How to make a brain

Question 1

what is neurulation

Answer 1

forming a tube from a plate

Question 2

what s the neural plate made from

Answer 2

ectoderm
it is where the neural plate starts

Question 3

what s the neural plate made from

Answer 3

ectoderm
it is where the neural plate starts

Question 4

what are the important days in the early development of the cns

Answer 4

plate (columnar epithelium) makes a tube in the end
first plate–> tube
day 19 a midline groove is apparent and neurulation is induced by the notochord
day 20-21 neural groove and fold formed on plate edge
day 21+ neural folds fuse in rostral caudal direction (apical constriction) to create a tube
day 25 rostral neuropore closure
day 27 caudal neuropore closure

Question 5

what happens if rostral neuropore doesnt close

Answer 5

forebrain doesnt form- anencephaly

Question 6

what are risk factors for neural tube defects

Answer 6

folate deficiency
diabetes
epilepsy drugs
previous anencephaly

Question 7

what happens if there are defects at the caudal neuropore

Answer 7

spina bifida

Question 8

what is the most severe form of spina bifida

Answer 8

myeloschisis

Question 9

what is myeloschisis

Answer 9

open neuropore, nervous system on surface as a pit

Question 10

what is meningomyelocele

Answer 10

closed neuropore but defect around spinal cord
defect in vertebrae and meninges are bulging
spinal cord on outside of protection of vertebrae

Question 11

what is meningocele

Answer 11

meninges bulging
spinal cord still within spinal column

Question 12

what is spina bifida occulta (1/10 individuals)

Answer 12

when a baby’s backbone (spine) does not fully form during pregnancy.

Question 13

what are the three swellings of the neural tube

Answer 13

fore, mid, hindbrain

Question 14

what are the vesicles in the brain

Answer 14

fore, mid, hindbrain vesicles

Question 15

wha does the space between the vesicles contain

Answer 15

csf, vesicles always connected

Question 16

what happens to forebrain during development

Answer 16

grows two lateral expansions (like ears), centre becomes diencephalon

Question 17

what happens to hindbrain during development

Answer 17

develops into brainstem and cerebellum with a central ventricle expanding

Question 18

what do the lumen of the tubes develop into

Answer 18

forebrain vesicle – two lateral ventricles and third ventricle (with interventricular foramen joining them together)
midbrain– cerebral aqueduct
hindbrain– fourth ventricle

Question 19

what do the walls of the tube form

Answer 19

forebrain- telencephalon, 2 cerebral hemispheres and diencephalon
midbrain- mesencephalon
hindbrain- metencephalon (pons, cerebellum), myelencephalon (medulla)

Question 20

where does the cerebral hemispheres derive from

Answer 20

forebrain vesicle

Question 21

what causes the c shape formation

Answer 21

The hemispheres grow round in a C-shape and then back again, pulling all structures internal to the hemispheres (such as the ventricles) with them.

Question 22

what is the cephalic flexure

Answer 22

occurs in week 6
s the first flexure or bend, that forms in the region of midbrain
found in mesencephalon

Question 23

what occurs at 12 weeks

Answer 23

strong temporal lobe growth
devloping insula

Question 24

what is the insula

Answer 24

grey matter

Question 25

what covers insula

Answer 25

operculum (lid) of cortex from adjacent lobe fronto-parietal and temporal operculum

Question 26

what happens at 16 weeks and later

Answer 26

c shape cerebral hemispheres lobes and grooves now evident

Question 27

what happens ar full term

Answer 27

ruffling and convolution crinkled surface

Question 28

what are gyri

Answer 28

they are the bumps, increase surface area and volume of grey matter

Question 29

how do you make the brain have a bigger surface area

Answer 29

sulcus and gyri

Question 30

name some c shaped structures

Answer 30

hippocampus (memory) lateral ventricle fornix corpus callosum caudate nucleus (curved shape of basal ganglia) that follows later ventricle

Question 31

why are there c shaped structures in the brain

Answer 31

due to temproal lobe growth

Question 32

what is the fornix

Answer 32

connects hippocampus with anterior structures

Question 33

what is the corpus callosum

Answer 33

connects the two hemispheres together

Question 34

where is the fornix

Answer 34

above thalamus

Question 35

what is the internal capsule and what does it do during development

Answer 35

white matter bundle divides basal ganglia- lentiform nucleus and caudate nucleus

Question 36

why can you see two parts of the caudate nucleus in a coronal slice

Answer 36

because it is c shaped, so cut twice

Question 37

why can you not see the cerebral aqueduct in a coronal slice

Answer 37

2D slice- therefore very rare to see

Question 38

how does the fourth ventricle form

Answer 38

opening out of neural tube forms roof o fourth ventricle around week 6

Question 39

what happens to the grey matter before and after the 4th ventricle forms

Answer 39

Before- sensory grey matter in dorsal position After- sensory grey matter becomes more lateral , motor is more medial

Question 40

what does the caudal neural tube become

Answer 40

the spinal cord

Question 41

what are the layers that start to make the spinal cord

Answer 41

ventricular layer (generating cells to make--> Mantle layer that becomes grey matter Marginal layer (outside) all white matter concentrates here Sensory neurons in dorsal region

Question 42

what forms the dorsal root

Answer 42

ingrowth of neurites from dorsal root ganglion

Question 43

what forms ventral root

Answer 43

outgrowth from neurons motor grey

Question 44

what does bmp stand for

Answer 44

bone morphogenetic protein

Question 45

what does bmp do

Answer 45

inhibits neural ectoderm, which promotes skin

Question 46

what induces the neural tube formation

Answer 46

notochord. produces noggin, chordin, follistatin, which block bmp therefore allows differentiation of neural ectoderm

Question 47

what happens to neural crest cells during neurulation

Answer 47

migrate away from neural tube epithelial mesenchymal transition spread through embryo and give rise to many different cell types.

Question 48

name some cells that neural cells form

Answer 48

4 genetic disorders of neural crest cranial nerve ganglia autonomic ganglia craniofacial skeleton melanocytes (dalmation dogs)- patchy and deaf schwann cells adrenal medulla cartilage bone neurons, glia connective tissue

Question 49

name some neural crest development defects

Answer 49

waardenburg's syndrome treacher collins syndrome

Question 50

what gene is deleted in waardenburgs syndrome

Answer 50

Pax-3 gene

Question 51

what protein is defected in treacher collins syndrome

Answer 51

TCOF1 gene