Umbilical Cord
1 Umbilical vein
2 Umbilical artery
Connecting link between fetus and placenta.
Umbilical cord length; 40cm (30-100cm)
Diameter; 1-2.5cm
Through which fetal blood flow to and from placenta.
Extends from fetal umbilicus to fetal surface of placenta.
Development
Umbilical cord
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Developed from connective stalk
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Elongation of connective stalk
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Enlargement of amniotic simultaneous
Structure of Umbilical Cord
1. Blood vessel;
2 Umbilical artery
1 Umbilical vein
2. Wharton's jelly
3. Yolk sac
4. Allantosis
5. Eonl
1. Blood vessel
2 arteries; derived from internal iliac artery of the fetus.
Carry venous blood from fetus to placenta.
1 vein; carry oxygenated blood from placenta to fetus.
2. Covering epithelium
Lined by single layer of amniotic epithelium.
3. Wharton's jelly
Consist of elongated cell in gelationous fluid (protect from umbilical vessels)
4. Yolk Sac (Umbilical vesicles)
Yolk sac is small body near attachment of cord to placenta, develop during early pregnancy, outside embryo.
It connected to umbilical cord by yolk stalk.
Before placenta form, yolk sac provide nutrition and gas exchange between mother and developing fetus first (11th-12th week) until placenta take place.
yolk sac connects to embryo via yolk stalk.
5. Allantosis
Allantosis is an extra-embryonic layer that present between amnion and chorion.
Composed of blood vessel (blood vessels become arteries and vein of umbilical cord).
Hollow sac like structure filled with clear fluid form into umbilical cord.
Two Vital Functions
1. Serves as respiratory organ for embryo.
2. Stores waste product produce by fetus.
3. Absorbing protein used by embryo for growth and development.
4. Allantosis form unique structure called Urachus (canal like structure).
6. Extra-embryonic coelom (called chorionic cavity)
Extra-embryonic coelom called chorionic cavity, which lined by chorion.
Extra-embryonic coelom is continuous with intraembryonic coelom.
Function
Allow transfer of nutrients from maternal blood to fetal blood.
Characteristics
1. Umbilical Cord length; 40cm (30-100)cm
2. Diameter; 1-2.5cm
3. Thickness; not uniform/ present nodes or swelling at places.
Swelling (false knots); due to kinking of umbilical vessels or local collection of Wharton's jelly.
Long cord form loop around neck
Shows spiral twist form left to right form early as 12th week due to spiral turn taken by vessels, vein around arteries.
Attachment
Point of attachment is moved permanently to centre of abdomen at four months.
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