Congentital and Childhood Disorders Flashcards
What trimester is the most critical for development?
First trimester
What occurs in the first trimester?
- Cell differentiation
- Brain, spinal cord, organ development, arms legs, eyes, and genital development
What controls embryonic development?
DNA
What occurs in the 2nd trimester?
- Rapid growth
- Differentiation
- Maturation of body tissues and organs
What occurs in the third trimester?
- Nervous system begins regulating the body tissues and organs
- Respiratory system matures
- Sexual development is completed
Excessive mutation can cause…
Spontaneous Abortion
When and what are the important nutrients needed for development and when are they essential
- Folic acid
- Essential during the first trimester
If you lack folic acid, what are its effects?
Effects the neural tube and can lead to spina bifida
This is any agent capable of causing a congential fetal abnormaility
Teratogen
What are the common tetatogens?
- Alcohol (MOST COMMON)
- Drugs
- Viral infections
- Toxins
This is any abnormality present at birth
Congential Defect
When do most birth defects occur and why?
Occur in the embryonic period (the first 8 weeks) because this is when the fetus is most vulnerable
What are common causes of birth defcts?
- Mechanical factors
- Genetic Factors
- Environmental factors
- Multifactorial
This is caused by maternal mechanical factors that distort the fetus
Congential Deformations
These are fetal defects due to genetic factors that interfere with the process of cell division
Congential malformations
What is an example of mechanical defect
Club Foot
Describe club foot
- Twisting inward or outward of the foot so that the sole is not on the ground
- Due to malformation of the uterus
- Multiple pregnancies
- Decreased amniotic fluid
What is the most common chemical/drug that effects the fetus? and how does it work?
Alcohol
- Alcohol is water soluble so it crosses the placenta and causes a negative effect
- Results in fetal alcohol syndrome
What are the effects of fetal alcohol syndrome?
- Thin upper lip
- Wide set eyes
- Intrauterine growth restriction
- Short eye syndrome
- Mental deficiency
What are the classes of drugs for pregnant women, what are their significance, and what is an example?
Classes of drugs= A, B, C, X
- Classes are descriptive for whether they are safe for pregnant women
- C drugs= mostly haven’t been tested yet
- Coumadin= teratogenic
Again, what is folic acid and B12 important for?
Development of the nueral tube (incases the spinal cord)
What are the 3 types of Spina bifida?
- Spina bifida occulta
- Spina bifida with meningocele
- Spina bifida with myelomeningocele
Describe spina bifida occulta?
- Mild
- Small Non closure of vertebral arch
- S&S= dimple, tuft of hair, hyperpigmentation in the lower lumbar region
Describe spina bifida with meningocele
- The meninges and CSF protrude through the deficit
- Large deficit
- Causes a cystic nature
Describe spina bifida with myelomeningocele
- When the spinal cord, meninges, and CSF protrude through the deficit
- Huge deficit in the vertebral arch
- Causes extreme harm
- Can lead to paraylzation
- Can become incontinent because the nerves that go to the bladder don’t work
What is vitamin A used for in development
Formation of…
- Heart
- Limbs
- Eyes
- Ears
How does ionizing radiation cause birth defects?
Effects the germ cells of the mother (ova) or the developing fetus and result in damaging DNA
-Damaged germ cells=defective baby
What is the name of the group that is the most common cause of microbe related teratogens
TORCH teratogens T=Toxoplasmosis O=Other (syphilis, hep B, AIDS) R=rubella C=cytomegalovirus H=Herpes
What are S&S of TORCH syndrome?
-Small skull Mental retardation -Cataracts -Heart problems -Liver problems (hemorrhages and jaundice)
How can TORCH problems be transferred?
- Transplacentally
- When the uterus exits the vagina during birth
What does a nucleotide contain?
-
- Sugar
- Phosphate
- Base
This is the sequence of nucleotide bases that code for DNA
-Genetic code
T/F- The majority of DNA is noncoding
True
T/F- Most genetic disorders are multifactorial?
True
How many chromosomes do humans have?
46
- 22 autosomes
- 1 pairs of sex chromosomes
This is a set of chromosomes
Karyotype
This is your genetic makeup
Genotype
This is your physical appearance
Phenotype
What are the 3 categories of genetic problems?
- Monogenic
- Polygenic
- Cytogenic
Describe monogenic (genetic problems)
-Passed down from parent to child
-Either autosomal ressessive/dominant
Ex. Sickle Cell disease
Describe polygenic (genetic problems)
-Multi gene influence as they interact with environmental factors (like obesity)
Ex. Type 2 diabetes, CAD, physical traits
Describe cytogenic (genetic problems)
-Large scale abnormalities of chromosomes caused by extra or absent WHOLE chromosomes or structural dislocations
-Most are not inheritable!!!!!!
-Most are this type
-Arise downstream, so they DO NOT EXIST IN THE ORIGINAL GERM CELL
Ex. Downs Syndrome
T/F- DNA mutation that occurs in the ova or the sperm are the only genetic mutations that can be transmitted to the offspring
TRUE
If the defective gene always expressed
Not necessarily
How many defective genes do you need for an autosomal recessive disease?
2
-if you only have 1 gene, you are a carrier
How many defective genes do you need for an autosomal dominant disease?
1
