Review Of Intro To Neuro

Question 1

What is the role of oligodendrocytes?

Answer 1

Only found in the CNS; one cell of these myelinates the axon segment of many neurons

Question 2

What is the role of Schwann cells?

Answer 2

Found in the PNS; one cell myelinates axon segment of one neuron

Question 3

What is the role of Astrocytes?

Answer 3

End feet of the BBB

Question 4

What is the role of microglia?

Answer 4

Immune function, modulates inflammation and cell survival in the brain

Question 5

What are the 3 conditions for a neuron to be at rest?

Answer 5

1) solutions inside and outside the cell are electrically neutral
2) the concentrations of intracellular and extracellular molecules must be in osmotic balance
3) there cannot be any net flux of ions

Question 6

What four ions contribute to resting membrane potential?

Answer 6

Sodium, potassium, chloride, and proteins

Question 7

Which ions are found in high concentration extracellularly?

Answer 7

Sodium and chloride

Question 8

What ions are found in high concentration intracellularly?

Answer 8

Potassium and proteins

Question 9

What forces act upon ions and contribute to the resting membrane potential?

Answer 9

Diffusive force, electrical force, sodium potassium pump, and permeability although not a force

Question 10

How many sodium and potassium ions are pumped in/out of the NA/K ATPASE per molecule of ATP?

Answer 10

3 sodium out, 2 potassium in

Question 11

What are the nodes of Ranvier?

Answer 11

Areas of densely populated ion channels that allow for “hopping” of the AP in propagation down the axon

Question 12

What are the four general categories of neurons and their functions?

Answer 12

1) sensory: take environmental signals and make them neuronal (sound, touch, pain)
2) motor: cause muscle contraction or control secretions
3) interneurons: modulate activity between nearby regions of the CNS
4) projection neurons: communicate between distant regions of the CNS

Question 13

What lobes of cortex are separated by the Sylvian/lateral fissure?

Answer 13

Frontal and temporal lobes

Question 14

What lobes are separated by the central sulcus?

Answer 14

Frontal and parietal lobes

Question 15

What is the corpus callosum made of, and what is its function?

Answer 15

Functions to connect the two brain hemispheres and is made of projection neuron axons

Question 16

What cells make up the BBB?

Answer 16

Endothelial cells, pericytes, & astroglial cells with tight junctions

Question 17

What are some examples of gases that can cross the BBB?

Answer 17

NO, CO2, O2

Question 18

What is the equilibrium potential of an ion?

Answer 18

The membrane potential where the net flow through any open channels is zero

Question 19

What is the reversal potential of an ionotropic receptor?

Answer 19

Also the membrane potential where the net flow of ions is 0, but the difference is that receptors can be permeable to multiple ions

Question 20

What are the 5 components of the AP and what are they characterized by?

Answer 20

1) Depolarization to threshold; sodium current
2) upstroke; sodium current and channels quick to open
3) downstroke; potassium current, K channels sluggish to open and quick sodium channels inactivated
4) after hyperpolarization; potassium current and K channels sluggish to close
5) refractory period; inactivation of NA

Question 21

Briefly describe the steps of vesicle fusion

Answer 21

1) AP enters terminal
2) membrane depolarizes and Calcium channels open
3) calcium moves into the neuron
4) synaptic vesicles fuse to the membrane
5) NTs released into the cleft

Question 22

What is the difference between a PSC and a PSP?

Answer 22

PSC refers to the currents that move through channels & PSP refers to membrane voltages

Question 23

What ions do glutamate channels conduct?

Answer 23

Sodium and calcium in and potassium out

Question 24

What ions do GABA channels conduct?

Answer 24

Chloride in or potassium out

Question 25

What is spatial summation?

Answer 25

Multiple inputs from multiple locations converge on the soma depending on distance from the soma

Question 26

What is temporal summation?

Answer 26

A single input fired at a high frequency

Question 27

What are the differences between APs and PSPs?

Answer 27

APs are all or none, always excitatory, and do not degrade

PSPs degrade, can be excitatory or inhibitory, and are proportional to the intensity of the stimulus

Question 28

What is the orientation of gray and white matter in the brain and spinal cord?

Answer 28

Gray is on the outside in the brain and on the inside in the spinal cord. White matter is on the inside in the brain and on the outside in the spinal cord.

Question 29

True or false: there are some regions of the brain that do not contain the BBB

Answer 29

True

Question 30

What is the role of SNARE proteins?

Answer 30

To mediate the vesicle fusion with the plasma membrane during NT release

Question 31

When there is no net flux of ions across the membrane, what two forces are balanced?

Answer 31

Diffusive and electrical

Question 32

What is the equilibrium potential for potassium?

Answer 32

-90 mV

Question 33

What is the equilibrium potential for sodium?

Answer 33

+60 mV

Question 34

What is the equilibrium potential for chloride?

Answer 34

-70 mV

Question 35

What is the equilibrium potential for calcium?

Answer 35

+ 134 mV

Question 36

What are the cell effects of glutamate and then GABA?

Answer 36

Excitatory and inhibitory, respectively