L9 (C1)

Question 1

what is the control system of the body

Answer 1

the nervous system

Question 2

what are the 3 over aching function of the nervous system

Answer 2

Major controlling, regulatory and communicating system in the body

Centre of all mental activity

Responsible for regulating and maintaining homeostasis

Question 3

why do we need to understand the cells in the brain

Answer 3

Basis of function – health and disease

Question 4

what are the 3 principal cell types in the nervous system

Answer 4

Neurons (nerve cells)

Neuroglia (glia):Greek “glue”

Cells from the vascular system

Question 5

when do we see the importance of cells

Answer 5

when their function changes

Question 6

describe the structure of a neuron

and the function that those section preform

Answer 6

dendrites
- receive signals from other cells

cell body
- organises and keeps the cell functional

nucleus
- controls the entire neuron

cell membrane
- protects the cell

axon hillock
- generates impulses of the neuron

axon
- transfers signals to other cells and organs

myelin sheath
- increases the speed of the signal

schwann cell
- produces the myelin sheath

node of ranvier
- allows for diffusion of ions

axon terminal
- forms junctions with other cells

Question 7

what is an action potential

Answer 7

An action potential is
the electrical signal
that travels through
the axon of a neuron
to send a message.

Question 8

how does neural communication work

Answer 8

The combined effect of multiple connections occur then they communicate

Question 9

what are the different signals in neural communication (within)

Answer 9

input is chemical

summation = electrical

conduction = electrical

output = chemical

Question 10

what are the nodes important for

Answer 10

saltatory conduction

Question 11

what are dendritic spines

Answer 11

they are small projections of the dendritic membrane of varying sizes

Question 12

what are the developmental phases of a dendritic spine

Answer 12

thinn, mushroom and stubby

Question 13

where does the dendrite spine attach to the neuron

Answer 13

the presynaptic bouton

Question 14

what creates the shape of the dendritic spine

Answer 14

actin

Question 15

what does the spine do when learning

Answer 15

Spines are plastic and row with learning.

Action creates the shape of the spine therefore the atin can move and retract with learning

Question 16

whe do we have the most dendritic spines

Answer 16

during spine maturation in childhood

Question 17

when does spine elimination start

Answer 17

adolescence

this is synaptic pruning

Question 18

why in AD and PD do you loose spines

Answer 18

because they loose neurons

Question 19

when does autism occur

Answer 19

Autism is when the spines aren’t prooned to the best of there ability which causes behavioural problems possibly because the brain is overexcitable

Question 20

what is a concussion

Answer 20

a traumatic brain injury

the brain is able to recover from

Question 21

what % of people recover from a concussion

Answer 21

80%

Question 22

what was seen when concussion patients performed a working memory task in a fMRI machine

Answer 22

Working memory task
NO difference on task performance

But persistent, significantly increased
activity in bilateral, dorsolateral prefrontal areas Injured athletes always need more brain activation

Question 23

when do we see the most amount of concussions

Answer 23

in the young and the old as they fall over more

Question 24

what causes Chronic traumatic encephalopathy (CTE)

Answer 24

CTE happens from repeated concussions

Question 25

what are the early and late signs of CTE

Answer 25

CTE happens in 20-30 leading to aggression CTE in older is dementia

Question 26

describe concussion at the level of the neurons

Answer 26

This is a mechanical injury in the neurons The trauma causes holes in the membrane (the proteins pop out) from the mechanical trauma Biomechanical injury -> mechanoporation Neurometabolic cascade results in a chemical injury Ionic flux – K+ out, Na+, Ca++ in, uncontrolled glutamate release This will causes depolarisation (like an open channel) which leads to glutamate release This can lead to excited toxicity ( too much K+ leaking out of the cell making it over excitable) which cases the cell to die Usually energy is used to maintain the energy potential but now that energy has to be redirected to repair the brain This is why when someone had a concussion we tell then to rest in a dark room and don't think about anything so that the brain can rest and not use this energy so that it would be used to think will be used to heal the brain

Question 27

describe a Transmission electron microscope (TEM)

Answer 27

Illumination source at the top Then there are converging lenses Electrons pass through the sample, some are deflected off the object and some go through to give us out image The electrons then go onto the observing lens

Question 28

what is the function of Transmission electron microscope (TEM)

Answer 28

Lets users look at a very thin cross-section of an object (such as a cell).

Question 29

what is the max magnification on a Transmission electron microscope (TEM)

Answer 29

5,000,0,00x

Question 30

a Transmission electron microscope (TEM) is best at looking at.......

Answer 30

Looking at internal structure of objects Looking at objects at very high resolution Looking at relationships between structures at high resolution.

Question 31

what is a disadvantage of TEM

Answer 31

Can’t be used to look at living things (samples need to be prepared extensively before visualising). Costly to run

Question 32

who would you produce a moving image of TEM

Answer 32

with sequential slides of tissue

Question 33

what is a neuorns shapes dependent on

Answer 33

its cytoskeleton

Question 34

what are neurons different shapes

Answer 34

They have these shapes to make the correct connections Where are they are where do they have to transmit these signals is what determines the shape

Question 35

´What is the best 3-D digital analysis tool in the world?

Answer 35

the human visual system

Question 36

what does a neuron start its life as

Answer 36

a columnar epithelial cell

Question 37

what do neurons have in common with epithelial cells

Answer 37

Plasma membrane = lipid bilayer with proteins - both have surface extensions, eg microvilli Organelles both contain ... - nucleus, m/c, RER, SER, Golgi, lysosomes Cytoskeleton both contain.. - microtubules, intermediate filaments (called neurofilaments in a neuron though) microfilaments

Question 38

what is the diameter of a microtubule

Answer 38

20 - 28nm

Question 39

what is the diameter of a neurofilament

Answer 39

10nm

Question 40

what is the diameter of a microfilament

Answer 40

5nm

Question 41

what is a microtubule made up of

Answer 41

tubulin molecules Made of dimers –⍺/ß tubulin soluble tubulin (⍺/ß) is located in cell

Question 42

what us a microfilament made up of

Answer 42

F-actin (filamentous) | G-actin (monomeric)

Question 43

are microtubule polarised

Answer 43

yes

Question 44

how does the axon grow

Answer 44

add tubulin dimers (to the microtubule) at +ive end to elongate the axon Labile – de- or re-polymerize as needed to retract and advance the microtubule

Question 45

what are Microtubule Associated Proteins (MAPs) important for

Answer 45

arranging microtubules into networks it is unique to soma and dendrites therefore it is used to identify soma and dendrite ((specific)

Question 46

where is Tau located

Answer 46

Tau in dendrite and axon, inc. distal axon

Question 47

if you were to look at a microtubule what would you see

Answer 47

structures branching off them (MAP2)

Question 48

describe the orientation of microtubule

Answer 48

in the axon they have a uniform orientation with the +ive end towards the axonal end (Tau) or you can have mixed ordination in the dendrites (MAP2)

Question 49

why do microtubules have a uniform orientation with the +ive end towards the axonal end

Answer 49

for axonal transport

Question 50

what orientation of the microtubules does Tau stabilise

Answer 50

in the axon they have a uniform orientation with the +ive end towards the axonal end

Question 51

what orientation of the microtubules does MAP2 stabilise

Answer 51

mixed ordination in the dendrites (MAP2)