Lecture 9 Flashcards
describe fetal respiratory? & circulatory conditions?
Lungs small and collapsed.
•Lungs filled with amniotic fluid.
•Lung volume too small to allow complete output of right
atrium through lung circuit.
another way to say Lungs small and collapsed. •Lungs filled with amniotic fluid. •Lung volume too small to allow complete output of right atrium through lung circuit.
Back-pressure of lungs too great
to allow much blood flow through lungs.
There is enough blood flow to allow growth and
development, but not
gas transfer
when do lungs not need to gas transfer?
in utero
Before birth, it would be desirable for blood leaving the
right atrium to – for the most part – bypass the lung. There
are two ways: explain
1st: This is done via a structure called the DUCTUS
ARTERIOSUS. The DUCTUS ARTERIOSUS is a
connection between the sixth aortic arch (Pulmonary Arch)
on the LEFT side and the arch of the aorta (also on the left
side).
2nd: The FORAMEN OVALE is a hole between the right
and left atria, allowing blood to pass from the right side to
the left and not ever get pumped to the lungs.
The DUCTUS ARTERIOSUS is a connection between
the sixth aortic arch (Pulmonary Arch) on the LEFT side and
the arch of the aorta (also on the left side).
The DUCTUS ARTERIOSUS allows blood to
skip past the lungs and join up with the partially oxygenated blood that is being pumped out of the left ventricle.
The FORAMEN OVALE is a hole between the
right and left atria, allowing blood to pass from the right side to the left and not ever get pumped to the lungs.
So…
…where does spent blood from the fetus go? what artery?
Well, mom of course. It goes to the placenta that contacts
mom’s uterine wall via the UMBILICAL ARTERY.
describe the umblical artery?
Remember that the distal end of the internal iliac artery is theold connection of the UMBILICAL ARTERY which goes
toward the placenta.
what are the branches of the Internal Iliac Artery (In order)
- Iliolumbar
- Lateral sacral
- Superior gluteal
- Inferior gluteal
- Internal pudendal
- Obturator
- Middle rectal
- Inferior vesicle
- Superior vesicle
- The old umbilical
artery connects to
end of internal
iliac.
The Umbilical Artery usually remains on_____
ONLY ONE SIDE, usually the left side.
Oxygenated blood returning to the fetus returns via the
UMBILICAL VEIN of the fetus
umbilical vein hooks up to
the fetus’ inferior vena cava
explain arterial blood
Arterial blood from mother & placenta – laden with nutrients and
oxygen – come into contact of placenta of fetus via (now).