Lecture 2 (Neurons Basics)

Question 1

Output information is encoded in electrical impulses that a neuron provides neural input to

Answer 1

to Innervate the neuron

Question 2

branches of neuron

Answer 2

arborization

Question 3

information flows from the cell body of the pre-synaptic neuron to the postsynaptic neuron (info enters through input zone and out of the output zone)

Answer 3

Dynamic polarization

Question 4

large collection of neurons

Answer 4

ganglia

Question 5

grey matter

Answer 5

cell bodies and dendrites (receives and transmits information)

Question 6

white matter

Answer 6

axons (coated in myelin sheath) transmits information

Question 7

Is the basal ganglia a white or grey matter structure

Answer 7

grey matter (cell bodies and dendrites, receives transmits information)

Question 8

Afference

Answer 8

information arrive at the neuron

Question 9

Efferent

Answer 9

information moves away from the neuron

Question 10

Components of the input zone:

Answer 10

a.) dendrites (receive information)
*dendritic spines
b.) Cell body/soma (receives synaptic input and decides whether or not to send signal)
* Nucleus
C.) Axon Hillock (integrates and gathers information from the soma)

Question 11

dendritic spines

Answer 11

small projections on the dendrites that add extra space for synapses. They come and come (neuro-plasticity and change as is memory encoded)

Question 12

Soma (roles)

Answer 12

Nucleus (receives synaptic inputs, and determines whether to send a signal)

synthesizes important substances

structural proteins (remodelling of cytoskeleton)

transmitters (synthesizes enzymes)

Question 13

Conduction zone (components):

Answer 13

1.) Axon (protection that leads away from the neuron –sends the neural impulse)

• Mylein sheath –> beaded fat insulator that speeds up action potential
• nodes of ranvier –> gaps in the myelin sheath
• axoplasmic transport –> transport of vesicles of neurotransmitter (via Motor proteins)

Question 14

axoplasmic transport

Answer 14

transport of vesicles of neurotransmitter in axon. via motor proteins (kinesin and dynein)

Question 15

Kinesin

Answer 15

workhorse of the cell = transports proteins via walking on microtubules (two feet like structures)

Question 16

wire and hose

Answer 16

wire: axon potential travels through axon
hose: transport flow of vesicles (axoplasmic flow)

Question 17

retrograde

Answer 17

movement towards cell body

Question 18

anterograde

Answer 18

movement away from the cell body

Question 19

Output zone (components):

Answer 19

1.) Axon collaterals
2.) Axon terminals (boutons)
3.) Synapse
*synpatic cleft (lipid bilayer)

Question 20

Synapse cleft is composed of a:

Answer 20

lipid bilayer (fat soluble, hydrophilic head, hydrophobic tail)

Question 21

Steps of transmitter signal from pre to post-synaptic membrane:

Answer 21

1.) electrical activity causes vesicles to fuse with the presynaptic membrane
2.) vesicles rupture releasing neurotransmitter into the cleft
3.) neurotransmitter crosses the cleft and matches with the receptor
4.) alters level of excitation in post-synaptic neuron, may send a signal of its own

Question 22

Three neuron shapes:

Answer 22

1.) Multi-polar = large neurons, long axon, dendritic arborization, several axon collaterals (MOTOR NEURONS)

2.) Bi-polar = very small, few dendritic branches, short axon (in your retina/vision)

3.) Mono-polar = dendrites are part of a single axon (Peripheral sensory neurons)

Question 23

Three types of neurons:

Answer 23

1.) Motor neurons
2.) Sensory neurons = affected by changes in environment
3.) Interneurons = receive and send input

Question 24

Four types of glial cells:

Answer 24

1.) Astrocytes

2.) Microglia

3.) Oligodendrocytes

4.) Schwann cells

Question 25

Astrocytes

Answer 25

• start shaped
• close to capillaries and blood vessels = control local blood flow (allows for blood to reach active areas of the brain)
  *contribute to tough membrane around brain
  *secrete growth factors
• can become cancerous

Question 26

Microglia

Answer 26

*Macrophage
* scavenge at damage sites
* release pro-inflammatory substances
*break down dead cells

Question 27

Glial cells that may worsen: edema – swelling after brain injury, Parkinson’s, Alzheimer’s

Answer 27

Microglia, and astrocytes

Question 28

Oligodendrocytes

Answer 28

source of myelin (allows for salutatory conduction)
found in brain and spinal cord

Question 29

Schwann cells

Answer 29

Peripheral nerves
source of myelin