9/18 Neurulation - Dennis (Completed)

Question 1

What happens during week 1? 4

Answer 1

Blastocyst begins to implant in uterus

Question 2

What happens by week 3? 4

Answer 2

Chorion, yoke sac, umbilical vesicle forms

Question 3

Where are all three germ layers derived from?

Answer 3

The epiblast

Question 4

Where are GI glands and glandular cells of the liver and pancreas derived from? 6

Answer 4

Endoderm

Question 5

Where are skeletal muscles, RBCs, and lining of the BVs derived from?

Answer 5

Mesoderm

Question 6

Where is the notochord and most of the cardiovascular system derived from? 6

Answer 6

Mesoderm

Question 7

Where is the epidermis of the skin derived from? 6

Answer 7

Ectoderm

Question 8

Where is the CNS/PNS, eyes, and internal ears derived from? 6

Answer 8

Ectoderm

Question 9

Where is the dermis derived from? 6

Answer 9

Mesoderm

Question 10

What induces neurulation? 8

Answer 10

The notochord

Question 11

What is induction? 8

Answer 11

Notochord instruction growth of the rest of the neural plate (neural ectoderm) and neural crest

Question 12

What is the progression into a functional neural tube? 10

Answer 12

Neural plate –> neural folds –> neural tube

Question 13

What is the neural plate?

Answer 13

A region of the ectoderm that has been specified to be a part of the nervous system

Question 14

Prior to neural fold formation what must happen? 10

Answer 14

Neural groove must be in place (think of it as a hinge point)

Question 15

What is the notochord’s orientation to the neural tube? 11

Answer 15

Notochord is inferior/ventral to the neural tube

Question 16

After the neural tube has formed what lies superior/dorsal to it? 11

Answer 16

Epidermis

Question 17

Where are neural crest cells found? Where are they after the neural tube has been formed? 11

Answer 17

The dorsal edge of the neural folds

Once the neural tube has been formed the neural crest cells are released and become free floating

Question 18

Where does secondary neurulation take place? What tissue are these secondary neurulation sites derived from? 12

Answer 18

Derived from mesenchyme

Takes place at the sacral vertebrae

Question 19

How are the neural crest cells released from the neural tube? 13

Answer 19

Neural crest at the most dorsal aspect of the neural tube pinch off and migrate away at the very end of neural tube closure, but some leave earlier

Question 20

What pharyngeal arch produces the laryngeal cartilage? 15

Answer 20

Arch 4

Question 21

What pharyngeal arch produces malleus, incus, and meckel’s cartilage? 15

Answer 21

Arch 1

Question 22

Which pharyngeal arch produces the stapes, styloid, and hyoid cartilage?

Answer 22

Arch 2

Question 23

What is the defect in Micrognathia? 17

Answer 23

Neural crest failure to form the lower jaw

Question 24

What are the meninges derived from? 19

Answer 24

From neural crest cells and mesenchyme

Question 25

What do the primitive meninges differentiate into? 19

Answer 25

Ectomeninx --> becomes compact, forms spaces for future venous sinuses Endomeninx --> becomes reticulate, subarachnoid space/cisterns appear

Question 26

How does the neural tube actually close? 20

Answer 26

Not a uniform closure along the entire length Closing begins at the thoracic region and spreads away from the middle in both directions

Question 27

What do we call the last portions of the neural tube to close (prior to their actual closing)? 21

Answer 27

Neuropore Cranial neuropore and Caudal neuropore

Question 28

What may arise from lack of closure 5 (5th site)? 22

Answer 28

Various forms of spina bifida

Question 29

What clinical manifestation may you see with lack of closure 2 (2nd site)? 22

Answer 29

Anencephaly

Question 30

Define Anencephaly. 23

Answer 30

Lack of brain, not compatible with life

Question 31

What are the types of Anencephaly? 23

Answer 31

Meroencephaly - some brain tissue Holoencephaly - single brain structure forms Craniorachischisis - cranial and other regions of neural tube open

Question 32

What happens in spina bifida occult? 24

Answer 32

Unfused neural arch (two sides) of vertebrae open

Question 33

What's happening in meningocele? 24

Answer 33

Meninges protrude past the body wall

Question 34

What's happening in meningomyelocele?

Answer 34

Both spinal cord tissue and meninges prodtrudes past body wall

Question 35

What's happening in myeloschisis? 24

Answer 35

Failure for closure of the neural tube

Question 36

What is the first fold that occurs in the developing brain? 27

Answer 36

The developing brain folds forward resulting in the forebrain Folding pushes the hear and mouth more Caudal LH

Question 37

What does the connecting stalk eventually become? 29

Answer 37

The umbilical cord

Question 38

What happens in Omphalocele? 32

Answer 38

Bowel w/ membranous sac outside of body wall

Question 39

What happens in Gastroschisis? 32

Answer 39

Exposed bowel protruding from body wall

Question 40

What's happening in Ectopia cordis? 32

Answer 40

Heart located beyond the body wall

Question 41

Watch videos on slide 34

Answer 41

Watch