Type A intercalated cells  secrete hydrogen ions by a hydrogen-ATPase transporter and by a hydrogen-potassium-ATPase transporter are especially important in eliminating hydrogen ions while reabsorbing bicarbonate in acidosis

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#Unit 5. Developmental Biology

Sox family of transcription factors

Inhibit the formation of epidermis and neural crest by blocking the transcription and signaling of BMPs

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#Id: 1029

#Unit 5. Developmental Biology

There are two principal modes of neurulation: 

1. Primary neurulation

2. Secondary neurulation

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#Unit 5. Developmental Biology

In primary neurulation, 

cells surrounding the neural plate direct the neural plate cells to proliferate, invaginate into the body, and separate from the surface ectoderm to form an underlying hollow tube.

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#Unit 5. Developmental Biology

In secondary neurulation, 

the neural tube arises from the aggregation of mesenchyme cells into a solid cord that subsequently forms cavities that coalesce to create a hollow tube.

 

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#Id: 1032

#Unit 5. Developmental Biology

Primary neurulation forms the anterior portion of the neural tube

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#Id: 1033

#Unit 5. Developmental Biology

Secondary neurulation forms the posterior portion of the neural tube