When does the human heart start beating during embryonic development?

The heart begins to beat by day 22 (end of the 3rd week of intrauterine life), with blood flow visible via Doppler in the 4th week.

What are the five regions of the early heart tube and what do they become?

The five regions are truncus arteriosus (becomes ascending aorta and pulmonary trunk), bulbus cordis (becomes outflow tracts of ventricles), primitive ventricle (becomes trabeculated parts of ventricles), primitive atrium (becomes rough parts of atria), and sinus venosus (becomes smooth part of right atrium and coronary sinus).

How does the heart form its chambers and septa during development?

Chambers and septa form through processes like fusion of AV endocardial cushions for the atrioventricular septum, formation of septum primum and secundum for the interatrial septum, development of muscular, bulbar, and membranous parts for the interventricular septum, and creation of a spiral aorticopulmonary septum from truncal ridges.

What are some common congenital heart defects related to heart development?

Common defects include atrial septal defect (ASD), ventricular septal defect (VSD), Tetralogy of Fallot, and persistent truncus arteriosus.

How does the pericardium develop in the embryo?

The pericardium develops with the visceral layer from splanchnopleuric mesoderm, the parietal layer and fibrous pericardium from somatopleuric mesoderm, and sinuses form from structures like the dorsal mesocardium.

What is the origin of the heart's conducting system?

The conducting system originates from specialized cardiomyocytes, with the SA node from the right sinus venosus wall, the AV node and bundle from the left sinus wall and AV canal, and bundle branches and Purkinje fibers extending through ventricular myocardium.

What causes cardiac looping during embryonic development?

Cardiac looping occurs as the heart grows and bends into a U-shaped bulboventricular loop due to space constraints in the pericardial cavity, forming cephalic and caudal limbs.

Heart Development – Looping, Septation & Defects

❓ Frequently Asked Questions