Embro 1

Embro 1

1. Blastomere

   • 4 days
     • inner cell mass (embyroblast)
       • epiblast
         • floor of the amniotic
         • proliferating epiblast
           • primitive streak
             • marks the tail (NOT the head)
             • primitive groove
             • Intraembyronic mesoderm
               • cells from the primtive streak that insinulate themslive between the NON-proliferating epiblast and hypoblast
               • growth
                 • Growth countinues
               • mesenchyme
                 • mesodermal cells that have not yet compact or organized into things
               • paraxial mesoderm
                 • closest to the notochord
               • Intermediate mesoderm
                 • between the paraxial and the lateral plate. plays a role in urogential development
               • lateral plate
                 • furtherest away and merges with the extraembryonic mesoderm
                 • maturation of mesoderm / seperation of the praxial mesoderm
                   • Somites
                   • microdroplets of interceullar fluid form
                     • intraembryonic coelom
                   • mesothelium
                     • mesodermal cells that come in contact with the fluid of the intraembryonic coelom. Epithelium are cells that serve as a special kind of connection between something else (fluid trasnport i.e,)
                   • cardiogenic mesoderm
                     • forms from the bend of the u shaped intraembronyic coelom. located on the left side (where your heart is)
                     • heart tubes
             • Primitive or Hensen's node
               • primitive pit
               • prechordal mesoderm
               • notochord
         • embyronic disc
         • ectoderm
           • what used to be the non-proliferating primtive streak
           • induction from notochord
             • Neural folds
               • neural plate
                 • combination of part of the neural fold and plate that lead to the spinal cord and brain
             • nerual groove
         • endoderm
           • some epiblast cells that get past the intraembyronic  mesoderm and push away the hypoblast. the entire roof of the yolk sac will soon be made of endoderm
           • cloacal membrane
           • allantoic diverticulum
       • aminoblast
         • roof of the amniotic
     • Trophoblast
       • Outer layer, "feeding layer" role for placenta
       • Cytotrophoblast
         • cytotrophoblast enlarges rapidly
           • Extraembryonic mesoderm
             • cells formed from the rapidliy growing cytotrophoblast. Mesoderm means middle skin, formed in the middle (Between thje cytotrophoblast and the walls of the yolk sac
             • somatic extraembryonic mesoderm
               • extraembryonic mesoderm that has contact with the cytotrophoblast
               • contact with cytotrophoblast
             • visceral extraembryonic mesoderm
               • extraembryonic mesoderm that has contact with the primary yolk sac
               • connecting stalk
                 • somatic and visceral combine over the roof of the amniotic sac. Merans of communcation between the embryonic disc and the placenta
               • contact with yolk sac
             • Extraembryonic coelom
               • space?
             • Amnion
               • connective tissue from the extraembryonic mesoderm lined by amnioblast cells. 
           • keeps growing
     • 5 days
       • Zona splits open
       • 6 days
         • Attaches to uterine
           • usually posterior, could be anterior. Problems otherwise
           • Syntrophoblast
             • formed when trophoblast cause proliferation of cells when attaches to uterine. merge of cytoplasm
             • Enlargment
             • produces hCG
               • stiumlates estrogen and progesterone
         • 6-7 days
           • proliferation of trophoblast
           • 7-8 days
             • 10 days
               • primary yolk sac
                 • The squamous grows and encircles itself to form a sac (the roof is still the cubiodal. there is no yolk in it
                 • Secondary yolk sac
                 • remenats of primary yolk sacs
                   • bottom of the primary yolk sac is pinched off, forming these
               • 11-12 days
                 • 13 days
                   • 2 weeks (14 days)
                     • everything has grown
                     • early 3 weeks (15-16 days)
                       • caudal (tail) rotation (90 degrees) of connecting stalk attachment
                         • later in 3rd week
                           • 18-19 days
                             • and the journey countiunes
                               • ^ |
                                 • heart tube extend gradually
                                   • they go around the oropharyngeal membrane and then just below (ventral) the notochord. Then they reach the allantoic diverticulum and again one will split left, the other right into the connecting stalk to the placenta (which is the trophoblast)
                                   • aortic arch (both left and right
                                     • Aorte (plural)
                                       • umbilical arteries
                                   • the heart tubes are NOT fused at the aortic arches and the allantosis
                                   • meanwhile in the carodgenic mesoderm
                                     • veins form
                                       • vitelline vein
                                         • runs foward towards the cranial end. empties blood into heart tube
                                       • umbilical vein
                                         • remember: one on each side
                                           • end of the third week, funcitioning circulatory system
                                       • cardinal vein
                                         • drain the embryonic dsic
                                         • Enter text here
             • cuboidal hypoblast
               • sheet of cells form and hold up the rest of the embryoblast
               • inner blastocoeles
                 • microdroplets between blastomeres form little blastocoeles
                 • amniotic cavity
                   • little blastocoeles combine
               • • flat hypoblast formed on the sides
               • Columnar hypoblast
                 • prochordal plate
                   • the head
                 • oropharyngeal membrane
             • 8-9 days
               • Squamous hypoblast
     • 3 1/2 days

2. Intercelluar fluid

   • Blastocoele (blastocyst cavity)

3. morula

   • into the uterus