Term
| What are the three mesodermal germ layers of the trilaminar germ disc? |
|
Definition
| Paraxial, intermediate, and lateral plate mesoderm |
|
|
Term
| When does mesoderm differentiate into its three germ layers? |
|
Definition
|
|
Term
| When does the respiratory diverticulum (lung bud) appear in embryonic development? |
|
Definition
|
|
Term
| Tracheoesophageal ridges fuse to form what? |
|
Definition
|
|
Term
| What does the tracheoesophageal septum separate? |
|
Definition
| Dorsal esophagus from the ventral trachea |
|
|
Term
| What maintains communication between the esophagus and the pharynx? |
|
Definition
|
|
Term
| What defect is known as esophageal atresia? |
|
Definition
| Upper part of esophagus remains a blind pouch with the lower segment forms a fistula with the trachea |
|
|
Term
| What are some possible complications of the formation of a tracheoesophageal fistula? |
|
Definition
| Pneumonia, polyhydramnios |
|
|
Term
| Cartilage and muscles of the larynx originate from what embryonic structures? |
|
Definition
| Mesenchyme of the fourth and sixth pharyngeal arches |
|
|
Term
| The intrinsic muscles of the larynx are controlled by what nerve? |
|
Definition
|
|
Term
| The trachea is formed from what embryonic structure? |
|
Definition
|
|
Term
| Where does the respiratory portion of the bronchial tree begin? |
|
Definition
| Respiratory bronchioles which divide into alveolar ducts |
|
|
Term
| What doe alveolar ducts divide into? |
|
Definition
|
|
Term
| What are the two types of cells found in alveolar squamous epithelium? |
|
Definition
|
|
Term
| Flattened cells with attenuated cytoplasm that form 90% of the surface lining of alveoli are known as what? |
|
Definition
|
|
Term
| Rounded cells commonly located in obtuse angles of alveoli that are surfactant secreting cells are known as what? |
|
Definition
|
|
Term
| When do terminal sacs/primitive alveoli first develop? |
|
Definition
|
|
Term
| What must be developed in order to allow for the possibility of postnatal survival with intensive care? |
|
Definition
| Terminal sacs/primitive alveoli |
|
|
Term
| What fraction of adult alveoli are present at birth? |
|
Definition
|
|
Term
| What partitions the pleural cavities form the rest of the intraembryonic coelom? |
|
Definition
| Pleuropericardial membranes, Pleuroperitoneal folds |
|
|
Term
| What forms visceral pleura covering the outside of the lung? |
|
Definition
|
|
Term
| What innervates the visceral pleura? |
|
Definition
| GVA fibers from the pumlmonary plexus, is insensitive to pain |
|
|
Term
| What forms parietal pleura covering the inside of the body wall? |
|
Definition
|
|
Term
| What innervates the parietal pleura? |
|
Definition
| GSA fibers from intercostal nerves, very sensitive to pain |
|
|
Term
| The potential space between the visceral plerua and the parietal pleura is known as what? |
|
Definition
|
|
Term
| Normal development of the lung is dependant on what? |
|
Definition
| Presence of fluid in the lung, fetal breathing moments, adequate amniotic fluid volume |
|
|
Term
| What are the sources of fluid in the lungs? |
|
Definition
| Secreted within the lung, some aspirated as amniotic fluid |
|
|
Term
| How is fetal breathing employed in the development of the lung? |
|
Definition
| Aspirating amniotic fluid and for conditioning respiratory muscles |
|
|
Term
| How does adequate amniotic fluid volume impact lung development? |
|
Definition
| Creates adequate space in the thoracic cavity for lung growth |
|
|
Term
| At birth, the lung is about half full of fluid. What routes clears the lung of fluid after birth? |
|
Definition
| Pressure on the fetal thorax during birth expels some of the fluid via the nose and mouth, resorption into respiratory capillaries, resorption into lymphatic vessels |
|
|
Term
| Insufficient synthesis of surfactant by type II alveolar cells (type 2 pneumocytes) is known as what disease? |
|
Definition
| Respiratory distress syndrome (hyaline membrane disease) |
|
|
Term
| What are the effects of respiratory distress syndrome? |
|
Definition
| Increased surface tension results in collapsed alveoli, may lead to fetal death |
|
|
Term
| How is respiratory distress syndrome treated? |
|
Definition
| Artifical surfactant or corticosteroid therapy |
|
|
Term
| Hypoplastic lung may be caused by what? |
|
Definition
| Oligohydramnios (prevents thoracic cavity expansion), congenital diaphragmatic hernia |
|
|
Term
| What incorpates the yolk sac into the primitive gut? |
|
Definition
| Cephalocaudal (longitudinal) and lateral (transverse) folding |
|
|
Term
| Where does the foregut of the primitive gut begin? |
|
Definition
| Buccopharyngeal (oropharyngeal) membrane |
|
|
Term
| What connects the midgut to the yolk sac? |
|
Definition
|
|
Term
| Where does the hindgut end in the primitive gut? |
|
Definition
|
|
Term
| What are the boundaries of the pharyngeal gut? |
|
Definition
| Buccopharyngeal membrane to the respiratory diverticulum (lung bud), forms head and neck portion of the foregut |
|
|
Term
| The foregut, apart from the pharyngeal gut, extends between what developing structures? |
|
Definition
| Respiratory diverticulum and the liver bud |
|
|
Term
| What are the boundaries of the developing midgut? |
|
Definition
| From just distal to the liver blood to the junction of the right 2/3 and left 1/3 of the transverse colon (left colic flexure) |
|
|
Term
| What are the boundaries of the hindgut? |
|
Definition
| Distal 1/3 of the transverse colon to the cloacal membrane |
|
|
Term
| What two tissues form the primitive gut? |
|
Definition
| Endoderm and splanchnic mesoderm |
|
|
Term
| The endoderm gives rise to what structures of the gut? |
|
Definition
| Epithelial lining of the gut, gives rise to parenchyma of glands (liver, pancreas, etc.) |
|
|
Term
| Splanchnic mesoderm gives rise to what structures in the gut? |
|
Definition
| Smooth muscle and connective tissue, visceral peritoneum of the gut wall |
|
|
Term
| Double layers of peritoneum that suspend portions of the gut tube from the gut wall are known as what? |
|
Definition
|
|
Term
| By when are foregut, midgut, and hindgut portions of the gut suspended from the posterior abdominal wall by the dorsal mesentary? |
|
Definition
|
|
Term
| What are the divisions of the dorsal mesentary? |
|
Definition
| Dorsal mesogastrium (greater omentum), dorsal mesoduodenum, mesentary proper, dorsal mesocolon |
|
|
Term
| The ventral mesentary develops into what structures? |
|
Definition
| Falciform ligament and lesser omentum by division of the septum transversum |
|
|
Term
| The remnant of the umbilical vein can be found in what structure? |
|
Definition
|
|
Term
| Incomplete recanalization of the esophagus following an epithelial proliferation phase leads to what dysfunction? |
|
Definition
|
|
Term
| A congenitally short esophagus pulling the stomach up through the esophageal hiatus is known as what abnomality? |
|
Definition
|
|
Term
| How does the primitive stomach rotate about its longitudinal axis during development? |
|
Definition
| 90 degrees clockwise, original left side ends up facing anteriorly |
|
|
Term
How does the primitive stomach rotate about its anteroposterior axis during development?
|
|
Definition
| 90 degrees, causing the lesser curvature to face upwards and the greater curvature to face downward and to the left |
|
|
Term
| Rotation of the primitive stomach creates what abdominal space? How? |
|
Definition
| Omental bursa behind the stomach and lesser omentum by pulling the dorsal mesogastrium to the left |
|
|
Term
| What anomaly is characterized by hypertrophy of the smooth muscles of the pyloric sphincter, leading to polyhydramnios and blockage of food passage into the duodenum? |
|
Definition
| Congenital pyloric stenosis |
|
|
Term
| Duodenal stenosis or atresia is caused by what? |
|
Definition
| Incomplete recanalization of the duodenum |
|
|
Term
| A "double bubble" ultrasound scan in the gut, polyhydramnios, and bile stained vomit shortly after birth are all signs indicating what dysfunction? |
|
Definition
| Duodenal stenosis or atresia |
|
|
Term
| The hepatic diverticulum begins as an endodermal poliferation on what other structure? |
|
Definition
| Middle of the descending duodenum |
|
|
Term
| What gives rise to the cystic duct, bile duct, and gallbladder? |
|
Definition
| Small ventral outgrowth on the hepatic diverticulum |
|
|
Term
| The hepatic diverticulum is closely related to what other endodermal poliferation? |
|
Definition
|
|
Term
| The connective tissue framework of the liver (stroma) are formed from what? |
|
Definition
| Mesoderm of the septum transversum |
|
|
Term
| What is an essential developmental function performed by the liver between week 6 to the 6th month of gestation? |
|
Definition
| Hematopoietic, colonized by hematopoietic cells from the aorta-gonad-mesonephros region |
|
|
Term
| When does bile excretion begin? |
|
Definition
|
|
Term
| What structures form the pancreas? |
|
Definition
| Dorsal pancreatic bud in the dorsal mesentary and ventral pancreatic bud that develops near the bile duct |
|
|
Term
| The ventral pancreatic bud forms which structures? |
|
Definition
| Uncinate process and inferior part of the head of the pancreas, dorsal pancreatic bud forms the rest of the gland |
|
|
Term
| The main pancreatic duct develops from what? |
|
Definition
| Distal portion of the dorsal pancreatic duct and the entire ventral pancreatic duct |
|
|
Term
| The accessory pancreatic duct forms from what structure? |
|
Definition
| Proximal part of the dorsal pancreatic duct |
|
|
Term
| Failure of the hepatic or bile duct to recanalize following a phase of epithelial proliferation is known as what defect? |
|
Definition
| Extrahepatic biliary atresia |
|
|
Term
| What condition refers to two components of the ventral pancreas bud migrating in opposite directions to encircle and possibly obstruct the duodenum? |
|
Definition
|
|
Term
| The primary intestinal loop of the midgut forms what structures? |
|
Definition
|
|
Term
| The cephalic limb of the midgut forms what structures? |
|
Definition
| Distal duodenum, jejunum, part of the ileum |
|
|
Term
| The caudal limb of the midgut forms what structures? |
|
Definition
| Lower ileum, cecum, appendix, ascending colon, 2/3 of the transverse colon |
|
|
Term
| Rapid growth of the liver that causes intestinal loops to enter the umbilical cord is known as what? |
|
Definition
| Physiological umbilical herniation |
|
|
Term
| What occurs concurrently with physiological umbilical herniation? |
|
Definition
| Primary intestinal loop rotates around the superior mesenteric artery a total of 270 degrees counterclockwise |
|
|
Term
| When do intestinal loops return to the enlarged abdominal cavity? |
|
Definition
|
|
Term
| What develops as the cecum bud of the colon descends from the upper right quadrant to the right lower quadrant? |
|
Definition
|
|
Term
| What occurs when the ascending and descending colons reach their final positions? |
|
Definition
| Mesentaries fuse with the peritoneum of the posterior abdominal wall, making the organs secondarily retroperitoneal |
|
|
Term
| What are the divisions of the cloaca? |
|
Definition
| Anterior urogenital sinus and posterior anorectal canal |
|
|
Term
| What forms the segments of the cloaca? |
|
Definition
| Mesodermal urorectal septum |
|
|
Term
| What is the origin of the caudal part of the anal canal below the pectinate line? |
|
Definition
|
|
Term
| Failure of recanalization of the lower portion of the anal canal following epithelial proliferation is known as what? |
|
Definition
|
|
Term
| When the opening of the hindgut shifts anteriorly, the defect is known as what? |
|
Definition
| Urorectal or rectovaginal fistula |
|
|
Term
| Absence of autonomic parasympathetic ganglia from a segment of the intestines is known as what? |
|
Definition
| Congenital megacolon or Hirschprung's disease |
|
|
Term
| The 5 paired structures arising from the aortic sac (the most distal portion of the truncus arteriosus) is known as what? |
|
Definition
|
|
Term
| The aortic arches are embedded in what? |
|
Definition
| Mesenchyme of the pharyngeal arches |
|
|
Term
| By forming right and left horns, the aortic sac gives rise tow hat structures? |
|
Definition
| Brachiocephalic artery and proximal (ascending) segment of the aorta |
|
|
Term
| The third aortic arch gives rise to what? |
|
Definition
| Common carotid, first part of internal carotid arteries, external carotid |
|
|
Term
| The fourth aortic arch gives rise to what? |
|
Definition
| Arch of the aorta on the left, proximal segment of righ subclavian artery on the right |
|
|
Term
| The fifth aortic arch gives rise to what? |
|
Definition
| Nuthin, SUCKA! It don't form good often |
|
|
Term
| The sixth aortic arch gives rise to what? |
|
Definition
| Proximal right pulmonary artery on the right, proximal segment of left pulmonary artery and ductus arteriosus on the left |
|
|
Term
| The ductus arteriosus closes shortly after birth and becomes what? |
|
Definition
|
|
Term
| Failure of ductus arteriosus to close is known as what? |
|
Definition
|
|
Term
| A patent ductus arteriosus leads to what? |
|
Definition
|
|
Term
| What kind of coarctation of the aorta is not fatal until age 50 which is when it requires surgical correction |
|
Definition
| Postductal coarctation (vs preductal coarctation which must be corrected in infancy) |
|
|
Term
| When the right dorsal aorta persists, what abnormality forms? |
|
Definition
| Double aortic arch which a vascular ring forms around the trachea and esophagus, can cause difficulty breathing and swallowing |
|
|
Term
| The vitelline arteries eventually fuse to create what? |
|
Definition
| Celiac, superior mesentary, and inferior mesentary arteries |
|
|
Term
| Umbilical arteries persist after birth as what? |
|
Definition
| Internal iliac and umbilical arteries |
|
|
Term
| What are the three major pairs of veins in the 5 week embryo? |
|
Definition
| Vitelline, umbilical veins, cardinal veins |
|
|
Term
| The vitelline vein forms what? |
|
Definition
| Hepatocardiac portion of the inferior vena cava, superior mesenteric vein |
|
|
Term
| The ductus venosus shunts most of the oxygenated blood from the placenta past the liver into where? |
|
Definition
| The heart for distribution to the rest of the body |
|
|
Term
| After birth, the left umbilical vein and ductus venosus are obliterated and form what? |
|
Definition
| Ligamentum teres hepatis, ligamentum venosum |
|
|
Term
| Supracardinal veins eventually form what structures? |
|
Definition
|
|
Term
| The right anterior cardinal and common cardinal veins form what? |
|
Definition
|
|
Term
| The anastomosis between the anterior cardinal veins develops into what? |
|
Definition
| Left brachiocephalic vein |
|
|
Term
| The terminal portion of the left posterior cardinal veins form the left superior intercostal vein |
|
Definition
|
|
Term
| The right sacrocardinal vein forms what? |
|
Definition
| Sacrocardinal segment of inferior vena cava |
|
|
Term
| The inferior vena cava has segments that derive from what structures? |
|
Definition
| Vitelline, subcardinal, sacrocardinal veins |
|
|
Term
| Blood islands develop from what? |
|
Definition
| Mesenchymal cells in splanchnic mesoderm |
|
|
Term
| When do blood islands form? |
|
Definition
|
|
Term
| What do blood islands eventually form? |
|
Definition
| Forms a horseshoe shaped plexus that eventually becomes endocardial tubes |
|
|
Term
| The cephalic central portion of blood island plexuses in front of the buccopharyngeal membrane is known as what? |
|
Definition
|
|
Term
| How does the cardiogenic area and buccopharyngeal membrane move together during development? |
|
Definition
| Pushed ventrally and caudally and rotated 180 degrees |
|
|
Term
| How is the heart tube formed? |
|
Definition
| Lateral folding of the trilaminar germ disc fuses two lateral endothelial tubes |
|
|
Term
| What initially separates the epimyocardial mantle from the endothelial heart tube? |
|
Definition
|
|
Term
| What are the three layers formed by the heart tube? |
|
Definition
| Endocardium, myocardium, epicardium |
|
|
Term
| The future bulboventricular region of the heart arises from what? |
|
Definition
| Intrapericardial part of the heart tube |
|
|
Term
| The bulbus cordis contributes to what? |
|
Definition
| 1/3 to right ventricle, 1/3 to outflow tracks for the ventricles, proximal portions of the aorta and pulmonary trunk |
|
|
Term
| The cephalad portion of the heart tube bends in what direction? |
|
Definition
| Ventrally and caudally to the right |
|
|
Term
| The caudal portion of the heart tube bends in what direction? |
|
Definition
| Dorsocranially and to the left |
|
|
Term
| When is the cardiac loop finished? |
|
Definition
|
|
Term
| The left sinus horn gives rise to what structures? |
|
Definition
| Oblique vein of the left atrium, coronary sinus |
|
|
Term
| The right sinus horn becomes encorporated into what structure? |
|
Definition
| Smooth wall of right atrium |
|
|
Term
| What is the temporary opening between the septum primum and the endocardial cushions |
|
Definition
|
|
Term
| The second crescent shaped fold that appears to the right of the septum primum that leaves the opening for the foramen ovale is known as what? |
|
Definition
|
|
Term
| What is incorporated into the left atrium to form its smooth walled section? |
|
Definition
| Pulmonary vein and its tributaries |
|
|
Term
| If the oval foramen persists, what kind of blood shunting occurs? |
|
Definition
| Left to right atrial shunting of blood |
|
|
Term
| Closure of the foramen ovale during fetal life causes what? |
|
Definition
| Hypertrophy of the right side of the heart, underdeveloped left heart, death |
|
|
Term
| What causes a common atrium? |
|
Definition
| Complete absence of atrial septum |
|
|
Term
| What connects tricuspid and bicuspid valve cusps to papillary muscles? |
|
Definition
|
|
Term
| Unequal division of the truncus arteriosus may result in Tetralogy of Fallot which is characterized by what? |
|
Definition
| Pulmonary stenosis, right ventricular hypertrophy, ventricular septal defect, overriding aorta, results in left to right shunt with cyanosis |
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|
