Pregnancy And Baby Care Articles Fetal Development

...barely visible embryo is ready to receive oxygen and nutrition from the placenta. During week 5 of the fetal development, the notochord begins to form; this is the backbone of the fetus which will later develop into the vertebral column. Some organisms like the hagfish, sturgeon, African lungfish and tadpoles retain the notochord. At the end of the notochord a tiny bulge is noticeable, which grows into the brain of the body.

In week 5, the fetus undergoes a phase known as ‘Gastrulation’. In this phase of fetal development, germ layers are developed, which eventually give rise to various tissues and organs. Germ layers are classified into three basic categories namely the ectoderm, the mesoderm, and the endoderm. The ectoderm forms the epidermis, comprised of skin, hair and nails and the neural tissues, forming the nervous system. The mesoderm, generates other vital organs such as the blood and blood vessels, the bone and the connective tissue. The endoderm makes the digestive system, the respiratory system and organs associated with the same, such as the liver and the pancreas.

The divisions of the vertebrae, also known as the somites, begin to form on the two sides of the neural tube. A fundamental heart tube also begins to form, which means there is a heart beat now. Between the fourth and the fifth week, the embryo grows two-folds in size, growing from 4-5mm to 1/8 inch in size. Now a head and a tail are also visible.

At the end of the fifth week, the first month of the pregnancy is over and a risk of a miscarriage is greatly reduced. The baby is now visible in an ultrasound and heart beat is audible. By week six, ears begin to form on the fetus and so the arms. In addition, the first signs of lungs appear as well as the gallbladder and pancreas start forming.

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