Embryology of Placenta
Give any 2 functions of placenta
Exchange of gases & metabolites
Acts as a barrier
Immunity to fetus (transports maternal IgG)
Name any one hormone secreted by placenta
Human Chorionic Gonadotropin (HCG)
Oestrogen
Progesterone
Human Placental Lactogen (HPL)
Which umbilical vessel disappears during embryonic life?
Right umbilical vein
Name the number of vessels present in umbilical cord with their names
Two umbilical arteries
One umbilical vein
Implantation of placenta at an abnormal site is known as?
Placenta previa
What is the normal site for implantation of placenta?
Upper segment of uterus
Whose blood is present in the intervillous space?
Maternal
What is the normal length of fully formed umbilical cord?
50cm
What is the connecting tissue surrounding umbilical vessels known as?
Wharton's jelly
The anomaly of placenta in which a small accessory lobe of placenta is formed is known as?
Placenta succenturiata
What are the polygonal structures seen on maternal side of a fully grown placenta known as?
Cotyledons
Name the layers in secondary villus from inside to outside
Extraembryonic mesoderm
Cytotrophoblast
Syncytiotrophoblast
Deoxygenated blood in umbilical cord is carried by?
Umbilical arteries
Which membrane lines the umbilical cord & name the epithelium forming it
Amniotic membrane - Simple cuboidal epithelium
What is battledore placenta?
Umbilical cord is attached to one side of placenta instead of centre
The chorionic villi developing around decidua basalis are known as?
Chorion frondosum
What type of cells are present in extraembryonic mesoderm of placenta and what are they called?
Macrophages - Hoffbauer cells
Umbilical cord is developed from which structure?
Connecting stalk
The connective tissue around umbilical vessels is of which type?
Embryonic or Mucoid type
What are the anomalies of placenta according to distribution of umbilical vessels?
Magistral type
Name the structures forming the placental membrane or barrier towards end of pregnancy
Endothelium of fetal blood vessels with basement membrane
Extra embryonic mesoderm
Syncytiotrophoblast
What are the outer & inner layers of syncytiotroblast at maternal side of placenta known as?
Outer SCT - Nitabuch's layer
Inner SCT - Rohr's fibrinoid stria
Wharton's jelly is formed from which structure?
EEM
What is the function of Wharton's jelly?
Provides Cushioning or support - resisting compression or kinking of umbilical vessels
According to the tissues forming the placental barrier, what type of placenta is found in man?
Haemochorial