Physiology Or Pregnancy And Fetus Flashcards
Placenta main functions
GUT : nutrients
LUNG : exchange O2 CO2
KINDEY : wastes and fluid volumes
ENDOCRINE : Hs. For metabolism
How is the blood supply of the mother and fetus
Separate however very juxtaposed
Fetal side of blood supply
Chorionic Villi
Many branched to increase SA
Mother components for blood supply
Spiral arterials go into the INTERVILLOUS SPACE and
- Drained by maternal V
- Site to exchange with Chorionic Villi
Where does the fetal blood come from
2 umbilical As : DEOXYGENATED
- they penetrate the chorionic plate and make the chorionic villi
Umbilical vein
Pick up O2 and nutrients from the intervillous space and returns back to fetus
Umbilical A and V are dilated at the tip
To slow blood and increase exchange
P O2 in mom and fetus circulation
And Hb
Lower in fetus allows for diffusion
Fetal Hb has stronger affinity
Affinity of CO2 in fetus and mom
Higher affinity in mom for CO2
Passive transfer in the placenta
Non-protien (urea, creatine) to mom
Lipid H.
Facilitated diffusion in placenta
Glucose to fetus
Primary + secondary transport
AA
VIT
Mineral
*all to fetus
Receptor mediated ednocytosis in placenta
Large molecules (LDL, Insulin, IgG, Abs)
Placenta functions on mom
Growth of breasts
Adopt to metabolic changes
hCG function
Stimulate CL to secrete P (and not regress after 2 weeks luteal phase)
- Made from syncytiotrophoblasts
- Can cause morning sickness (peak at early pregnancy)
- Some gets into male fetus : Leydig —> testosterone
hPL (Human Placental Lactogen)
hCS (human chorionic somatomammotropin)
- made by syncytiotrophoblasts
- converts glucose -> FA + Ketones make Blood Glucose increase
- Lipogenesis : form mom to use fat more
- develop breasts
- ——I Insulin (can lead to diabetogenicity)*
Progesterone from Placenta has what role
Stimulate endometrium adhesion + glands
Reduce mobility in uterus
——I contractions * (by inhibiting oxytocin R)
Breast growth
Estrogen from the placenta has what role
- increase endometrium growth (during period)
- increase progesterone R,
- increase BV to placenta
- increase LDL R, prostaglandins R, oxytocin R = parturition
- growth of breasts
M-P-F unit
P and E rises a lot during pregnancy due to
Mother - cholesterol
Fetus : enzymes that placenta doesn’t have
Placenta : uses these to make E and P
Progesterone shift being made from CL to Placenta happens when
Week 8
What makes placenta Abel to make progesterone
Syncytiotrophoblasts: get cholesterol from MOM
- they have CYP11A1 +3B-HSD =P ——mom circulation
How is Estrogen made by the placenta
* dont need to know in detail or the enzymes from this lecture
cholesterol from MOM
Fetus produces 16a-Hydroxylase = E
17a-Hydroxylase = E
17,20 Desmolase = E
3 circulatory shunts of the fetus
- Ductus Venosus : Bypass LIVER
- Foramen Ovale : movesblood from right antrum to left (Bypass RIGHT VENTRICLE)
- Ductus Arteriosus : moves blood from pulmonary A -> Aorta (Bypass LUNGS)
Ductus Venosus
From placenta (Umbilical V + IVC) ——> Right Atrium
Foramen Ovale
From Left Ventricle ——> Carotid + Brain
Ductus Arteriosus
From Pulmonary A ——> Aorta
Back to placenta (umbilical Arteries)
*closes within some 1st breaths (as lungs expand)
how does the ductus Arteriosus close
Lungs expand from first breaths
= decrease P in LUNGS increased P in AORTA
Patent Ductus Arteriosus (PDA)
Shunt doesn’t close all the way (heart murmurs)
= oxygenated Blood (aorta) mix with deoxygenated blood (pulmonary A)
= increases pulmonary BP
Closure of foramen Ovale happens how
pressure gradient reverses *increased venous return to LA =Increased P LEFT ATRIUM =decreased P RIGHT ATRIUM * left and right circulatory system made *closedrigth away also
Patent Foramen Ovale (PFO)
Shunt not closed all the way (20% by 2yo)
RA increased P can open the flap (cough, sneeze, bowel movement)
= pulmonary HTN
= not always sympathetic (can be in chronic migraine patients)
Closure of Ductus Venous
Within 1-3 hrs muscle walls contract -close within 1-2days
Due to decreased BF and pressure changes
Portal Vein P increased :
* permanent closed within 1-3mo
