Final Exam 2 Flashcards
What is the embryonic origin of the mesoduodenum?
Dorsal mesentery
The intraembryonic coelom forms where?
between somatic and splanchnic mesoderm
Which feature do the parietal pleura, parietal pericardium and parietal peritoneum share in common?
derive from somatic mesoderm
Which structure does not contribute to diaphragm development?
pleuropericardial folds
Delayed/failed closure by which structure typically accounts for diaphragmatic hernia formation?
pleuroperitoneal membranes
An organ that develops in the peritoneal cavity and is then displaced outside of the parietal peritoneum is referred to as?
secondary retroperitoneal
Which two chick embryo “extraembryonic” membranes derive from somatopleure?
amnion and chorion
Which term best describes the human placenta?
hemochorial
The maternal portion of the placenta develops in which area?
decidua basalis
Which extraembryonic membrane actually covers the umbilical cord?
amnion
The somatopleure is a membrane comprised of which two tissues?
ectoderm and somatic mesoderm
The placental barrier “thins” during gestation to improve exchange. How does this occur?
loss of mesenchyme and cytotrophoblast within the placental villi
What is the primary source of amniotic fluid after 12 weeks of gestation?
fetal urine production
Where does the allantois originate?
embryonic endoderm
Why is the allantois important?
umbilical cord blood vessel formation
Which layer disappears during gestation?
decidua capsularis
Based on amnion/chorian arrangement, which situation would most likely produce conjoined twins?
monochorionic, monoamniotic twins
Splitting of the embryo at the inner cell mass stage would result in which membrane arrangement?
monochorionic, diamniotic twins
Differentiation of mesoderm-derived angioblasts into endothelial cells is an example of which process?
vasculogenesis
Where is the first site of intraembryonic blood cell formation?
AGM (aorta-genial-mesonephric region)
The “fetal” hemoglobin contains which two pairs of globin molecules?
2 alpha, 2 gamma
Which cell is the immediate precursor to erythrocytes?
reticulocyte
The Rh-incompatibility syndrome (hemolytic disease of the newborn) occurs when?
Rh- mother has a Rh+ fetus
What is the source of the mesothelium that makes up the parietal pericardium?
lateral somatic mesoderm
What is the source of the mesothelium that makes up the visceral pericardium?
proepicardial primordium
The mesenchyme of the pleuropericardial folds gives rise to which layer?
fibrous pericardium
The smooth part of the definitive left atrium derives from which structure?
pulmonary veins
The sinus venarium derives from which structure?
right sinus venosus
The coronary sinus predominately derives from which structure?
left sinus venosus
The crista terminalis marks the separation between which two structures?
primitive and definitive right atrium
Where would you expect to find the “moderator band”?
right ventricle
Atrial septation and foramen ovale formation requires closure of which passageway?
osteum primum
Atrial septal and membranous interventricular septal defects could occur due to failed development where?
endocardial cushion
The definitive right ventricle derives primarily from which are of the embryonic heart tube?
bulbus cordis
Which fetal shunt directs blood from the pulmonary trunk to the aorta?
ductus arteriosus
A majority of the blood in the fetal left atrium enters from which source?
right atrium
The definitive left ventricle derives primarily from which area of the embryonic heart tube?
primitive ventricle
What is the source of the cardiac endothelium and myocardium?
lateral splanchnic mesoderm
The ventricular papillary muscles derive from which source?
myocardium
Which cells are essential to artrioventricular valve development?
epicardial cells &
endothelial derived endocardial cushion cells
What is the origin of the left subclavian artery?
left 7th intersegmental artery
Which structure derives from or is contributed to by the 3rd aortic arch?
common carotid arteries
Which structure derives from or is contributed to by the left 6th aortic arch?
ductus arteriosus
Which structure derives from or is contributed to by the right 4th aortic arch?
right subclavian
The brachiocephalic artery primarily derives from which structure?
aortic sac
The yolk stalk (and therefore the mindgut) is most closely associated with which artery?
superior mesenteric
A lateral anastomosis of the first 6 cervical intersegmental arteries is the basis for which major adult artery?
vertebral
Relative to the paired dorsal aortas, how are the syndromes of double aortic arch and right aortic arch similar?
the right dorsal aorta is retained in both
Which cardiac defect always accompanies failed conotruncal septation?
interventricular septal defect
The cardiac malformation “transposition of the great vessels” primarily reflects failed development in the?
conotruncus
The definitive adrenal and gonadal arteries derive from?
lateral intersegmental arteries
List four primary defects characterizing Tetralogy of Fallot
pulmonary trunk stenosis
rightward displacement of aorta
ventricular septal defect
right ventricular hypertrophy
List the four mechanisms that can explain atrial septal defects (ASDs)
osteum secundum defects
osteum primum defects
sinus venosus related defects
failed endocardial cushion defects
List 3 cell types that comprise the midgestation human “placental membrane”
syncytiotrophoblast
cytotrophoblast
fetal endothelium
Name the 3 primary routes fro blood circulation in the 4th week human embryo
cardinal-aorta
vitelline-yolk sac
umbilical
Use abbreviation RV=Right ventricle PT=Pulmonary trunk, etc
A.Trace the path a red blood cell would follow from the adult superior vena cava to the right internal carotid artery. Include all valves.
A. The red blood cell (RBC) will travel from the superior vena cava (SVC) to the right atrium (RA) – tricuspid valve (TV) – right ventricle (RV) – pulmonary semilunar valve (PSV) – pulmonary trunk (PT) – pulmonary arteries (PA) - Lungs – pulmonary veins (PV) – left atrium (LA) – bicuspid (mitral) valve (BV) – left ventricle (LV) – aortic semilunar valve (ASV) - aortic arch (AA) – brachiocephalic (BRA) – right common carotid (CC) – right internal carotid (IC).
B.A red blood cell in the fetal superior vena cava craves oxygen. Trace the shortest route the cell would follow to reach the placental villi.
B) The red blood cell (RBC) will travel from the SVC to the RA - TV – RV – PSV – PT – DA – AO – common iliac (CI) – intenal iliac (II) – umbilical arteries (UA) – placenta
What are the fundamental differences between persistent truncus arteriosus and transposition of the great vessels?
In persistent truncus arteriosus the conotruncal ridges fail to form in the truncus arteriosus so there is a large common overriding outflow tract for right and left ventricular output. Always includes a ventricular septal defect.
In transposition of the great vessels the conotruncal ridges form and partition the truncus but fail to spiral. The right ventricle pumps blood into the aorta and the left ventricle pumps blood into the pulmonary trunk. Accompanied by patent ductus arteriosus and atrial and/or ventricular defects.
A large dissecting needle has been passed through the outermost layer of the pericardium to the left ventricular chamber. Name the layers the pin passes through.
Fibrous pericardium Parietal (serous) pericardium Pericardial cavity Visceral (serous) pericardium (epicardium) Myocardium Endocardium (endothelium)
Outline the cardiac conduction system and describe its function.
SA node – atrial pathways – AV node – Bundle of His – bundle branches, left and right – Purkinje fibers The SA node serves as the pacemaker to initiate cardiac contraction and the conduction system serves to coordinate atrial and ventricular contraction.
