Anatomy and Physiology Week 12

This week one of the things we talked about was Fetus Circulation. There is one umbilical vein and two umbilical arteries to the fetus. The umbilical vein carries oxygenated blood and the right and left umbilical arteries carries partially oxygenated blood. In the fetus the oxygen rich blood mixes with the oxygen poor blood through the liver to make partially oxygenated blood. The liver filters the blood coming from the mother before it circulates through the fetus' body(what a great idea). The ductus venosus dumps partially oxygenated blood from the liver into the inferior vena cava to the heart. At the right atrium a small amount of blood goes to the lungs, the other portions go through 2 other pathways. One is from the right atrium to the left atrium through the interatrial septum(through the foramen ovale of the heart). The other is from the right atrium to the right ventricle to the pulmonary semilunar valve to the pulmonary trunk through the ductus arterious to the aortic arch. 6-8 weeks after birth the ductus venosus and ductus arteriosus fills with collagen and closes. The ductus venosus then becomes the ligamentum venosum and the ductus arteriosus becomes the ligamentum arteriosum. At birth when the infants bottom is spanked to catch its first breath there are pressure changes in the thoracic cavity from the diaphram which causes the foramen ovale to close becoming the fossa ovalis. This is all very amazing to me. It is crazy to think about all the things that have to come together at the right times for us to be alive.

Anatomy and Physiology Week 11

This week we had vacation. I left friday to go down to Florida with my husband. While we were down there we looked at houses for our possible future move after I graduate and spent some time at the beach and universal/islands of adventure. It was actually a really rainy week and wasn't what I had hoped, especially since Wednesday I got sick and spend most of the rest of my vacation in Florida sleeping. Oh well! Hopefully I will have better luck the next time I have a break from school!