Fetal development - Weeks 9 to 38

193

0

HWC

By: HWC

Date Uploaded: 09/29/2019

Tags: Fertilization   human body  

Weeks 9-12 • Fetal development during the third month includes: • A large head, about 1/2 the length of the fetus. • Visible eyes and ears. • A detectable heartbeat. • Kidneys that form urine. • Gender identification. • Weak, undetectable body movements. • By the end of the twelfth week after fertilization, the placenta is exchanging nutrients and producing essential hormones. Weeks 13-16 • In the fourth month of fetal development, the face looks more human as the eyes and ears move to their final positions • Organ Systems continue to rapidly develop. • The gender is usually easily determined now. • The fetus grows to a length of about 6 or 7 inches and weighs about 4 ounces. Weeks 17-38 • By the end of the fifth month of development: • The fetus grows to weigh about one pound. • Fetal movements become perceptible. • Fine hair called lanugo forms over the fetus. • The head becomes less disproportionate as limbs and trunk grow. • During the seventh month : • The fetus increases in weight to 2 to 3 pounds as it gains body fat. • Testes begin to descend. • Many infants born prematurely at this time do survive with intensive medical support. • In the ninth month: • Much of the fine lanugo hair is shed. • The brain continues to develop. • The fetus now weighs 7 to 8 pounds and is about 20 inches long. • About a quart of amniotic fluid surrounds and protects the fetus. • In the span of only 9 months, a fertilized oocyte develops from a single cell into a mature 8-pound fetus, ready to leave the womb and begin life on its own.

Share

Embed

Copy and paste this code into your website or blog.

Add To

You must login to add videos to your playlists.

Comments

0 Comments total

to post comments.

No comments have been posted for this video yet.