Cardiopulmonary Development Flashcards
where is the laryngotracheal groove located?
caudal to 4th pair of pharyngeal pouches
the endoderm is the embryonic origin of what structures?
epithelium, glands of larynx, trachea, bronchi, lungs
the splanchnic mesoderm is the embryonic origin of what structures?
connective tissue, cartilage, smooth muscle
what forms from the respiratory diverticulum?
lung bud
when does the respiratory diverticulum appear?
end of 4th week
what does the visceral pleura develop from?
splanchnic mesenchyme
what does the parietal pleura develop from?
somatic mesoderm
what do the primary bronchial buds grow laterally into?
pericardioperitoneal canals
what do the primary bronchial buds differentiate into? with what embryonic layer?
bronchi
splanchnic mesenchyme
primary bronchial buds are the primordium (origin) of what structure in the tracheobronchial tree?
main bronchus
when is the pseudoglandular period?
6-16 wks
what are defining characteristics of the pseudoglandular period?
resembles exocrine gland, no gas exchange
when is the canalicular period?
16-26 wks
what are defining characteristics of the canalicular period?
lumina of bronchi and bronchioles form, formation of alveolar ducts and terminal saccules, well-vascularized, some gas exchange possible
when is the terminal saccular period?
26 wks - birth
what are defining characteristics of the terminal saccular period?
more terminal saccules develop, thin alveolar walls, surfactant is secreted
when is the alveolar period?
32 wks - 8 yrs
what are defining characteristics of the alveolar period?
most of alveoli develop (95% postnatally), tremendous increase in alveoli and capillaries
heart and vessels are derived from what embryonic structures?
splanchnic mesoderm, paraxial and lateral mesoderm, neural crest
what forms from the cardiogenic mesoderm?
angioblastic cords, heart tubes
the umbilical arteries will later become parts of which arteries?
internal iliac artery, superior vesical artery
what is the function of the umbilical artery?
carry deoxygenated blood to placenta
the vitelline arteries will later become which arteries?
celiac trunk, superior mesenteric artery, inferior mesenteric artery
the dorsal intersegmental arteries will later become which arteries?
vertebral arteries, intercostal arteries, lumbar arteries, common iliac arteries, lateral sacral arteries
where does the heart and great vessels develop from in the embryo?
aortic sac
what are the first recognizable vessels in an embryo? what do they form?
paired dorsal aortae
single dorsal aorta
where does the heart begin to develop?
cardiogenic area
what are the angioblastic cords? how do they form? where are they?
endocardial heart tubes
fuse with lateral folding
superior to endocardium
what layer of the embryonic heart is separated from the heart tube by cardiac ‘jelly’? what does this become in the adult heart?
primordial myocardium
myocardium
what is the external surface of the sinus venosus?
epicardium
elongation/bending of the heart tube leads to what structure that connects the ventricles to the aortic sac and aortic arches?
truncus arteriosus
what embryonic structure will form the right ventricle?
bulbus cordis
what embryonic structure will form the left ventricle?
bulboventricular loop
what structures are dorsal on the embryonic heart?
atrium, sinus venosus
what structures are ventral on the embryonic heart?
truncus arteriosus, ventricle
what area does the heart tube fold into?
pericardial cavity
what structures develop away from the embryonic heart?
dorsal aorta
what structures develop towards the embryonic heart?
common cardinal veins (to embryo), umbilical veins (to placenta), vitelline veins (to yolk sac)
the first heart beat is also known as what of the sinus venosus, atrium, and ventricle?
peristaltic contractions
the ventricle leads to what structures?
bulbus cordis, truncus arteriosus, aortic arch
when does partitioning of the primordial heart occur?
end of 4th wk
what structure lies within the atrioventricular canal?
endocardial cushions
what is the function of the endocardial cushions? how and where do they form?
form valves and membranous septa
fuse and divide AV canal into right-left sides by forming from the dorsal to ventral walls of the AV canal
the primordial atrium is separated by what two structures?
septum primum, septum secundum
what does the septum primum do to separate the atria into right and left halves?
grows toward the endocardial cushions
what is the foramen primum? what is its function?
opening between crescentic edge and endocardial cushions
shunts blood from right to left atrium
what occurs when the septum primum fuses with the endocardial cushions?
foramen primum disappears
what is the foramen secundum? what is its function?
performations in the central part of the septum primum
shunts blood from right to left atrium
where does the septum secundum grow? what is its function?
to the right of the septum primum
covers foramen secundum as a flap valve to create the oval foramen
what are the pressures in the atria before birth?
right - high pressure
left - low pressure
what are the pressures in the atria after birth?
right - low pressure
left - high pressure
what are the main changes to the sinus venosus during embryonic heart development?
enlargement of right horn, left horn becomes smaller
what occurs from the enlargement of the right horn of the sinus venosus?
shunt becomes left to right, will become wall of right atrium
what occurs from the smaller left horn of the sinus venosus?
will become coronary sinus
the primary pulmonary vein will develop during embryonic heart development - what is it an outgrowth of?
dorsal atrial wall
the primary pulmonary vein will become incorporated into what structure?
wall of left atrium
what forms to partition the primordial ventricle?
primordial interventricular septum
how does the primordial interventricular septum form? what does it form?
crescentic fold from floor of ventricle
forms muscular part of septum
where is the interventricular foramen? what occurs to close this space?
between IV septum and fused endocardial cushions
closed by fusion of bulbar ridges and endocardial cushions
where is the membranous part of the septum?
between right side of endocardial cushion to IV septum
the bulbar ridges and truncal ridges develop from what embryonic cells?
neural crest mesenchyme
what is the name of the right bulbus cordis after partitioning?
conus arteriosus
what is the name of the left bulbus cordis after partitioning?
aortic vestibule
during the partitioning of the bulbus cordis and truncus arteriosus, the bulbar ridges and truncal ridges spiral, creating what structure? what vessels does this form?
aorticopulmonary septum
aorta, pulmonary trunk
what develops from the swellings of the subendocardial tissue?
semilunar and AV valves
what are the four main types of anomalies of the heart and great vessels?
atrial septal defects, ventricular septal defects, transposition of great arteries, tetralogy of fallot
what are types of atrial septal defects?
patent oval foramen, ostium secundum defect, endocardial cushion defect with ostium primum defect, sinus venosus defect, common atrium
what are types of ventricular septal defects?
membranous ventricular septal defect, muscular ventricular septal defect
which septal defect is known as “swiss cheese vsd?”
muscular ventricular septal defect
what leads to transposition of the great arteries?
linear septation so that the pulmonary artery and aorta are coming off the wrong chambers
what is tetralogy of fallot?
type of ventricular septal defect that causes pulmonary stenosis, leading to dextroposition of aorta and right ventricular hypertrophy
fetal blood circulation occurs through which vein?
umbilical vein
what vessels does the umbilical vein drain into?
ductus venosus, inferior vena cava
during fetal circulation, what where does the inferior vena cava shunt blood?
left atrium, left ventricle, aorta
what happens to the small amount of blood in the right atrium and right ventricle during fetal circulation?
ductus arteriosus
what parts of the body receive well-oxygenated blood after fetal circulation?
heart, head, neck, upper limbs
what four main events occur in neonatal circulation?
aeration of lungs, oval foramen closes, ductus arteriosus constricts, umbilical arteries constrict
what occurs due to aeration of lungs in neonatal circulation?
fall in pulmonary vascular resistance (increase in pulmonary blood flow), thinning of walls of pulmonary arteries
