REPRODUCTIVE SYSTEM Day 2 Human Development: From Conception to Birth 1

Goodmorning! Bellringer: *Get out notes to be checked* Answer in your notebook: 1. Where is sperm produced in men? 2. Where does fertilization occur in the female? 3. What is the male and female gamete? Label each. 4. What would happen if a man’s vas deferens was not working?

Announcements: Unit 4 (Human Body) Exam next class!!! -STUDY STUDY STUDY :) -Extra credit and class treat for the highest scoring period -Complete Review Packet over the weekend

EOC Blitz!!!!!! Which of the following is a proof of evolution that compares embryos of different species to determine common ancestor. This also shows that there are shared patterns of development Comparative anatomy Comparative embryology Fossil records

Elephant Fetus

sperm cell + egg cell = zygote. What is fertilization? Fertilization : sperm cell + egg cell = zygote. Occurs in upper third of Fallopian tube Only 1 sperm can fertilize an egg To the Teacher: 12

What is gestation? Gestation is the carrying of an embryo or fetus inside female viviparous animals, including mammals, as well as some non-mammalian species. Gestation: The act of BEING PREGNANT

How do we get from this to that Talk about mitosis. Show picture of baby compared to food sizes.

What cellular processes make it all happen? Growth or the increase in the number of cells. Development or the arrangement of the cells into specific organs. Differentiation or the specialization of cells to perform specific tasks and functions. To the Teacher: Use the frog diagram to explain cellular processes. 15

Conception and Growth http://www.whattoexpect.com/pregnancy/week-by-week/weeks-1-and-2.aspx

If the ovaries release two eggs, and sperm fertilizes both eggs, you get fraternal twins! What about twins you ask? If one egg fertilizes one sperm and that zygote splits into two, you get identical twins.

Why must the zygote move into the uterus? https://www.youtube.com/watch?v=HsYHtczWiWI

Why must the zygote move into the uterus? https://www.youtube.com/watch?v=HsYHtczWiWI

Four days after fertilization, the embryo is a solid ball of about 64 cells called a morula. The stages of early development include implantation, gastrulation, and neurulation.

What are the different parts that hold the baby when it starts to develop?

The embryo secretes enzymes that digest a path into the soft tissue Between 24-72 hours after sexual intercourse…. Fertilization can occur. Step 1: Fertilization Egg+ Sperm = zygote Implantation Zygotes travels to and implants itself onto the uterus and is now called a blastocyst. The embryo secretes enzymes that digest a path into the soft tissue A zygote (the fertilized egg) has 46 chromosomes. Review meiosis here…………

Gastrulation The blastocyst gradually sorts itself into three layers. The final layer is produced by a process of cell migration known as gastrulation. 24

Gastrulation As a result of gastrulation three layers are formed: Ectoderm (Skin and nervous system) Endoderm (Lining of digestive system and many digestive organs) Mesoderm (Several internal tissues and organs) Ectoderm will develop into the skin and the nervous system. Endoderm forms the lining of the digestive system and many of the digestive organs. Mesoderm cells differentiate to form many of the body’s internal tissues and organs. Referred to as the primary germ layers because all the organs and tissues of the embryo will be formed from them. 25

Neurulation is the development of the nervous system. What is neurulation? Neurulation is the development of the nervous system. Neural folds create neural tube. One end of the neural tube will develop into the brain, the other end develops into the spinal cord. 27

The Path of Human Development Zygote  Blastocyst  Embryo  Fetus Infant

Later Development During the second trimester, the tissues of the fetus become more complex and specialized, and begin to function. The fetal heart becomes large enough so that it can be heard with a stethoscope. Bone continues to replace the cartilage that forms the early skeleton. A layer of soft hair grows over the fetus’s skin. 29

Later Development During the third and last trimester, the organ systems mature. Fetus grows in size and mass. Lungs and other organs undergo a series of changes to prepare them for life outside the uterus. Regulates its body temperature. CNS and lungs complete their development. 30

The First Trimester (3 months) Week 1 Week 3 Week 4-5 Week 8 Week 10-12 Blastocyst implants into uterus Becomes Embryo Heart begins to beat and Nervous system forms Placenta forms to pass nutrients from mom to embryo Umbilical cord develops and attaches to placenta to pass oxygen to embryo. Also used for embryo to release waste into mother’s blood stream (blood is NOT shared!) Becomes fetus Organs begin to develop Hearing develops 2 in. long Active (kicks) The amniotic sac is a fluid filled sac for protection Water breaks is amniotic sac breaking. Add pics. People that eat placentas for nourishment after pregnancy What could happen to the baby if you're unhealthy (drinking/smoking) in the first couple weeks of becoming pregnant?

The Second Trimester (4-6 months) Week 13-16 Week 17-24 Taste buds develop Sucks Thumb Embryo becomes fetus Gender is evident at week 20 Can dream Lanugo, a fine hair that protects the baby, develops https://www.youtube.com/watch?v=bZcGpjyOXt

The Third Trimester (7-9 months) Fetus’ head moves towards vagina Week 26-28 weeks Week 36 Fetus’ head moves towards vagina Lungs develop Opens and closes eyes

Notebook Output: Based on what you just learned, why do Pre-Mature infants have to be on a respirator for a while after birth?

Why is Early Development so Important? Early development can be disrupted by a number of external factors. Many substances can penetrate the placenta. AIDS and German measles. Alcohol and other addictive substances. Medications. 35

Class Presentation: Fetal Development We Do On my own: Research your assigned week of the “segment” On my expert group: Share my findings, decide on what we will present to other expert groups. On my base group: Receive all information gathered by everyone Class Presentation: Fetal Development 36

Independent practice *Complete by the end of class*

Exit Ticket -on Google Classroom -Submit before the end of class Don’t forget to pick up your Review Packet and put away your Tablet!

Homework: