Differentiation and Birth

The development of a human being is a lengthy and intricately detailed process. In escence a miracle of life. The human body starts to develop at different times and different parts as well. This is called differentiation. Simply the single cell ( zygote ) undergoes miotic division and produces the thousands of cells that create us into a unique organism. THis simple cell makes multiple identical copies of itself and then they by become specialized cells. We discussed this earlier in the unit on how we get individual cells with specific functions.

Today in class you were given a handout to each of the 3 trimesters. This will help you understand the development of a fetus in each of it's tissue and organ developments.

Birth is not just one final act. It is actually made up of three differnt stages.
Stage 1. Dialation:
Uterine contracts, cervix opens, amniotic fluid breaks and may last between 2 to 20hrs.
Stage 2. Expulsion: The contractions become stronger and the baby is pushed out through the cervix and birth canal.
Stage 3. Placenta: The placenta and umbilical cord are expelled from the mother. This happens 15 min or so after the baby is born.

HOMEWORK:
Please answer all the questions on the sheet pertaining to Differentiation and Birth.
Note the chapter 3 questions at teh bottome of the page. Start those tonight and you can finish some in class tomorrow.
You will be given more UNIT REVIEW questions for class while I am on a feild trip. Remeber Practice makes perfect, or as close to it as you can get.

THANKS CLASS FOR DOING A GREAT JOB ON COLLECTING 500 OR SO CANS.
SPECIAL THANKS TO THE CAMBELLS KID, and HER FRIEND THE NOODLE.
(You know who you are!)
See you on Thursday for the UNIT TEST.


SPECIAL POSTING ( for DAN . B)

Dan, I recieved your phone call today. Take the time to recover and don't stress about the Unit Test. You and I can make alternative arrangements after the CHristmas break. You just get better form surgery and concentrate on having a good Holiday.

If you need anything just write on the Blog and I can get back to you!
Feel better soon.