Repro System Embryology 1 Flashcards
What days on the menstrual cycle form the menstrual phase?
Days 1 to 4
The secretory or luteal phase occurs on what days of the menstrual cycle?
Days 15 to 28
The proliferative or follicular phase occurs on what days of the menstrual cycle?
Days 4 to 14
What hormone is released to promoste the development of the follicle?
FSH
What causes a surge in LH?
Estrogen
What is the zygote?
Diploid cells resulting from union of sperm and ovum
What structure consists of 12 to 15 blastomeres?
Morula
What contains a fluid-filled cavity that separates the blastomere into two parts?
Blastula
How soon after fertilization does implantation in the endometrial epithelium of the uterus take place?
6 days (but can range up to 12 days).
What forms the wall of the gestational or chorionic sac?
Chorion membranes
What forms the floor of the amniotic cavity?
Epiblast
What forms the roof of the exocoelomic cavity?
Hypoblast
What is the process of bilaminar embryonic disc development into trilaminar embryonic disc called?
Gastrulation
What are the three trilaminar layers called?
Ectoderm
Mesoderm
Endoderm
What germ layer forms the reproductive organs?
Mesoderm
What fetal organs are developed at 4 weeks gestation?
Heart
Forebrain
Upper and lower limbs
Ears
Lens of the eye
At what stage does the external auditory canal develop?
6 weeks (up to week 18),
At what stage do the external genitalia develop?
8 weeks. By week 12, male and female external genitalia are distinguished.
At what stage do the intestines develop?
Week 7
At what stage does the ossification of bone begin?
Week 7
True or False: Fibrocartilage forms the temporary fetal skeleton, which eventually is replaced by bone.
False, it is Hyaline cartilage
Describe the schema for fetal circulation.
Oxygenated blood from placenta via umbilical vein; through ductus venosus (bypasses the liver), into IVC and right atrium; through foramen ovale to left atrium and left ventricle, or into right ventricle to pulmonary trunk to ductus arteriosus (bypasses lungs); from aorta to internal iliac and umbilical arteries, to the capillaries in the chorionic villi of the placenta.
