NeurulationNeurulationBy Brett & JoshuaBy Brett & Joshua

These slides will be uploaded after tonights session.

Please see presenter notes under the slides for a description of the pictures.

These slides will be uploaded after tonights session.

Please see presenter notes under the slides for a description of the pictures.

Describe the formation of the morula and blastocyst and the process of blastocyst implantation

Describe the process and resultant effect of gastrulation

Describe the main derivatives of the 3 core embryonic tissues (endoderm, mesoderm and ectoderm)

Describe the longitudinal and lateral folding of the embryo and describe the cavities, structures and regions that this create

Describe the process and result of ‘reversal’ during folding

Describe the process and result of neurulation (neural tube formation), how the notochord is involved and describe the range of defects that can occur

Describe the origin of neural crest cells, their migration and the tissues that they form/contribute toward

Explain the basic structure, content and arrangement of the pharyngeal arches and the outline the regions that they become (more of this in later blocks)

Review the formation of the gut tube and the defects that can occur

Objectives

R G Tunstall 2013

What is neurulation?

The formation of the neural tube, which later develops into the brain, spinal cord and retina

What are the three germ layers?

Ectoderm

Mesoderm

Endoderm

From which germ layer does the neural tube derive?

Ectoderm

What else is derived from ectoderm?

Skin

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Neural Crest Cell Migration

Crest cells are involved in:

Dorsal root ganglia Adrenal medulla Melanocytes Meninges (Arachnoid & pia) Autonomic nerve ganglia GI tract ganglia (Parasympathetic) Septation of heart Skull & face connective tissues

Crest cells spread throughout body

Re-differentiate into other cell types

Defective neural crest cell migration – malformed face, nervous system absences, cardiac/gut defects

~ Day 21

~ Day 19

Cells from neural crest migrate & form many important structures

R G Tunstall 2013

DAMMAGeSS

Tube Closure

Tube has two openings - at cranial end and at caudal end

What are these called?

Neuropores

When does each close?

Cranial day 25

Caudal day 27

Neural Tube Defects

Prevention?

Neural Tube Defects

Neural Tube Defects

Any questions?Any questions?

Labelling time!Labelling time!

Mini QuizMini Quiz

What is neurulation?

The formation of the neural tube, which later develops into the brain, spinal cord and retina

What embryological structure sends signals to initiate neurulation?

Notochord

What is the region above the notochord called?

Neural plate

The neural plate involutes to form the...?

Neural groove

What is the name of the cells indicated by the black dots?

Neural crest cells

Name THREE things the neural crest cells migrate and redifferentiate to become. [3]

Crest cells are involved in:

Dorsal root ganglia Adrenal medulla Melanocytes Meninges (Arachnoid & pia) Autonomic nerve ganglia GI tract ganglia (Parasympathetic) Septation of heart Skull & face connective tissues

DAMMAGeSS

The neural tube longitudinally but is open at either end. What are these endings called?

Neuropores

On what day does the cranial neuropore close?

Day 25

On what day does the caudal neuropore close?

Day 27

What is this called?

Spina bifida occulta

What other feature might someone with spina bifida occulta have?

Tuft of hair over region

What is this called?

Meningiocoele

What is this called?

Myelomeningiocoele

How can spina bifida be prevented?

• Folic acid supplements during pregnancy

Thank you :)Thank you :)