Embryology and Gestational Development

Question 1

Embryology

Answer 1

study of embryos and their development

Question 2

Gestation

Answer 2

period of time required for full development of a fetus in utero

Question 3

Pre-embryonic Stage

Answer 3

first 2 weeks

Question 4

Embryo

Answer 4

weeks 3-8

Question 5

Fetus

Answer 5

9th week of gestation until birth
all organ systems are structured

Question 6

Steps of Initial Cellular Divisions

Answer 6

unfertilized oocyte > fertilized oocyte > two-cell stage > four-cell stage > eight-cell stage > morula (16 cells) > blastocyst > embryo hatches > blastocyst rotates and implants into uterus

Question 7

Ectopic Pregnancy

Answer 7

occurs when a fertilized egg implants and grows outside the main cavity of the uterus

Question 8

Gastulation

Answer 8

3rd week; epiblast and hypoblast cells undergo a highly differentialized process

Question 9

Superdifferentiation

Answer 9

epiblast > meso-, ecto-
hypoblast > endo-

Question 10

Structures Derived from Endoderm

Answer 10

epithelial lining of digestive and respiratory tracts
lining of urethra, bladder, and reproductive system
liver and pancreas

Question 11

Structures Derived from Mesoderm

Answer 11

notochord (vertebrae)
musculoskeletal system
muscular layer of stomach, intestine, etc
circulatory system

Question 12

Structures Derived from Ectoderm

Answer 12

epidermis
cornea and lens of eye
nervous system