Embryology 1.13 Flashcards Preview

NMSK-B I > Embryology 1.13 > Flashcards

Flashcards in Embryology 1.13 Deck (45)
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1
Q

Which structure fives rise to the CNS?

A

neural tube

2
Q

When does gastrulation occur during development?

A

Week 3

3
Q

What do the epiblast cells give rise to?

A

3 germ layers

4
Q

Which germ layer is responsible for most of the nervous system?

A

ectoderm

5
Q

What is the notocord?

A

-induce ectoderm to thicken into neural plate and later neural tube

6
Q

What is neuralation?

A

folding of neural plate into a closed tube of ectoderm

7
Q

When does the formation of the neural plate occur?

A

16-18 days post fertilization

8
Q

When do the neural folds elevate?

A

19-20 days post fertilization

9
Q

When does the fusion of neural folds occur?

A

21-24 days post fertilization

10
Q

When does the cranial neuropore close?

A

25 days post fertilization

11
Q

When does the caudal neuropore close?

A

27 days post fertilization

12
Q

What are the regions of the brain?

A

forebrain (prosencephalon)
midbrain (mesencephalon)
hindbrain (rhombencephalon)

13
Q

What occurs at 4 weeks into development?

A

-segmentation of the CNS
-3 primary brain vesicles formed
prosencephalon
mesencephalon
rhombencephalon

14
Q

Where is the cephalic flexure during brain development?

A

midbrain

15
Q

Where is the cervical flexure during development?

A

hindbrain and spinal cord

16
Q

What occurs at 5 weeks into development?

A

primary vesicles (prosencephalon, mesencephalon, rhombencephalon) form secondary vesicles

telencephalon
diencephalon
-----
mesencephalon 
-----
metencephalon
mylencephalon
myelon
17
Q

What does the telencephalon give rise to?

A

cerebral hemispheres

18
Q

What does the diencephalon give rise to?

A

thalamus

hypothalamus

19
Q

What does the mesencephalon give rise to?

A

midbrain

20
Q

What does the metencephalon give rise to?

A

pons

cerebellum

21
Q

What does the mylencephalon give rise to?

A

medulla

22
Q

What does the myelon give rise to?

A

spinal cord

23
Q

What is anencephaly?

A
  • result of failure to close anterior (cranial) neuropore

- failure to form brain and cranial vault

24
Q

What is Spina Bifida?

A
  • results from incomplete closure of embryonic neural tube
  • sacrolumbar
  • patch of skin
25
Q

What is meningocele?

A
  • severe form of spina bifida

- protrusion of meninges

26
Q

What is meningomyelocele?

A
  • severe form of spina bifida

- protrusion of meninges and spinal cord

27
Q

What is rachischisis?

A
  • severe form of spina bifida

- open neural tube

28
Q

How can neural tube defects be prevented?

A

FOLIC ACID

29
Q

When do sulci and gyri form in the cortex?

A

30 weeks post fertilization

30
Q

Which process is responsible for brain growth after birth?

A

myelination begins in 3rd trimester and continues after birth

31
Q

When is embryonic CSF formed?

A

week 5

32
Q

What occurs when the ventricular system in blocked?

A

hydrocephalus due to accumulation of CSF

33
Q

How does eye formation begin?

A

diverticulae of forebrain and formation of optic groove which becomes optic vesicles

34
Q

What is the choroid fissure?

A
  • location of lens of the eye

- forms when the optic vesicle and optic stalk invaginate inferiorly

35
Q

What is the neural retina?

A
  • part of the retina which contains photoreceptors (rods and cones)
  • forms from inner layer of optic cup
36
Q

What is coloboma?

A

incomplete closure of the choroid fissure; normally fuses during week 7

37
Q

What does the neural tube form during development?

A
  • ventricular layer, surrounded by
  • mantle layer (gray matter)
  • marginal layer (white matter after myelination)
38
Q

What is the sulcus limitans?

A
  • structure in the spinal cord which separates developing gray matter into dorsal alar plate and ventral basal plate
  • forms central canal of spinal cord (narrows)
39
Q

How does the spinal cord change positions during development?

A

begins by extending all the way to the “sacrum” but ascends as we grow taller/longer during development

40
Q

What does the peripheral nervous system develop from?

A

neural crest cells at zone between neural plate and surface ectoderm

41
Q

What are the nerve fibers categorized as in the DRG?

A
  • sensory

- neural crest-derived

42
Q

How does referred pain work?

A

-afferent neurons from the source of pain (organ) and referred pain area (skin) both synapse on same spinal segment

43
Q

What is the sympathetic innervation of the heart?

A

T1-T4 (explains referred pain down left arm during heart attack)

44
Q

Which cranial nerves are derived from neural crest cells?

A

CN V, VII, VIII, IX, X

sensory ganglia!!!

45
Q

What is Hirschsprung’s disease?

A
  • congenital aganglionic megacolon
  • absence of ganglia in lower colon
  • results from failure of neural crest migration due to mutations in several genes