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
This is the term for the agents that produce birth defects.
Teratogens
This is the term for an abnormality of a tissue due to an abnormal intrinsic developmental process.
Dysplasia
This is the term for a group of anomalies seen in more than one individual that cannot yet be attributed to a definitive cause.
Association
These are the primary errors of morphogenesis. They are usually multifactorial, involving a number of etiological agents including genetic and environmental factors.
Malformations
This is the term for disturbances in otherwise normal morphogenetic processes. Examples include amniotic bands.
Disruptions
These are also disturbances in otherwise normal morphogenetic processes. These are typically caused by abnormal biomechanics forces such as uterine constraints. Clubfoot is an example.
Deformations
This is the term for a series (cascade) of events triggered by one initiating factor (sort of like the complement cascade or the hemostatic cascade discussed previously). An example used earlier in the text is oligohydroamnios (decreased amniotic fluid) which leads to a variety of events, including fetal compression and other problems stemming from the fetal compression.
Sequences
These are constellations of congenital anomalies that are thought to be pathologically related but cannot be explained on the basis of a single local initial event. They are often caused by a single event such as a viral infection.
Syndromes
Explain why developmental insults during the first three weeks of development are unlikely to result in defective development.
1) They kill the embryo
2) Are compensated for by the powerful regulatory properties of the early embryo
Explain why major structural anomalies are unlikely to occur after the eighth week of pregnancy.
By this point most organs have become well established.
There are three groups of causes of congenital anomalies, which are…
Genetic
Environmental
Multifactorial
Gene mutations include inborn errors of metabolism, which are rare. They are inherited most commonly as _______ _______ or _______ diseases. A few are inherited as ________ traits. They often affect enzymes and biochemical pathways.
Autosomal recessive
X-linked
Dominant
This gene mutation is a congenital deficiency of phenylalanine 4-monooxygenase. It causes inadequate formation of L-tyrosine, elevation of serum L-phenylalanine, excretion of phenylpyruvic acid, and accumulation of phenylalanine.
Phenylketonuria
This gene mutation is a congenital deficiency of galactosyl-1-phosphate uridyltransferase. It results in tissue accumulation of galactose 1-phosphate.
Galactosemia
This gene mutation is an inherited disorder that affects mostly the lungs but also the pancreas, liver, kidneys, and intestine. It is inherited in an autosomal recessive manner with mutations in both copies of the CFTR protein gene. The CFTR protein is a membrane protein chloride channel/transporter.
Cystic fibrosis
Types of chromosome rearrangements include…
Deletions
Duplications
Inversions
Translocations
This is the term for a change in chromosome number beyond the 2N state. 80-90% of fetuses with this and other abnormalities of chromosomes die in utero, the majority in the earliest stages of gestation (i.e., Trisomy 21, Trisomy 13).
Aneuploidy
This is a type of aneuploidy that results in an X0 genotype. There is a total of 45 chromosomes and only one X chromosome. It occurs to 1 in 3000, and its characteristics include a female with underdeveloped sex characteristics, low hairline, broad chest, folds on neck, usually sterile, and usually of normal intelligence.
Turner syndrome
This is a type of aneuploidy that has a genotype of XXX. It occurs to 1 in 1000, and its characteristics include being tall and thin, usually fertile, and most have normal intelligence.
Poly-X syndrome
This is the term that involves the addition of a complete set of chromosomes in addition to the diploid (2N) stage. It is often the result of a retention of a polar body or by fertilization by more than one sperm. Typically results in early spontaneous abortion.
Euploidy
Things like viral infections, bacterial infections, protozoans, radiation, maternal diabetes, and drugs and other chemicals are all considered (GENETIC/ENVIRONMENTAL) factors that can lead to congenital anomalies.
Environmental
This was a drug used for morning sickness, but was discovered to cause horrible birth defects when taken during the 1st trimester.
Thalidomide
This can be used for the treatment of acne, but can be a potent teratogen when taken orally. It can produce a wide spectrum of defects, most of which are related to derivatives of the cranial neural crest. These involve a variety of facial structures, the outflow tract of the heart, and the thymus.
Retinoic acid
A deficiency of this can cause neural tube defects in the developing fetus.
Folic acid
What are the second most common causes of neonatal mortality?
Prematurity
Fetal growth restrictions
Major risks factors of _________ include:
- Preterm premature rupture of placental membranes
- Intrauterine infections
- Uterine, cervical, and placental structural abnormalities
- Multiple gestation
Prematurity
Hazards of ________ include:
- Hyaline membrane disease
- Necrotizing enterocolitis
- Sepsis
- Interventricular hemorrhage
- Long-term complications including developmental delay
Prematurity
Fetal factors resulting in fetal growth restriction include…
1) Chromosome disorders
2) Congenital anomalies
3) Congenital infections
Placental factors resulting in ______ ______ restriction:
- Umbilical-placental vascular anomalies
- Placenta previa
- Placental thrombosis and infarction
- Multiple gestations
- Placental genetic mosaicism
Fetal growth
Maternal factors resulting in fetal growth restriction:
- ________
- Chronic _______
- Maternal use of drugs, narcotics, alcohol, nicotine
- Maternal malnutrition
Preeclampsia
Hypertension
This condition is related to immaturity of the lungs and, therefore, is related to premature birth.
Neonatal respiratory distress syndrome
The incidence of neonatal respiratory distress syndrome is (DIRECTLY/INVERSELY) proportional to gestational age.
Inversely
Neonatal respiratory distress syndrome occurs in _____ of infants born at less than 28 weeks.
60%
Neonatal respiratory distress syndrome occurs in _____ of infants born between 28 and 34 weeks.
30%
Neonatal respiratory distress syndrome occurs in less than _____ of infants born after 34 weeks.
5%
In neonatal respiratory distress syndrome, the fundamental deficiency is in the lack of pulmonary ________.
Surfactant
This is a mixture of lipids and proteins which is secreted by epithelial type II cells into the alveolar space. It reduces the surface tension of fluid in the lungs and helps make the small air sacs in the lungs (alveoli) more stable.
Surfactant
This is another name for neonatal respiratory distress syndrome. It refers to the glassy or transparent appearance of the membrane lining the alveoli, making gas exchange difficult or impossible.
Hyaline membrane disease
Fetal ______ refers to the accumulation of edema fluid in the fetus during intrauterine growth. Until recently, the most common cause was hemolytic anemia caused by blood group incompatibility between mother and fetus.
Hydrops
(NONIMMUNE/IMMUNE) hydrops is caused by blood group incompatibility between mother and fetus.
Immune
This is a rare kind of brain damage that can happen in newborns with jaundice. It happens when babies build up too much of a chemical called bilirubin in their blood (this causes the yellow color of jaundice).
Kernicturus
Why is Rh disease not a problem with the first pregnancy?
Maternal antibodies have not had enough time to produce sufficient quantities
List some of the consequences of Rh disease (5).
Erythroblastosis fetalis Hydrops fetalis Jaundice Brain damage (kernicturus) Anemia
Fetal red blood cells reach the maternal blood stream during the last trimester or during childbirth itself. The major factor is ____ antigen of the Rh group. _____ incompatibility is generally not a problem, because maternal antibodies remove any incompatible fetal RBCs that cross the placenta.
D
ABO
(NONIMMUNE/IMMUNE) hydrops is caused by cardiovascular defects such as congenital cardiac defects and arrhythmias. It can also be caused by chromosomal anomalies such as Turner syndrome, and trisomies 21 and 18. This is generally due to the cardiac structural aberrations that accompany these anomalies.
Nonimmune
This is the term for pregnancy induced hypertension. It consists of persistent elevated blood pressure (140/190) that develops after 20 weeks of gestation and returns to normal after birth. There is also proteinuria (protein in the urine), weight gain, and edema.
Preeclampsia
This is similar to preeclampsia but much more serious. It consists of extremely high blood pressure and grand mal seizures or coma.
Eclampsia
