Auxiliary structures, and Fetal circulation

PLACENTA

what does the placenta do

• exchange nutrients and waste products

• produces hormones that maintain pregnancy

• performs metabolic functions

• limits transfer of some medications

mother side of the placenta

• dark red, rough, attaches to the uterus

baby side of the placenta

• smooth, shiny, branching veels

umbilical cord attaches here

what are the placenta lobes called

cotyledons

what can retained placenta tissue cause

• bleeding and infection

UMBILICAL CORD

what do the two umbilical arteries carry

deoxygenated blood and waste away from the fetus to the placenta

what does the umbilical vein carry

oxygenated blood and nutrients to the fetus

whartons jelly

cushions the cord vessels against compression

20 inches ling in delivery

a cord with one artery and one vein may be associated with

fetal anomalies including genitourinary abnormalities

FETAL MEMBRANES

amnion

inner membrane

chorion

outer membrane

membranes usuallt

rupture together

AMNIOTIC FLUID

where does the amniotic fluid come from

fetal urine and fluid transferred from maternal body across amnion

what should the amniotic fluid look like

• clear, pale yellow with no odor

at what week does the volume increase

at 34 weeks then decreases toward the end

what are some functions of the amniotic fluid

• cushions the fetus against injury and compression

• maintains a stable temperature

• allows for movement and growth

• prevents membranes from adhering to uterus

• supports lung development

• allow swallow practice

polyamniohydrosis

too much amniotic fluido

oligohydroamnios

too littel amniotic fluid

how much fluid is present toward the end of pregnancy

700-880

how much before the end of pregnancy

800-1200

FETAL CIRCULATION

before birth, what provides o2 to the fetus

the placenta

do the fetal lungs perform gas exchage

no

what are the 3 fetal shunts

ductus venosus

foramen ovale

ductus arteriosus

what does the ductus venosus do

connects from umbilical vein to the IVC

bypasses much of the liver

what does the foramen ovale do

connects right atrium to left atrium

bypasses the lungs

what does the ductus arteriosus do

connects the pulmonary artery to the aorta

bypasses the lungs