What are the main stages of embryonic development?

The process of prenatal development occurs in three main stages. The first two weeks after conception are known as the germinal stage, the third through the eighth week is known as the embryonic period, and the time from the ninth week until birth is known as the fetal period.

How many stages are there in embryonic development?

The embryonic period of human development was divided into eight main stages described as 1–unicellular, 2–blastomere stage, 3–blastoderm stage, 4–bilaminar stage, 5–trilaminar stage, 6–early somite stage, 7–stage of limb development, 8–late embryonic stage.

What happens at 6 week of human embryonic development?

Week 6: The neural tube closes The baby’s brain and spinal cord will develop from the neural tube. The heart and other organs also are starting to form. Structures necessary to the formation of the eyes and ears develop. Small buds appear that will soon become arms.

What is the correct order of development during the embryonic?

A baby goes through several stages of development, beginning as a fertilized egg. The egg develops into a blastocyst, an embryo, then a fetus.

What is the last major step of embryonic development?

Some of the ectoderm cells from the blastula collapse inward and form the endoderm. The final phase of gastrulation is the formation of the primitive gut that will eventually develop into the gastrointestinal tract. A tiny hole, called a blastopore, develops in one side of the embryo.

What happens in the first 6 weeks of pregnancy?

6 weeks pregnant: What to expect You might have PMS symptoms like fatigue, sore breasts, and headaches. You may experience morning sickness. Your baby is still teeny-tiny: About the size of a grain of rice or a pomegranate seed. Your baby is growing their brain and spinal cord, and their heart is beginning to beat.

What does a six week embryo look like?

Your baby when you’re 6 weeks pregnant Overall, your baby looks a bit like a tadpole, and is about 5 mm from head to tail. On an ultrasound (which isn’t usually done at this stage), your baby looks like a tiny bright dot, with its heart beating really quickly and rhythmically.

What is the pre embryonic stage?

The pre-embryonic period, known as the germinal phase, is the first and shortest phase of embryonic development. It lasts from fertilization to the second week of the embryo’s life. In this phase of embryo development, the zygote repeatedly self-replicates.

What is the correct order of development during the embryonic period quizlet?

The three phases of early embryonic development in animals are cleavage, gastrulation, and organogenesis. During cleavage, the zygote divides multiple times, producing a larger number of smaller cells.