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Lab 4 Online Assessment

  1. The allantois, identified in the placental cord, is continuous with what anatomical structure?
  2. Identify the 3 vascular shunts, and their location, in the embryonic circulation.
  3. Identify the Group project sub-section that you will be researching. (Add to project page and your individual assessment page)



--Z3289991 12:55, 28 July 2011 (EST)

Questions and Answers to Lab Assessment 1

1. Identify the origin of In Vitro Fertilization and the 2010 nobel prize winner associated with this technique.

1. In vitro fertilization originated from the American doctor John Rock’s extraction of an intact fertilized egg. Since IVF (In Vitro Fertilization) involves the artificial insemination of sperm and eggs outside of the body, John Rock’s method paved the way of IVF clinics coming into practice (Gladwell, 2000). The first pregnancy which began off as successful using IVF was reported in the Lancet medical journal by scientists from the Australian Monash University (IVF, 2011). Unfortunately, the pregnancy did not progress any further as the embryo failed to implant properly in the uterine wall. This occurred in 1973. Robert Edwards, who was the 2010 Nobel Prize winner (Committee, 2010), carried out the successful insemination of a sperm and egg outside of the body which led to the healthy birth of a newborn in 1978 (News, 2011). Embryos can now be successfully frozen and transferred from embryonic donors to acceptors.

2. Identify a recent paper on fertilisation and describe its key findings.

2. In 2010, a study was done into finding a therapy for allowing fertilization to occur even when there was sperm centrosomal dysfunction. Reproductive technologies will be invented in the coming years to analyse sperm centrosomal function and counter sperm centrosomal dysfunction. These reproductive technologies will be referred to as assisted reproductive technologies (ART). These technologies are necessary since the sperm centrosome was found to play an important role in the fertilization process after the intracytoplasmic sperm injections (ICSI). This all occurs within the cytoplasm of the oocyte. The answer was sourced from the single reference, (Yukihiro Terada, 2010), details of which can be found in the reference list.

3. Identify 2 congenital anomalies.

4. Two distinct congenital anomalies are amniotic band syndrome and atrial septal defect. Amniotic band syndrome is a limb anomaly which is caused by foetal parts such as limbs of the foetus being stuck in amniotic fibrous bands whilst the baby is in utero. Two main theories have been brought forward to explain how it is caused. The amniotic band theory suggests that there was partial rupture of the amniotic sac (Rapini, Bolognia, & Jorizzo, 2007). However, the chorion remains stable. Hence, fibrous bands of the ruptured ammonium float in fluid and entrap the limbs. The second theory suggests that there may have been vascular disruption to the foetus whilst in utero. Atrial septal defect is a congenital anomaly of the heart. It enables blood flow between the left and right atria via the inter arterial septum (Ira H Gessner, 2008). Thus, there is a mix of venous and arterial blood. This can be clinically significant, depending on how bad the defect is due to mixing oxygenated blood with deoxygenated blood.

Bibliography

Committee, N. P. (2010). The Nobel Prize in Physiology or Medicine 2010. Retrieved July 30, 2011, from Nobel Prize: http://nobelprize.org/nobel_prizes/medicine/laureates/2010/press.html

Gladwell, M. (2000, October 3rd ). John Rock's Error. The New Yorker . New York, New York, America.

Ira H Gessner, M. (2008). Ostium Secundum Atrial Septal Defects. Retrieved July 30, 2011, from Medscape Reference: http://emedicine.medscape.com/article/890991-overview

IVF, M. U. (2011). History of IVF. Retrieved July 30, 2011, from Monash IVF- Life Starts Here: http://www.monashivf.com/About_Monash_IVF/History_of_IVF.aspx

News, B. (2011). On This Day. Retrieved July 30, 2011, from BBC News: http://news.bbc.co.uk/onthisday/hi/dates/stories/july/25/newsid_2499000/2499411.stm

Rapini, R. P., Bolognia, J. L., & Jorizzo, J. L. (2007). Dermatology: 2-Volume Set. St. Louis: Mosby.

Yukihiro Terada, G. S. (2010). Essential Roles of the Sperm centrosome in human fertilization: Developing the therapy for fertilization failure due to sperm centrosomal dysfunction. Journal of Experimental Medicine , 247-258.

--Z3289991 09:02, 3 August 2011 (EST)


--Mark Hill 09:47, 3 August 2011 (EST) A very complete answer to all 3 questions, well done.

--z3289991 11:23, 4 August 2011 (EST)



Lab Assessment 2 Questions and Answers

1. Identify the ZP protein that spermatozoa binds and how is this changed (altered) after fertilisation.

1. ZP-3 (Zona pellucida sperm binding protein-3) is a protein which is coded for by the ZP3 gene. It is the receptor in the zona pellucida which binds with sperm at the beginning of fertilization. The protein encoded by this gene is a major structural component of the zona pellcida and functions in the primary binding and stimulation of the sperm acrosome reaction. Typically, the acrosome reaction will not occur until the sperm comes into contact with the jelly layer of the oocyte. After the jelly layer has been penetrated, the acrosomal enzymes will dissolve and the actin filaments will contact the zona pellucida. A signalling cascade will happen as the calcium influx occurred. ZP3 will not bind sperm to the membrane after this and it will now act to block polyspermy.

2. Identify a review and a research article related to your group topic. (Paste on both group discussion page with signature and on your own page)

2. See main group assessment page, group 3, as well as below:

--Robert Klein 06:19, 9 August 2011 (EST)