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50 Cards in this Set
- Front
- Back
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What are some important points about the embryology of the skeletal system?
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Origin: neural crest --> mesoderm --> mesenchyme--> skeletal system
----- 4th week= buds form the limbs ----- Vertebra derive from Sclerotome compartments of the somites ---- Ribs + sternum derive from paraxial mesoderm --- mesenchyme cells are directly made into osteoblast |
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What are some important points about the embryology of the muscular system?
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muscles derive from mesoderm
-------- somites= axial muscles somitomeres= muscles of the head -------- epimere= form vertebral extensors hypomere= limb + body wall muscles -------- Somites, somatic mesoderm= connective tissue vs. neural crest= head connective tissue -------- splanchnic mesoderm= smooth muscle + cardiac muscle --------VS----- ectoderm= pupil smooth muscle + mammary gland + sweat glands |
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From what embryonic origin is the Diaphragm derived from?
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1. septum transversum (also liver/gallbladder)
2. pleuroperitoneal membranes 3. dorsal mesentary of the esophagus 4. muscular components of the abdominal wall -------- Left side congenital defects on pleuroperitoneal membrane => herniated bowels on left side of thorax |
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What does the PleuroPERICARDIAL membrane separate during cavity development?
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1. pericardial cavity
2. pleural cavity => lungs |
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The mesenteries (double peritoneum) suspend the gut tube and provide what?
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pathway for vessels, nerves, lymphatics
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What are some body wall defects and their cause?
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Thorax:
-Ectopic Cordis=> failure of the cephalic and lateral folds to progress and close=> heart pops out through sternum ----- Abdomen: -Oophalocele: 6th to 10th week: bowls fail to return to body cavity after physiological herniation=> covered by amnion= chromosomal defects present -Gastroschisis: herniation(Right side) of bowls after they were already inside= not covered by amnion=> amniotic fluid damages bowels= maternal cocaine use **both Oophalocele + gastroschisis= high levels of alpha-feto protein |
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If the small muscular fibers of the diaphragm fail to develop what can result?
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Parasternal hernia= small bowels herniate into thoracic cavity= assymptomatic
----VS---- esophageal hernia= congenital shortness of the esophagus= pulls stomach up |
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Why are cranio-abnormalities common birth defects?
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Neuroectoderm=> seeds off neural crest cells=> migrate and form facial skeleton=> huge target for teratogens @ 3rd to 8th week= organogenesis
---- Teratogens= -ACEi=> renal damage -Cocaine=> gastroschisis/addiction -DES=> clear cell adenocarcinoma=vagina -Iodide=> goiter/hypothyroidism -Retinoic Acid -Thalidomide=>Rx for sleeping pill/AIDS=> flipper limbs -Tobacco= ADHD, preterm, |
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Why does anencephaly result when the cranial NEUROPORE fails to close?
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Amniotic fluid degenerates brain tissue that seeps in from amniotic sac
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What is a AD genetic skeletal defect that includes the LONG bones?
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Achondroplasia= affects mid-face area => the problem is in the FGF receptors the stimulate growth of bones
---- limbs are smaller than trunk and with a large head |
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What is associated with short digits, Didelphic uterus and hypospadias?
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hand-foot-genital syndrome= HOX genes
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What is associated with breech posture during delivery in a female which results in laxity of the hip joint?
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Congenital Hip Dislocation=> underdevelopment of the acetabulum + head of femur => females have higher risk
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How is Spina Bifida Occulta different from Spina Bifida Cystica?
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Occulta= failure of vertebral arches to fuse= SC is ok
------ Cystica= failure of the vertebral arches, neural tube to close=> SC is exposed= elevated levels of alpha-fetoprotein ***prevention with FOLIC ACID |
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When you can see through the abdominal wall in a newborn what is the problem?
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No abdominal muscles formed=> also has urinary tract and bladder problems
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What two septums must fuse in order for the foramen ovale to close after the atrial pressure on the LEFT side > RIGHT?
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Septum Secundum + Septum Primum
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The great vessels develop only if the CONOTRUNCAL SEPTUM (which divided the aortic/pulmonary channels) comes in contact with?
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the membranous portion of the interventricular septum
*** most common site of patency |
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What does retinoic Acid target early in the pregnancy and what is the effect of its teratogenicity?
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targets Neural Crest Cells (ectoderm origin) which develop the bones in the face + part of the Conotruncal septum
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What tissue is important in developing the four chambers of the heart?
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Endocardial cushions => also form the pulmonary and aortic channels via the conotruncal septum which spirals to seperate them
----- they form= membranous part of the interventricular septum + form the AV valves, and close off the Atrial septum + ventricular septum |
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How can defects the development of the vasculature cause an inability to swallow?
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Vascular components fail to regress:
-Right Dorsal Aorta= wraps around esophagus -Right Aortic Arch= leaves ligamentum arteriosum on the left which wrapps around the esophagus |
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Where does the entire cardiovascular system derive from?
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Mesoderm = 4th week the heart the endocardial tube creates the four chambers of the heart=> spetum formation arises from endocardial cushions
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What do the Vitelline arteries initially supply and then later?
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1. Yolk Sac --> change into Celiac/SMA/IMA
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What part of the Iliac Arteries regress after birth?
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Distal --> form the medial umbilical ligaments
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Which parts of the venous system regress after birth?
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1. Vitelline System=> portal system
2. Cardinal System ==> IVC/SVC 3. Umbilical system== REGRESS |
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From where does the Thoracic duct develop?
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Right and left thoracic duct
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How does Dextrocardia develop?
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instead of the heart looping to the right it loops to the LEFT
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What is the most common atrial septal defect?
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ostium secundum
----VS--- Premature closure of the Foramen ovale => R Atrium/ventricle hypertrophy=> death at birth |
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What happens when the tricuspids are fused?
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Right ventricle is very small and right atrium is hypertrophied => persistent foramen ovale=> Left atrium/ventricle hypertrophy
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When the Conotruncal ridges fail to move down to the ventricles what can happen?
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Persistant truncus arteriosus + interventricular septal defects
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When the Conotruncal septum fails to spiral and just runs straight down what is the result?
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Transposition of the great vessels
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What are the remnants of normal embryological vasculature?
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-Ductus Arteriosus=> Ligamentum arteriosus
-Umbilical Arteries=> Medial umbilical ligaments ---------------- -Umbilical VEIN= Ligamentum teres hepatitis |
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What accounts for the increase in lung growth AFTER birth?
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Number of respiratory bronchioles + aveoli but NOT size of alveoli
------ Type 1: blood/lymph capillaries Type 2: surfactant ---- esophagotracheal septum seperates the trachea from the foregut |
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What is associated with esophageal atresia with fistulas?
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VACTERL=> polyhydraminos
V= vertebral anomalies A= Anal atresia C: cardiac defects T: Tracheoesophageal fistula => pneumonia L: limb defects |
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Origin of the Digestive System is?
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Endoderm but the peritoneal components such as the muscles, connective tissues = MESOderm
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What derives from the endodermal epithelium of the upper part of the duodenum?
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Liver, pancreas, biliary apparatus
------ liver + biliary apparatus= grow out via the Septum Transversum --- Origin of hematopoietic cells, Kupffer cells, connective tissue in LIVER originate from MESOderm |
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When does the MIDGUT physiologically herniate and when does it return back?
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Out: 4th week
Returns: 10th week -------- Rotation: CCW= 270* |
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Where does the Allantois enter?
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the future Urogenital Sinus
---VS---- hindgut= cloaca= future anal hole |
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What is the temporal order of the Urogenital System?
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Pronephros (C region) --> Mesonephros(T/L) --> MeTenephros(pelvic)
--------- Mesenephros= early kidney + connenct the wolffian ducts=> later the SEEV coarse of sperm -------- Metanephros= permanent kidney |
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What is the origin of the Kidney's nephron, ureter, renal pelvis, calyces, collecting system?
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Ureteric Bud (which pops out from mesonephros)
------ touches the meTanephric blastema and induce it to grow=makes GLOMERULUS + RENAL TUBULES |
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What does the Y chromosome produce that can make
1. gonads 2. genital ducts 3. external genitalia ...male? |
Y => SRY=> TDF ==> make these changes:
1. testis cords develop 2. tunica albuginea develops 3. ovarian cords regress ------ No SRY= female phenotype ----- premoridal germ cells must get to the indifferent gonads otherwise absent gonads |
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What influences the indifferent duct sytem + external genitalia to develop?
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Males: testosterone from Leydig cells
-----VS---- Sertoli cells from the testes=> MIF = block regress the Paramesonephric duct ------ External genitalia = DHT = males: penis, scrotum, PROSTATE ---------VS----------- ESTROGEN=females=paramesonephricducts(uterine tube/uterus/upper vagina) + external genitalia |
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Inability of the fetus to produce hormones (Testosterone/DHT/Estrogen) become females because?
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Maternal hormones + Placental hormones influence=> females
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What is the difference between Male and Female Pseudohermaphrodites?
**chromosomal sex is ok |
Female= absence in 21-hydroxylation => increase androgens from a lack of cortisol ==> external male genitalia
------VS----- Male=low androgens or no MIS= variable external but internal female genitalia ----VS----- Androgen Insensitivity Syndrome= cannot respond to Androgen(bad receptors) BUT MIS is present so patients do have testes(undescended=malignancy) + external female genitalia |
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What is the possible reason why neural crest cells migrating to form the head are susceptible to teratogens: alcohol + Vit A toxcity?
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they do not have catalase or SOD= free radical damage
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What is the mutation in Hirschsprung's Disease?
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RET gene= no Tyrosine Kinase Receptor=> no development of the PNS=> neural crest cells fail to migrate because there is no GDNF=> leads to MEGACOLON
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What infections in the brain can result in Hydrocephalus?
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CMV or Toxoplasmosis => location more common is the cerebral aqueduct
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Which muscle is innervated by the Superior Laryngeal Nerve (CN X)?
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cricothyroid muscle => tenses the vocal cords
------ The rest of the pharyngeal muscles are innervated by the Recurrent Laryngeal Nerve also from CN X ------ -Superior Laryngeal Nerve=pharynx = swallow=>Arch 4= cricothyroid muscle -Recurrent Laryngeal Nerve=larynx=sing= Arch 6= not cricothyroid muscle |
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When do you get 2 amniotic sacs in fetal development?
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-Before Day 8
----------- After day 3 you get 2 placenta ----------- so between day 3 and 8 you can get 2 amniotic sacs, 2 placentas |
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Trisomy 18=
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born dead with CLENCHED fists
-----VS--- Trisomy 21= #1 overall is Duodenal atresia but with heart problems: #1 heart defect= ASD #2 heart defect= VSD **remember low alpha-feto protein but high B-hCG and Nuchal Translucency |
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What are the causes of LATE cyanosis?
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1. ASD= fixed A2P2
2. VSD= rubella=holosystolic murmur 3. PDA= rubella=machine gun murmer ******** Rubella= congenital deafness= destroys Organ of Corti = inner ear (destruction of the otic vesicle |
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What kind of resulting problems derive from Oomphalacele vs. Gastroschisis?
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Gastroschisis= bowel ischemia
------- Oomphalacele= cardiac abnormalities=death |
