From Embryology

Lab 1 Questions:

Q1. What is the protein that sperm binds to on the surface of the ova?

ZP3, a protein from the zona pellucida

Q2. Name the 3 stages of follicular development in the ovary:

primordial, preantral and antral

present--Gabriela Pinget 13:14, 6 August 2009 (EST)

Lab 2 Questions

1. What factor do the synctiotrophoblast cells secrete to support the ongoing pregnancy?

The Human Chorionic Gonadotropin (hCG) hormone and the proteolytic enzymes- they degrade the extracellular matrix around cells

2. What does the corpus luteum secrete to prevent continuation of the menstrual cycle?

progesterone as signaled by the hCG hormone produced by the trophoblast cells of the blastocyst

3. What are the 2 main tissues to be derived from the germ cell layer continuous with the lining of the amniotic sac?

ectoderm and endoderm

--Gabriela Pinget 13:55, 13 August 2009 (EST)

Week 3 Lab Questions:

What period of human development (in weeks) do the 23 Carnegie stages cover?

Carnegie Stage 23 is equivalent to week 8. Hence this covers week 0 to week 8 in the stages of development.

What part of the somite will contribute to the vertebral column?

The medially differentiated cells in the somite form the sclerotome which forms the vertebral column.

At what Carnegie stage does the human neural tube normally completely close?

By Carnegie stage 13, the neural tube is normaly completelly closed

--Gabriela Pinget 13:51, 20 August 2009 (EST)

Lab 4 Questions

1. Into what structure do most blood vessels empty before they enter the embryonic heart?

sinus venosus

2. What do the dorsal aortas become in the adult?

The two dorsal aortas joint to form the descending aorta in later development

3. What are the layers of cells found in a tertiary villi?

The tertiary villi are the third stage of development of the villi and is characterised by the development of capillaries within the mesoderm. Also making up the layers of the tertiary villi are the cytotrophoblast and extraembryonic mesoderm.

--Gabriela Pinget 14:02, 27 August 2009 (EST)

Lab 5 Questions

1. What was the question I said in the respiratory lecture would be part of this week's assessment?

The topic pertaining to the question for this week's lab is the developmental abnormality "congenital diaphragmatic hernia". Although this topic was explained, no question was actually posed.

2. What is the answer to the above question?

As stated above, no question was posed but the information given explained that the failure of the foramen of Bochdalek to close results in the the viscera into the thorax which allows the stomach or spleen to push through into the pleural cavity, compressing onto one of the lungs. This is usually more common on the left lung than the right.

--Gabriela Pinget 13:00, 3 September 2009 (EST)

Lab 6 Questions

1. Which is the more common clefting, cleft lip or cleft palate?

Cleft lip is more common as a cleft palate is always followed by a cleft lip but a cleft lip can happen independently.

2. What structures does pharyngeal pouch 1 form?

Pharyngeal arch 1 forms all the tools necessary for mastication. The pouch of pharyngeal arch 1 forms the tubotympanic recess, tympanic cavity, mastoid antrum (cavity of the middle ear), eustachian/ auditory tube (links the pharynx to the middle ear)

3. Neural crest forms which cells within the skin?

Neural crest cells invade the mesenchyme to form connective tissue components. In the skin, the melanocytes have a neural crest origin.

--Gabriela Pinget 14:39, 17 September 2009 (EST)

Lab 7 Questions

1. Briefly; what is a myotube and how is it formed?

a myotube is the initial multinucleated cell formed by fusion of myoblasts during skeletal muscle development.

2. What changes would I expect to see in the muscle fibre types in my legs if I:

a) Suffered a spinal cord injury

depending on the type of spinal cord injury, you would most likely experience lack of motor output to muscles which are supplied by nerves below the severed spot of the spinal cord. This would subsequently cause degeneration of those muscles- if you don't use it, you lose it

b) Took up marathon running

increase in the slow twitch muscle fibres


--Gabriela Pinget 13:11, 24 September 2009 (EST)

--Gabriela Pinget 13:18, 1 October 2009 (EST)

--Gabriela Pinget 14:39, 8 October 2009 (EST)

Lab 10 Questions

Question 1. Identify and name 3 tissue types which contain adult (somatic) stem cells that were used/studied from the 5 articles discussed during the tutorial.

muscle,bone marrow, fat

Question 2. Name 2 reprogramming strategies/methods used in generating human induced Pluripotent Stem Cells (iPSCs) from the 5 articles discussed during the tutorial.

adipose tissue can be induced into pluripotent stem cells. This is done by reprogramming the four genes which turn the cells into embryonic like stem cells. Lenti virus was used to induce those four genes.

to induce iPSC in skin cells, the developers wanted to use a virus free method to deliver the 4 genes, so they used episomal vectors. This is because the virus may insert itself to the cell, making this risky.

Question 3. Is the following statement TRUE or FALSE? "Unlike the nuclear genome, the mitochondrial DNA in the embryo is derived almost exclusively from the egg; that is, it is of maternal origin."

True, mitochondrial DNA can only be passed on by the mother hence if there is any mutation in the DNA, the offspring automatically inherits it as there is no competing DNA.

very difficult to see and handle if one wants to remove it.

--Antonio Lee 15:11, 31 October 2009 (EST) 3/3 Correct.