Embryology

Question 1

What is the Graafian Follicle?

Answer 1

A large secondary follicle with the potential for ovulation with a large antrum

Question 2

What cells surround the oocyte as it leave the follicle?

Answer 2

Cumulus oophorus cells

Question 3

What hormone signals the endometrium to proliferate?

Answer 3

progesterone

Question 4

What secretes progesterone?

Answer 4

The corpus luteum

Question 5

What stage of cell division is the oocyte in just before fertilisation?

Answer 5

Metaphase of the 2nd meiotic division

Question 6

What layers must the sperm penetrate in order to fertilise the egg?

Answer 6

Corona radiata and the zona pellucida

Question 7

What type of cell do the male and female pronuclei form when they mingle?

Answer 7

A diploid cell

Question 8

When is the morula formed?

Answer 8

Day 4

Question 9

Describe the blastocyst

Answer 9

Trophoblast formed from surrounding supporting tissue

Embryoblast forms the embryo proper

Question 10

When does implantation occur?

Answer 10

Day 5.5.-6

Question 11

Where does implantation usually occur?

Answer 11

Anterior or posterior portion of uterus

Question 12

What does the syncytiotrophoblast do?

Answer 12

Secretes enzymes that allow the blastocyst to embed into the uterine wall.

Question 13

At day 9 what does the blastocyst cavity become?

Answer 13

The exocoelomic cavity

Question 14

What do amnioblasts do?

Answer 14

Secrete amniotic fluid into the amniotic cavity.

Question 15

When does the primitive yolk sac?

Answer 15

Day 12

Question 16

What is the purpose of the maternal sinusoids?

Answer 16

Supply the developing embryo with nutrients

Question 17

What is the importance of the prechordal plate at 13 days?

Answer 17

Important in the formation of the oral cavity formed by the fusion of ectoderm and endoderm

Question 18

When does gastrulation occur?

Answer 18

16-17 days

Question 19

When is the baby known as an embryo?

Answer 19

Week 4-8

Question 20

When is the baby known as an foetus?

Answer 20

Week 9-Birth

Question 21

Define gametogenesis?

Answer 21

Germ cell formation

Question 22

Define fertilisation?

Answer 22

Formation of the zygote

Question 23

Define cleavage?

Answer 23

Period of rapid cell division, formation of morula then blastocyst

Question 24

Define gastrulation?

Answer 24

Formation of germ layers and establishment of body axes

Question 25

Define organogenesis?

Answer 25

Primordia of all organ systems