Week 4 Flashcards
Which type of cells are responsible for production of surfactant?
Type II alveolar cells
What is surfactant comprised of?
Phospholipids, proteins, fats and cholesterol.
What is the funtion of surfactant?
To reduce surface tension in the alveoli.
Where is amniotic fluid secreted from?
Amniotic membranes;
excreted by fetus;
Fetal GI tract and respiratory tract;
Diffuses from maternal interstitial fluid across the amniochorionic membrane from the decidua.
How often does the amniotic fluid circulate?
Every 43 hours
How is the amniotic fluid circulated?
The fetus swallows the fluid and then it is diffused into fetal blood circulation, then through the placenta to the maternal ciruclation.
How much amniotic fluid is expected at 37 weeks?
700 - 1000 mls
What are the functions of amniotic fluid?
Barrier to infection;
Prevents adherence of the amnion to the embryo and fetus;
Cushions against injuries
Assists in body temperature regulation;
Enables free fetal movement - aiding muscular development;
Assists in homeostasis of fluid and electrolytes.
What is polyhydramnios?
Excessive amniotic fluid.
What is olygohydramnios?
Very low amniotic fluid of 500ml or less at term.
What is the foramen ovale?
The hole in the wall of the right atrium of the fetal heart that allows blood to flow directly to the left atrium, bypassing the fetal lungs.
What is the ductus venous?
The vessel that allows blood travelling from the umbilical vein to bypass the liver (portal vein) and to join directly to the inferior vena cava.
What is the ductus arteriosus?
The connection of the pulmonary artery to the aorta allowing blood to travel directly to the aorta and out to the body without travelling first to the lungs.
