Cells of the Nervous System Lecture

Question 1

Stomach to brain is sensory or motor?

Answer 1

sensory; brain to stomach would be motor

Question 2

which part of the nervous system is responsible for slowing down the heart beat rate?

Answer 2

autonomic - motor control over the cardiac muscle

Question 3

which part of neuron is responsible for receiving the signals

Answer 3

dendrites, the cell body, and part of the axon - these are all options of parts that can receive signals

Question 4

what is the axon responsible for

Answer 4

delivering the neural signal also known as the action potential

Question 5

where does the action potential start

Answer 5

the axon hillock or the trigger zone

Question 6

what is around the axon

Answer 6

myelin sheath

Question 7

why is myelin sheath important

Answer 7

speeds up the propagation of the signal; insulation; increases conduction speed

Question 8

do all axons have a myelin sheath

Answer 8

no

Question 9

is the myelin sheath continuous

Answer 9

no - there are segments of the myelin sheath

Question 10

how is the myelin sheath formed

Answer 10

an independent cell makes the myelin sheath - cross section of the myelin sheath would show the axon and then the cell around it - concentric circles like a snail shell

Question 11

why is the sheath not continuous

Answer 11

we need segments to help with action potential propagation

Question 12

what are the “nascar team supporting” cells to neurons?

Answer 12

the glial cells

Question 13

which cell is responsible for removing blood clots from the brain

Answer 13

microglia

Question 14

what are the microglia

Answer 14

they serve as kind of like the immune system of the CNS; pathological agents, remnants and other residual stuff it cleans it up

Question 15

what are astrocytes

Answer 15

make up structural framework of CNS; hold the capillaries; they support and brace neurons and they also help to control the chemical environment - astrocytes can be one of the ways to absorb, remove or secrete ions ; they can absorb neurotransmitters

Question 16

what do the oligodendrocytes do

Answer 16

they form the myelin sheath around the axons; they make different myelin sections of different neurons by connecting to multiple cells/neurons; insulators of the thick neurons of the CNS

Question 17

what do the ependymal cells do

Answer 17

they help with the circulation of the CSF

Question 18

what is outside of the cells? what are cells embedded within

Answer 18

extracellular fluid - ECF or interstitial fluid

Question 19

capillaries bring nutrients to the __ and then the ___ brings the nutrients into the cell

Answer 19

ECF , ECF

Question 20

what are the myelin forming cells of the PNS

Answer 20

schwann cells

Question 21

why do we need microglial in the CNS?

Answer 21

because our immune cells aren’t meant to be in the brain; CNS is too sensitive; we need to protect our brain

Question 22

what keeps the immune cells out of the CNS

Answer 22

the blood brain barrier (BBB)

Question 23

where is the BBB found

Answer 23

the capillaries in the brain and the ECF in the brain

Question 24

T/F? we control to some extend what goes through the BBB because there are a lot of things on the capillaries that we don’t want to get into the CNS

Answer 24

true

Question 25

do we have a spinal cord blood barrier too

Answer 25

yes

Question 26

what induces the formation of the BBB

Answer 26

the astrocytes and pericytes

Question 27

is the membrane that is formed by the ependymal cells permeable or impermeable and what is it called

Answer 27

permeable; barrier between CSF and capillaries called the CSFBB

Question 28

where are the borders

Answer 28

between ECF and brain tissue

between capillaries and CFS

Question 29

ECF is outside of line of ependymal cells (ciliated epithelial cells line the central cavities of the brain and spinal column) - what do they do

Answer 29

they form a permeable barrier between the CSF and nervous tissue

Question 30

what do the beating cilia do on the barrier built by ependymal cells

Answer 30

they help circulate the CSF

Question 31

where will you see a higher concentration of tie junctions

Answer 31

in the capillaries - like putting cement in between bricks of a well to keep things from moving through leaky part of the membrane and then the only way to get through the membrane is through the cells so we control through things like receptors

Question 32

who tells the endotheilial cells in the capillaries to make more tie junctions

Answer 32

the astrocytes

Question 33

the astrocyte’s arms bind to the endotheilial cells and molecularly tell the cells to make more tie junctions

Answer 33

(pericytes too)

Question 34

where is the CSF found

Answer 34

it coats the entire brain ; the brain “floats” inside a thin layer of CSF ; CSF helps with cushioning; it is a shock absorber and it feeds the brain

Question 35

inside the CSF there are spaces called

Answer 35

ventricles that are filled with CSF

Question 36

border made up of ependymal cells that belong to epithelial family of cells

Answer 36

true

Question 37

is the barrier formed by ependymal cells permeable

Answer 37

yes

Question 38

we cannot have any fluid in our body that just sits there which is why cilia are used to do what

Answer 38

circulate the CSF

Question 39

what would happen to people without ependymal cells or people with ependymal cells with cilia that are not moving? what is the condition called?

Answer 39

accumulation of CSF in the brain would lead to an oversized/inflammed brain?
hydrosephalus - “water on the brain”; excess CSF