Neurulation and Organogenesis

The inner cell mass divides to form the epiblast and hypoblast, which will eventually give rise to the embryo's tissues and the yolk sac, respectively.

Gastrulation (occurs between 15-20 days) and Neurulation (occurs between 20-23 days), resulting in the formation of the three primary germ layers and the establishment of the neural tube, respectively.

Gastrulation results in the formation of the three primary germ layers: ectoderm, mesoderm, and endoderm.

<p>The establishment of the embryonic axis (anteroposterior, dorsoventral, and mediolateral) during gastrulation provides a framework for the organization of subsequent embryonic development.</p> Signup and view all the answers

<p>The epiblast gives rise to all the tissues of the embryo, while the hypoblast lines the blastocoel and gives rise to the yolk sac.</p> Signup and view all the answers

<p>Heart development begins around 23 days, after the completion of gastrulation and the initiation of neurulation.</p> Signup and view all the answers

<p>The primary function of the notochord is to induce the formation of the central nervous system (CNS) by signaling to the ectoderm layer above it to form the neural plate.</p> Signup and view all the answers

<p>The three primary germ layers are Ectoderm, Mesoderm, and Endoderm. Ectoderm gives rise to the CNS, epidermis, and melanocytes, Mesoderm gives rise to the heart, muscles, and kidneys, and Endoderm gives rise to the lung, thyroid, and pancreatic cells.</p> Signup and view all the answers

<p>The primitive streak is the region through which epiblast cells migrate to form the three primary germ layers: Ectoderm, Mesoderm, and Endoderm.</p> Signup and view all the answers

<p>Gastrulation begins around 18 days and is complete by 23 days. During this process, a 2-layered embryo is converted into a 3-layered embryo, and the three primary germ layers are formed.</p> Signup and view all the answers

<p>The notochord is a flexible rod that induces the formation of the central nervous system (CNS) and establishes the embryonic axis. It signals to the ectoderm layer above it to form the neural plate, which ultimately gives rise to the neural tube.</p> Signup and view all the answers

<p>Neurulation begins after the completion of gastrulation, around 23 days. During neurulation, the neural tube forms from the neural plate, and the central nervous system (CNS) begins to take shape.</p> Signup and view all the answers

<p>while gastrulation is still occurring</p> Signup and view all the answers

<p>to induce the overlying ectoderm to form the neural plate</p> Signup and view all the answers

<p>neural tube</p> Signup and view all the answers

<p>neural crest</p> Signup and view all the answers

<p>primary neurulation</p> Signup and view all the answers

<p>organogenesis</p> Signup and view all the answers

<p>During blastulation, the zygote undergoes several cell divisions, resulting in the formation of the embryoblast (inner cell mass) and hypoblast (outer cell mass), which are essential for further embryonic development.</p> Signup and view all the answers

<p>During gastrulation, the blastula undergoes a series of complex cellular movements, resulting in the formation of the three primary germ layers: ectoderm, mesoderm, and endoderm.</p> Signup and view all the answers

<p>The neural plate is a thickened layer of ectoderm that gives rise to the neural tube, which will eventually form the central nervous system.</p> Signup and view all the answers

<p>The lens vesicle is a critical structure that forms during week 5-6, which will eventually give rise to the lens of the eye.</p> Signup and view all the answers

<p>During weeks 3-10, the neural tube gives rise to the optic cup, which will eventually form the retina, and the lens vesicle, which will form the lens of the eye.</p> Signup and view all the answers

<p>The choroid fissure is a critical structure that forms during eye development, allowing for the invagination of the optic cup and the formation of the retina.</p> Signup and view all the answers