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Lab 7--Z3330795 10:56, 12 September 2012 (EST) --Mark Hill 17:26, 11 September 2012 (EST) You need to use the signature tool to log lab attendance.

Fertilization

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.

References: http://science.howstuffworks.com/

"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).

[1]

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.

[2]

--Mark Hill 17:30, 11 September 2012 (EST) Question 1 has been answered correctly. Question 2 has been answered, but not in sufficient detail (2 lines) to describe the findings in full and the link is not correctly displayed. You should use just the number as here PMID 22762979 or remove the brackets around your link. You have lost marks for the lack of a full description, not the reference formatting.6/10

"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.

[3]

Sexual development of MYT1 mutants.jpeg


--Mark Hill 17:38, 11 September 2012 (EST) Question 1 image has been uploaded correctly. In the summary box you have included the citation and copyright information, but not a template indicating that this is a student image. {{Template:Student Image}}. There is also no legend describing what A, B and C are showing, this could have been derived from teh original figure template. Question 2 protein associated with the implantation, chemokines are a relevant "class of proteins", not a specific protein and the article you have selected is a review, not a big issue but you need to also clearly identify that it is a review and not a research article. 7/10

"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.

[4]

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.

[5]


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.

[6]


--Mark Hill 17:43, 11 September 2012 (EST) Question 1 you have identified the difference between "gestational age" and "post-fertilisation age. Your terminology though is confusing "where as Gestational age (approximately 2 weeks later)", you should have then said "than Post-fertilization age". Question 2 you have identified 3 different tissues and the textbook link is appropriate. There are several typos throughout your answer that you should have corrected, I have not removed marks for this, but it suggests to the reader that you have not checked your work. 9/10

"Lab 4 Assessment"

1. Identify the 2 invasive prenatal diagnostic techniques related to the placenta and 2 abnormalities that can be identified with these techniques.

a)Fluorescence in-situ hybridization is an invasive technique which analyses fetal blood cells present in maternal blood samples. These cells gain access through placental villi. This test can screen for conditions such as the trisomies and monosomy X.

b)Maternal serum alpha-fetoprotein is an invasive technique that measures the level of alpha-fetoprotein (AFP) in maternal blood, knowing that adults exclusively have albumin in their blood we exploit this technique. Typically the fetus will only release small amounts of AFP going across the placenta into the mother blood, although large amount of AFP in the maternal blood sample can indicate a neural tube defect or spina bifida.

[7]

2. Identify a paper that uses cord stem cells therapeutically and write a brief (2-3 paragraph) description of the paper's findings.

My selected Paper "Stem cell therapies for spinal cord injury." describes the benefits of use along with its many implications. Spinal Cord injuries(SCI) either complete or incomplete pose a catastrophic stress on the individual both physical and emotional. The possibility of treatment for SCI is an area with enormous potential giving hope to those who are unfortunate enough to come across this terrible injury.

There are currently many implications surrounding stem cell therapy such as tumor formation. The controversy surrounding research in this area is supported by data concluding that there is no way around biological implications caused by treatment.

The basic principle behind stem cell therapy is using multipotential cells to create new and functional tissue, this therapy involves a combination of many complex treatments each addressing different components. Cutting edge research has involved using animal models although these types treatments are still in the development of making safe & ethical therapies that can be used in a clinical setting. As we look to the future of Stem cell therapies there are many more methods being explored for example using induced pluripotent stem cells (force expression of certain genes).

[8]

--Mark Hill 17:50, 11 September 2012 (EST) Question 1 Fluorescence in-situ hybridization and Maternal serum alpha-fetoprotein are not an invasive technique, the analysis of fetal cells in maternal blood is exactly the opposite, it is replacing invasive techniques. I think you have misinterpreted what I meant by invasive technique, such as chorionic villi sampling or amniocentesis. Question 2 you have identified a stem cell paper, a review rather than research article. Though I did not specify this in the question I am usually asking for research articles. Your description is sufficient. 5/10

"Lab 5 Assessment"

1.

(A) Muscles satellite cells are sometimes reffered to as Myosatellite cells, these cells contain a single lobed nucleus and have tendency to differentiate into a specific cell type, similar to stem cells (mononuclear progenitor cell), they are located on the outer surface of muscle fibres and remain dormant until activation occurs


(B)

"Regeneration of adult skeletal muscle is an asynchronous process requiring the activation, proliferation and fusion of satellite cells, to form new muscle fibres." Cooper, S. Tajbakhsh, V. Mouly, G. Cossu, M. Buckingham and G. S. Butler-Browne (1999). Satellite cells are responsible for the growth and regeneration of muscle, although there are chemical mediators that activate these cells proven by an experiment by Anderson J, Pilipowicz O.(2002), concluding Nitric Oxide (in vivo) is required to activate satellite cells and also hepatocyte growth factor (HGF) and Nitric Oxide (NO) also participate in mobilizing satellite cells. Ryuichi Tatsumi, Xiaosong Liu, Antonio Pulido, Mark Morales, Tomowa Sakata, Sharon Dial, Akihito Hattori, Yoshihide Ikeuchi, and Ronald E. Allen (2005) Concluded that when a muscle is stretched beyond resting range Satellite cells are activated. This article also states that when muscle hypertrophy occurs satellites cells are recruited, although what is unsure is the chemical signalling involved. In conclusion 2 actions that activate Satellite cells are stretching and hypertrophy. The passive stretching of skeletal muscles triggers the release and interaction of chemical mediators HGF and NO, which in turn are responsible for activation of satellite cells. If skeletal muscle receives any form of damage through exercise or injury, satellite cells are activated and are attracted to the site of disturbance. Hernandez and Kravitz (1999)


2. Burnham, Martin, Stein, Bell, MacLean, Steadward (1997) concluded that after a Spinal Cord Injury (SCI) an individuals muscles fibres will undergo alteration from type 1 slow and type 2 fast, to become type 2 fast glycolytic fibres also known as "fast twitch B" which feature less myoglobin and mitochondria. Roberto Scelsi (2001) reported a change in the muscles fibers and micro vascular change after conducting various invasive tests on a paraplegic individual. These changes have a clear relationship with the time elapsed. Scelsi reported adaption of the muscle fibers after 1 month, although for the changes to be prominent 7-8 months has elapsed. To retard this unnatural transition, therapy must be used within week of the SCI such as, Functional Electrical Stimulation, (FES) is a recognised treatment allowing some kind of stimulation to these unused muscle fibres and could improve function. Christopher and Dana Reeves Foundation (2012)

" Lab 6 Assessment"

Vision development review:

The key points are Cleary described and Topics have been divided in an efficient way allowing maximum information and an extensive insight into each of these segments, although at this stage there is not enough detail for each. There is a substantial amount of visual stimulus although the quality of these stimuli is questionable. Proper citation is evident however; there is a minority of untidy citations along with no copy write information for a certain image. Significant, deep research is not evident, I believe more research is required; There is a respectable attempt to relate content to learning aims of embryology. To improve more information on each topic is required, review of visual displays and copy write information is essential.