From Embryology

Lecture Questions- Student: z3295026

Lab 1 Questions:

1. What is the protein that the sperm binds to on the surface?

Zona pellucida protein ZP3 acts as receptor for sperm

2. Name the three stage of follicle development in the ovaries?

1. Primordal follicle

2. Secondary follicle- (Pre-antral follicle)

3. Graffian follicle- (Antral follicle):is the mature follicle

--Joe Nassif 14:06, 13 August 2009 (EST)

Lab 2 Questions:

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

Syncitiotrophoblasts - form a multinucleated cytoplasmic mass by cytotrophoblast cell fusion and both invade the decidua and secrete hCG which act on ovaries to stop menstration , cell inovaries secretes hormones to to stop the cycle from continuiing (corpus lutuem)

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

The corpus luteum produces progesterone. Progesterone makes the lining of the uterus thick for implantation and is necessary to sustain a healthy pregnancy. The corpus luteum produces progesterone until the placenta begins to take over progesterone production around ten weeks gestation. Another hormone secrete is estrogen.

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

formed by two germ cell layers including :

1.Epiblast= ecoderm which forms= Central nervous system ( edge of ecoderm= epidermis)

2.Mesoderm ( spread entire cavity)= extra-embryonic mesoderm (connective tissue in orgin)


--Joe Nassif 14:06, 13 August 2009 (EST)

Lab 3 Questions:

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

8(weeks) and 4(days) to full development

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

Only the ventromedial portion known as the sclerotome contributes the axial vertebral column

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

Stage 13 (4 weeks) the neural tube is normally completely closed

--Joe Nassif 14:06, 13 August 2009 (EST)

Lab 4 Questions

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

The blood gets dumped into the common cardinal veins, and these common cardinals empty into the sinus venosus

What do the dorsal aortas become in the adult?

Descending aorta

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

Layers of troph ecoderm cell, extraembryonic mesoderm, and celluar material that lines blood capillarys( endothial) :TROPHOBLAST,MESODERM AND BLOOD VESSELS. --Joe Nassif 14:29, 20 August 2009 (EST)

Lab 5 Questions:

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

What is Congenital Diaphragmatic Hernia and how does it affect the human lungs?

What is the answer to the above question?

Congenital means born with and a hernia is a problem where something goes through a hole it is not supposed to. The hole is in your baby's diaphragm. The diaphragm is a muscle that helps us to breathe and keeps the organs in the abdomen from going into the chest cavity In your baby's case, the hole stayed open. This allowed some of the intestines to go into the chest cavity. Since the intestines were in the chest cavity and not where they were supposed to be, the lungs could not grow in the normal space that they need (they had to share the space with the intestines). This means that the lungs are smaller than they should be.

Lab 6 Questions

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

  • Cleft Lip

What structures does pharyngeal pouch 1 form?

  • Tubotympanic recess, tympanic cavity, mastoid antrum, eustachian tube

Neural crest forms which cells within the skin?

  • Neural crest cells- (melanocytes) migrate into epithelium. These are the pigment cell of the skin.

" Lab 7 Questions"

Briefly; what is a myotube and how is it formed? It is the initial multinucleated cell formed by fusion of myoblasts during skeletal muscle development

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

a) Suffered a spinal cord injury: Mucle fiber converts from type 1 to type 2.

b) Took up marathon running: Muscle fiber converts from type 2 to type 1.


"Lab 9 Questions"

What is a myotube and how is it formed?

A myotube is a multinucleated cell which is an undifferentiated contractile apparatus. It is formed by fusion of myoblasts which happens during skeletal development. What changes would I expect to see in the muscle fibre types in my legs if I:

a) Suffered a spinal cord injury; muscle atrophy as well as conversion of slow twitch muscle fibres to fast twitch muscle fibres. b) Took up marathon running; muscle growth (hypertrophy) and conversion of fast twitch fibres to slow twitch fibres.

" Lab 10 Questions"

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.

1.Muscle (muscle stem cells)

2.Neural stem cells (nerve cells (neurons) and two categories of non-neuronal cells—astrocytes and oligodendrocytes)

3.Mesenchymal stem cells (bone cells (osteocytes), cartilage cells (chondrocytes), fat cells (adipocytes), and other kinds of connective tissue cells such as those in tendons).

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

1. Virus: viral vectors – viruses with the potential to affect the transcriptional profile of cells, sometimes inducing cell death or tumors. ( plasmid usually used)

2. Non viral: injecting gene using lenti-viruses neural stem cell with the presence of virus to re-programm it.

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."


--Antonio Lee 15:19, 31 October 2009 (EST) 3/3 Correct. (NB Q2, non-viral method does NOT involve use of virus)