Early Embryogenesis Flashcards
What is organogenesis
the formation of body structures and organs
What is another word for cell division?
proliferation
what’s another word for cell differentiation?
specialization
What is cell differentiation?
It’s a commitment of a cell to become something specific - it’s progressive - not instantaneous
What is the embryonic period?
the time from fertilization to the earliest primordial stages of organ development
Fertilization to organ development
What is the fetal period?
from the emryonic period to parturition
Where does fertilization take place?
uterine tube
What are the steps of fertilization?
Fusion of the spermatozoon
spermatozoon binds to glycoprotein on zona pellucida surrounding oocyte
spermatozoon releases enzymes to degrade the zona
spermatozoon and oocyte plasma membranes fuse
oocyte cancels membrane pot with Ca
male and female haploid pronuclei make contact and lose their nuclear membranes
off to mitosis
What is an oocyte?
Has a zona pellucida
oogonia to primary ooctyes by mitosis in embryo
How does the spermatozoa get to the females tract?
It’s propelled from the vagina to uterine tube by contraction of female genital tract
What are the 3 germ layers?
ectoderm
mesoderm
endoderm
What does Ectoderm form?
epidermis, nervous and sense organs
What does mesoderm form?
muscle
connective tissue
bone
circulatory, urinary and genital systems
What does endoderm form?
mucosal epithelium
glans of respiratory and digestive system
What is gastrulation?
formation of germ layers
What are the two forms of mesoderm?
mesenchyme
epitheliod
What are mesenchyme cells?
bunches of stellate cells - motile - not good for communicating
What are epithelioid cells?
mesoderm cells that are oraganized - they touch each other so they are good for communication
What does the neural crest become?
pigment cells of skin
peripheral nervous system
adrenal medulla
mesenchyme - which then becomes meninges, bones, fascia, and teeth
What does paraxial mesoderm become?
somites
What are the 3 regions of somites?
schlerotome
dermatome
myotome
What does the schlerotome give rise to ?
vertebrae, ribs, endochondral bones
What does dermatome give rise to?
dermis of skin
What does myotome give rise to?
skeletal muscles
How do you get from a flat embryo to a cynlindrical tube?
1) Head process formation
2) Tail Formation
3) Lateral Body Folds
what do the lateral body folds give rise to?
embryonic coelom
somatopleure
splanchnopleure
