User:Z3252833

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 Work

Lab 1

The assessment item is to create the links shown below.

Examples:

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

Exercise:

Internal link: This is Not a Link

Lab 2

  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

Reference

Lab 3

  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

  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.