Prenatal Vocab: Week 1

Question 1

Fertilization begins in the

Answer 1

ampulla of the uterine tube

Question 2

An acrosomal reaction is initiated when

Answer 2

the sperm successfully penetrates the ovum

Question 3

Syngamy

Answer 3

a “successful completion of a fertilization”

Question 4

Cleavage is

Answer 4

Mitotic

Question 5

Cleavage is two things:

Answer 5

asymmetric and holoblastic, the last term means the cells divided completely through their cytoplasm

Question 6

Name the first 4 structures after fertilization

Answer 6

Zygote–>blastula—>morula—>blastocyst

Question 7

When is an embryo considered totipotent?

Answer 7

Up to the 8 cell stage of cleavage, meaning any of those cells can give way to a fully functional embryo (person)

Question 8

When is an embryo considered pluripotent?

Answer 8

after the 8 cell stage: it can undergo gastrulation and differentiate into germ layers, but the cells can’t produce a new person individually

Question 9

Implantation consists of 1…..2….3….4

Answer 9

1) the zona pellucida deteriorates
2) the blastocyst implants within the POSTERIOR SUPERIOR WALL of the uterus
3) the blastocyst implants into the functional layer of the endometrium during secretory phase
4) the trophoblast differentiates into the syncytiotrophoblast and the cytotrophoblast

Question 10

When does the blastocyst implant itself into the functional layer of the endometrium?

Answer 10

during the secretory phase

Question 11

Ectopic pregnancy results when

Answer 11

a blastocyst implants outside the uterus; very dangerous.

Question 12

“Twinning” : identical and fraternal

Answer 12

Identical results when the ICM is cleaved in two; two embryos ensue with identical gnomes

fraternal occurs when two sperm both successfully penetrate the ovum, but with respective genomes

Question 13

Conjoined twins result when

Answer 13

the inner cell mass is incompletely split in two