2. -Mention the functions of the
placental barriers
-Mention examples of substances
and micro-organisms that can
pass
through the placental barrier.
-List organisms that play a role in
congenital diseases & growth
retardation.
4. PLACENTA
The placenta is
an organ that connects
the developing fetus to
the uterine wall to allow
nutrient uptake, waste
elimination, and gas
exchange via the mother's
blood supply.
5. Structure of placenta:
The structure of the placenta consist of two
parts :
1- fetus part (chorion frondosum)
2-maternal part (decidua basales )
6. CONT….
1ry-a core of cytotrophoblast surrounded by
syncytiotrophoblast .
2ry- as the 1ry but invaded with a core of mesoderm
(3week)
3ry- as the 2ry and the fetal capillaries (in third week )
7.
8. Function of the placenta :
1- nutrition:
Vitamins, electrolytes , glucose .
They come from maternal blood to fetal blood .
2- excretion:
Waste products of the fetus go to maternal blood .
3-respiration:
fetal blood .maternal blood
O2
CO2
9. CONT..
4- Protection:
(toxins, bacteria, some virus )prevented
to pass from mother to fetus .
5- Endocrine function :
a)Hormones :progesterone, estrogen,
human chorionic gonadotropin and
human chorionic somato-
mammotropin.
b)Melanophore spreading factor :
-Dark brown colouration of
the areola of breast.
-Dark brown coloouration of
linea alba umbilicus to
symphysis pubis (linea nigra).
10. PLACENTA BARRIER
Definition :
The semipermeable layer of tissue in the
placenta that serves as a selective
membrane to substances passing from
maternal to fetal blood.
11. It is composed of the following in mid-
pregnancy mother :
-Endothelium of the fetal blood vessels
-Extera embryonic mesoderm
-The cytotrophoblast
-The syncytiotrophoblast
12. The placental barrier is composed of the
following in late-pregnancy :
-The syncytiotrophoblast.
-The endothelium of the fetal blood
vessels.
13. At the end of pregnancy:
The permeability decreases as a
fibrinoid material is deposited
on the
outer surface of the villi,
Endothelium of fetal capillaries,
ST, fibrinoid
material.
14. The function of the placenta barrier
prevent mixing of fetal blood with the
maternal blood through which
exchange of gases and metabolic
products take place .
That’s include :
-Respiratory function.
-Nutritive function.
-Excretory function.
-Endocrine function.
-Protective function.
15.
16. examples of substances and micro-organisms that can pass
through the placental barrier.
-nutrients and gases ( glucose – oxygen )
occurs by diffusion of gases and transport
of nutrients.
-Antibodies can also pass from the mother to
the fetus, providing protection from
certain diseases.
-Amino acids are transported through
specific receptors.
-Some proteins are transferred slowly
through the placenta, mainly via
pinocytosis.
-Steroid hormones easily cross the placental
barrier.
17. Dangerous Substances :
SOME DRUGS :
Like:
(Thalidomide , Anticonvulsan , warfarin)
heart, kidney, gastrointestinal
And facial abnormalities.
Cleft lip, minor skeletal defects
Nasal / facial abnormalities.
Alcohol:
microcephaly, abnormal facies, growth
disturbance.
Smoking:
Smoking can damage the baby lungs.
18. Micro-organisms that cause congenital
anomalies and growth retardation.
Viruses :
-rubella virus
-CMV
-hepatits B,C Virus
-Herps simplex virus type-2
-HIV
Bacteria :
-Treponema pallidum
Group B streptococcus-
-Neisseria gonorrhae
Parasite :
-Toxoplasmosis
20. 1-RUBELLA :
Rubella
is a disease caused by the
rubella virus.
It is transmitted via the
placenta (prenatal).
Its effects:
-Cataracts.
-Deafness.
-Heart defects.
-Mental retardation.
22. 2-Cytomegalovirus
-Inflammation of the retina
-Jaundice
-Large spleen and liver
-Low birth weight
-Mineral deposits in the
brain
-Rash at birth (petechiae)
-Seizures
-Small head size
(microcephaly)
SYMPTOMPS
23. 3-Herpes simplex virus type-2
Congenital herpes simplex is
an infection caused by
exposure in the uterus
Its transmitted at the time of
birth = (natal)
Symptoms:
-irritability
-seizures.
-trouble breathing .
-shock .
24. 4-Hepatitis B
-Hepatitis B
Hepatitis B virus (HBV) is a double-
stranded DNA virus in the
Hepadnaviridae family.
-Its transmitted to the baby during
birth (natal) and breast feeding
(postnatal)
25. 5-Hepatitis C
Hepatitis C is an infectious
disease affecting primarily
the liver, caused by
the hepatitis C virus (HCV)
its transmitted during
birth .
Symptoms:
-fever
-weight loss
-Fatigue
26. 6- HIV
human immunodeficiency virus
(HIV) is the cause of acquired
immunodeficiency syndrome
(AIDS)
Its transmitted via breast feeding
(postnatal) also at the time of
birth (natal)
28. 7-Toxoplasmosis
Toxoplasmosis
is a parasitic disease caused
by the protozoan Toxoplasma gondii
It is transmitted via :
placental (prenatal)
Its effects:
Microcephaly.
Jaundice.
Rash.
29. 8-Congenital Syphilis
Syphilis:
is a sexually transmitted infection
caused by type of bacteria called treponema pallidum.
Its transmitted transplacentally (pre natal)
Its effects:
Interstitial keratitis.
Saddle nose.
CNS anomalies.
Heart problem .
32. 9-Gonorrhea
Gonorrhea a sexually
transmitted disease is
caused by the
bacteria Neisseria
gonorrhoeae
it transmitted during birth .
SYMPTOMS :
meningitis (an inflammation
of the membranes around
the brain and spinal cord)
and an eye infection
33. 10-Group B streptococcus
-is a type of bacterial
infection that can be
found in a pregnant
woman’s vagina or
rectum. This bacteria is
normally found in vagina .
It transmitted at the time of
birth (natal)
Streptococcus agalactiae is
the cause bacteria
34. Summary :
-The Placenta and its barrier .
-Functions of the placental barrier.
-Respiratory function.
-Nutritive function.
-Excretory function.
-Endocrine function.
-Protective function.
-Substances and micro-organism that
pass through placental barrier .
-Some pathogen that cause congenital
disease
If women contract rubella in early pregnancy, the infection can cause fetal death or birth defects, known as Congenital Rubella Syndrome (CRS).The three main birth defects associated with CRS include: sensorineural deafness, congenital heart disease (e.g., patent ductus arteriosus), and eye abnormalities (e.g., retinopathy, cataract and microphthalmia), but CRS can also lead to mental retardation and liver or spleen damage
Symptoms of congenital herpes usually appear within the first month of the infant's life. Signs that your baby may have herpes are:
The hepatitis B virus is a DNA virus, meaning that its genetic material is made up of deoxyribonucleic acids. It belongs to a family of viruses known as Hepadnaviridae. The virus is primarily found in the liver but is also present in the blood and certain body fluids.
Congenital syphilis occurs when a baby is born already infected with the bacteria that cause Syphilis. Syphilis is a sexually transmitted disease caused by a type of bacteria called a spirochete. Syphilis is passed from a mother to her baby during pregnancy.
Treponema pallidum is a Gram-negative bacteria which is spiral in shape. It is an obligate internal parasite which causes syphilis, a chronic human disease. Syphilis is a sexually transmitted disease but transmission can also occur between mother and child in utero; this is called congenital syphilis
The infection is spread to infants before or during delivery.