From Embryology

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)

Lab Attendance

--z3272325 18:03, 28 July 2011 (EST)

--z3272325 13:01, 4 August 2011 (EST)

--Rahul Mohan 11:20, 25 August 2011 (EST)

Dear Dr Hill, I've attended every lab without fail- except for once in August as I'd fallen ill then. However, I've forgotten to indicate my attendance in the labs here. I am deeply sorry. -Rahul Mohan z3272325

Lab 1

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

The history if IVF could be said to be traced back to the first successful case of embryo transplantation by Walter Heape n 1891- who was able to successfully transplant an embryo from one species of rabbit to the uterus of another, thereby proving that an embryo could be transplanted into a carrier and have its development unaffected by the movement.

In the 1970s a collaboration between Robert Edwards, a physiologist and Patrick Steptoe, a gynaecologist, resulted in the first incidence of human in-vitro fertilisation (IVF)- with the embryo being implanted in the mother in 1977, and the first human in-vitro fertilised baby being born in 1978.

In 2010, Robert Edwards was awarded the Nobel Prize, for the development of the therapy.

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

The paper describes how strontium can be utilised to activate oocytes and how this subsequently leads to improved fertilisation rates and embryo quality, when used in tandem with intracytoplasmic sperm injection. 1

Identify 2 congenital anomalies. Congenital Diaphragmatic Hernia: the baby is born with a hole in the diaphragm, or with the complete absence of the diaphragm

Omphalocele: there is a defect in the development of the muscles of the abdonmial wall, which leads to the abdominal organs to protrude through, in the general area of the umbilical cord.

References 1 Chen J, Qian Y, Tan Y, Mima H. (2010). Successful pregnancy following oocyte activation by strontium in normozoospermic patients of unexplained infertility with fertilisation failures during previous intracytoplasmic sperm injection treatment. Reproduction, Fertility, and Development, 22(5), 852-855. [PMID: 20450837]

Lab 2

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

Spermatozoa binds to the glycoprotein, zone pellucid glycoprotein 3 or ZP3 in the Zona Pellucida. After fertilisation, an increase in cytosolic calcium ions is induced in the fertilised egg cell. This calcium wave in turn initiates the cortical reaction within the cell- in which the enzymes within the cortical granules are released into the cytosol of the fertilised egg cell. This would alter the structure of the zone pellucid that surrounds the egg, preventing further sperm from being able to penetrate it.

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)

Review: Inhaled bronchodilators for cystic fibrosis. Halfhide C, Evans HJ, Couriel J. Cochrane Database of Systematic Reviews 2005, Issue 4. Art. No.: CD003428. DOI: 10.1002/14651858.CD003428.pub2 from

Research Article: Identification of airborne dissemination of epidemic multiresistant strains of Pseudomonas aeruginosa at a CF centre during a cross infection outbreak. Jones AM, Govan JR, Doherty CJ, Dodd ME. Isalska BJ, Stanbridge TN, Webb AK. Thorax 58(6), 525-527. from

Lab 3

Differentially expressed RefSeq genes in human trisomy 21

What is the maternal dietary requirement for late neural development?

Many nutrients are required for late neural development to occur successfully. Amongst them, of vital importance are folic acid- for neurogenesis in the central nervous system of the embryo [1] and the closure of the neural tube, iodine for the development of the hippocampus [2] and cerebellum [3], choline for stem cell proliferation [4] and Omega 3 for the maintenance of normal neurogenesis and neurological function [5]

Upload a picture relating to you group project. Add to both the Group discussion and your online assessment page. Image must be renamed appropriately, citation on "Summary" window with link to original paper and copyright information. As outlined in the Practical class tutorial.

In vitro fetal palate explant culture[6]


  1. <pubmed>20838574</pubmed>
  2. <pubmed>20412599</pubmed>
  3. <pubmed>21611807</pubmed>
  4. <pubmed>PMC2438605</pubmed>
  5. <pubmed>19214053</pubmed>
  6. <pubmed>PMC2841638</pubmed>

Lab 4

1 The allantois, identified in the placental cord, is continuous with what anatomical structure?

The allantois is continuous with the bladder via the urachus- which forms a connecting stalk that links the umbilical region and the bladder.

2. Identify the 3 vascular shunts, and their location, in the embryonic circulation:

Ductus Venosus: Between the umbilical vein and the inferior vena cava
Foramen Ovale: Between the left atrium and the right atrium in the fetal heart.
Ductus Arteriosus: Between the pulmonary artery and the aortic arch

3. Identify the Group project sub-section that you will be researching.

Current Research, Associated Figures.

Lab 5

Which side (L/R) is most common for diaphragmatic hernia and why?

Diaphragmatic hernias are most commonly found to occur on the left side. This could possibly be attributed to the fact that the fusion of the membrane of the left pleuroperitoneal canal occurs at a later stage than the right pleuroperitoneal canal. In addition, the anatomical location of the liver on the inferior aspect of the right side of the diaphragm could act as a means of mechanical protection to the membrane- preventing it further from the possibility of herniation.

Lab 6

What week of development do the palatal shelves fuse?

Palatal shelves fuse in week 9 of development.

What animal model helped elucidate the neural crest origin and migration of cells?

The quail-chick chimera served as an animal model that helped the elucidation of neural crest origin and migration of cells.

What abnormality results from neural crest not migrating into the cardiac outflow tract?

Abnormalities that result from the neural crest not migrating into the cardiac outflow tract include, but are not limited to: -Cushion hypoplasia -Persistent truncus arteriosis -Tetralogy of Fallot

Lab 7

Are satellite cells (a) necessary for muscle hypertrophy and (b) generally involved in hypertrophy?

Satellite cells are not necessary for muscle hypertrophy- as evident from experiments in which these cells were inactivated, and yet muscle hypertrophy continued. However, they serve to facilitate hypertrophy as similar experiments with activated cells have indicated that there is a greater increase in muscle cells when they are activated. Thus, it can be concluded that they are generally involved in hypertrophy.

Why does chronic low frequency stimulation cause a fast to slow fibre type shift?

Chronic low frequency stimulation is a process in which electrical stimulation is applied on muscle cells in a manner that resembles that received by slow twitch fibres. Thus, repeated and chronic application of such electrical stimulation on fast twitch fibres causes physiological changes in fast twitch cells that transforms it into a slow twitch cell.

Trisomy 21 review

-The flow of contents within the whole page- (with respect to headings) seems rather disjointed. For instance, prevalence could have come below the introduction section- as it would give readers a sense of how common this disease is.
-Within the introduction section, it would have been better if it portrayed more generic information that gave the reader a top down view of the topic. Also, the picture of Down J.L.H would have been better included in this section, instead of further down.
- The pictures attached fail to have copyright information included.
- The placement of links to genetics and diagnosis links seems misplaced and messy in the introduction.
- Under the "some recent findings" section- which could have been better placed at the end of the page, before the conclusion- it would have been better if the papers were described in text, instead of simply listing the title and the abstract.
-There is excessive use of dot points in this site. More text and descriptions is needed.
-Under prevalence- whilst it is stated that data from different world regions is described, only data from atlanta (US) and Galway (Ireland) are included
-There is good use of charts and tables to highlight data.
-Under "Screening by country"- only data from Spain is included.
-There are irrelevant sections included in the wiki- such as Aneuploidy- which merely states definitions.
-The inclusion of relevant journals and books in the reference section is a good idea, that enables the reader to engage in further research on the topic if required.

Lab 10

Besides fetal alcohol syndrome, identify another environmental teratogen that can lead to hearing loss.


Identify 3 factors that contribute to poor neonatal drainage of the middle ear.

1. The Eustachian tube is almost horizontal- and thus doesn't promote drainage. 2. The Eustachain tube is both shorter and narrower in neonates, as opposed to that in adults. 3. The Eustachian tube in neonates is acted upon by the tensor palati only, whilst that in adults is acted upon by both levator palati and tensor palati muscles.

Identify 1 genetic abnormality that affects hearing development and link to the OMIM record. (Your individual abnormality should be different from all other students)

Arthrogryposis Multiplex with deafness, inguinal hernias and early death [OMIM - ARTHROGRYPOSIS MULTIPLEX WITH DEAFNESS, INGUINAL HERNIAS, AND EARLY DEATH]

Lab 11

Name the components that give rise to the interatrial septum and the passages that connect the right and left atria.

The components that give rise to the interatrial septum and the passages that connect the right and left atria include the septum primum and the septum secundum. The septum primum is derived from the roof and the atria whilst the septum secundum grows adjacent to it. The wall between the atria is incomplete and the holes present are the foramen ovale and the foramen secundum.

Identify the cardiac defects that arise through abnormal development of the outflow tract.

The cardiac defects that arise through abnormal development of the outflow tract include:
-Transposition of the Great Vessels
-Tetrallogy of Fallot
-Aortic Stenosis
-Pulmonary Artresis
-Pulmonary Stenosis
-Hypoplasia of the left heart
-Interrupted aortic arch

Lab 12

Give examples of 3 systems that continue to develop postnatally.

3 systems that continue to develop postnatally include the cardiovascular system, the neural system and the musculoskeletal system.

Identify the abnormalities detected by the Guthrie Test and link to one abnormality listed in OMIM.

The abnormalities detected by the Guthrie test include, but are not limited to: Phenylketonuria, Adrenal Hyperplasia, Cystic Fibrosis, Homocystinuria, Maple Syrup Urine Disease (OMIM), Toxoplasmosis and Hypothyrodism.