Flashcards in Midterm Deck (68):
1
What is malformation
Intrinsic disturbance in morphogenesis
2
What is disruption and what is an example
Extrinsic disturbance in morphogenesis causing secondary damage in developmentally normal tissue
Amniotic band
3
What is deformation and what are maternal and fetal factors
Deformation is extrinsic disturbance in morphogenesis due to compression by abnormal mechanical forces
Maternal factors- first pregnancy, small uterus, leiomyoma (benign smooth muscle tumor of the uterus)
Fetal factors- oligohydramnios and multiple fetuses
4
What is sequence and give an example with causes and the sequence
Sequence is when one initiating aberration leads to many secondary defects
Oligohydramnios "Potter Syndrome"
Causes- renal agenesis, placental insufficiency due to maternal HTN, and amniotic leak
Sequence- fetal compression, flat face, mispositioned hands and feet, and lung hypoplasia
5
What is a syndrome
A syndrome is a combination of anomalies usually as a result of a single pathology that affects many tissues
6
What is:
Agenesis
Aplasia
Atresia
Dysplasia
Agenesis- lack organ and its primordium
Aplasia- lack organ due to failure of its developmental analogue
Atresia- lack opening
Dysplasia- loss of cellular uniformity and organization
7
What are the 2 general causes of anomalies (broad categories)
Genetic causes
Environmental causes
8
What are the genetic causes of anomalies and give an example of one
Chromosomal abnormalities
Single gene mutations (mutation in hedgehog results in holoprosencephaly)
9
What are the 3 environmental causes of anomalies
Viruses
Alcohol
Maternal Diabetes
10
Explain viral causes of anomalies and give two examples
Cytomegalovirus- 2nd trimester results in microcephaly, mental retardation, and deafness
Rubella- before 16 weeks causes congenital rubella sydrome resulting in cataracts, deafness, heart defects, and mental retardation
11
Explain alcohol with regards to anomalies and explain the major example
Fetal alcohol syndrome is associated with growth retardation, microcephaly, maxillary hypoplasia, and ASD
12
Explain the affect of maternal diabetes with regards to anomalies
Maternal diabetes causes fetal hyperinsulinemia which causes increased body fat and muscle mass and causes organomegaly
13
With regards to pathogenesis of anomalies explain:
Early embryonic period
Weeks 3-9
Fetal Period
Early embryonic period (first 3 weeks)- injury either kills the fetus or it can recover
Weeks 3-9- embryo is very sensitive to teratogens
Fetal period (following organogenesis)- fetus is susceptible to growth retardation
14
What is the definition of premature
Gestational age less than 37 weeks aka preterm
15
What are the 3 major risk factors of prematurity, explain them
PPROM- preterm premature rupture of placental membrane is associated with smoking, malnutrion, preterm labor, and gestational vaginal bleeding
Intrauterine infections- associated with chorioamnionitis and funisitis; TLR activation deregulates PG resulting in uterine contractions
Twins
16
What is fetal growth restriction
Small for gestational age (bottom 10%)
17
What are the 3 general classes of abnormalities that contribute to fetal growth restriction
Fetal, placental, and maternal abnormalties
18
Explain fetal abnormalities with regards to fetal growth restriction
Fetal abnormalities cause symmetric growth restriction
Causes include chromosomal abnormalities, congenital anomalies, and ToRCH infections
19
Explain placental abnormalities with regards to fetal growth restriction
There is extensive fetal growth in the third trimester which places heavy demand on utero-placental blood supply to allow adequate placental growth
Disrupt placental blood flow results in asymmetric growth restriction
20
Explain maternal abnormalities with regards to fetal growth restriction
Maternal abnormalities include preeclampsia, HTN, hypercoagulability, malnutrition, smoking, and drinking all of which disrupt placental blood flow
21
What are the causes of neonatal respiratory distress syndromes
RDS (hyaline membrane disease), maternal sedation, fetal head injury during delivery, fetal hypoxia, and maternal diabetes
22
Explain the pathogenesis of RDS with regards to:
-incidence
-mutant genes
-hypoxia
-clinical info
Incidence of RDS is inversely proportional to gestational age
Mutant SFT genes decrease surfactant production which increases alveoli surface tension which increases pressure requires to expand alveoli
Hypoxia causes acidosis which causes vasoconstriction and hypoperfusion which causes tissue damage which allows plasma to enter alveoli where it complexes with fibrin and necrotic cells to form hyaline membranes which impede gas exchange
Hyperinsulinemia decreases surfactant production while corticosteroids increase production
23
Explain the morphology of RDS
Lungs are solid, airless, and reddish purple
Alveoli are poorly developed
Protein membranes line bronchioles and alveoli
Eosinophilic hyaline membranes
24
Explain clinical info of RDS with regards to:
-measuring lung maturity
-treatment if unable to delay delivery and outcomes
-associated disorders
Lung maturity is measured by amniotic fluids lecithin:sphinogmyeline ration
If unable to delay delivery treat with replacement surfactant and O2 therapy (associated with retinopathy and bronchopulmonary dysplasia)
RDS is associated with PDA and NEC
25
What is NEC
Explain the incidence of NEC
What are predisposing factors
NEC- necrotizing enterocolitis
Incidence of NEC is inversely proportional to gestational age
Predisposing factors of NEC include bacterial colonization of the gut and enteral feeding which induce inflammatory mediates such as PAF leading to enterocyte apoptosis
26
What areas does NEC affect
What is a major sign of NEC
What is the morphology of NEC
NEC affects the distal ileum, cecum, and right colon
Associated with bloody stools
Morphology- coagulative necrosis, ulceration, and submucosal gas bubbles
27
Explain Transcervical Ascending Infections
Most bacterial infections occur via cervicovaginal route
Infants become infected by inhaling infected amniotic fluid or by passing through infected birth canal
Associated with chorioamnionitis and funisitis
Results in pneumonia, meningitis, and sepsis
28
Explain Transplacental Infections
Most parasitic infections, viral (ToRCH) infections, and some bacterial infections (listeria and syphillis) enter fetal blood via chorionic villi
Results in spontaneous abortion, still birth, or hydrops fetalis
Long term effects of ToRCH include growth/mental retardation, cataracts, and heart defects
29
Explain infantile sepsis; early vs late onset
Earl onset- first 7 days- usually by group B strep
Late onset- 7 days to 3 months
30
What is Hydrops Fetalis
What are the two forms
What is the morphology
Hydrops fetalis is edema of fetal compartments
Immune and non-immune hydrops
Morphology- pale fetus and placenta, hepatosplenomegaly, bone marrow hyperplasia, and extramedullary hematopoiesis
31
Explain Immune Hydrops
-etiology and patho
-Ab against Rh or ABO?
Immune hydrops is due to blood group incompatability
Fetal RBC enter maternal circ and mother produces IgM Ab that do not cross placenta, subsequent pregnancy produce IgG that does cross leading to fetal RBC hemolysis
Usually due to Rh incompatibility because fetal RBC poorly express ABO Ag and Ab against ABO Ag are usually IgM
32
Explain the clinical features of immune hydrops
Anemia due to hemolysis; anemia leads to liver ischemia (dec oncotic pressure) and heart ischemia (inc hydrostatic P) resulting in edema
Jaundice to due hemolysis increases unconjugated bilirubin which crosses BBB and causes kernicterus
33
Explain causes of non-immune hydrops
CV defects
Chrom abnormalities- Turner syndrome
Fetal anemia (homozygous alpha-thalassemia or parovirus B19)
34
What is PKU
What does PKU lead to
How do you diagnose and treat
What is benign PKU
PKU is autorecessive mutation in PAH, converts phenylalanine to tryosine, leading to building up of phenylalanine
PKU causes mental retardation, dec pigmentation, and eczema
Benign PKU- small inc in phenylalanine with no neuro deficits
Diagnose via urine and treat via dietary restriction
35
What is galactosemia
What is the cause
What are the effects
Galactosemia is an autorecessive disorder resulting in the accumulation of galactose-1-phosphate due to lack of GALT or deficiency of galactokinase
Accumulates in the liver, spleen, lens, and CNS
Activates alt pathways producing galactitol and galactinate
Results in hepatosplenomegaly, cirrhosis, cataracts, and mental retardation
36
What is cystic fibrosis and what does it lead to
CF is an inherited defect in CFTR resulting in viscous secretions that obstruct organ passages leading to chronic lung disease, pancreatic insufficiecny, steatorrhea, malnutrition, cirrhosis, and male infertility
37
What is CFTR and what are its functions
CFTR is a chloride channel that also regulates other ion channels such as ENaC and SLC26
38
Explain CFTR and ENaC with regards to CF
Eccrine Sweat ducts- in CF ENaC loses its function resulting in hypertonic sweat rich in chloride
Lungs/Intestines- in CF ENaC is active leading to water reabsorption which results in dehydrated mucus secretions
39
Explain CFTR and SLC26 with regards to CF
SLC26 is a bicarbonate transporter; loses its function in CF resulting in acidic secretions that obstructs ducts
40
What are the 6 classes of CFTR mutations
1- lack of CFTR
2- defective processing leading to CFTR degradation
3- CFTR can't be phosphorylated and activated
4- dec activity
5- dec production
6- altered function
41
What is the morphology of CF:
-pancreas
-intestines
-liver
-lungs
-male genital tract
Pancreas- mucus accumulates in ducts resulting in dilation and atrophy, dec secretion impairs fat absorption, squamous metaplasia
Intestines- meconium ileus leading to obstruction
Liver- cirrhosis
Lungs- mucus hyperplasia- inc risk of infection
Male genital tract- infertility and lack of ductus deferens
42
Explain the clinical aspect of pancreatic insufficiecny with regards to CF
Pancreatic insufficiency leads to malabsorption of fats resulting in fatty smelly stools and deficiency of fat soluble vitamins
43
What is SIDS
When do infants usually die from SIDS
SIDS is sudden death of infant less than 1 y/o that is unexplained after case investigation, autopsy, examination of death scene, and review of clinical history
Infants usually die while asleep in the prone and lat recumbent positions
44
What is the morphology of SIDS
Petechiae- thymus, pleura, and epicardium
Arcuate nucleus hypoplasia
Evidence of upper resp tract infection
45
What is the pathogenesis of SIDS and some paternal and infant factors
immaturity of areas of brainstem (arcuate nucleus) involved in arousal and respiratory control
Infections fatally impair those control systems
Parental factors- young mother, short inter-gestational period
Infant factors- preterm, low birth weight, respiratory infections, male
46
What are hemangiomas
where are they found
What do they look like and what are they called
Hemangiomas are infantile benign tumors affecting the skin of the face and scalp
They are flat, irregular, blue-red masses called port wine stains
47
Explain congenital infantile fibrosarcoma
Congenital infantile fibrosarcoma is the result of a chromosomal translocation producing ETV-NTR fusion protein which is a constitutively active tyrosine kinase
48
Where are infantile teratomas usually found; are they usually benign or malignant
Infantile teratomas are found in the sacrococcygeal region and are usually benign
49
Where are neuroblastic tumors usually found?
Adrenal medulla or sympathetic ganglia
50
What are features of neuroblasomas
What is the morphology of neuroblastoma
How do they diagnose neuroblastomas
Features- spontaneous regression, develop into mature elements, usually sporadic
Morphology- small round blue neuroblasts, homer-wright rosettes, ganglioneuromas
Diagnose via catecholamines in blood/urine
51
What is Wilms Tumor
Pediatric kidney cancer
52
What is WAGR syndrome
What is the cause
Wilms tumor, aniridia (lack iris), genital anomalies, and mental retardation
Due to deletion of chrom 11q13 which encodes WT1 and PAX6
53
What is Denys-Drash syndrome
What is the cause
Genital dysgenesis and nephropathy
Mutant WT1 has dominate negative effect
54
What is Beckwith-Wiedemann syndrome
Hemihypertrophy (half of body is bigger than other half) and Wilms tumor
55
Explain the difference between manner of death and cause of death
Manner of death is the direct underlying physiological mechanism leading to death (natural, accidental, suicide, homicide, undetermined NASHU)
Cause of death is what leads to the manner of death
Ex. Cause- gunshot wound manner- hemorrhage
56
Define:
Livor mortis
Rigor mortis
Algor mortis
Livor mortis- blood collects in dependent parts of body
Rigor mortis- body stiffens
Algor mortis- body cools
57
Explain time of death:
<3 hours
3-8 hours
8-36 hours
>36 hours
<3 hours- body is warm and not stiff
3-8 hours- body is warm and stiff
8-36 hours- body is cool and stiff
>36 hours- body is cool and not stiff
58
Explain putrefactive decomposition
Putrefactive decomposition refers to the breakdown of the body by degradation of proteins and tissues with liquefaction of organs due to gut bacteria digesting material and releasing gas
Greenish patch in LLQ
59
What is adipocere formation
Epidermis dissolving in bodies found in water
60
What is mummification
Preservation of soft tissues in areas of low humidity
61
What is the role of the medical examiner in a forensic investigation
Assign a cause of death and opinion a manner of death; focus is not on natural causes
62
Ionizing radiation
1-2 Sv
2-10 Sv
10-20 Sv
>50 Sv
1-2 Sv- affects lymphocytes- granulocytopenia and lymphopenia
2-10 Sv- affects bone marrow- leukopenia, hemorrhage, hair loss
10-20 Sv- affects small bowel- diarrhea, fever, electrolyte imbalance
>50 Sv- affects the brain- convulsions, ataxia, and coma
63
What is the Wounding formula and explain it
W= E x 1/T x 1/A x K
E is nrg transferred; T is time of nrg transfer; A is area of transfer; K is modifying factors
Increase time or area results in dec wound
64
What is a contusion
What color is significant
Contusion is a bruise as a result of hemorrhage into soft tissue due to rupture of subcutaneous vessels; epidermis intact and thus no external bleeding
Yellow indicates the bruise is at least 18 hours old
65
What is an abrasion
What is a brush abrasion
What is a patterned abrasion
Abrasion is when epidermis is injured produced by friction scrapping away epidermis
Brush abrasion- due to grazing or sliding motion; inspection reveals rolls or heaps of tissue at margin of wound opposite in direction of force
Patterned abrasion- instrument that causes an injury leaves behind its appearance in the wound
66
What is a contact gunshot wound
What do they look like
Muzzle is pressed against the skin
Circular wound with blackened seared margins
67
What is an intermediate gunshot wound
has stippling (powder tattooing) on skin surrounding entry wound
68