Wk1 Flashcards
1
Q
3 main germ layers in development
A
endoderm
mesoderm
ectoderm
2
Q
mitosis is the process of __
A
cell division
3
Q
what is the first stage of the embryo
A
morula
4
Q
what stage of embryonic development starts to accumulate liquid on the inside?
A
blastocyst
5
Q
what are the two main layers of the bilaminar embryo?
A
epiblast
hypoblast
6
Q
where is an embryo generated from?
A
epiblast
7
Q
where do extra embryonic cells originate?
A
hypoblast
8
Q
what is gastrulation?
A
the stage when the embryonic disk collapses in on itself to form the embryonic (germ) layers
9
Q
in gastrulation, cells fold around the __
A
midline
10
Q
in gastrulation, cells on the surface of the ___ move ___
A
epiblast
inwardly
11
Q
what does the ectoderm form? 2
A
skin
nervous system
12
Q
what does the mesoderm form? 5
A
muscle connective tissue blood cells urogenital system most internal organs
13
Q
what does the endoderm form? 2
A
respiratory and digestive tubes
14
Q
where does the mesoderm form?
A
in between the ectoderm and endoderm
15
Q
early nutrition that feeds the embryo comes through the ____ from the ___
A
vitelline duct
yolk sac
16
Q
what happens in neurulation?
A
the ectoderm folds in on itself to create a neural tube
17
Q
on which orietnation of the embryo does the neural tube form?
A
dorsal ( back)
18
Q
how early is the neural tube starting to develop? when is it complete?
A
21 days
24-25 days
19
Q
the neural tube closes like __ towards ___
A
a zipper each end (having started in the middle)
20
Q
where does the neural tube form from?
A
ectoderm
21
Q
a neural tube will close when the ___ meet
A
neural folds on the surface of the ectoderm
22
Q
what comes from the hollow centre of the neural tube?
A
CSF
23
Q
def neural plate (in development)
A
region of the ectoderm that will form the neural tube
24
Q
what happens to the ectoderm layer once the neural tube has closed?
A
it will form skin
25
in what way does the nervous system arise from the ectoderm?
ectoderm forms the neural tube and the NS comes from this.
26
where are neurons of the Nervous system generated from in embryo?
neural tube (not ectoderm)
27
what happens to the neural fold once closed?
they become neural crest cells that go on to form bone, cartilage, nerves, and hair
28
how is hair important for developing a head and a face?
it reflects the compactness of sensation nerves in the brain, like nose and eyes etc. other animals without hair, like jellyfish, have more distributed nervous systems like a web instead of brain
29
what is produced at the ventral aspect of the neural tube?
SHH
30
the notocord produces a protein called ___
SHH
31
where is BMP formed?
dorsal aspect of the neural tube, near nerual fold
32
what is the significance of two proteins, BMP and SHH?
they are created at opposing sites (dorsal vs ventral) of the neural tube and thus form a gradient of protein expression as they diffuse along the neural tube tissue, which determines later neuron types
33
2 'plates' of neural tube and position?
roof plate = dorsal
| floor plate = ventral
34
different __ of proteins are important for giving __ to neurones as they develop in embryo and could determine whether neurones are ____
gradients
pattern/types
sensory or motor
35
motor neurons are located more towards the __ aspect of the neural tube. the opposite aspect would have ___ neurons
ventral
| sensory
36
3 primary vesicles of the brain?
prosencephalon
mesencephalon
rhombencephalon
37
what are the 5 secondary vesicles and which primary vesicle do they form from?
pros- :
tel- & di-
mes -> mes-
rhomb- :
met- & myel-
38
secondary vesicles have formed around ___ weeks
7-8
39
hypothalamus primarily regulates __
bodily functions (effector) like temperature, sleep, breathing
40
thalamus is primarily a __
sensory relay
41
the functional differences between the thalamus and hypothalamus is a continuation of what division in the neural tube?
sensory is dorsal, effector (muscle) is ventral
42
what sense does not go through the thalamus? why?
olfactory,
| an ancient sense (sub-aquatic origins)
43
only mammals have a __ cortex
cerebral (neo-)
44
a basic function of the cerebrum is __
association (intelligence)
45
what neuro-psychopharmalogical processes are finished by birth? 3
neurulation
neuronal proliferation
neural migration (at birth)
46
which neuropsychopharmalogical process continues into adulthood?
myelination
47
which neuro developmental process stops around adolescence? how does it relate to / explain adolescence?
synaptogenesis
| dopaminergic system is still maturing (synapses from ventral tegmentum to PFC)
48
what protein is produced anteriorly which allows a 3d protein gradient
Fgf
49
how are brain areas specified in development?
the combination of proteins that are expressed in different combinations (protein gradient)
50
what evidence demonstrates that protein gradient determines brain areas in rodents? 2
the whisker sensitive area of somatosensory cortex was moved towards or away from proteins that were injected
injecting a protein in an unusual place bisected the usual gradient (creating 2 areas)
51
how do newborn neurons migrate? which way do they go?
using radial glial cells as a scaffolding
| from the inner surface of the brain to the outer
52
what happens in 'inside out' development of the cortex?
cells start in the CSF and use the glial scaffold radiate outwards.
53
which layers of the cortex are the first to be formed?
deeper layers (5 & 6)
54
as new neurons are produced where do they migrate? and through what?
to upper layers of cortex
| through existing layers of cortex that have already been previously established
55
why are there gyri and sulci, from a neuronal development perspective?
because of overshoots in neurons that are produced and migrated more densely into upper layers
56
which cortical layers are developed first and which last?
deeper layers are the first to recieve migrating neurons
| upper layers receive neurons at a later stage which have migrated through the early layers
57
inside out development of the cortex only happens in __
mammals
58
what are the primary neurons that migrate radially? what type of neuron are they?
pyramidal
| excitatory
59
most common excitatory (1) and inhibitory (1) neurotransmitters?
glutamate
| GABA
60
what type of neurons migrate tangentially? what type of neuronal action do they have?
interneurons
| inhibitory
61
what type of developing neuron would migrate along the lines of the tissue?
interneurons
62
what protein is critical for inside out development, instead of outside in?
reelin
63
where is reelin produced?
Cajal-Retzius cells in the pial (external) surface
64
mutant rodents that dont produce reelin have ___ . new neurons will __
outside in development/ organisation of the cortex stay at the bottom
65
reelin is essential for __
allowing new neurons to migrate up through existing layers
66
the longest axon is __
20 meters in whales
67
what feature is essential for axons to find their target?
the growth cone
68
which part of the growth cone moves?
peripheral domain (as opposed to central domain)
69
which two parts of the growth cone cytoskeleton allow axon guidance?
microtubules and actin filaments
70
how does an axon move towards or away from attractors and repulsors?
repulsive - actin filaments will be severed, stopping microtubules developing in that direction
attractive - actin extends towards, allowing microtubules to expand in that direction
71
4 factors that determine the mechanisms for growth cone guidance?
extracellular matrix
chemorepulsion/attraction
contact inhibition / adhesion
pioneer neurons
72
how would suppressing the activity of calcium spikes impact the development of neurons due to electrical activity? what would be the opposite effect of increasing spikes?
more excitatory neurons
| more inhibitory neurons develop
73
netrin is a protein that causes __
chemorepulsion of the growth cone
74
electrical activity can determine whether growth cones are guided __ a repulsive molecule. what does this show?
towards or away from
the (electrical) environment is a strong determinant of how axons are guided, and it can change its response to apparently respulsive proteins
75
what is the effect of silencing electrical activity on developing neurons 2
it decreases the speed of axonal growth
| disrupts axonal branching
76
the Kir gene can __ electrical activity
silence
