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What is malformation

Intrinsic disturbance in morphogenesis


What is disruption and what is an example

Extrinsic disturbance in morphogenesis causing secondary damage in developmentally normal tissue

Amniotic band


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


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


What is a syndrome

A syndrome is a combination of anomalies usually as a result of a single pathology that affects many tissues


What is:

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


What are the 2 general causes of anomalies (broad categories)

Genetic causes
Environmental causes


What are the genetic causes of anomalies and give an example of one

Chromosomal abnormalities
Single gene mutations (mutation in hedgehog results in holoprosencephaly)


What are the 3 environmental causes of anomalies

Maternal Diabetes


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


Explain alcohol with regards to anomalies and explain the major example

Fetal alcohol syndrome is associated with growth retardation, microcephaly, maxillary hypoplasia, and ASD


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


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


What is the definition of premature

Gestational age less than 37 weeks aka preterm


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



What is fetal growth restriction

Small for gestational age (bottom 10%)


What are the 3 general classes of abnormalities that contribute to fetal growth restriction

Fetal, placental, and maternal abnormalties


Explain fetal abnormalities with regards to fetal growth restriction

Fetal abnormalities cause symmetric growth restriction
Causes include chromosomal abnormalities, congenital anomalies, and ToRCH infections


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


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


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


Explain the pathogenesis of RDS with regards to:
-mutant genes
-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


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


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


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


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


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


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


Explain infantile sepsis; early vs late onset

Earl onset- first 7 days- usually by group B strep
Late onset- 7 days to 3 months


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


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


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


Explain causes of non-immune hydrops

CV defects
Chrom abnormalities- Turner syndrome
Fetal anemia (homozygous alpha-thalassemia or parovirus B19)


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


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


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


What is CFTR and what are its functions

CFTR is a chloride channel that also regulates other ion channels such as ENaC and SLC26


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


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


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


What is the morphology of CF:
-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


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


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


What is the morphology of SIDS

Petechiae- thymus, pleura, and epicardium
Arcuate nucleus hypoplasia
Evidence of upper resp tract infection


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


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


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


Where are infantile teratomas usually found; are they usually benign or malignant

Infantile teratomas are found in the sacrococcygeal region and are usually benign


Where are neuroblastic tumors usually found?

Adrenal medulla or sympathetic ganglia


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


What is Wilms Tumor

Pediatric kidney cancer


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


What is Denys-Drash syndrome
What is the cause

Genital dysgenesis and nephropathy
Mutant WT1 has dominate negative effect


What is Beckwith-Wiedemann syndrome

Hemihypertrophy (half of body is bigger than other half) and Wilms tumor


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


Livor mortis
Rigor mortis
Algor mortis

Livor mortis- blood collects in dependent parts of body
Rigor mortis- body stiffens
Algor mortis- body cools


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


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


What is adipocere formation

Epidermis dissolving in bodies found in water


What is mummification

Preservation of soft tissues in areas of low humidity


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


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


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


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


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


What is a contact gunshot wound
What do they look like

Muzzle is pressed against the skin
Circular wound with blackened seared margins


What is an intermediate gunshot wound

has stippling (powder tattooing) on skin surrounding entry wound


Explain entry and exit head gunshot wounds

Entry- outer table sharply circumscribed and inner table beveled

Exit- outer table beveled and inner table sharply circumscribed