Embryogenesis Flashcards
What is differentiation?
A group of unspecialized cells that develop into recgonizable groups with common functions
What does the Endoderm contain?
- The digestive system
- Lungs
- Endocrine System
What does the Mesdoderm Contain?
- Muscle
- Skeleton
- Cardiovascular
- Reproductive system
What does the Ectoderm contain?
- Nervous system
- Skin
- Hair
What is the male in sex determination? What is the determination based off of? What species does this apply to?
- The male is a heterogametic sex
- The sperm determines the sex of the embryo (X,Y)
- Mammals
What is the female in sex determination? What species does this apply to? What are the sex determining letters for these species?
- The female is the heterogametic sex
- Applies to birds and some reptiles
- ZW=Females , ZZ=Male
What can determine the sex in reptiles such as turtles, and crocodiles? Which steroid hormone is different in reptiles?
- The environment is what determines the sex
- Estradiol is what works differently in reptiles compared to other animals.
What does the primordial germ do to initiate sex determination?
Primodrial germ cell migrates to the genital ridge during embryo development and then resides on the bipotential gonad
What can the Bipotential gonad turn into?
It can develop into ovaries or testis
What occurs during the trimester?
- Migration of primodrial germ cells from yolk sac
- Sex cords develop in gonad, paramesonephric ducts develop
- Sex evident from structures
What occurs during the time that the first trimester goes into the second trimester?
- Development of male/female ducts and testes/ovaries (depending on the sex)
What occurs during exclusively to the 2nd Trimester? Which species of animal contains testicular descent during the second trimester?
- The formation of a broad ligament
- Bull & Ram
What occurs during the third trimester and for which animals?
- Testicular descent
- Colt, Boar & Human
What is the Mesonephric ducts? What is another name for them?
- They are part of the male tract
- Another name for them are the Wolffian duct
What are the Paramesonephric ducts? What is another name for them? What must happen to them in order for the male to form?
- They are part of the female tract
- Another name is the Müllerian ducts
- They must regress in order to make the male