BL. embryology. session 3.

Question 1

how many somites are present at the end of week 5?

Answer 1

42-44 pairs

Question 2

how many somites and spinal nerves remain after the segmentation process?

Answer 2

31

Question 3

left and right side programming is modulated by the actions of ?

Answer 3

motile cilia.

absence of motile cilia? internal organs re-distribute on wrong sides. Situs inversus.

Question 4

sign of situs inversus

Answer 4

immotile cilia in the respiratory tract

- still have normal numbers of cilia.

Question 5

where does the blastocyst implant in placenta praevia

Answer 5

implants into the wall of the uterus close to the opening of the uterine cervix close to the opening.