From Embryology

Lab Attendance

Lab 1 --Z3375390 11:49, 25 July 2012 (EST)

Lab 2 --Z3375390 10:40, 1 August 2012 (EST)

Lab 3 --Z3375390 10:07, 8 August 2012 (EST)

Lab 4 --Z3375390 10:07, 15 August 2012 (EST)

Lab 5 --Z3375390 10:07, 22 August 2012 (EST)

Lab 6 --Z3375390 10:07, 29 August 2012 (EST)

Lab 7 --Z3375390 10:01, 12 September 2012 (EST)

Lab 8 --Z3375390 10:05, 19 September 2012 (EST)

Lab 9 --Z3375390 11:21, 26 September 2012 (EST)

Lab 10 --Z3375390 10:44, 3 October 2012 (EST)

Lab 11 --Z3375390 10:09, 10 October 2012 (EST)

Lab attendance logged for 11 classes --Mark Hill 07:32, 18 October 2012 (EST)

Lab Assignments

Lab 1 Assessment

1. The idea of In Vitro Fertilisation was influenced by the study of fertilisation of rabbit egg cells in test tubes. However as the cycle of human eggs is different to that of rabbits, further study and experimentation had to be done in order to achieve it. The first successful birth of an IVF baby occurred in 1978. Robert G. Edwards was awarded the Nobel Prize in 2010 for the development of In Vitro Fertilisation. [1]

Mark Hill - Q1 is correct. Wher is Q2 answer? (Identify and add a PubMed reference link to a recent paper on fertilisation and describe its key findings (1-2 paragraphs).) 5/10

Lab 2 Assessment

An important protein associated with the process of implantation is Rac1. It is of the RhoGTPases family of proteins, and aids the embryonic trophoblast with invasion of the endometrium. Together with a protein known as RhoA, they are able to regulate cell migration and motility. It has been proven that motility is required in order for the trophoblast to invade the endometrium and for the embryo to be implanted within the uterine wall. Rac1 is needed as it promotes the trophoblast invasion. However, as this process must be tightly controlled, the protein RhoA is needed in order to restrict it. Therefore a balance between the two proteins must be achieved for successful implantation of the embryo in the endometrium.

Mark Hill - Q2 answer is fine and includes link to reference. Where is Q1 answer? (Upload an image from a journal source relating to fertilization or the first 2 weeks of development as demonstrated in the practical class. Including in the image “Summary” window: An image name as a section heading, Any further description of what the image shows, A subsection labeled “Reference” and under this the original image source, appropriate reference and all copyright information and finally a template indicating that this is a student image. Template:Student Image) 5/10

Lab 3 Assessment

1.Gestational age refers to the time between the end of the mother’s last menstrual cycle and the birth of the baby. It is measured in weeks and determined by the size of the fetus using ultrasound before birth. After birth it is determined by the babies weight, length and other features. Postfertilization age refers to the time passed since fertilization of the egg. The exact time of fertilization however cannot be determined, so therefore it is inferred. Usually, gestational age is two weeks longer than postfertilization age.

Gestational age is used when describing human development as it can be clearly determined and hence the calculations are more accurate than postfertilizaton age.

2.Some of the tissues formed from the somites include skeletal muscle, skin and bone.

  • Skeletal muscle
    • Skeletal muscle cells develop from the myotome
    • Myoblasts undergo frequent division and merging in order to form myotubes
    • As development of the muscle cells continues, the nuclei move from the centre to the periphery of the cell.
  • Dermis of the dorsal skin
    • Develops from dermatome and wandering mesenchymal cells
    • Lies between the epidermis and the hypodermis
    • Collagen producing fibroblasts are found in the dermis
    • Composed of two layer:
      • Papillary layer
      • Reticular layer – made of dense irregular connective tissue
  • Vertebrae
    • Develops from sclerotome

Mark Hill - Q1 correct. Q2 correct, sources? 10/10

Lab 4 Assessment

1. Invasive prenatal diagnostic techniques:

  • Amniocentesis
    • This procedure consists of a needle being inserted into the mothers lower abdomen and through to the amniotic cavity
    • Usually performed between weeks 14 and 20 when there is enough amniotic fluid present for the procedure to be successful
    • Fetal cells acquired from the amniotic fluid are grown in culture for analysis of chromosomes, biochemicals and molecular biology
    • Amniotic fluid can also be used to determine the maturity of the fetal lung in the third trimester
    • Fetal loss and maternal Rh sensitisation are risks associated with this procedure
    • It also increases fetal mortality rate by 0.5%
  • Chorionic Villus Sampling
    • Consists of a catheter passing through the cervix and into the uterus usualy via the vagina
    • Cells acquired from the placental chorionic villi are used in chromosome analysis in order to determine the karyotype of the fetus, can also be used for biochemical and molecular biologic analysis
    • Usually performed between weeks 9 and 13 of gestation
    • Limb defects in a fetus is an abnormality associated with CVS
    • It may also increase the morbidity rate of the fetus

2. Preterm delivered infants are at high risk of developing a chronic lung disease known as Bronchopulmonary Dysplasia (BPD). This abnormality arises after ventilator and oxygen therapy for respiratory failure, which is usually associated with premature birth. Indicators of BPD include arrested alveolar growth and lung vascular growth. These abnormalities continue after childhood, putting lung structure and function at risk. Arrested alveolar growth, onset emphysema and pulmonary hypertension have all been linked to BPD and preterm delivery. Hence it is important to understand the developmental procedure of alveoli and the underlying capillary network in order to develop therapies for lung diseases characterised by impaired alveolarization. Research of stem cells shows that cell-based treatments are possible to repair the damaged organs.

Stem cells have been found to be capable of self-renewal and have the potential to differentiate into multiple cellular phenotypes. They play a very important role in organ repair and tissue regeneration throughout the life span of an organism. Embryonic stem cells are the most potent form of stem cells as they are able to differentiate into cell types derived from the mesoderm, endoderm and ectoderm. They are also capable extensive self-renewal. Adult stem cells however are very limited in the sense that they can only differentiated into a certain number of cell types and sometimes only one. Embryonic stem cells are therefore very useful in cell-replacement therapy.

Embryonic stem cells could be used to regenerate lung cells destroyed by disease and injury. BPD could lead to a deficiency of Adult Stem Cells within the lung that contribute to the growth and maintenance of the alveoli, lung matrix and pulmonary microvasculature. Therefore, if these injured and limited cells were to be replaced with EBC's that could repopulate and help with lung growth, the lung can once again carry out its function.

Mark Hill - Q1 correct and well described. Q2 This may well be a paper related to stem cells but you have provided no reference to check the source and content shown here. 6/10

Lab 7 Assessment

1. a) Muscle satellite cells are dormant cells located between the plasma membrane and the basement membrane of the muscle fibres. They function in maintenance, regeneration and growth of skeletal muscle.

b) Satellite cells are activated after a period of prolonged exercise, their responsiveness influences muscle adaptations. In cases of muscle injury, satellite cells are activated. They then proliferate and fuse together to form new muscle fibres.

2. Injury or death of motor neurons generally results in the denervation of the muscle fibres. This means that muscles are no longer able to function as they used to and hence the muscle cells will undergo atrophy and may eventually die. Or, an adjacent neuron may reinnervate the muscle fibres. Muscle atrophy leads to a decrease in muscle mass which results in an increase of fat storage and decrease of metabolic rate.

Mark Hill - Q1 OK. Q2 Have described muscle wasting, but not the fibre type changes and changes in individual fibre size. 7/10

Lab 8 Assessment

Vision: Good introduction, introduces the main components of the eye that will assumedly be focused on when talking about development. More information is needed in the history section however and the images used also need copyright permission.

Wording is simple and understandable, it’s also good to see that you guys have a glossary up so to make it easier to comprehend what is being read. However you need more information under current research. Also you should focus on the other components of the eye other than the Optic nerve and the Retina and add more pictures or diagrams to illustrate what it is you’re explaining.

You should also try using some dot points because reading long paragraphs could get tiring and allow the person to lose focus.

Taste: The overall set up of the page I think is very good. In the introduction there is a balance between pictures and text which makes it a bit easier to read. Also its easy to follow, the text itself isn’t confusing and is understandable.

There is a good overview of the different types of receptors and their function, also there is a brief section on the adult tongue which is good, however there needs to be more focus on the embryological development rather than just a simple table on that. There also needs to be some images added to that component as well to make it more understandable.

The sections on abnormalities and current research need to be organised a bit better because they are a little hard to follow, especially with the placing of the images. The glossary is simple and understandable, however there needs to be more work done on the reference list.

Olfaction: The work needs to be spell checked before you submit it, make sure you get all your grammar right as well. I think you should add more to your introduction, and make it a little simpler, easier to follow. Also throughout your project you tend to use a lot of long paragraphs, especially in the current research section.

Though the developmental timeline that is set up is very detailed, it can be a bit hard to follow and a little confusing. There is too much text and no pictures at all to help demonstrate what is being said about the development. The ratio of images to text in the anatomy and abnormalities sections however is very good and makes it more interesting to read.

It’s good to see that you have some external links put up on the page and also that you’ve used quite a few references to do your research rather than just a few.

Abnormal Vision: The text on this page is very good, detailed and to the point. However a lot more images are needed on the page to make it more appealing, interesting and easier to follow.

The section under Ocular Manifestations is a little difficult to keep track of, there needs to be more of an introduction in that section highlighting the two sections that are to be discussed, then there should be a clear division between the two.

Also the placement of the few images on the page need to be organised a little better. The referencing on this page is done very well and its good to see an extensive use of resources.

Hearing: This whole page I think is done really well. There is a balance between texts and images, it goes through the developmental process in detail, all information is relevant, there is an extensive use of resources and a pretty good glossary as well. The image right at the beginning of the dog is very smart as it draws attention to the whole page. Also the “Can you hear me” at the beginning gives the expectation that the page as a whole is going to be really good so I thought that was very effective. More information can be added to the current research section, and also you should try referencing throughout the entire page could be done a little better.

Mark Hill - Reasonable peer assessment, perhaps with a few more specific comments. 10/10

Lab 9 Assessment

2. The cells that form the tooth bud originate from the ectomesenchyme, the neural crest and the ectoderm. The embryonic development first begins late in stage 18. The tooth buds are formed via interaction between the neural crest and the ectoderm. The ectomesenchume surrounds the tooth bud and forms the dental follicle.

Mark Hill - Q1 (Identify and write a brief description of the findings of a recent research paper on development of one of the endocrine organs covered in today's practical.) no answer provided here. Q2 good answer. 5/10

Lab 11 Assessment

This journal article looks at ways that stem cells could be used in therapeutic cell transplantation and regeneration within the myocardium of the heart. Some studies have shown that adult stem cells have the ability to improve the myocardium though only for a short time. Therefore there is a need for a cell type that is able to provide long-lasting engraftment and myogenesis, such iPS cells.

It concluded that a combination of surface markers could identify and enrich stem cell derived transcription factors with trilineage cardiovascular potential in vitro and also the ability to fragment and differentiate into mature adult cardiomyocytes.


Mark Hill - Good paper, description a little light. 10/10

  1. <pubmed>23056209</pubmed>