Heart Devo

Front 1

Angioblasts/Hemangioblasts

Back 1

The initial precursor cells for the CV system; MESENCHYME cells in the mesoderm

Front 2

Blood islands

Back 2

Angioblast aggregation; differentiate into endothelial cells (internal lining of all blood vessels) and Hematopoietic stem cells (blood cell formation)

Front 3

Heart is derived from?

Back 3

Splanchnic Mesoderm; Cardiogenic crescent or primary heart field; forms the endothelial plexus--->endocardium (internal lining of the heart); The mesoderm of the crescent--->myocardium

Front 4

Septum Transversum

Back 4

Accumulation of mesoderm derived from mesenchyme adjacent to the transverse portion of the U-shaped coelom; Once folding completes, it becomes caudual to the heart; become part of diaphram

Front 5

Pericardial coelom turns into?

Back 5

The pericardial cavity d/t folding in the transverse plane; surrounds the heart tube

Front 6

Initial heart tube

Back 6

mostly Primitive Left Ventricle and a small portion of the primitive right ventricle; The segments of the primitive tubular heart DO NOT equal the chambers of the mature heart

Front 7

Secondary Heart Field

Back 7

Source of cardiac progenitor cells; crescent shaped located dorsal and medial to the primary heart field; FORMS the primitive right ventricle, outflow region and the Sinus venosus

Front 8

Primary heart field forms

Back 8

The Primordial Atrium and the Atrioventricular Canal

Front 9

Cardiac Jelly

Back 9

Between the myocardium and the endocardium; accum. of ECM; look like primitive valves in the outflow region; Endocardial cushions; bulbar and conotruncal ridges

Front 10

Epicardium

Back 10

Over the myocardium; derived from the proepicardial organ; -->Fibrous CT of the visceral pericardium also the formation of the coronary vessels; derivative of the coelomic epithelium that overlies the inflow region

Front 11

What three connections are responsible for venous inflow of the primitive heart tube

Back 11

Umbilical Veins (oxygen rich); Vitelline Veins (oxygen poor blood from the gut); and Common Cardinal Veins (oxygen poor blood from the head and trunk)

Front 12

Outflow connections from the primitive right ventricle

Back 12

The pharyngeal arch arteries or aortic arches; originate from the aortic sac

Front 13

The primary heart field express what gene?

Back 13

Nkx2.5; cardiac master gene; aka tin man gene

Front 14

The secondary heart field express what gene?

Back 14

Isl-2 is the master gene; allows for elongation of the primitive heart tube

Front 15

Ventricular myocyte also forms?

Back 15

Purkinje Fibers

Front 16

Cardiac Looping and Early phase

Back 16

Elongating heart tube begins to bend to the RIGHT; Early phase: proper anatomical relationships between the heart segments are established and inflow/outflow regions are approximated

Front 17

Outer curvature ballooning

Back 17

when the atria and ventricle chambers expand

Front 18

Late phase of looping

Back 18

Late phase: both limbs of the loop contact each other along the bulboventricular groove (level of AV canal; Inner curvature is the hinge); proximal portion of the outflow region is "wedged" into the AV canal

Front 19

Changes in blood flow

Back 19

Initially flow is back and forth; Flow becomes unidirectional by day 26 (with help of SA node); 2 separate streams leave the heart by day 28

Front 20

Partitioning of the tubular heart into four chambers include

Back 20

1. cardiac muscle
2. cardiac mesenchyme
3. Extracardiac mesenchyme
4. neural crest

Front 21

Definitive right atrium forms from?

Back 21

the Primordial Right atrium and portions of the sinus venosus; The left (proximal) and right umbilical and left vitelline vein atrophy; ALL systemic venous return NOW enters the right side of the heart

Front 22

The Inferior Vena cava forms from?

Back 22

The cranial portion of the Right Vitelline Vein

Front 23

The superior Vena cava forms from?

Back 23

The proximal portion of the right anterior cardinal vein

Front 24

The right sinus valve forms?

Back 24

Crista terminalis, valve of the Inf. vena cava, valve of the coronary sinus

Front 25

The absorbed right Sinus venosis forms?

Back 25

the smooth area of right atrium

Front 26

The left sinus venosus forms?

Back 26

The coronary sinus

Front 27

The absorbed pulmonary veins form?

Back 27

The smooth part of the left atrium; a single pulmonary vein grows out of the left atrium

Front 28

The tradbeculated part of the auricle is derived from?

Back 28

The primitive Atrium

Front 29

What change occurs to the Common AV canal?

Back 29

It divides into the right and left AV canals; This process separates the atria from the ventricles; REALIGNMENT IS NEEDED with the help of the inner curvature of the heart transforming cushion tissue into cardiac muscle

Front 30

The Endocardial Cushion Tissue aka Cardiac Mesenchyme forms in what two segments?

Back 30

The AV canal and the Outflow region

Front 31

Fusion of the dorsal and ventral endocardial cushions forms?

Back 31

Septum Intermedium; acts as a guide and glue for positioning and attachmet of the forming septa; The distance between the septum intermedium and the superior edge of the muscular interventricular septum remains constant

Front 32

Cardiac Mesenchyme forms

Back 32

Valve leaflets of the mitral, tricuspid, aortic, and pulmonary valves as well as the chordae tendinae and the cardiac skeleton

Front 33

What are the two parts of the IV septum?

Back 33

Muscular and Membranous (formed from the cushion tissue of bulbar regions) portions; it is the separation of the ventricles

Front 34

The primary interventricular foramen never closes; What does it form?

Back 34

The opening into the aorta (aortic vestibule)

Front 35

The secondary interventricular Foramen is closed by what?

Back 35

The membranous portion of the IV septum

Front 36

Divison of the common atrium

Back 36

Requires a special septum; two offsetting septa are needed to divide the atrium the two offset (primary atrial septum aka septum primum AND septum secudum); the compression of the septum primum against the septum secudum prevents flow from left to right; form the foramen ovale!!!

Front 37

The interatrial septa requiremednt

Back 37

must separate two atria, must allow for right-to-left shunting of blood; It must provide for only one way shunting

Front 38

The proximal outflow region forms?

Back 38

Ventricular Outlets (right and left); bulbar ridges contribute; cardiac muscle

Front 39

The distal outflow region forms?

Back 39

Pulmonary and aortic valves and pulmonary and aortic root; partitioned by fusion of bulbar ridges; neural crest contribution; cardiac muscle

Front 40

The aortic sac forms?

Back 40

Pulmonary (ventral component) and aortic root (dorsal component); The aortic sac is divided by a neural crest derived mesenchyme that forms the aorticopulmonary septum

Front 41

The cushion tissue in the outflow segments is called

Back 41

Conotruncal ridges or the bulbar ridges

Front 42

Formation of the Membranous Interventricular Septum

Back 42

2 components fuse together; Conotruncal septum (dorsal); Endocardial Cushion (ventral); and then they fust with the muscular interventricular septum

Front 43

Inlet portion of the right ventricle forms from?

Back 43

Primitive right ventricle; same for left ventricle

Front 44

Outlet portion of the right ventricle forms from

Back 44

Proximal outflow region; same for left ventricle

Front 45

Fetal Circulation facts

Back 45

Right heart pressure is greater than the left; blood returns through the placenta through the umbilical arteries; Pulmonary circulation is inactive (high vascular resistance)

Front 46

Ductus venosus

Back 46

Oxygen rich blood from the placenta is shunted around liver though the ductus venosus

Front 47

Oval Foramen

Back 47

Blood in the IVC is shunted to the left atrium through the Oval Foramen

Front 48

Ductus Arteriosus

Back 48

Blood leaving the right ventricle is shunted into the aorta through the Ductus Arteriosus

Front 49

Pharyngeal Arch 1 vessel development?

Back 49

contributes to maxillary and ex. carotid arteries

Front 50

Pharyngeal Arch 2 vessel development?

Back 50

Stems of the hyoid and stapedial arteries

Front 51

Pharyngeal Arch 3 vessel development?

Back 51

Proximal: common carotid arteries; Distal: internal carotid arteries

Front 52

Pharyngeal Arch 4 vessel development?

Back 52

Left-part of the aortic arch; Right-proximal right subclavian artery

Front 53

Pharyngeal Arch 6 vessel development?

Back 53

Left- proximal: left pulmonary artery, distal-ductus arteriosus; Right- proximal- right pulmonary artery, distal: degenerates