Quiz 4 Heart And Respiratory Flashcards
The foramen primum is in septum ______ while foramen secundum is in septum ________
Septum primum. Both foramens form in the same septum
Septum primum grows from the roof of the atrium toward the
Endocardial cushions
Septum primum partially divides
The common atrium into left and right
Foramen secundum forms to ensure
Oxygenated blood can continue moving from right to left atrium
What vein carries O2 and nutrition from placenta to fetus prenatal and postnatal becomes ligamentum teres?
Umbilical vein
What vein splits blood flow prenatally, so that 1/2 bypasses liver to enter IVC and 1/2 flows through liver sinusoids and enters IVC via hepatic veins and postnatally closes and becomes ligamentum venosum
Ductus venosus
When the umbilical cord is clamped, what happens to the umbilical arteries?
They constrict
Where are obliterated umbilical arteries located in adults?
Medial umbilical folds / ligaments
Angioblastic cords develop from
Cardiogenic mesoderm
Angioblastic cords are canalized to form
Small endocardial tubes
Paired longitudinal endocardial tubes fuse to form
Primordial heart tube
Fusion of the heart fold is driven by the
Head fold
Mesenchyme cells in the extraembryonic mesoderm differentiate into
Angioblasts
Angioblasts cluster to form
Blood islands
Blood islands are formed by angioblasts in what mesoderm?
Extraembryonic splanchnic mesoderm
Blood cells develop from
Endothelial cells in vessel adjacent to umbilical vesicle
The sinuatrial node forms in the wall of
Sinus venosus
right wall of sinus venarum
Whatkind of mesoderm gives rise to the cardiomyocytes and conducting system?
Intraembryonic splanchnic mesoderm in the head region (head mesoderm)
Location of atrioventricular node cushions formations
Base of interatrial septum and superior to endocardial cushions
AV bundles (of His) travesl
Interatrial septum to interventricular septum
What is the correct way of the heart to loop
Loop to right, bulge to left
After heart looping, the atrium and sinus venosus end up in this direction
Dorsal
Cranial
After heart looping, bulbus and ventricle end up in this direction
Ventral
Caudal
Hepatic segment of IVC is derived from
Part of right vitelline vein
The prerenal segment of IVC is derived from
Right subcardinal vein
Renal segment of IVC is derived from
Subcardinal-supracardinal anastomosis
Left and right
Postrenal segment IVC is derived from
Right supracardinal vein
The only segment of the IVC that comes from the left is the
Renal segment (subcardinal-supracardinal anastomosis)
Aorticopulmonary septum formation is when what arteries do a twist
Bulbar and Truncal ridges
How does Bulbar and Truncal ridges do aorticopulmonary septum formation?
- Drop into heart
- 180˚ spiral
- Fuse and form aorticopulmonary septum
Fate of endocardial cushions
AV valves + contribute to the formation of membranous interventricular septum
Thick primordial myocardium is derived from
Splanchnic mesoderm around pericardial cavity
Fate of splanchnic mesoderm (S.M.)
- Primordial myocardium (heart muscle)
- Blood islands form in EXTRAembryonic SM
- Cardiomyocytes and conducting system form from INTRAembryonic SM
- Visceral pleura around the primary bronchial buds
Pleuropericardial folds form on
Lateral wall of pleural cavity SUPERIOR TO bronchial buds
Pleuropericardial folds fuse medially with _______ to separate pericardial and pleural cavities (to make mediastinum) while pleuroperitoneal folds fuse transversely with _______ to separate pleural and peritoneal cavities (to make thoracic diaphragm).
Septum transversum
pleuropericardial folds contribute to formation of
Mediastinum
Parietal pleura, somatic mesoderm
Pleuroperitoneal folds form on
Lateral wall of pleural cavity INFERIOR to bronchial buds
Pleuroperitoneal folds form
Primordial thoracic diaphragm
Parietal pleura, somatic mesoderm
Secondary buds develop and become secondary bronchi. On the right side the upper secondary bud supplies the upper lobe while the lower secondary bud supplies
Middle and lower lobes
Tertiary (segmental) bronchi form to supply
Bronchopulmonary segments
Bronchopulmonary segments have how many on the right and left
R - 10
L 8-9
Thoracic diaphragm initially forms where?
Opposite the cervical somites
Myoblasts from the somites migrate into diaphragm
Myoblasts from somites migrate into diaphragm and are innervated by
Cervical somites
“3, 4, 5 keeps diaphragm alive”
Fluid is removed from lungs at birth in 3 ways
- Squeezed out in the vag
Absorbed into pulmonary
- vasculature
- lymphatics
Initial breathing due to:
Less O2, more CO2 in delivery
Cutaneous stimulation
Cold air stimulation
Strong contraction of thoracic diaphragm
Rate of newborn breathing is
40 breaths/min
T/F. Pseudoglandular stage of lung maturation is stage one, and there is alveoli.
False
Stage two of lung development is
Canalicular stage
What happens in canalicular stage?
Vascularized lung tissue
Viability is minimal
Terminal sac stage of lung maturation is when respiration is
Possible, viability is more likely
Alveolar stage of lung development is when interalveolar capillaries bulge into
Alveolar lumen
Mature alveoli develop when?
After birth
Common cardinal veins do what?
Provide venous return from embryo
Vitelline veins do what
Provide venous return from yolk sac
Umbilical veins do what
Provide venous return from placenta
