Embryo final Flashcards
Phases of mitosis
- Interphase
- Prophase
- Prometaphase
- Metaphase
- Anaphase
- Telophase
- Cytokinesis
Meiosis takes place in
Germ cells
Interphase is when we duplicate the DNA
So in meiosis we only have one phase of Interphase.
Spermiogenesis is
the transformation of Spermatids into Spermatozoa
What happens in the transformation of spermatids into spematozoa
formation of the acrosome, which covers half of the
nuclear surface and contains enzymes to assist in
penetration of the egg and its surrounding layers
during fertilization
condensation of the nucleus
formation of neck, middle piece, and tail
shedding of most of the cytoplasm.
Corpus letuem produces
Progesterone
Spermatozoa must undergo……….. to able to fertilize
- capacitation
2. Acrosome Reaction
Acrosin enzyme function
allows sperm to penetrate the
zona
Inner cells of the morula are called
Embryoblast
Outercells of the Morula are called
Trophoblast
Implantation happens in
Epithelial cells of the uterine mucosa
The wall of the uterus consists of three layers:
endometrium or mucosa lining the inside wall
myometrium, a thick layer of smooth muscle;
perimetrium, the peritoneal covering lining the outside wall
Which layers of the endometrium disappear at the menstrual phase
Spongy and compact layers.
Epiblast gives rise to
- Amniotic cavity
2. amnioblast cells which are the roof of the amniotic cavity
Amniotic cavity floor and roof
floor: epiblast cells
roof: amnioblast cells
exocoelomic
(Heuser’s) membrane
appears in the hypoblast
Extraembryonic mesoderm is Formed by
Cytotrophoblast
Syncytiotrophoblast is formed by
Cytotrophoblast
extraembryonic mesoderm arises
- extraembryonic splanchnopleuric mesoderm, which covers the yolk sac and the germ disc
- extraembryonic somatopleuric mesoderm, which covers the amniotic cavity and lines the inner aspect of the cytotrophoblast.
Chorion
The extraembryonic somatopleuric mesoderm together with the surrounding cytotrophoblast and syncytiotrophoblast form
DON’T MESS UP THE NOTIONS!!
-bilaminar or trilaminar germ disc is not the same with bilaminar and trilaminar blastocyst stage.
Implantation site
anterior or posterior surface of uterus
Abnormal sites: abdominal cavity, Douglas pouch,
uterine tube (mostly ampulla)-95% of
extrauterine/ectopic pregnancies, omentum, ovary
When the blastocyst implants close to the internal
opening of cervix, resulting placenta praevia –
severe bleeding during second part of pregnancy
and delivery.
Mesoderm
refers to cells derived from the epiblast and extraembryonic tissues.
Mesenchyme
refers to loosely organized embryonic connective tissue regardless of origin.
At its cephalic end, the foregut is temporarily bounded by
buccopharyngeal membrane
vitelline duct is
The way of communication for the midgut and yolk sac
Duration pf pregnancy
280 days, or 40 weeks after the onset of the last normal menstrual period.
266 days or 38 weeks after fertilization.
Fetal period is
9th week to birth
During the 6th week
intestinal loops cause a large swelling (herniation) in the umbilical cord,
placental membrane layers
the endothelial lining of fetal vessels;
the connective tissue in the villus core;
the cytotrophoblastic layer;
the syncytium
primitive umbilical ring
At the fifth week of development, the following structures pass through the ring
- connecting stalk,
- yolk stalk (vitelline duct)
- canal connecting intraembryonic and extraembryonic cavities
