Cardiorespiratory Development Flashcards
(93 cards)
1
Q
mesoderm types
A
paraxial, intermediate, lateral plate
and cardiac type (sort of a fourth type)
2
Q
cardiac mesoderm
A
goes to cranial portion of embryo
-in cardiogenic field
3
Q
two folds
A
lateral and head tail
head tail fold pulls the cardiogenic region into thorax
4
Q
cardiac crescent
A
mesoderm organized into two tubes
lateral fold puts two heart tubes together
-they fuse
5
Q
endocardial tube
A
fusion of two tubes
gives rise to all of heart
-except fibrous skeleton and heart valves
6
Q
blood flow in primitive heart?
A
caudal - venous
cranial - arterial
7
Q
around day 22?
A
starts beating and actually contracts
8
Q
differential of heart tube?
A
caudal > cranial
sinus venosus, atrium, ventricle, bulbus cordis
9
Q
cardiac looping
A
ventricles grow rapidly, cause heart to fold
cranial - ventral, caudal, to the right
caudal - dorsal, cranial, to the left
10
Q
sinus venosus
A
incorporated into right atrium as sinus venarum
major venous end of heart
-to right atrium
left sinus horn regresses
11
Q
left sinus horn
A
forms coronary sinus
venous drainage of heart
12
Q
left atrium smooth portion
A
from pulmonary vein
13
Q
primitive atrium
A
lined with pectinate muscles
auricles of left and right atrium
14
Q
sinus venarum
A
right atrium
15
Q
primitive ventricle
A
only forms trabeculated portion of left ventricle
16
Q
three regions of bulbus cordis
A
1 trabeculated part of right ventricle
2 conus cordia
3 truncus arteriosus
17
Q
conus cordia
A
forms smooth walled outflow tracts of both left and right ventricles
-aortic vestibule of left V and conus arteriosus of right V
18
Q
truncus arteriosus
A
forms the two great arteries
- pulmonary trunk from right V
- aortic artery from left V
19
Q
blood flow through primitive heart?
A
sinus venosus
primitive atrium
**
20
Q
partitioning of heart
A
where most of anomalies take place**
-starts around day 30
-forms septa
21
Q
prenatal heart
A
needs to shunt blood away from developing lungs**
lungs not functioning, but they are highly vascularized
22
Q
ductus arteriosus
A
arterial blood shunt
23
Q
what diverts blood around right ventricle?
A
foramen ovale
ductus arteriosus
**these must close immediately at birth
24
Q
osteum
A
means opening
25
step 1 partitioning
septum primum forms in common atrium
mostly fibrous
first partition - separates right and left atrium
26
step 2 partitioning
ostium primum forms
| -eventually closes and will fuse with atrioventricular septum
27
steps 3 and 4 or partitioning
as ostium primum closing, second opening (ostium secundum) forces cell death in septum primum
28
step 5 partitioning
septum secundum forms within right atrium
-thick and muscular
forms interartial septum
29
step 6 partitioning
septum secundum is incomplete
-its foramen is foramen ovale
-original septum now referred to as valve of foramen ovale
30
prenatally and postnatally
pre-
high pressure right side
low pressure left side
blood shunted through foramen ovale
post-
lower pressure right atrium
higher pressure left atrium
valve of oval foramen closes
31
septum primum and septum secundum
will fuse
32
patent foramen ovale
septum primum never fuses to secundum
asymptomatic - it is closed, so it functions, but it just doesn't fuse
pressure on right side of heart can open it up
33
bulboventricular flange
regresses and allows opening of atrioventricular canal
so RA and RV, LA and LV can communicate
33
bulboventricular flange
regresses and allows opening of atrioventricular canal
so RA and RV, LA and LV can communicate
34
endocardial cushion
superior and inferior and two lateral parts
superior and inferior will fuse (AV septum)
-left and right halves
34
heart valves
form from neural crest
34
interventricular septum
muscular portion from muscle of ventricle wall
| membranous portion from endocardial cushions
34
conotruncal ridges
left and right
will fuse to form conotruncal septum
separates outflow tract of heart
it spirals****
caudally to cranial 180 degrees
34
importance of spiral
so right ventricle - pulmonary trunk
and left ventricle - aorta
if doesn't spiral - transposition of the great vessels**
34
neural crest disorder?
heart valve issues
34
cardiac defect
most common congenitally
34
VSD
ventricle septal defects (hole in the heart ventricle)
in the interventricular septum
- muscular type
- membranous type (more common)
symptoms depend on size of hole
will get left-right shunting of blood
- pressure higher on left side postnatally
- increased pulmonary blood flow
- decreased systemic blood flow
34
ectopic cordis
body wall defect
thoracic wall doesn't fuse
heart herniates and forms externally
35
ASD
atrioseptal defect (hole in heart atrium)
osteum secundum - cell death
1 excessive resorption of septum primum - lose valve, can't close foramen ovale
2 septum secundum doesn't close
left to right shunting of blood
35
endocardial cushions form?
AV septum
part of atrial septum (closes ostium primum)
membranous part of interventricular septum
35
endocardial cushion defects
neural crest defects
results in:
1 persistent AV canal
2 ASD
3 VSD
35
endocardial cushions form?
AV septum
part of atrial septum (closes ostium primum)
membranous part of interventricular septum
36
pulmonary, aortic stenosis
narrowing of vessels
due to abnormal valves
36
tetralogy of fallot
conal truncal ridges form and spiral - but don't equally divide (large aorta and small pulmonary trunk)
```
four features always present**
1 pulmonary stenosis (narrowing)
2 overriding aorta (very large)
3 hypertrophy (right ventricle)
4 VSD (membranous)
```
right ventricle hypertrophy - because of pulmonary stenosis
one of most common causes of cyanosis in newborn
36
transposition of the great vessels
conal truncal ridges don't spiral
aorta on right side
pulmonary on left side
37
persistent truncus arteriosus
conotruncal ridges fail to form
cyanotic infant
mixing of blood because aorta and pulmonary arteries are all together
38
dextrocardia
pretty rare
right sided heart
39
ectopic cordis
body wall defect
thoracic wall doesn't fuse
heart herniates and forms externally
40
di-george syndrome
chromosome 22 deletion
neural crest disorder
CATCH-22
```
Cardiac defects
Abnormal facial features
Thymic aplasia
Cleft palate
Hypocalcemia (parathyroid deficiency)
```
41
one question on exam
from one of the questions on the development of vascular system slide*****
42
two ways vessels form
vasculogenesis
angiogenesis
43
vasculogenesis
de novo synthesis of brand new vessels
aortic arch arteries and cardinal veins
44
angiogenesis
postnatally
sprouts from already formed
45
VEG-F
main signalling molecule
signals mesoderm to form blood islands which becomes vessel
46
fetal vasculature?
yolk sac
umbilical
fetus
47
major arteries of fetus
```
aortic sac
aortic arches (6 pairs)
dorsal aorta
```
48
major veins of fetus
cardinal veins (anterior, posterior to common)
umbilical vein
vitelline vein
49
yolk sac system
gone by week 12
| -vitelline vein and vitelline artery
50
placental system
two umbilical arteries (to placenta)
| one umbilical vein (oxygenated back to heart)
51
aortic arches
truncus arteriosus > aortic sac
aortic sac gives off 6 pairs (right and left)
form cranial to caudal in the neck
drain to dorsal aorta (left and right)
-thorax they fuse to form dorsal aorta
52
what happens?
arch 1 regresses
dorsal aorta between 3 and 4 on L and R regresses
-forms cranial and caudal blood suppliers
right branch of dorsal aortic artery regresses
arch 1, 2 and 5 regress on L and R
arch 3 - forms common carotid artery L and R
arch 4 - forms right subclavian (right side) and arch of aorta (left side)
arch 6 - ductus arteriosus (second blood shunt) on left / right regresses
53
arch 3
forms common carotid artery L and R
| -main arteries to head and neck
54
arch 4
forms right subclavian side (right)
| forma aortic arch (left)
55
arch 6
right regresses and left forms ductus arteriosus
56
look at the final organization
in notes****
57
ductus arteriosus
second blood shunt
- blood from pulmonary trunk goes to aorta
- so it skips lungs
58
postnatally ductus arteriosus
closes, becomes ligamentous
ligamentum arteriosum
59
recurrent laryngeal nerves
forms with aortic arch apparatus
-forms in neck and pulled to thorax by heart
given off by vagus nerve
at level of 6th arch to get to larynx
60
right recurrent laryngeal nerve?
loops under right subclavian
61
left recurrent laryngeal artery?
loops under aortic arch
under ductus arteriosus (from left 6th arch)
62
patent ductus arteriosus
ductus arteriosus doesn't close
| -left to right blood shunt (from aorta to pulmonary system)
63
coarctation of the aorta
constriction of aorta
preductal - proximal to ductus arteriosus
-infantile (at birth, bypass closes)
postductal - distal to ductus arteriosus
- adolescent (intercostal arteries become huge)
- get blood back to aorta
- upper limb HTN, lower limb low BP
64
retroesophageal right subclavian artery
right subclavian that passes posterior to esophagus
- 4th aortic arach regresses
- intersegmental forms subclavian - growth puts it behind
can cause dysphagia lusoria
65
dysphagia lusoria
difficulty swallowing because of vessel
66
double aortic arch
constrictive loop around esophagus
-will frequently see dysphagia
get a right and left aortic arch
67
respiratory diverticulum
aka lung bud
forms lungs
68
tracheoesophageal septum
between trachea and esophagus
formation of this septum is cause of fistula
69
fistula
abnormal opening between two structures
70
tracheoesophageal fistula
septum deviates through esophagus
- proximal ends blindly
- distal fistula ends in trachea
babies can't eat, immediately regurgitate
stomach distended (full of air)
71
larynx
upper portion of lung bud
72
week 5 lungs
to primary bronchi
then secondary, tertiary, bronchioles, alveolar ducts
walls get progressively thinner
73
pseudoglandular stage
week 5 - 16
lung not functional
have terminal bronchiole
74
canalicular stage
week 16-26
survivability increases rapidly
have respiratory bronchioles (capable of air exchange)
have surfactant
75
surfactant
if its there, you can survive!
76
terminal sac stage
week 26 weeks to birth
capable of respiration
survivability increases rapidly
77
alveolar stage
week 32 weeks to 8 years old
form alveolus
78
respiratory distress syndrome
not enough surfactant
- alveoli can't open
- too much surface tension
can give glucocorticoids to mother
-will stimulate surfactant
79
fetal circulation
compare prenatnal and postnatal circulation
