infancy and childhood Flashcards
malformations are
primary errors of morphogenesis
intrinsically developmental process
disruptions result from
secondary destruction of an organ or body region that was previously normal in development
malformations are ___ but disruptions and deformations are ___
intrinsic; extrinsic
are disruptions heritable
no
deformation pathogenesis
localized or generalized compression of the growing fetus by abnormal bechanical forces –> structural abnormalities
most common cause of deformation
uterine constraint
maternal conditions of deformations
first pregnancy, small uterus, malformed uterus, leiomyomas
fetal conditions of deformations
multiple fetuses, oligohydramnios, abnormal fetal presentation
what is oligohydramnios
decreased amniotic fluid
sequnce can be caused by
maternal: chronic leakage of amniotic fluid from rupture of amnion
placental: uteroplacental insufficiency from maternal HT ir toxemia
fetal: renal agenesis
what is oligohydrambios sequence
fetal compression due to oligohydramnios
flattened faces, positional abnormalities of hands feet, hips may be dislocated, comprised growth of chest wall and lungs
what is malformation syndrome
presence of several defects that cannot be explained on basis of single localizing error in morphogenesis
often from single causative condition
agenesis
complete absence of an organ
aplasia
incomplete organ development
hypoplasia
underdevelopment of organ
atresia
absence of opening
types of perinatal infections
transcervical(ascending) and transplacental
how do you get transcervical infections
spread from cervicovaginal canal
acquired in utero or during birth
transplacental infections
gain access to fetal bloodstream by crossing placenta via chronionic villi
examples of transcervical infections
bacterial (strep) or viral (herpes) anf pneumonia, sepsis, meningitis
examples of transplacental infections
HBV HIV, parasitis (toxoplasma, malaria), viral, bacterial (listeria, treponema)
TORCH- toxoplasma, rubella, cytomegalovirus, herpes, other microbes
what happens with early transplacental (torch) infections
growth retardation, mental retardation, cataracts, congenital cardiac anomalies
what happens with late transplacental (torch) infections
tissue injury and inflammation
encephalitis, chorioretinitis, hepatospenomegaly, pneumonia, myocarditis
prematurity is when gestational age is
less than 37 weeks
major risk factors of prematurity
premature rupture of membranes, intrauterine infection leading to chorioamniotitis, structural abnormalities of uterus cervix placenta, multiple gestation
complication sof prematurity
RDS, NEC, sepsis, intraventricular and germinal matrix hemorrhage, long term sequelae
what are fetal factors
conditions that intrinsically reduce growth potential of fetus despite an adequate supply of nutrients from mother
what are placental factors
any factor that compromises the uteroplacental supply line
placenta previa
low implantation of placenta
placental abruption
seperation of placenta from decidua by retroplacental clot
growth retardation is symmetric when the cause is
intrinsic
growth retardation is asymmetric with
placental and maternal causes of growth restriction
maternal factors is the most common cause of
growth deficit in SGA infants
drugs causing fetal growth restriction
teratogens and non teratogenic afents
causes of respiratory distress in newborn
excessive sedation of mother,
fetal head injury in deliver
aspiration of blood or amniotic fluid
intrauterine hypoxia secondary to compression from coiling of umbilical cord on neck
RDS is the most common cause of
respiratory insufficiency because formation of membranes in peripheral air spaces
what happens in RDS
no surfactant
lungs not ready for exchange
in infants affected with RDS ___ is required
oxygen
necrotizing enterocolitis (NEC) is most commonanges in
premature infants
inflammatory mediators of NEC
platelet activating factors PAF
increasing mucosal permeability, promoting enterocute apoptosis, compromising intercellular tight jxns
NEC typically involves
terminal ileum, cecum, right colon
involved segment in NEC is typically
distended, friable, congested, frankly ganrenous
microscopic examination of NEC
mucosal or transmural coagulative necrosis ulceration bacterial coloniztion submucosal gas bubbles reparative changes
clinical course of NEC
bloody stools, abdominal distention and circulatory collapse
gas within abdominal walls
SIDS is leading cause of death in US infants ages
1month to 1 year
SIDS pathogenesis
multifactoral condition
triple risk
1.vulnerable infant: delayed development of arousal and cardiorespiratory
2. critical development period
3. one or more exogenous stressors
-prone sleeping, sleeping on soft surfaces, thermal stress
SIDS morphology
multiple petechiae
congested lungs
vascular engorgement with or w/o pulm edema
hypoplasia of arcuate nucleus or a subtle decrease in brain stem neuronal populations
most likely basis for SIDS is
delayed development in arousal reflexes and cardiorespiratory control
what is fetal hydrops
accumulation of edema fluid in fetus during intrauterine growth
immune hydrops
hemolytic anemia caused by Rh blood group incompatibility b/t mother and fetus
nonimmune hydrops is due to
successful pregnancy prophylaxis
fetal hydrops is usually lethal when the intrauterine fluid accumulation is
progressive, generalized edema of fetus
fetal hydrops is compatible with life when the intrauterine fluid accumulation is
more localized and less marked edema
immune hydrops results from
Ab induced hemolytic disease in newborn caused by blood group incompability between mom and fetus (ABO and Rh)
factors associated with SIDS
maternal smoking during pregnancy, drug abuse, low socioeconomic group, males, African Americans, prone position while sleeping, hyperthermia, sleeping with parents in 1st 3 months of life
most common cause of immune hemolytic disease of newborn
fetomaternal ABO incompatibility
major causes of nonimmune hydrops
cardiovascular defects
chromosomal anomalies- 45 X karyotupe, trisomy 21, trisomy 18
fetal anemia
what happens in fetal hydrops
tissue ischemia secondary myocardial dysfunction circulatory failure secondary liver failure hypoalbuminemia reduced plasma osmotic pressure edema
fluid accumulation in hydrops detalis is particularly prominent in
soft tissues in neck
transpalacental infection by ____ is increasingly recognied as an important cause of fetal hydrops
parvovirus B19
kernicterus is
hemolysis in Rh or ABO incompatibility –> increased circulating bilirubin from RBC breakdown
characteristic yellow hue to the parenchyma (
____ are prone to deposition of bilirubin pigment
basal ganglia and brainstem
what is heterotopia or choristoma
microscopically normal cells or tissue that are present in abnormal locations
hamartoma is
focal overgrowth of cells and tissues native to organ in which it occurs
hemangioma is most common
tumor of infancy
hemangioma is types
cavernous and capillary
hemangioma produces
flat to elevated, irregular, red blue masses, flat larger lesions
lymphangioma occurs on
skin also in deeper regions of neck, axilla, mediastinum, retroperitoneum
lymphangioma are histologically
benign
sacrococcygeal teratoma is most common
germ cell tumor of childhood
neuroblastoma are tumors of
sympathetic ganglia and adrenal medulla derived from primordial neural crest cells
neuroblastoma is second most common
solid malignancy of childhood after brain tumors
mutation of neuroblastoma
ALK
morphology of neuroblastoma
minute nodules to large masses
cut surface: soft, gray tan brain like tissue
ganglioneuroma arise from
spontaneous or therapy induced maturation of neuroblastomas
most important prognosis of neuroblastoma
stage of tumor and age of patient
neuroblastomas arise from
neural crest derived cells in sympathetic ganglia and adrenal medulla
homer wright pseudo rosettes are characteristic of
neuroblastomas
neuroblastomas secrete
catecholamines
retinoblastoma is most common
primary intraocular malignancy of children
familial cases of retinoblastoma are
multiple bilateral tumors
sporadic cases of retinoblastoma are
nonheritable and unilateral and unifocal
patients with familial retinoblastoma are at increased risk for
osteosarcoma
clinical features of retinoblastoma
poor vision, strabismus, whitish due to pupil, pain and tenderness in eye
most common sites of distant metastases of retinoblastoma
CNS skull distal bones lymp nodes
wilms tumor is most common
primary tumor of kidney in children
nephroblastoma
morphology of wilms tumor
blastemal component: sheets of small blue cells
epithelial differentiation: abortive tubules or glomeruli
stromal cells: fibrocytic, myxoid or skeletal muscle differentiation
complains of wilms tumor are related to
tumor size
clinical of wilms tumor
palpable abdominal mass and fever and abdominal pain
