Embryology Chapter on Embryonic Disc Development

<p>They remain close together. (D)</p> Signup and view all the answers

<p>Intra-embryonic coelom (C)</p> Signup and view all the answers

<p>On either side of the midline (D)</p> Signup and view all the answers

<p>Closed cavity (C)</p> Signup and view all the answers

<p>Notochordal canal (A)</p> Signup and view all the answers

<p>Secondary yolk sac (A)</p> Signup and view all the answers

<p>Nucleus pulposus (B)</p> Signup and view all the answers

<p>Yolk sac (D)</p> Signup and view all the answers

<p>It begins to break down and create openings (C)</p> Signup and view all the answers

<p>Notochordal plate (D)</p> Signup and view all the answers

<p>Vertebral column (B)</p> Signup and view all the answers

<p>To separate the canal from the cavity of the yolk sac (A)</p> Signup and view all the answers

<p>It is connected by a canal (A)</p> Signup and view all the answers

<p>Notochord (B)</p> Signup and view all the answers

<p>Blastopore (B)</p> Signup and view all the answers

<p>Cranially in the middle line (C)</p> Signup and view all the answers

<p>Creation of a solid rod called the notochord (C)</p> Signup and view all the answers

<p>Deep to the ectoderm (B)</p> Signup and view all the answers

<p>Supporting the development of the central nervous system (A)</p> Signup and view all the answers

<p>Prochordal plate (D)</p> Signup and view all the answers

<p>Notochordal process (B)</p> Signup and view all the answers

<p>It forms a solid rod of cells. (C)</p> Signup and view all the answers

<p>It can persist into adult life in some chordates. (B)</p> Signup and view all the answers

<p>Overlying the notochord. (C)</p> Signup and view all the answers

<p>Flat. (C)</p> Signup and view all the answers

<p>The notochord is completely separated from the endoderm. (B)</p> Signup and view all the answers

<p>During the embryonic development. (A)</p> Signup and view all the answers

<p>The prochordal plate. (C)</p> Signup and view all the answers

<p>The spinal cord. (A)</p> Signup and view all the answers

<p>Brain (C)</p> Signup and view all the answers

<p>Stomodaeum (B)</p> Signup and view all the answers

<p>It disappears (A)</p> Signup and view all the answers

<p>All three germ layers (A)</p> Signup and view all the answers

<p>It induces the formation of the neural tube (B)</p> Signup and view all the answers

<p>Day 15 (A)</p> Signup and view all the answers

<p>Heart tube (C)</p> Signup and view all the answers

<p>Rich in proteoglycans (B)</p> Signup and view all the answers

<p>It connects the gut to the yolk sac. (C)</p> Signup and view all the answers

<p>The part of the gut cranial to the vitello-intestinal duct. (B)</p> Signup and view all the answers

<p>Ectodermal tissue. (B)</p> Signup and view all the answers

<p>Lateral folds. (D)</p> Signup and view all the answers

<p>The vitello-intestinal duct. (B)</p> Signup and view all the answers

<p>It is a result of the lateral folds closing around the embryo. (A)</p> Signup and view all the answers

<p>As the embryonic disc folds on itself. (C)</p> Signup and view all the answers

<p>Epithelial tissue. (D)</p> Signup and view all the answers

A thickened area at the cranial end of the primitive streak.

A solid cord formed by cells multiplying and migrating from the primitive knot.

A solid rod formed by the notochordal process.

A structure that initiates the formation of the notochord.

A region near the head of the embryo that the notochord is associated with.

The opening formed at the end of the primitive streak.

The cavity formed within the notochordal process.

The flat, layered structure that gives rise to the embryo.

The notochord grows longer as the embryo develops.

The notochord does not directly create the vertebral column but its cells affect other regions indirectly.

Cells from the floor of the notochordal canal mix with endoderm cells.

The notochordal canal connects with the yolk sac and amniotic cavity.

Part of the notochord that persists in intervertebral discs.

The notochord forms from the notochordal plate, a curved tube, which then transforms into a solid rod of cells, becoming the definitive notochord.

The notochord serves as the central axis of the body in some chordates, such as Amphioxus; in others, it's present in embryos and leaves only small remnants.

The neural tube forms from ectoderm overlying the notochord and extends from the prochordal plate to the primitive knot.

The process of forming the neural tube from ectoderm is called neurulation.

The neural tube ultimately develops into the brain and spinal cord, the central nervous system.

During early embryonic development, the developing brain forms as a large, prominent mass on the dorsal aspect of the embryo.

The intra-embryonic mesoderm is divided during development, leading to distinct regions - the paraxial mesoderm, intermediate mesoderm, and lateral plate mesoderm.

The paraxial mesoderm gives rise to somites, segmented blocks of tissue that form the vertebral column, ribs, skin, and muscle.

A fluid-filled cavity that forms within the embryonic disc, eventually becoming the main body cavity.

A fluid-filled cavity that surrounds the embryo, similar to the intra-embryonic coelom but located outside of the embryonic disc.

A fold that forms at the cranial end of the embryonic disc, helping to shape the head and bringing the head closer to the tail end.

A fold that forms at the caudal end of the embryonic disc, similar to the head fold but located at the tail end.

The yolk sac, after the extra-embryonic coelom forms, becomes smaller and lined with cubical cells.

The shape of the intra-embryonic coelom as it forms, with two halves connected at the cranial end.

It communicates with the extra-embryonic coelom, allowing for fluid exchange between the two.

It grows progressively larger, while the head and tail ends remain relatively close.

A narrow channel connecting the gut to the yolk sac in an embryo.

The part of the gut in an embryo located cranial (toward the head) to the vitello-intestinal duct.

The middle part of the embryonic gut, located between the foregut and hindgut.

Folds that form on each side of the embryonic disc during development, contributing to the embryo's enclosure by ectoderm.

The circular aperture through which the vitello-intestinal duct passes, connecting the gut to the yolk sac.

The amniotic cavity, initially small, significantly expands during development, eventually encompassing the entire embryo.

The embryonic disc, initially flat, folds upon itself during development, leading to the establishment of the gut tube.

The connection between the embryo and the placenta, formed gradually through folding of the embryonic disc and the connecting stalk.

A depression on the ventral aspect of the embryo that forms the mouth opening.

A membrane that temporarily separates the stomatodaeum from the foregut.

Tumors in the sacral region that are derived from remnants of the primitive streak.

Precursors to somites, found in the head region and contribute to some mesenchyme.

Gelatinous substance in the umbilical cord, rich in proteoglycans.

The notochord induces the formation of the neural tube.

Somitomeres are found in the head region, cranial to somites.

The notochord doesn't directly form the vertebral column, but it influences surrounding cells to differentiate into vertebrae.