Topic 5 & 6 Cardiac Part 2 Flashcards
Heart Tube day 23
Newly formed heart tube starts to bend
Cephalic part bends ?
ventrally, caudally, and to the right.
Heart Tube day 23
Newly formed heart tube starts to bend
Caudal part bends ?
dorsocranially, and to the left.
Newly formed Heart Tube day 23 does 3 things ?
- -Newly formed heart tube starts to bend
- -Bulges into the pericardial cavity
- -Attached to dorsal wall by mesoderm
Newly formed heart tube (day 23ish)– when attached to dorsal wall by mesoderm what eventually happens?
Mesoderm eventually ruptures
Leaves heart tube suspended in pericardial cavity
Regions: Dorsal Aorta and Aortic Sac become?
Becomes the common outflow tract
Bulbus Cordis become?
Primitive RV
KNOW
Primitive Ventricle become?
Primitive LV
KNOW
Atrioventricular Sulcus become?
Divides atria from ventricles
KNOW
Paired Primitive Atria become?
Will form common atria
KNOW
Sinus Venosus become?
Eventually forms the coronary sinus and oblique vein of the LA
KNOW
Day 23-28
Heart undergoes a series of folding that leads to the formation of what?
the bulboventricular loop
Day 23-28
Heart undergoes a series of folding creating the bulboventricular loop. The Heart tube also grows rapidly where? forming what?
Heart Tube grows rapidly in length, especially the midsection (Bulbus Cordis and Ventricle)
Because the two ends are fixed, heart tube is forced to bend in order to adapt itself to the pericardial space.
Forms what shapes? what order are the components in?
a U-Shape
Then Forms an S-Shape
Oriented so that the atrium and sinus venosus lie superior to the bulbus cordis, ventricle and dorsal aorta/aortic sac
Because the two ends are fixed, heart tube is forced to bend in order to adapt itself to ?
the pericardial space
Atria initially paired–forms ?
common atrium
Atrioventricular unction remains narrow
Forms ?
AV Canal–connects common atrium and ventricle
Bulbus Cordis is narrow, except what ? which forms what?
proximal 1/3
Will form trabeculated part of RV
Junction between the ventricle and the bulbus cordis externally is the
bulboventricular sulcus
Remains narrow
Called the primary interventricular foramen
When the heart is folding the primary interventricular foramen is what?
bulboventricular sulcus (Junction between the ventricle and the bulbus cordis externally) Remains narrow
Atrial portions of the Heart Tube dilate Form?
[Heart folding Atrium]
Common Atrium
Atrium “climbs up” the dorsal pericardial wall
Takes what with it?
[Heart folding Atrium]
Atrioventricular junction with it
Atrioventricular junction remains narrow
Now called? does what?
[Heart folding Atrium]
AV Canal
Forms the communication between the atrium and the primitive ventricle.
During Heart folding – Ventricle also dilates
Acquires a ?
larger lumen
Junction of the ventricle and the bulbus cordis remains narrow
During Heart folding – Ventricle
Junction of the ventricle and the bulbus cordis remains narrow, Junction is now called?
intraventricular foramen
Heart Folding –Bulbous Cordis
At the venous pole, growth proceeds to a point where the expanding common atrium has drawn the originally paired sinus venosus together until it consists of _____?
a midportion and right and left horns
Heart Folding –Bulbous Cordis
At the venous pole, growth proceeds to a point where the ______ has drawn the originally paired _____ together until it consists of a midportion and right and left horns?
expanding common atrium
sinus venosus
Heart Folding Day 24
Diverticula appear in two sharply defined areas
-Along front of endocardial tube
-Just proximally and distal to the primary
interventricular foramen
Heart Folding Day 24
Diverticula appear – Just proximally and distal to the primary interventricular foramen.
–Early embryonic Ventricle is the?
Primitive LV
Heart Folding Day 24
Diverticula appear – Just proximally and distal to the primary interventricular foramen.
–Proximal 1/3 of bulbus cordis is the??
Primitive RV
Heart Folding Day 24
Diverticula appear – Just proximally and distal to the primary interventricular foramen.
–Primitive LV is the?
Early embryonic Ventricle
Heart Folding Day 24
Diverticula appear – Just proximally and distal to the primary interventricular foramen.
–Primitive RV is the?
Proximal 1/3 of bulbus cordis
Diverticula on the Folding Heart do what?
expand the capacity of the heart
Give them the densely trabeculated appearance
The trabeculae inside the heart leads to? (4)
valves, chordeae tendinae, papillary muscles, and atrioventricular valves
During heart folding the heart is still a single tube, Externally, it’s appearance is suggestive of a 4-chambered organ.
Abnormalities in Cardiac looping, is responsible for what cardiac defects? (3)
Ventricular inversion (corrected transposition), juxtaposition of the atrial appendages, and Double outlet right ventricle
-Aortic arches–the order of BC, CC, TA during heart folding
truncus arteriosus–conus cordis –bulbus cordis
Mid 4th week the sinus venosus receives blood from the right and left what?
right and left sinus horns