Chapter 19 Prenatal Development and Birth Pick up the Chapter 19 Packet.

Conception and Implantation Fertilization (a.k.a. Conception) is the union of a male sperm cell and a female egg cell. Picture on Page 486 (Look at it) First Trimester Implantation, which is defined as, the attachment of the zygote to the uterine wall, takes place. Three tissue layers form, which become the respiratory and digestive systems; the muscles, bones, blood vessels, and skin; and the nervous system, sense organs and mouth.

Fertilization

Implantation

First Trimester (cont.) The amniotic sac grows around the embryo for protection. The umbilical cord connects the embryo to the mother’s placenta. During this time, all organs form, the heart starts beating, the cardiovascular system begins to function, and a human profile develops. End of First Trimester is 14 weeks gestation.

Second Trimester Further Changes: Formation of eyebrows and Eyelashes Ability to blink eyes Full proportion of limbs Ability to grasp and kick Ability to hear conversation Increase in weight Regular cycle of waking and sleeping

20 Weeks Gestation

Third Trimester Begins at 28 weeks Other Developments: Use of all five senses. Passing of water from bladder Some dreaming during sleep Weight of 6-9 pounds Third Trimester Ends at 40 Weeks, although baby could survive with little or no problems at 37 weeks gestation.

37 Weeks & 40 Weeks Gestation

Labor Stage 1: Dilation Stage 2 : Passage through the birth canal. Stage 3 : Afterbirth (delivery of the placenta).

Chapter 19 Lesson 2 Warm Up In your packet from yesterday, Copy the Vitamin information from page 493 on #2 on Activity #70.

#1 – Why are prenatal visits important? During prenatal visits the female will have a complete physical that includes blood tests and a pelvic exam, in order to identify and treat any problems as early as possible. Weight and blood pressure are also monitored throughout the pregnancy.

#3 - Why should you avoid… Caffeine? A high intake of caffeine during pregnancy has been linked to an increased risk of birth defects and low birth weight. Alcohol? Alcohol consumed during pregnancy quickly passes through the umbilical cord to the fetus. The fetus breaks down the alcohol slower, and can result in permanent damage – Fetal Alcohol Syndrome – creates physical and mental problems.

#3 - Why should you avoid… Tobacco? Higher risk of low birth weight, premature babies, and infant deaths. Also may affect the growth, mental development, and behavior of child until 11 years old. Drugs? Prescription, over-the-counter, and illegal drugs can harm the mother and fetus during pregnancy. Can harm fetal development – serious birth defects, premature labor, or miscarriage. Baby can be born addicted to the drugs used during pregnancy.

#3 - Why should you avoid… Lead? Has been linked to miscarriage, low birth weight, mental disabilities, and behavior problems in children. Smog? Linked to birth defects, low birth weight, premature birth, stillbirth, and infant death. Greatest risk during 2nd month of pregnancy. Radiation? (Xrays) can affect fetal growth and cause mental retardation. Cat Litter? Can cause disease called toxoplasmosis – can result in miscarriage, premature labor, and health problems in newborns.

#4 Two complications that can occur are miscarriage and stillbirth. Receiving the proper prenatal care during pregnancy can reduce the risk or severity of any problems that do arise.

Rest of Packet Complete Activities 71 and 72 on your own, turn in the packet when you are finished. It will be graded. If you do not finish it today, take it home and it is due tomorrow at the beginning of the period.