Z3126345
ANAT2341 Embrology
Progressive Assessment
Lab 1 Questions
1. What is the zona pellucida protein that binds spermatozoa to the oocyte surface?
A: ZP3 glocoprotein allows binding of zona pellucida to spermatozoa. Zona pellucida is a glycoprotein membrane surronding the plamsa membrane of an oocyte. In addition, there are three major types of glycoprotein of zona pellucida. Such as ZP1, ZP2 and ZP3. ZP3 is responsible for sperm binding, adhering to proteins on the sperm plasma membrane.
2. Name the 3 main stages of follicle development in the ovary?
A: There are 3 main stages of follicle development in the ovary. These stages are primodial follicle stage, pre-antral/primary follicle stage, and antral/secondary follicle stage. In addition, there is stage after antral/secondary follicle stage, which is Graffian follicle stage, or mature cell.
Lab 2 Questions
1. What factor do the synctiotrophoblast secrete to support the ongoing pregnancy?
A: Syntiotrophoblast secrete Human Chorionic Gonadotropin to support the ongoing pregnancy. In addition, Human Chorionic Gonadotropin is a peptide hormone produced in pregnancy, which is made by the embryo soon after conception and later by synctiotrophoblast. Its main role is to prevent the disintegration of the copus luteum of the ovary and therefore maintain progesterone production which is critical for a pregnancy in humans.
2. What does the corpus luteum secrete to prevent continuation of the menstrual cycle?
A: Corpus luteum secretes estrogens and progesterone to prevent continuation of the menstrual cycle. In addition, estrogens and progesterone are steroid hormones responsible for the thickening of the endometrium and its development as well as maintenance.
3. What are the 2 main issues to be derived from the germ cell layer continuous with the lining of the amniotic sac?
A: There are 2 main issues derived from the germ cell layer continuous with the lining of the amniotic sac. These issues are ectoderm which forms the nervous tissue, and epithelium of epidermis.
Lab 3 Questions
1. What period of human development (in weeks) do the 23 Carnegie stages over?
A: Appoximately 8 to 9 weeks.
2. What part of the somite will contribute to the vertebral column?
A: Sclerotome of somite contributes to the formation of axial vertebral column.
3. At what Carnegie stage does the human neural tube normally completely close?
A: Human neural tube normally completely close at Carnegie stage 13(appox.4 weeks).
Lab 4 Questions
1. Into what structure do most blood vessels empty before they enter the embryonic heart?
A: sinus venous
2. What do the dorsal aortas become in the adult?
A: descending aorta
3. What are the layers of cells found in a tertiary villi?
A: layers of trophectoderm cells, extra-embryonic mesoderm, and cells that line the blood capillaries.
