Fertilization, Development, Teratogens, STIs PDF 2020

# Fertilization & Development - occurs in the oviduct during luteal phase when progesterone levels are high (so the endometrium is ready for implantation). - **1) A secondary oocyte is released into the oviduct (ovulation)** - 2n - **2) Sperm are attracted to the oocyte, hydrolytic...

# Fertilization & Development - occurs in the oviduct during luteal phase when progesterone levels are high (so the endometrium is ready for implantation). - **1) A secondary oocyte is released into the oviduct (ovulation)** - 2n - **2) Sperm are attracted to the oocyte, hydrolytic enzymes from the acrosome break down jelly.** - **3) Sperm surface proteins bind egg's receptors** - **4) Sperm cell membrane fuses w/ egg cell membrane.** - oocyte completes Meiosis II - 2n - **5) the mature ovum forms, a polar body is removed & sperm & ovum nuclei fuse = fertilization** - 1n - 1n - 2n zygote # Development - **growth & specialization of cells & tissues** ## Zygote: - 2n - mitosis ## Cleavage: cell division, no growth, the cells are undifferentiated (stem cells) ## Day 1-4: could be anything - solid ball cells - blastula - blastocyst - 1 week - implants into endometrium - will form the extraembryonic structures - fluid - embryo ## Gastrulation - issues of the embryo specialize & reorganize. Formation of 3 germ layers ### Ectoderm- ### Mesoderm- ### Endoderm- - "blastopore" - "invagination" - Gastrola - anus - mouth, fully formed, alimentary canal (gut) - anus ### Spinal cord & brain # Ectoderm - nervous system - senses - skin - teeth - mouth lining # Mesoderm - connective tissue - muscle - bone - blood vessels # Endoderm - endocrine glands - liver - bladder - lining of respiratory tract. # Expecting Better # Do chocolate lovers have sweeter babies? # Teratogens: - mutagenic compounds that interfere w/ development causing birth defects "congenital" born with - **ex. alcohol,** - **narcotics,** - **thalidomide** - **mercury** - **viruses(zika)** - **acts on hox genes** - **attacking the devil** # Sexually Transmitted Infections - STI's - viruses - bacteria - parasites - fungi - infectious agents - transmitted through intercourse - tissue damage or fluids - damage reproductive structures resulting in fertility issues, sterility, or miscarriage. (b/c of inflammation) - *Pelvic Inflammatory Disease* - *Ectopic Pregnancy: zygote implants in the oviduct, oviduct ruptures* * you are responsible for identifying reproductive structures, not knowing the names/ particulars of specific STIs