How is prechordal plate formed?

The prechordal plate is a thickening in the endodermal layer which is formed by mesendodermal cells from the primitive node that migrate rostrally along the midline between the ectoderm and endoderm layers. These same cells also form the notochord.

What is prechordal plate composed of?

The prechordal plate, sometimes called the head organizer, consists of early mesendodermal cells passing through the primitive node. These cells are structurally and functionally closely associated with cells of the underlying anterior endoderm.

When does the prechordal plate appear?

The prechordal plate, which has been unequivocally found first at stage 7, is usually detectable at stage 8 as a highly developed mesendodermal mass in contact with the floor of the neural groove.

What is the difference between prechordal plate and oropharyngeal membrane?

The notochordal process grows cranially until it reaches the prechordal plate, the future site of the mouth. In this area the ectoderm is attached directly to the endoderm without intervening mesoderm. This area is known as the oropharyngeal membrane, and it will break down to become the mouth.

Where is the prechordal plate located in the heart?

The prechordal mesenchyme proliferates laterally over the junction of the dorsal aorta and first aortic arch on each side. Gilbert P.W., (1957) The prechordal plate contributes largely to the premandibular condensation and the mesenchyme of the heart such that little is seen in the median plane at this stage.

Can a pleural plaque be calcified on a chest radiograph?

The plaques may be calcified; however, most (85-95%) are not 1,2. Pleural plaques exhibit the so-called “incomplete border sign” on chest radiograph. The inner margin is often well-defined because it is tangential to the x-ray beam and the adjacent lung is a good contrast medium.

What does plaque mean in relation to cardiovascular disease?

It means a build-up of plaque in the artery wall that could restrict blood flow. It comes from the Greek roots “athero” (meaning “artery”) and “skleros” (meaning “hardening” or “scarring”). Arterial plaque is made up of fats, cholesterol, and other substances that get stuck within the artery walls.

What causes pleural plaques on the inside of the lungs?

After prolonged exposure to asbestos, pleural plaques can develop on both layers of the pleura, which is the thin membrane that surrounds the lungs and envelops the inside of the chest. The majority of people with pleural plaques do not show obvious symptoms. But some patients describe pain or an uncomfortable,…