BIO 12 UNIT 4: Study Notes

FETAL VS ADULT CIRCULATION 

FETAL: Receives O2ated blood from the placenta and bypasses pulmonary circulation, 4 structures that adult does not have:

1. Oval Opening (Foramen Ovale): Between L and RA (flap acts as a valve), blood from the RA is shunted into the LA (does not need to go through the process of moving to the RV)
2. Arterial Duct or Ductus Arteriosus: Connection between pulmonary artery and aorta, reroutes blood away from lungs and sends it directly to the aorta
3. Umbilical Arteries and Veins: Arteries send deO2ated blood and wastes away from the heart and towards the placenta, Veins send O2ated blood and nutrients from the placenta to the fetus (heart)
4. Venous Duct or Ductus Venosus: Connection between umbilical vein and vena cava (liver), mixture of O2ated blood (umbilical vein) and deO2ated blood   (Vena Cava)

PATHWAY OF BLOOD: UMBILICAL VEIN-->VENOUS DUCT-->INFERIOR VENA CAVA-->RA-->OVAL OPENING-->LA-->LV-->AORTA


or UMBILICAL VEIN-->VENOUS DUCT-->INFERIOR VENA CAVA-->RA-->RV-->PULMONARY TRUNK/ARTERY-->ARTERIAL DUCT-->AORTA-->BODY (UMBILICAL ARTERIES-->PLACENTA)




A Great Video explaining Fetal Circulation:
http://www.youtube.com/watch?v=uwswhoKfkmM

ADULT: Has none of the fetal structures mentioned above AND has both Pulmonary and Systemic Circulation (uses lungs)