Physiology of pregnancy
Download
Report
Transcript Physiology of pregnancy
Physiology of pregnancy
Zhao aimin
Definition of pregnancy
Pregnancy is defined as the course of
embryo and fetal growth and
development in uterine
It begain at the fertilization and end the
delivery of the fetal and it’s attachment
Definition of fertilazation
Fertilization is defined as the course
of combination of the oocyte and
sperm
It onset 12h after ovulation usually in
ampulla of the oviduct(fallopian tube)
The Development of the
fertilizated egg
3 days after ovulation, the morula
(early blast)is fomulated
4 days after ovulation, the late blast
is fomulated
6-7 days after ovulation, the egg
imbeds in the uterus
The stage of egg imbed
Apposition
Adhesion
Penetration
The necessary conditions
of imbed
Disapearing of the pellucid zone
Syntrophoblast formed from the
blast
Synchronizing development of blast
and the endometriun
P Secretory enough
Changes of endometrium after
the egg imbed
The
endometrium
changes into
dicedua
Basal decidua
Capsular
decidua
True decidua
Attachment of the fetal
Placenta
Fetal membranes
Umbilical cord
Amniotic fluid
placenta
It’s an exchange organ between
maternal and fetal
Amniotic membrane
chorion frondosum
Basal decidua
chorion frondosum
13-21 days after ovulation, villi
fomulating gradually
Grade I viili
Grade II Iviili
Grade III viili
Structure of placenta
Round
Weight:450-650g
Diameter:16-20cm
Thickness:1-3cm
thick in center and thin in margin
Function of placenta
One important function of placenta is
substance exchange between maternal
and fetal
The position of exchange is VSM(vasculosyncytial membrane)
VSM is comprised of
Syntrophoblastocyte
Basal membrane of Syntrophoblastocyte
Stroma of villi
Basal membrane of capillary
Endothelium of capillary
The way of substance exchange
Simple diffusion
Facilitated diffusion
Active transportion
phagocytosis
The functions of placenta
Gas exchange
Suply of nutrition
Depletion of fetal product of metabolisn
Defense function
Hormone synthesis
Human chorionic gonadotropin(HCG)
Human placental lactogen(HPL)
Pregnancy specific -glycoprotein(PS 1G)
Human chorionic thyrotropin(HCT)
Estrogen, P, Oxytocinase, heat stable alkaline
phosphatase(HSAP)
Fetal membrane
Chorion
Amnion
Umbilical cord
Length:30-70cm average:50cm
Consist of 2 artery and 1 vein
Amniotic fluid
Source: early from serum dialysis
late fron fetal urine
Absorse: by fetal membrane, fetal
swallowing(500ml/day)
Amniotic exchange: between maternal
and fetal 400ml/h
Volume of amniotic fluid
8 weeks:5-10ml
10 weeks:30ml
20 weeks:400ml
38 weeks:1000ml
Status of amniotic fluid
pH:7.20
Density:1.007-1.025
Contained: water(98-99%)
inorganic substance
organic substance(1-2%)
The function of amniotic fluid
Protect maternal and fetal
Maternal changes during pregnancy
The maternal system may produce a
series of changes in order to adapt to the
needing of fetal growth and development
influenceed by placenta hormone and
neuro-endocrine
Changes of reproductive system
Uterus
Body: become enlargement and soft
from 7×5 ×3cm pre-pregnancy to
35×25 ×22cm at term
Volume of uterus cavity:
become enlargement from 5ml pre-pregnancy to
5000ml.at term
Weight: be increased from from 50g prepregnancy to 1000g at term
Wall: become thickness and the thickist at midperiod from 1 cm pre-pregnancy to 2-2.5
cm at term
Blood suply:blood flow increased significantly
upto 500- 700ml/min,increased 4-6
times and most of blood flow is
transported to the placenta(80-85%)
Isthmus: be dialated and become soft
from 1cm
pre-pregnancy a portion of the uterus
after 12 gestational weeks
Cervix: be soft and coloration or stain
secrete amount of mucus avoiding the
uterus cavity suffer from infection
Changes of ovary
Stop ovulation
Corpus luteum formation and maintains for
10 weeks
And the function of corpus luteum is
substituted by the placenta
Corpus luteum atretic gradually after 3-4
months gestation.
Changes of the circulation
Heart border: become enlargement
Heart rate: increased 10-15 beat per min at the
late pregnancy
Heart volume: increased 10% at the late
pregnancy
Cardiac output
Very important for fetal growth and development
Incrased begain 10 weeks and upto the peak
at 32 weeks
80ml/bp and keeps the level to the term
pregancy
Blood pressure changes due to pregnancy
No obvious change in Systolic pressure
Mild decreased in diastolic pressure
Vein pressure
No significantly changes in Upper limb vein
pressure
Lower limb vein pressure increased because of
the disturbance of vein reflux
Changes of blood system
Volume: increased (30-45% ) begain 6- 8 weeks
and up to the peak at 32-34 weeks
increased about 1500ml including
plasma 1000ml and red cell 500ml
Changes of blood component
Red cell: reticulocyte increased
red cell decreased 3.6×1012(4.2×1012)
Hb decreased 110g/L(130g/L)
WBC: neutrophilic granulocyte increased
lymphocyte mild increased
no change in orther blood cells
Coagulation
Hypercoagulability
Factor ⅱⅴⅶ ⅷ Ⅸ ⅹ increased
ESR increased significantly upto 100mm/h
Plasma protein
albumin decreased