The process in Simple Steps:
Step 1 - Many sperm travel from the Male testes to the Female Egg located in the Fallopian tube.]
Step 2 - Once the sperm reach the egg, many try and "enter" by releasing enzymes breaking down the outer layer of the egg.
Step 3 - Only one sperm can penetrate and once this happens, a chemical reaction occurs "pushing" away any other sperm attempting to penetrate.
This now fertilized egg is referred to as a zygote
Step 4 - pronuclei of the egg merges with the pronuclei of the sperm resulting in cell division.
Step 5 - days later this zygote is moved along the fallopian tube and is now called a blastocyst.
Step 6 - the blastocyst is embedded in the uterine wall activating the start of pregnancy.
"Lab 1 Assessment"
1.Identify the origin of In Vitro Fertilization and the 2010 nobel prize winner associated with this technique and add a correctly formatted link to the Nobel page.
The British scientist Robert Edwards has been researching and devloping IVF since the 1950's, the first successful IVF treatment was in 1978 when the worlds first baby was born from this fertilization technique. Following this success methods have been continually rejuvenated with state of the art techniques and research.
Robert Edwards was the winner of the 2010 Nobel Prize in medicine for his efforts in the development of in-vitro fertilisation (IVF).
2.Identify and add a PubMed reference link to a recent paper on fertilisation and describe its key findings (1-2 paragraphs).
This paper is explores the potential of screening sperm before fertilization, to predict fertilization rate depending on the "quality" of the sperm. This technology would be of extreme importance and make the IVF process more efficient.
"Lab 2 Assessment"
Identify a protein associated with the implantation process, including a brief description of the protein's role.
Chemokines are a protein directly associated with the implantation process. Current research has shown that Chemokines play an executive role within the endometrium, specifically throughout implantation. It has been proven that these proteins direct the invading trophoblasts within the maternal vasculature and decidua. This invading process is critical in early development and chemical signally from these proteins allows precise depth of insertion in preparation of the crucial weeks ahead.
"Lab 3 Assessment"
1.Identify the difference between "gestational age" and "post-fertilisation age" and explain why clinically "gestational age" is used in describing human development.
a) The overlap and confusion of these terms is very common due to physicians frequently using either one to describe the early stage of pregnancy. Technically there is a distinct difference between the two."Post-fertilization age" is the time elapsed after egg fertilization, where as "Gestational age"(approximately 2 weeks later) is the time since the mothers last menstrual cycle prior to pregnancy.
b) In a clinical setting is important to use consistant terminology, “Gestational age” is the preffered term used to describe this early stage of pregnacy for the obvious reason that the average women will know when their last menstral cycle began although she will typically have less certainty surrounding when ovulation occured. The delvery date is a simple caculation given acuracy of the Gestational age.
2. Identify using histological descriptions at least 3 different types of tissues formed from somites
Somites form Cartilage (ribs and vertabrae), skeltal muscle (ribs, limbs and back) and also the dermis of the dorsal skin. The cells of the Somites remain multipotential for a long time during development, therefor somite cells can become any somite structure until maturation where they become commited to form structures repective of their regions.
The Somites have three different regions with different tissue outcomes. The somite cells located closest to neural tube turn into mesenchymal cell (through complex cellular processes) this is portion that become chrondocytes of the cartilage formed. The cells in the two lateral portions of the somite structure divide to produce the myoblasts which are muscle precursers cells. This is now a 2 layered segment, the top layer is called dermamyotome, and the lower myotome. Depending on the location of the myoblasts determines their fate (epaxial or hypaxial muscles). the final area is located in the centre of the dermamyotome is called the dermatome, producing connective tissue of mesenchymal origin which will mature and eventually form the tissue of ventrally located skin.