Teratogens are compounds and environmental conditions which interfere with normal in utero development [161].There is a long list of known human teratogens (Table 23.3).There is an increasing understanding that stress, nutrition, infections, and the microbiome can also play a role in altering gene programming and expression during embryonic and fetal growth.101. Some teratogens have a threshold effect, which means that they are _____. A) harmful no matter what the level of exposure B) rarely harmful C) harmless until exposure reaches a certain level D) always harmless 102. Thresholds, as they relate to harm from any teratogen, are difficult to set because one teratogen may _____ the threshold of another teratogen.Some teratogens have a threshold effect, which means that they are _____. A. rarely harmful B. harmful no matter what the level of exposure C. harmless until exposure reaches a certain level D. always harmlessSome teratogens have a threshold effect, which means that they are _____. harmless until exposure reaches a certain level Harry was a preterm newborn who was born after 26 weeks of prenatal development.As a baby grows in the womb, teratogens may affect parts of the baby's body as they are forming. For example, the neural tube closes in the first 3 to 5 weeks of the pregnancy. During this time, teratogens can cause neural tube defects such as spina bifida. Some organs are sensitive to teratogens during the whole pregnancy.
A teratogen is any agent or condition that increases the
Although physical outcomes resulting from teratogen exposure cannot be reversed, with hope, some of the behavioral effects of Teratogens may have a decreased impact on the life of the child, though all mothers should pay special attention to the health of their child throughout their pregnancy.Teratogens are environmental factors that can contribute to birth defects, and include some maternal diseases, pollutants, drugs and alcohol. Factors influencing prenatal risks: There are several considerations in determining the type and amount of damage that might result from exposure to a particular teratogen (Berger, 2005).The threshold effect means that this agent is virtually harmless until exposure to it reaches a toxic level, or in some cases would affect the fetus if it was at a lower birth weight, or if a pregnant mother fails to gain sufficient weight during the pregnancy or may be simply be harmful to some organs if exposure occurred at a time when those organs were developing.Thresholds, as they relate to harm from any teratogen, are difficult to set because one teratogen may _____the harm from another teratogen. - increase Some teratogens have a threshold effect, which means that they are: - harmless up to a certain Level:. Mandy is pregnant yet she still smokes cigarettes, drinks alcohol, and does not eat well.
Developmental Psych Quiz 4 Flashcards | Quizlet
Definition of Teratogen. Category D drugs have enough possible effect on a pregnancy that they are avoided. Category X drugs are the most harmful to a developing fetus. Some bacteria canTeratogens are drugs, chemicals, or even infections that can cause abnormal fetal development. There are billions of potential teratogens, but only a few agents are proven to have teratogenic effects.Teratogens act via a specific mechanism on developing cells and tissues to initiate a cascade of altered developmental events. Teratogenic effects are dependent on the nature of the teratogen, including chemical properties of the chemical, route of exposure, maternal/fetal bioactivation, placental transport, etc.Effects of teratogens during this period of developmental often times results in an "all or none effect." That is, the effect of the teratogen, if it is to have any effect, will be so profound as to cause a spontaneous abortion. Some examples of teratogens known to cause human malformations are listed in the table below (Table 23-2).Some teratogens have a threshold effect, which means that they are _____. A) harmful no matter what the level of exposure B) rarely harmful C) harmless until exposure reaches a certain level D) always harmless 54. Thresholds, as they relate to harm from any teratogen, are difficult to set because one teratogen may _____ the threshold of another
The word Teratogen, in Greek, means "monster forming". Teratogens in, modern scientific vernacular, are agents that intrude with commonplace development of an embryo.
Many things can also be listed as teratogens and clearly some are extra severe than others. Exposure to some teratogens, even in trace quantities, can have devastating effects. Some teratogens are benign till they build to "threshold concentration" levels in the mother and then their results are noticed. Some teratogens are dangerous all through a pregnancy and some are bad handiest at explicit points of embryonic building.
The handiest safe course of action is to actively avoid identified teratogens earlier than and all over pregnancy. The checklist underneath is not all inclusive however does record some well known and threatening brokers that are proven teratogens.
Varicella Virus (Chickenpox)
Exposure to chickenpox virus, clearly, is very common as it's a not unusual airborne disease and shut proximity to an inflamed particular person may cause publicity - exposure too can happen via entering direct touch with the rash of an infected individual. The danger to a developing fetus, whose mother is *newly* infected, can also be critical, together with: pores and skin scarring, a small head, blindness, seizures, low birth weight, and mental retardation.
Tobacco
Exposure to tobacco is, of course, not unusual via smoking cigarettes or differently consuming tobacco or being the recipient of 2nd hand smoke (10% of U.S. girls (minimal) smoke while pregnant.). The possibility to a creating fetus, whose mother is uncovered to tobacco, is that the placenta would possibly not expand usually causing stipulations like a placenta previa that can cause severe complications, together with loss of life, right through being pregnant and/or supply (my spouse had this situation and needed to be hospitalized for weeks). The fetus could also be at higher possibility of creating heart defects and being born at a low birthrate. Babies that do live on are often tough to convenience and are once in a while described as frightened or "jittery". Another tangential point is that small children that proceed to be uncovered to tobacco (second hand smoke) after birth have larger risk of SIDS, asthma, and other lung related issues.
Alcohol
When a pregnant woman drinks alcohol, so does her unborn child. There isn't any recognized secure amount of alcohol to drink while pregnant and there also does no longer appear to be a protected time to drink during pregnancy either. Therefore, it is recommended that women abstain from drinking alcohol at any time all over pregnancy. Women who are sexually active and do not use efficient beginning keep an eye on should additionally refrain from consuming because they could turn out to be pregnant and now not know for a number of weeks or extra.
Prenatal exposure to alcohol may cause a vary of issues, known as fetal alcohol spectrum problems (FASDs). One of the most critical effects of drinking right through pregnancy is fetal alcohol syndrome (FAS). FAS is without doubt one of the main identified preventable reasons of psychological retardation and birth defects. If a woman beverages alcohol all through her being pregnant, her baby will also be born with FAS, a lifelong situation that reasons bodily and psychological disabilities. FAS is characterised by means of peculiar facial features, expansion deficiencies, and central apprehensive system (CNS) issues. People with FAS might have problems with studying, memory, attention span, conversation, vision, listening to, or a combination of those. These issues steadily result in difficulties in class and issues getting along side others. FAS is a permanent condition. It affects each aspect of a person's lifestyles and the lives of his or her family.
Accutane
A person affected by severe pimples is also exposed to Accutane throughout remedy. Accutane is a prescribed medication that controls and stops some of the mechanisms in the glands that give a contribution to acne. A developing fetus, whose mother is uncovered to Accutane, is extremely more likely to expand both facial deformities, middle defects, a small head, a cleft lip and palate, a buildup of fluid in the brain, or mental retardation. This is a very dangerous substance for a creating fetus.
HIV
HIV, in fact, is the virus that reasons AIDS. A person normally turns into infected with HIV by means of having vaginal or anal sex (particularly unprotected intercourse) with a service or being uncovered to infected blood (maximum ceaselessly through sharing needles) - There are other, extra unusual, strategies of exposure like oral sex and blood transfusions. The well being risk to a growing fetus, whose mother is inflamed, is that they will contract the virus themselves (congenital HIV) now and again spontaneously aborting or surviving but being born inflamed with, the currently incurable, HIV. Being born infected with HIV is one of the most commonplace delivery defect in the world these days. Medications to scale back the virus ranges within the mother's blood and a quick supply by caesarian can a great deal cut back the danger to the baby. An infected mom can move the virus on to her child all over breastfeeding.
DES (diethylstilbesterol)
This is an especially unhappy teratogen because the exposure is because of a pregnant girl taking medicine in an strive to protect her fetus and save you a miscarriage. DES was in medicine used to prevent those miscarriages; it increases manufacturing of certain hormones created by way of the placenta. A female fetus uncovered to DES is at risk for growing vaginal and cervical cancer in addition to uterine defects. A male fetus uncovered to DES is vulnerable to growing ordinary genitalia
Thalidomide
Thalidomide is an infamous teratogen. Women can also be uncovered to this substance whilst looking to keep watch over nausea all over pregnancy. Thalidomide was once given (mostly in the overdue fifties) as a medicine to keep watch over the nausea (it was once got rid of from the market in 1961). Thalidomide reasons severe malformation risks to a creating fetus. It could cause faulty intestines, hearing defects or the fetus no longer creating ears at all, and anomalies with eyes and imaginative and prescient. However, the chance to the fetus that is maximum notorious is the severe limb malformations the place the bones within the arms and legs do not expand to their right kind duration or don't increase in any respect.
Radiation
There are a number of techniques to be uncovered to radiation: having a scientific X-ray, running at a nuclear energy plant, running in any commercial setting the place X-rays or different radioactive ingredients are used, nuclear injuries (like Chernobyl) nuclear bomb detonations (trying out or the Japanese wartime explosions) and countless other minor resources like TVs, smoke detectors, and airplane journeys. Radiation exposure at prime enough levels could cause developmental dangers to a creating fetus like a relief in height, critical mental retardation, small head size, impaired brain development, adolescence leukemia, and cancer in later existence.
Lead
Exposure to steer is commonplace. Lead is utilized in batteries, metals, paint, ceramic glazes, cable overlaying, ammunition, and just lately, toys from China. Pesticides, paint and gas had enormous quantities of lead till the hazards of lead had been more fully learned. Old houses may have lead in the faucet water because it seeps from leaded pipes. A fetus, whose mother is exposed to guide, runs the developmental risk of being spontaneous aborted, being born with a low delivery weight, being born upfront, and creating skin tags or different abnormal markings. A male baby is also in danger for undescended testicles.
Rubella
Rubella is very contagious illness led to through a virus. Exposure can happen via normal interaction with an inflamed particular person the place fluid from the nose or throat of the inflamed individual will get handed (shaking palms, sharing drinks, and so forth). There is a vaccine for the disease however for a pregnant girl who has no longer been vaccinated, there are serious and sundry risks to her fetus. They include imaginative and prescient and listening to issues, middle abnormalities, psychological retardation, even loss of life of her fetus, and stillbirth. If the baby survives they are still at risk for diarrhea, pneumonia, meningitis and anemia. They are even at risk for diabetes and cerebral palsy. There are so many imaginable defects that the time period 'congenital rubella syndrome' is used as an umbrella term for the entire possibilities. Get vaccinated!!
Syphilis
Syphilis is a sexually transmitted illness led to via a bacterium. Exposure occurs in the commonplace manner of most STDs: vaginal, anal, or oral intercourse (especially unprotected). The possibility to the fetus is that the fetus turns into inflamed with the micro organism. This can cause stillbirth or demise in a while after delivery. Infected small children that are living via delivery are nonetheless in danger for being developmentally not on time, having seizures, or even demise. Syphilis is reasonably simple to remedy in adults.
Toxoplasmosis
Toxoplasmosis is an extremely commonplace parasitic infection. Pregnant women can also be exposed to this parasite in some ways together with: handling infected meat, cleansing a cat's clutter box and breathing in the parasite (cats devour diseased animals and their feces transform infected), touch with soil or sand that would possibly have been used by cats, and many others. The risk to the fetus in construction, especially a fetus whose mother is *newly* infected with the parasite, is the greater chance for mental retardation, pneumonia, eye infections, jaundice, and hydrocephalus ("water on the brain"). A surviving child could also be vulnerable to seizures and to growing cerebral palsy.
Cytomegalovirus (CMV)
CMV is and extraordinarily commonplace herpes virus. Exposure to this virus can happen thru sexual contact, kissing, or touch with the saliva, urine, tears, or nearly another bodily fluid of an inflamed individual. The risk to a growing fetus, particularly a fetus whose mother is *newly* infected, include listening to loss, psychological retardation, imaginative and prescient loss, liver/lung/spleen problems and dental anomalies.
Phenytoin (or Dilantin)
Phenytoin is a medication used to treat epilepsy and save you seizures. Exposure to this medicine is not unusual for mothers suffering from epilepsy and due to this fact who have been prescribed the medicine. The threat to the fetus happens, partly, as a result of Phenytoin metabolizes another way for the fetus and the fetus receives a much upper dose than the mummy. An exposed fetus has increased chance for developing a cleft palate, growing center defects, having small heads, abnormalities within the arms and nails, and some mild developmental disabilities. The mixture of defects is known as "Fetal Hydantoin Syndrome".
Mercury
Mercury is a glossy silver steel that is in liquid shape at room temperatures. Exposure to mercury may occur around broken thermometers, dental fillings, broken florescent light bulbs and eating fish that have top ranges of mercury (especially swordfish, shark, king mackerel and tilefish). A fetus, whose mom is uncovered to mercury, might be in severe threat. Mercury can forestall the duplication means of cells and lead to the loss of life of the fetus. It can also alter the cells because the divide and introduce a number of unpredictable mutations in the growing fetus, especially to their frightened device.
Arsenic
Arsenic is a metal like mercury. Exposure can happen when ingesting neatly water that is contaminated with arsenic, dwelling near or running at an commercial incinerator that burns waste containing arsenic, or dwelling near or running at business metal smelters. Building lumber was treated with arsenic till 2003, so even strolling barefoot on a yard deck might permit exposure to arsenic. A fetus, whose mother is exposed to high levels of arsenic, has an larger chance of being spontaneous aborted, being born with a low start rate, or even stillbirth.
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Some teratogens have a threshold effect which means that ...
At around 38 weeks after conception the starts the ...
At around 38 weeks after conception the starts the ...
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