Z3295026

Lecture Questions- Student: z3295026

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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)

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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)

3.Endoderm'

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

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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)

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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) --Joe Nassif 14:29, 20 August 2009 (EST)