Presentation on theme: "Pregnancy: When male gametes are deposited into a woman’s vagina, they swim first toward the uterus, then the fallopian tubes. Of the several million spermatozoa."— Presentation transcript:
Pregnancy: When male gametes are deposited into a woman’s vagina, they swim first toward the uterus, then the fallopian tubes. Of the several million spermatozoa released, only a few thousand will reach the ovum (see below). Only one of these will succeed in fertilizing the ovum. Book A = 266 Book B = 262
Embryo and Placenta: Two important tissues form in the 10th and 14th day of development: 1. The Amniotic Sac that contains the embryo and the amniotic fluid; they protect the embryo from shock. 2. The Placenta; it carries the oxygen and nutrients for cell growth and waste removal. Week 1 – 9 Pregnancy Video Week 1 – 9 Pregnancy Video
Embryo to Fetus Three layers of Gastrula form in the Zygote; Cell layers to create the different parts of the body: Cell Differentiation. The embryo grows very quickly; 500 X bigger by the 4 th week. (sesame seed to grape). From this point on the growth of the embryo will grow into a fetus. Time is now broken into Trimesters.
Week Embryo or Fetus Key Aspects Week 4 Week8 Week 12 Week 10 – 14 Video Week 10 – 14 Video
Week Embryo or Fetus Key Aspects Week 4 Live is in the form of an embryo at 28 days. It measures 1 cm long. Brain, heart, limbs, eyes and spinal column start to form. Week8 Baby is now considered a fetus. 3 cm long. 1 st bone cells produced. Arms and legs – no digits. Week 12 Fetus: it can move.8 – 10 cm long. Sprouting Organs: Liver, stomach, brain & heart. Sex determined and Week 10 – 14 Video Week 10 – 14 Video
K E Y A S P E C T S Week 16 Week 20 Week 24 Week 15 – 20 Week 15 – 20 Week 21 – 27 Week 21 – 27 Week
K E Y A S P E C T S Week 16 Week 20 Week 24 Fetus is ~ 16 cm long. Skeleton forms Fingers and toes; nails start to grow Genital organs form Brain develops quick and nervous sys. starts to work Most organs present, but no functioning. 25 – 30 cm Hair on head starts Teeth buds under gums Starts to hear sounds Can suck thumb Digestive system starts by swallowing amniotic fluid. 27- 35 cm Lungs form, but not able to breath. Finger prints develop Jumps when sudden noise made Week 15 – 20 Week 15 – 20 Week 21 – 27 Week 21 – 27 Week
28 – 37 Week 28 – 37 Week K E Y A S P E C T S Week 28 Week 32 Week 36
Week 28 – 37 Week 28 – 37 Week K E Y A S P E C T S Week 28 Week 32 Week 36 ~ 38 cm long Immune system develops Bones begin to harden It can open its eyes ~ 42 cm long Grows about 1 cm a week Lungs and Brand continue to develop Fetus is running out of room inside Head starts to drop into birth position. ~ 50 cm long Can distinguish light and dark Recognizes mother’s voice Nails/Hair continue to grow. Get hiccups often.
Risk Questions. Risk Questions. Which Trimester and Week does… 1.The heart start to develop? 2.The lower limbs stop developing? 3.A) It become a major risk to have major malformations to the exterior genitalia? 4.B) It become only possible minor malfunctions to the exterior genitalia?