Embryology - CVS

Question 1

Cardiogenic Field Formation

Answer 1

Forms the primordial CVS made up of fused heart tubes which join the blood vessels

1. blood vessels arise from angiogenic cell clusters
2. 2 heart tubes form in lateral splanch. mesoderm

Question 2

Pericardium Formation

Answer 2

somatic mesoderm => serous parietal + fibrous pericardium

intra-embr. coelom => pericardial cavity

splanchnic mesoderm => visceral serous pericardium

Question 3

Primitive Heart Tube Fusion

Answer 3

bulging + differentiation

=> arterial (cranial) + venous (caudal) ends

=> primitive heart tube invaginates pericardium d/t size and sinks and folds

=> bulbus cordus + ventricles enlarge = BULBOVENTRICULAR LOOP

Question 4

Heart Tube Parts and their products

Answer 4

1. AORTIC SAC = aortic arches
2. TRUNCUS ART = ascending ao and pulm trunk
3. BULBUS CORDIS = RV, outflow tracts
4. PRIMITIVE VENTRICLE = LV
5. PRIMITIVE ATRIUM = RA, LA, Auricles
6. SINUS VENOSUS = SVC, RA

Question 5

Cardiac looping of the Heart

Answer 5

Loops to the right

Question 6

Primitive Heart PArtitioning

Answer 6

L and R atrioventricular canal forms via fusion of supr. and inf. ENDOCARDIAL CUSHIONS @ midline + gaps = L + R gaps

Question 7

Atrial Partitioning

Answer 7

1. septum primum grows to endocard. cushion
2. ostium primum forms
3. aptopsis @ top = ostium secundum + ostium primum closes via septum primu,
4. septum secundum forms + leaves gap = foramen ovali
5. septa fuse and give rise to fossa ovalis

Question 8

Ventricle Partitioning

Answer 8

1. muscular interventricular septum grows from the primitive ventr wall = INTRAVENTRICULAR FORAMEN
2. truncus arteriosus: spiral septum grows = aorticopulmonary septum separating trunc. art. into pulmonary trunk and aorta
3. aorticopulm. septum fuses w/ muscular interventr. septum

=> membranous interventr. septum closes the interventr. foramen (musc. + membranous portions)

Question 9

What facilitates the right-left atrial shunt during embryological and foetal development?

Answer 9

ostium secundum and foramen ovale (skip pulmonary circulation)

Question 10

Bulbus cordis + truncus arteriosus partitioning

Answer 10

aorticopulm septum (truncus art.) divides aorta and pulm trunk

Question 11

What are the valve precursors?

Answer 11

endocardial cushions

SEMILUNAR = subsendocardial valve tissue

CHORD TEND + PAPILLAR + CUSP = ventricular wall

Question 12

Precursors of conducting system

Answer 12

• cardiomyocytes = prim. atrium + sinus venosus
• SA node entrance of SVC
• AV and BoH = AV canal + sinus venosus

Question 13

Aortic Sac Formation

Answer 13

fusion of ventra aortae above truncus arteriosus

Question 14

Aortic Arches

Answer 14

aortic sac gives rise to aortic arch branches from the L and R horns

6 pairs unite with dorsal aortae

Question 15

Aortic arches and development

Answer 15

1 + 2: disappear

3: COMMON CAROTID ARTERY

R AND L 4: 4 AND L SUBCLAVIANS

5: disappear

R6: R pulmonary art

L6: L pulm art + DUCTUS ARTERIOSUS

=> 3 4 6

Question 16

Difference between vasculogenesis and angiogenesis

Answer 16

VASCULOGEN: new primitive vasc network

ANGIOGEN: growth from pre-existing vasc.

Question 17

Major Embryoloigical vessels to adult vessels

Answer 17

vitellin (y. sac) => adult gut vessels

umbilical (placenta) => internal iliac

cardinal vessels => SVC + IVC

Question 18

Embryological Thoracic Ducts

Answer 18

L: proximal 1/3 adult thoracic duct

R: lower 2/3 adult thoracic duct