From Embryology

Attendance in Labs

Lab 1 - Present --z3252833 23:34, 28 July 2010 (UTC)

Lab 2 - Present --z3252833 23:50, 4 August 2010 (UTC)

Lab 3 - Present --z3252833 23:05, 11 August 2010 (UTC)

Lab 4 - Present --z3252833 23:18, 18 August 2010 (UTC)

Lab 5 - Present --z3252833 00:32, 26 August 2010 (UTC)

Lab 6 - Present --z3252833 23:06, 1 September 2010 (UTC)

Lab 7 - Present --z3252833 23:06, 15 September 2010 (UTC)

Lab 8 - Present --z3252833 23:17, 22 September 2010 (UTC)

Lab 9 - As always, present --z3252833 23:06, 29 September 2010 (UTC)

Lab 10 - Present and accounted for --z3252833 23:22, 6 October 2010 (UTC)

Lab 11 - Still here... --z3252833 22:17, 13 October 2010 (UTC)

Lab 12 - As always, present. --z3252833 22:16, 20 October 2010 (UTC)

Lab Work

Lab 1 - Cell Division/Fertilisation

The assessment item is to create the links shown below.


A picture of an early zygote from the 'Fertilization' page

Picture can be seen on the right.

Making internal links: Cell Division and Fertilisation Lecture

Making external links: SMH Main Website


Internal link: This is Not a Link

Lab 2 - Weeks 1 to 3

  1. What factor do the synctiotrophoblast cells secrete to support the ongoing pregnancy?
  2. What does the corpus luteum secrete to prevent continuation of the menstrual cycle? 

1. The syncitiotrophoblasts secrete Human Chorionic Gonadotropin (hCG) to maintain the decidua and corpus luteum, thereby supporting the pregnancy. The presence/concentration of hCG is also the basis of pregnancy tests using urine.

2. If fertilisation occurs, the corpus luteum secretes progesterone to maintain the pregnancy and prevent continuation of the menstrual cycle.


Search Bookshelf: Ultrasound

Search Pubmed: Ultrasound

Ultrasound and the risk of nosocomial cross infection [1]


  1. <pubmed>20681005</pubmed>

Lab 3 - Trilaminar Embryo to Early Embryo

  1.  What Carnegie stages occur during week 3 and week 4?
  2. What is the change in overall embryo size from the beginning of week 3 to the end of week 4?
  3. Approximately when do the cranial (anterior) and caudal (posterior) neuropores close in the human embryo?

1. During week three, Carnegie stages 7 (days 15-17), 8 (days 17-19), and 9 (19-21) occur. During week four, Carnegie stages 10 (days 22-23), 11 (days 23-26), 12 (days 26-30) and 13 (also 26-30) occur.

2. At the beginning of week three, the embryo is approximately 0.4mm diameter in size. At the end of week four, the embryo is about 3-5mm in size, a difference of about 2.6-4.6mm.

3. In the human embryo, the cranial neuropore closes bidirectionally (from the dorsal and terminal lips) during Carnegie stage 11 at about 24 days within a few hours. The caudal neuropore closes over the course of a day during Carnegie stage 12, at about 26 days into development. If the caudal neuropore fails to close this can lead to the neural tube defect spina bifida.

Lab 4 - Vascular and Placenta

  1. Name the vessels that drain into the sinus venosus?
  2. What is the fate of the vitelline artery and vitelline vein?
  3. Name the 4 layers that constitute the placental barrier?
  4. What stem cells are found in abundance, and may be harvested from the placenta for therapeutic uses?

1. Three pairs of veins drain into the sinus venosus - the vitelline, umbilical (placental) and common cardinal veins.

2. The vitelline arteries arise from the dorsal aorta and contribute to the adult GIT arteries. The vitelline veins empty into the sinus venosus and contribute to the adult portal venous system.

3. The four layers are: syncitiotrophoblast, cytotrophoblast, villi connective tissue and fetal capillary endothelium. They separate the foetal and maternal blood.

4. Haematopoetic stem cells can be sourced from foetal blood precursors in the placenta at birth; but recently cells in Wharton's jelly (gelatinous connective tissue of the umbilical cord) has been identified as a potential source of stem cells.

Lab 5 - Endoderm and Respiratory

  1. What is the origin of the gastrointestinal tract smooth muscle?
  2. At what Carnegie stage does the buccopharyngeal membrane begin to break down?
  3. Identify the lung developmental stage in late embryonic to early fetal period.
  4. In premature infant birth, which respiratory cell type may not have fully developed?

1. Gastrointestinal smooth muscle is derived from splanchnic mesoderm.

2. The buccopharyngeal membrane breaks down at Carnegie stage 11.

3. Lung development (budding of lungs from the trachea) starts to occur in Carnegie stage 22.

4. Premature babies may not have fully developed type 2 alveolar cells which secrete surfactant, meaning they lack the surfactant necessary to breathe properly on their own.

Lab 6 - Head and Neural Crest

No questions were posted on the student page.

Lab 7 - Musculoskeletal

  1. Briefly; what is a myotube and how is it formed?
  2. What changes would I expect to see in the muscle fibre types in my legs if I:
   a) Suffered a spinal cord injury 
   b) Took up marathon running

1. A myotube is a developing muscle fibre. It is formed by the ordered fusion of myoblasts; once a motor nerve contacts that myotube it begins to mature into a fibre and other myotubes grow around it.

2.a) After suffering a spinal cord injury, the muscle fibres in the patient's legs would transform to be mostly composed of type II (fast glycolytic) fibres.

b) After taking up marathon running, some muscle fibres would transform to be slow twitch fibres.

Peer Assessment of Group Projects

Group 1 -
Group 2 You have found so many great pictures! Your page looks amazing. I just wonder where the files came from – I saw you put up the copyright notices, but I couldn’t find the file sources. Your timeline was great too; I really like how you put up the concise timeline and then expanded a bit on the major developments afterwards. Are the transabdominal and the transcervical pictures the student-drawn ones? If so, well done! They’re really clear and beautifully done, but you should probably label them as student drawn and put in the copyright statement. If I could suggest something, it would be that you put the advantages/disadvantages of CVS over other techniques in a table. Otherwise, your page is really easy to read, and again has brilliant visuals – great job!
Group 3 You have a great distribution of your pictures around the page, it really breaks up the text and makes it easier to read and to look at. I noticed a few spelling/grammar errors throughout your page, though (e.g. “likelihood of baring a child” – it should be bearing) so you might want to proofread it a couple of times. It would make your text easier to read, too – your information is great but sometimes I had to read over bits a few times where the grammar was a little fuzzy. I think you’ve used the table really well to describe disorders detected by amniocentesis. Also, good job of putting the copyright statement with your student-drawn diagrams. Well done!
Group 4 Firstly - are the drawings of the PUBS procedure in the table student-drawn? If so, they’re amazing! Just… wow. But you might want to label them and add the appropriate copyright statement to the picture information page. You’ve got a lot of really informative text, but you might want to think about finding some pictures to add to break up all the writing, like images of defects that PUBS can detect. If I could give another suggestion it would be that perhaps the history section could be moved forward, to after the introduction – it seems a little out of place to me where it is. And maybe the advantages and disadvantages could be put in a table rather than listed, again to break up the text. But I really liked the way all the information has been written; it’s concise, not too dense, and quite easy to read. Great job!
Group 5 I’m guessing that the fetal fibronectin diagram at the top of the page is your student drawn diagram. Nice job on it. You might want to more clearly indicate that it is student drawn, though, and you should probably include the copyright statement. Also, you might want to think about adding some more pictures to your page to break up the text a little bit and make the page more eye-catching and easy to look at. I have to say that I really liked the way that you’ve set out the section on the test results. It was very easy to read. If I had another suggestion, it would be to move your glossary up to before the references – I almost didn’t notice you had a glossary hidden there. If someone wasn’t really looking, they might not spot it. Other than that, nice job!
Group 6 Good job with the referencing and copyright information on your pictures, including the student-drawn ones. It would be nice to see descriptions of the pictures in that caption-area, just to make it more clear what part of your writing they were relating to. I love that you included a link to a video in your intro; it made me want to watch and find out more. I would suggest moving your other links for further reading to before your glossary though, just so they don’t get lost in the page – once people hit the glossary I find they tend to think that’s the end and stop reading (at least I tend to). Other than that, it says “ babys’ ” instead of “baby’s” in the Maternal Serum Alpha Protein as a Screening Test section first paragraph; but other than that I didn’t spot much else in the way of typos, and I found your language quite easy to read. Other suggestions would just be maybe to break up the text a bit, perhaps with some more pictures, just to make the page more eye-catching. Perhaps something with colour, if you can find it. Overall, though, well done!

Lab 8 - Kidney and Genital

No questions were posted on the student page.

Lab 9 - Stem Cells

No questions were posted on the student page.

Lab 10 - Endocrine

  1. Development of which endocrine organ is affected by low dietary iodine?
  2. What are the effects of this deficiency on other non-endocrine system development?
  3. At approximately what week in development do many endocrine organs appear to begin their function?

1. Development of the thyroid is affected by low dietary iodine.

2. Iodine deficiency in the mother can cause miscarriage, stillbirth and mental retardation. Children with an iodine deficiency can grow to be stunted, apathetic, mentally retarded and not be capable of normal speech, hearing or movement.

3. Many endocrine organs (e.g. pituitary, thyroid, secretion of insulin by pancreas) appear to being functioning at about 10 weeks.

Lab 11 - Heart and Integumentary

No questions were posted on the student page.

Lab 12 - Fetal

  1. During which trimester does fetal length change the most and when does fetal weight change the most?
  2. What is the name of the theory that links postnatal health with prenatal development?
  3. Which hormone initiates and maintains labour during birth and where does it come from?

1. Change in fetal length is at its greatest in the second trimester of pregnancy, whilst the greatest change in fetal weight occurs in the third trimester of pregnancy, close to the time of birth.

2. The Fetal Origins Hypothesis.

3. Oxytocin, which is a peptide hormone secreted by the mother's posterior pituitary, is involved in the initiation and maintenance of labour. Oxytocin is also secreted by the fetus as well, so the fetus itself plays a part in initiating labour. Prostaglandins, synthesised by the uterus and placenta, also play a role in labour initiation and maintenance.