Embryology Of Heart Flashcards
_____ is the 1st major system to develop
CVS
during the ____ week, a primordial uteroplacental circulation develops
3rd
____ week –angioblastic cords appear
Canalization of cords form ___________
2 tubes fuse to form ____ heart – _______ week
Heart beat begins –day __-___
3rd
endocardiac heart tubes
tubular; late 3rd
22-23
The endothelial heart tubes fuse to form a single _______ with a cranial (____) end and a caudal ( ______ ) end.
primitive heart tube
arterial
venous
As heart tube fuses, Surrounding mesenchyme ______ to form
•___cardium
•___cardium
➢ The two layers are separated by __________
thickens
Myo
Epi
cardiac jelly
__________ becomes endocardium
Endothelial tube
The primitive heart tube ______ and develops alternate ______ and _____ giving rise to an ___-shaped heart- the __-chambered heart
elongates
dilatations and constrictions
S
5
the 5-chambered heart •1- \_\_\_\_\_\_\_\_ •2-\_\_\_\_\_\_\_ •3-\_\_\_\_\_\_\_ •4-\_\_\_\_\_\_\_\_\_ •5-\_\_\_\_\_\_\_
truncus arteriosus.
bulbus cordis.
primitive ventricle.
primitive atrium.
sinus venosus.
The truncus arteriosus is continuous (cranially or causally?) with the _____, from which the _________ arise.
Cranially
aortic sac
pharyngeal arch arteries
The sinus venosus is continous (cranially or caudally?) and receives the
- ______ vein from the ____
- ______ vein from the ______
- ________ vein from the ____
Caudally
Umbilical; chorion
Vitelline; umbilical vesicle
Common cardinal; embryo
Bulboventricular loop
Because the ____ and ____ grow faster than other regions, the heart ___ upon itself, forming a ___-shaped bulboventricular loop.
As the primordial heart bends, the atrium and sinus venosus come to lie (ventral or dorsal?) to the TA, bulbus cordis, and ventricle
bulbus cordis
ventricle
bends
U
Dorsal
Partitioning of AV canal
•The junction between the ____ and _____ forms the AV canal
•Towards the end of 4th week, masses of tissue (_______) form on the _____ and ____ walls of the AV canal
•During the 5th week, the cushions _______ and _____, Partitioning the canal into ___ and _____
primitive atrium and ventricle
endocardial cushions
dorsal and ventral
approach each other and fuse
rt and lf AV canals
Partitioning of Primordial Atrium
•By the end of the 4th week, the primordial atrium is divided into ____ and ____ by 2 septa (______ and ____)
rt and lf atria
Primum and Secundum
Partitioning of atrium
- Septum primum- (thin or thick?) , _____ shaped membrane
- Grows from (roof or floor?) of _____ towards ________
- Leaves gap at its (upper or lower?) end- _____
- Atrium partially divided into Rt. & Lt. chambers & gap acts as a ____.
- As ostium primum becomes smaller, _____ appears at _____ part of the septum – ______
- Concurrently free edge of septum primum fuses with (right or left?) side of _____
Thin; cresentic
Roof; primordial atrium
fusing endocardiac heart cushion
Lower; ostium primum
shunt
Perforations; central
ostium secundum
Left
fused endocard. Cushion.
Septum secundum- A ____-shape, muscular membrane grow (upwards or downwards?) from ventrocranial (roof or floor?) of _____
To the (left or right?) side of _________
- ____week – overlaps foramen _____
- Forms incomplete partitioning- _____
cresentic
Downwards
Roof; rt atrium
Right; septum primum
5-6th
secundum
foramen ovale
Fate of Cranial portion of septum primum ???
Fate of Caudal part of septum primum becomes a ___ like valve of _____
It disappears
flap
foramen ovale
Foramen ovale
- Before birth allow __________ of blood
- Due to increase in ______ pressures at birth there is ______ of the foramen ovale
•Complete partitioning of the ____
right to left shunt
left atria
closure
atria
Changes in the Sinus venosus
•(decease or Increase?) in left horn of sinus venosus
•(decease or Increase?) right horn of sinus venosus
•Left horn becomes ______
•Right horn becomes ___________
Decrease
Increase
coronary sinus
incorporated into the wall of right atrium
______ horn of sinus venosus becomes the smooth wall of right atrium
Rough part of right atrium is derived from _______, both region separated by the ________ (externally) & _______(internally)
Right
primitive atrium
sulcus terminalis
crista terminalis
Left atrium
•Mostly smooth – derived from incorporation of the ___________
•Left auricle is derived from _______
primordial pulmonary vein.
primordial atrium
Atrial septal defects- 4 types
- ________ type
- _______ with _____ defect
- _______ type
- _______ type
ostium secondum
Endocrdiac cushion; ostium primum
Sinus venosus
Common atrium
Partitioning of Primordial Ventricle
•First seen as a _______ growing from the (roof or floor?) of the ventricle near its apex- ______________
muscular median ridge
floor
Interventricular septum (IV)
The IV septum grows by (dilation or constriction?) of the _____ and by active proliferation of ____ in the septum
Till the ___ week, there is a _____-shaped IV foramen btw the free edge of the septum and the fused endo. cushions
Dilation; ventricles
myoblasts
7th; crescent
The IV foramen permits communication btw _______
the 2 ventricles
The IV foramen usually closes by the ________ week when the ________ fuse with the _____
Closure of IV foramen is from 3 sources: list them!!!!!
end of the 7th
bulbar ridges; endocardial cushion.
Right & left bulbar ridges, endocardiac cushion
Membranous interventricular septum-
•Extension of tissue from ___. Side of endocardiac cushion to muscular part of interventricular septum
Rt
After closure of IV foramen-
•Pulmonary trunk now communicates with ___ ventricle, while aorta communicates with ___ ventricle
right
left
_______ of ______ gives rise to trabeculae carnae, papillary muscles, chordae tendinae
Cavitation of ventricles
Partitioning of bulbus cordis & truncus arteriosus
- ____ week –active proliferation of mesenchyme- ___ ridges in bulbus cordis & ____ ridges in Truncus arteriosus
- Undergoes ___o spiraling forming a spiral __________ septum
5th
bulbar
Truncal
180
aorticopulmonary
The aorticopulmonary septum divides the BC and TA into 2 (arterial or venous?) channels- _____ and ____
Because of the spiralling of the AP septum, the ___ twists around the ______
arterial
ascending aorta and pulmonary trunk
pulmonary trunk
ascending aorta
Fate of Bulbus cordis ?????
It is _________ into ____ of _____
- Right side becomes- _______ or ____
- Left side – ______ of ______
incorporated into wall of definitive ventricles
conus arteriosus or infundibulum
vestibule of the aorta
_____– most common type of coronary heart defects
VSDs
Ventricular septal defects
•Occur more frequently in ____ gender
males
small VSDs may close spontaneously
T/F
T
large VSDs allow _______
shunting of blood from lf-rt
Muscular VSDs- May appear anywhere in the _____ part of the IV septum
muscular
multiple small ventricular septal defects- _______ VSD
Absence of the IV septum = ________
Swiss cheese
single ventricle
Tetralogy of Fallot
•Abnormality resulting from _______ within the _________ region
- Displacement of the septum produces 4 cardiovascular alterations;
- __________
- _________
- An _________
- __________
unequal division within the conutruncal region
Pulmonary stenosis
Large VSD
overriding aorta
Rt ventricular hypertrophy
PERSISTENT TRUNCUS ARTERIOSUS
•Results when ___________
•Hence no division of _____
- Pulmonary artery arises some distance (above or below ?) the origin of the ________
- VSD
- Undivided tuncus overrides _______
conutruncal ridges fail to form
outflow tract
Above
undivided truncus
both ventricles
Transposition of great vessels
- Occurs when _______ fails to ______________
- Hence, Aorta originates from ______ and pulmonary artery from ______
conotruncal septum
follow its normal spiral course
rt ventricle
left ventricle
