T10- Cardiovascular system development Flashcards
Pectinate muscles
Trabiculated muscles that line right and left atria
Sinus venarium
smooth reigon of atrial wall between openings of vena cava
Fossa ovalis
located on interatrial septum; embryological location of foramen ovale
Right auricle
flap that externally overlaps the ascending aorta
Interatrial septum
separates right and left atrium
Tricuspid valve
where deox blood passes through RA to RV
What is the tricuspid and bicuspid valve held in place by?
chordae tendinae which are connected to papillary muscles
What are trabiculae carnae
muscular, irregular ridges in RV
Interventricular septum
separates right and left vetricles
Blood flow of deox blood
pulmonary valve->pulmonary trunk->left/right pulmonary arteries-> lungs
Oxy blood enters LA via:
right/left superior and inferior pulmonary veins
Where is the valve of the foramen ovale located
Left atrium
Blood exits LA via what
Bicuspid valve
Blood flow of oxy blood
aortic valve->aorta
Coronary sinus opens into what
right atrium
When and how do cells of primordial heart and primordial BV appear
middle of third week as a U-shaped heart field
Splanchnopleure differentiates into what
angioblasts which cluster as angioblastic cords
Angioblastic cords canalize to form what
endocardial heart tubes
How do endocardial heart tubes fuse as a single heart tube
lateral folding
Heart tube is suspended in the pericardial cavity via what
Dorsal mesocardium
Super cool thing #1 (days 22-28)
dorsal mesocardium degrades into transverse pericardial sinus
Super cool thing #2 (days 22-28)
3 layers of heart: endocardium, myocardium, and epicardium
Endocardium
inner endothelial lining derived from endothelial tube
Myocardium
Middle muscular layer derived from splanchnic mesoderm; starts off as cardiac jelly
Epicardium
Comes from secondary heart field; forms coronary vessels
Heart looping What is it?
A series of contractions and dialations of the heart tube
Heart looping Position of truncus arteriosus (TA)
continuous cranially with aortic sac; stuck in position because of pharyngeal arch arteries
Heart looping Sinus venosus (SV)
recieves venous blood; “stuck” in position because of septum transversum
Heart looping Step 1
BC and PV grow faster than rest of heart tube initiating “looping”
Heart looping Step 1: how does the cranial end of heart tube move?
The cranial end bends ventrally, caudally, and slightly to the right
Heart looping Step 1: how does the caudal end of heart tube move?
The caudal end shifts dorsally, cranially, and slightly to the left
Heart looping Step 2
PV and BC start to form trabiculae
Heart looping Step 2: what does trabiculated PV become?
Primative left ventricle
Heart looping Step 2: what does trabiculated BC become?
Primative right ventricle
Heart looping direction (normally)
counterclockwise
Dextrocardia
result of clockwise heart looping
Whart are initial heart “contractions”
peristalsis like waves that begin caudally at SV and travel cranially toward TA
When is uniderectional blood flow clearly established?
by end of week 4
What separates primordial atrium from primordial ventricle
Atrioventricular canal
Where do dorsal and ventral endocardial cusions form?
on dorsal and ventral surfaces of AV canal
Fusion of dorsal and ventral cusions lead to what?
right AV canal and left AV canal
Which day is this
day 20
Which day is this
day 21
Which day is this
day 22
Which day is this
day 28
When and how do the right and left AV canal form
during week 5, when cushions are invaded by mesenchyme, proliferation causes them to grow and fuse together
Interatrial septum formation
How does the septum primum grow?
from the roof of the primordial atria, down towards the center endocardial cushion
What is the foramen primum?
the space between the leading edge of septum primum and central endocardial cushion
Fate of sinus venosus veins on the right
Right sinus horn
Becomes incorporated into the right atrium forming the smooth sinus venarium of the dorsal right atrium; connects superior and inferior vena cava
Fate of sinus venosus veins on the right
Right common cardinal vein
Forms a portion of the SVC
Fate of sinus venosus veins on the right
Right anterior cardinal vein
- during the 8th week a venous shunt forms which connects the right and left ant. cardinal veins, this shifts bloodflow from left to right
- forms portion of the SVC caudal to the shunt
What does the venous shunt that forms at the 8th week become?
The left brachiocephalic vein
Right posterior cardinal vein
develops with early kidneys; transforms and regresses along with those tissues
Fate of sinus venosus on the right
Right umbillical vein
regresses
Fate of the sinus venosus on the right
Right vitelline vein
- forms a portion of the IVC
- forms most of the hepatic portal system
Fate of the sinus venousus on the left
Left Sinus horn
Becomes coronary sinus
Fate of the sinus venousus on the left
Left common cardinal vein
regresses
Fate of the sinus venousus on the left
Left anterior cardinal vein
Same thing as the right anterior cardinal vein except caudal to the shunt, the left anterior cardinal vein regresses
Fate of the sinus venousus on the left
Left posterior cardinal vein
develops with the early kidneys; will transform and regress along with those tissues
Fate of sinus venosus on the left side
Left umbillical vein
- Cranial part (between heart and liver) regresses
- Caudal part persists as umbillical vein
What is the ductus venosus and what does it do
it is a large venous shunt that connects the umbillical vein to the IVC so that embryonic oxygenated blood can bypass the liver and go directly to the heart
Fate of the sinus venosus on the left side
Left vitelline vein
regresses
Fate of vitelline arteries
Celiac artery, superior mesenteric artery, and inferior mesentaric artery
Fate of umbillical arteries
Proximal parts: become internal illiac arteries and superior vesicle arteries
Distal parts: become medial umbillical ligaments
Vitelline arteries in embryo
travels along omphaloenteric duct towards umbillical vessicle
Umbillical arteries in embryo
Branches off the dorsal aorta and travels along the umbillical cord carrying poorly oxygenated blood towards the placenta
Dorsal aortae in embryo
- Connected to Aortic Sac via Pharyngeal Arch Arteries within pharyngeal arches
- Initially, paired Dorsal Aortae run the entire length of the embryo
Fate of dorsal aortae
Left side becomes the primative aorta and the right side regresses
Caudal portions fuse to form a single thoracic/abdominal aorta
What happens to the first pharyngeal arch arteries?
They largely disappear, but the remnants form part of the maxillary arteries
What happens to the second pharyngeal arch arteries
They largely disappear, but the dorsal remnants form the stem of the very small Stapedial arteries
What happens with the third pharyngeal arch arteries
Proximal parts form the common carotid arteries
Distal parts join the distal aorta to form the interal carotid arteries
Where do the external carotid come from?
They are an offshoot from the root of the ICA
Which week is this
week 8 onwards
What do the 4th pharyngeal arch arteries form
the proximal part of the right subclavian artery, and on the left, a small segment of the aortic arch
What happens to the 5th Pharyngeal Arch arteries
absent or rudimentary and will degenerate
What happens to the 6th Pharyngeal Arch arteries
On the right, the proximal part forms a small portion of the Right Pulmonary artery; distal part degenerates
On the left, the proximal part forms a small portion of the left pulmonary artery; distal part forms the ductus arteriosus
Fate of the Umbillical vein
Becomes the ligamentum teres
What is the function of the superior vesicle arteries in the neonate
supplys the bladder with arterial blood
What does the ductus venosus become
The ligamentum venosum
What does the ductus arteriosus become
ligamentum arteriosum
