage dependent Ca2+ channels

2) Ca2+ interact with vesicle and membrane proteins allowing for fusion

3) Vesicle fuses as omega figures and releases NT

Front 40

How does a post-synaptic potential differ from an action potential?

Back 40

1) Post-synaptic potentials can be graded and summated, whereas action potentials are all or nothing at an invariable magnitude

2) Action potentials are generated by voltage-gated channels whereas local potentials are generated by chemically-dependent channels, usually NT

Front 41

How do we make a "bigger" post-synaptic potential?

Back 41

1) Increase concentration of receptor

2) Increase concentration of NT

Front 42

What is neural integration?

Back 42

The algebraic summation of post synaptic potentials

Front 43

Which type of ion channel requires energy input and is also slower?

Back 43

Metabotropic