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Flashcards in Neurulation Deck (48)
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1
Q

When does the epiblast migrate through the primitive streak

A

3 weeks

2
Q

What does the endoderm give rise to?

A

Epithelial linings of resp. tract and digestive system, GI glands and glandular cells of liver and pancreas

3
Q

What derivatives come from the mesoderm?

A

Skeletal muscles, blood cells, the lining of blood vessels, smooth muscle, trunk Ct, most of CV system, notochord

4
Q

What is the ectoderm derived from?

A

Epiblast

5
Q

What is the mesoderm derived from?

A

Epiblast that penetrated the primitive streak

6
Q

What are the derivatives of the ectoderm?

A

Epidermis of the skin, epidermal derivatives, CNS, PNS, neural crest cells, eyes, internal ears

7
Q

What is the notocord made of

A

Primitive pit and mesodermal cells

8
Q

What induces ectoderm to become the neural plate?

A

Notochord

9
Q

Surface ectoderm forms what?

A

Epidermis

10
Q

Neuroectoderm forms the

A

Neural plate and neural crest

11
Q

What is neurulation

A

The process by which the notochord, neural plate and neural crest become distinct

12
Q

What acts as a hinge for neurulation

A

Neural groove

13
Q

Where does the neural plate begin to fold

A

Lumbar area up

14
Q

What does the neural tube arise from

A

Mesenchyme

15
Q

What is the process of forming the neural tube called?

A

Secondary neurulation

16
Q

Where does secondary neurulation occur?

A

The level of the sacral vertebrae

17
Q

What do the mesoderm of the head and neck come from?

A

The neural crest

18
Q

Defects in the folding of the neural tube at S1 S2 S3 typically manifest as what

A

Congenital heart defect

19
Q

What is the most common closure deficiency

A

Congenital heart issues

20
Q

Goldenhar syndrome is characterized by what

A

A neurocristopathy where incomplete closure of the mouth and nose area, ocassionally causes the mouth to be shifted

21
Q

What is TCS

A

A neurocristopathy disorder which cases the face of a person to have sunken in eyes and a mouth that projects anteriorly

22
Q

What is hirschsprung disease

A

Neurocristopathy in which patients have megacolon

23
Q

What is craniosynostosis

A

Neurocristopathy in which patients have an anterior projecting forehead

24
Q

What is micrognathia

A

Neurocristopathy in which a jaw is small or lacking

25
Q

What is piebaldism

A

Neurocristopathy in which areas of melanocytes have no pigment

26
Q

What do the meninges develop from

A

Neural crest cells and mesenchyme

27
Q

When do the meninges migrate to surround the cns? What does this form?

A

20-35 days, primitive meninges

28
Q

What do the primitive meninges differentiate into

A

Ectomeninx and endomeninx around 34-48 days

29
Q

What happens between 45-60 days

A

Ectomeninx becomes more compact and forms spaces for future venous sinuses

Endomeninx becomes more reticulated and suharachnoid space appears

30
Q

What dissociates giving rise to the epidural space

A

Spinal ectomeninx

31
Q

How does the neural tube close and what do they form

A

Initiated at 5 sites and goes in both directions; cranial and caudal neuropore

32
Q

What does a closure defect at closure 5 cause

A

Spina bifida

33
Q

What is a defect at closure 2

A

Anancephaly

34
Q

What is a defect at closure 1

A

Craniorachischisis

35
Q

What is encephalocele

A

When parts of the brain go into a sac behind the head

36
Q

What is meroencephaly

A

Acrania, from the lumbar portion up the spinal cord is open

37
Q

What is cranioachischisis

A

When the spinal cord is open from sacral region up

38
Q

What is spina bidfida oculta

A

When the neural arch doesn’t close completely

These patients have a tuft of hair above this area

39
Q

What is meningocele

A

Where there is a sac filled with CSF extending from a portion of the spine

40
Q

What is meningomyelocele

A

Meningocele but with the spinal cord in that sac

41
Q

What is myeloschisis

A

Where the spinal cord is hemisected and open to the skin

42
Q

When does head and tail folding begin

A

Week 4

43
Q

What happens during the head fold

A

Neural folds project dorsally into the amniotic cavity

Neural folds grow cranially into oropharyngeal membrane and overhang the primordial heart
Forces translocation of septum transversum, primordial heart, peridcardial coelom to ventral surface

44
Q

What forms the future anus

A

Cloacal membrane

45
Q

When does the umbilical cord form?

A

After dorsal/ventral folding and lateral folding

46
Q

When does the abdominal wall fuse

A

Lateral folding

47
Q

What are some anterior body wall malformations

A

Omphalocele - bowel in membranous sac

Gastroschisis - bowel is exposed and protruding through body wall

Ectopia cordis - heart outside the rib cage

48
Q

What is the pentalogy of cantrell

A
Anterior body wall malformation
Needs 
-midline abdominal defect
-anterior diaphragmatic hernia
-cleft strenum
-pericardial defect 
-intercardiac defect