Scribe Post for Monday, January 9, 2012

Today In Class:

-Checked UP pgs. 9-14

-Almost Finished Notes on Pregnancy (One slide left)

Key Things to Remember from Notes:

- Gestation: the carrying of developing child in the womb from conception to birth

-Child is carried for approximately 266 days (9 months)

-About one week after conception, the blastocyst implants in the endometrial wall of the uterus

-Trophoblast: outer cell layer of the blastocyst, which becomes part of the placenta

-Placenta: the organ that provides nourishment and oxygen to the embryo, and gets rid of metabolic waste

4 Pieces of Life Support After

Implantation: (See image above)

1. Amnion: fluid filled sac that encloses and protects the embryo, breaks before child-birth

2. Yolk Sac: produces embryo's first blood and germ cells

3. Allantois: forms part of urinary bladder and umbilical cord

4. Chorion: part of placenta, maintains high levels of estrogen and progesterone in mother's blood for 2 reasons: so new follicles do not mature, and to prevent menstruation

The placenta...

-carries chronic villi: embryonic blood vessels in close contact with material blood supply

-keep in mind: mother and baby's blood DO NOT MIX.

-By diffusion, nutrients, oxygen, antibodies, viruses, and drugs move from mother to embryo and waste moves from embryo to mother.

First Trimester

5-9 weeks

Makes change from embryo to fetus.

5 week embryo

-7 mm from crown to rump (not legs)

-brain and spinal cord

-starting to produce limbs, small tail and gill pouches

9 week fetus

-5.5 cm

-placenta, umbilical cord, amnion

-all organs and body parts present

-can move

Second Trimester

increase in size and refinement

14 week fetus

-6 cm (not large size difference)

Ultrasound

-can be performed when fetus is 18 weeks

-shows sex and physical abnormalities

20 week fetus

-19 cm

-1 lb

-nails, eyelashes, and hair are present

Third Trimester

rapid growth

Birth

-Premature babies 24 weeks or older may survive with medical care

-circulatory and respiratory systems prepare for breathing

-head of fetus rotates toward cervix

-Birth Averages: 50 cm (20 inches), 2.7-4.5 kg (6-10 lbs)

-rhythmic contractions of uterus controlled by estrogen and oxytocin

estrogen induces oxytocin receptors

oxytocin causes uterus to contract

3 Steps of Childbirth

1. CERVIX DILATES (from 0 to 10 cm) Ave 6-12 hours

2. Full dilation of cervix, strong contractions (Ave 20-60 mins)

-clamp umbilical cord as soon as baby comes out so it gets used to breathing air

3. Delivery of PLACENTA

-afterbirth

-15 mins. after birth

HOMEWORK:

-Stem Cell Debate Wednesday

-Study for QUIZ WEDNESDAY and TEST THURSDAY

-Review for finals!

Thanks,

Sophia

NEXT SCRIBE: ***ALEXIS***