Lecture 12 (Exam 2) Flashcards
The purpose of this structure is to diffuse oxygen and carbon dioxide between the mother and fetus. It also diffuses foodstuffs, and excretes waste products.
Placenta
The (EARLY/LATE) placenta is thick, has low permeability, a small surface area, and the total diffusion conductance is miniscule.
Early
The (EARLY/LATE) placenta is thin, has high permeability, a large surface area, and has a large increase in placental diffusion.
Late
The oxygen pressure gradient (near end of pregnancy) of the mother is _____ mmHg. For the fetus, it is _____ mmHg.
50
30
What are the 3 reasons why adequate oxygenation (between mother and fetus) can occur with such a low pressure gradient (mean diffusion gradient pressure = 20 mmHg)?
1) Fetal hemoglobin has a higher affinity for oxygen
2) Fetal blood hemoglobin concentration is 50% greater than maternal
3) Bohr effect
In the Bohr effect, hemoglobin can carry more oxygen at a low _____.
CO2
In the Bohr effect, fetal blood coming into the placenta carries more (OXYGEN/CO2). The excess is then diffused into maternal blood. This causes fetal blood to become more (ACIDIC/ALKALINE) and maternal blood becomes more (ACIDIC/ALKALINE).
CO2
Alkaline
Acidic
In the Bohr effect, the changes of fetal and maternal blood cause a(n) (INCREASE/DECREASE) in capacity of fetal blood to combine with oxygen, and a(n) (INCREASE/DECREASE) in capacity of maternal blood to combine with oxygen.
Increase
Decrease
This refers to the double shift in the maternal blood and in the fetal blood.
Double Bohr effect
The PCO2 of fetal blood is 2-3x (HIGHER/LOWER) than maternal blood.
Higher
In the diffusion of foodstuffs, there is facilitated diffusion of _______ via trophoblast cells and a slower diffusion of ______ ______ into fetal blood.
Glucose
Fatty acids
In the excretion of waste products, _____, _____ _____, and _______ diffuse from the fetus to maternal blood.
Urea
Uric acid
Creatinine
This is secreted by the syncytial trophoblast cells into maternal fluids. It functions to prevent the involution of the corpus luteum, causes the corpus luteum to increase secretion of progesterone and estrogens, causes increased growth in the corpus luteum, and exerts interstitial cell-stimulating effect on testes of male fetus (results in production of testosterone until birth).
Human Chorionic Gonadotropin (HCG)
This is secreted by syncytiotrophoblast cells of placenta and the secretion level is 30x mother’s normal level toward the end of pregnancy.
Estrogens
Placental estrogens are formed almost entirely from _______ _______ compounds. These are formed in the mother’s and fetal’s adrenal glands and converted by trophoblast cells into estradiol, estrone, and estriol.
Androgenic steroid
The functions of this include:
- Uterine enlargement
- Breast enlargement
- Growth of breast ductal structure
- Enlargement of maternal external genitalia
- Relaxation of pelvic ligaments
- May also effect aspects of fetal development
Estrogens
This is secreted in small quantities by the corpus luteum early and then in large quantities by the placenta.
Progesterone
The functions of this include:
- Causes decidual cells to develop in the endometrium
- Decreases contractility of pregnant uterus
- Increases secretions of fallopian tubes and uterus
- May work with estrogen to prepare breasts for lactation
Progesterone
This is secreted by the placenta beginning in the 5th week of pregnancy. Its functions include causing decreased insulin sensitivity and decreased utilization of glucose by the mother. It is a general metabolic hormone.
Human Chorionic Somatomammotropin
This theory regarding placental immunology states that there is a lack of expression of major histocompatibility _______ by syncytiotrophoblast and cytotrophoblast (placental components). The fetus does not present foreign antigens to the mother’s immune system.
Antigens
This theory regarding placental immunology is that the mother’s immune system is somehow _______ during pregnancy so that it does not react to the fetal antigens to which it is exposed.
Paralyzed
This theory regarding placental immunology is that local _______ barriers prevent either immune recognition of the fetus by the mother or the reaching of competent immune cells from the mother to the fetus.
Decidual
This theory regarding placental immunology is that molecules formed on the fetal placental surface are able to inactivate the ______ or other immune cells locally that could reject the embryo.
T-cells
This is the term for the maternal consumption of alcohol during pregnancy that can lead to a well-defined constellation of developmental abnormalities that includes poor postnatal growth rate, microcephaly, mental retardation, heart defects, and hypoplasia of facial structure.
Fetal alcohol syndrome
If the fetal erythrocytes are positive for the Rh antigen, and the mother is Rh negative, the presence of fetal erythrocytes in the maternal circulation can stimulate the formation of anti-Rh antibody by the immune system of the mother. The fetus in the first pregnancy is usually spared the effects of the maternal antibody, but in subsequent pregnancies, Rh-positive fetuses are attacked by the maternal anti-Rh antibodies, which make their way into the fetal bloodstream. This antibody causes hemolysis of the Rh-positive fetal erythrocytes, and the fetus develops _________ _________.
Erythroblastosis fetalis
In severe cases of erythroblastosis fetalis, the bilirubin released from the lysed red blood cells causes water accumulation in the fetus, called ______ ______. This is accompanied with jaundice and brain damage in addition to anemia.
Hydrops fetalis
An abnormal implantation site within the uterine cavity is known as _______ _______. When part of the placenta covers the cervical outlet of the uterine cavity, its presence is a mechanical obstacle in the birth canal. In addition, hemorrhage, which can be fatal to the fetus or the mother, is a common consequence as a result of the premature separation of part of the placenta from the uterus.
Placenta previa
A _______ _______ is a noninvasive condition in which many of the chorionic villi are characterized by nodular swellings that give them an appearance similar to bunches of grapes. Commonly, much of the villous surfaces of the placenta takes on this appearance; in addition, the embryo is either absent or not viable. The villi show no evidence of vascularization. Result of paternal imprinting.
Hydatidiform mole
What is the most common cause of neonatal mortality?
Congenital anomalies
This is the term for the study of congenital malformations.
Teratology