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💀anatomy and physiology i review

Atrioventricular Cushions

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

The atrioventricular cushions are thickenings of the cardiac jelly that form between the atria and ventricles during the development of the heart. These cushions play a crucial role in the formation of the atrioventricular valves and septa, which are essential components of the mature heart's structure and function.

5 Must Know Facts For Your Next Test

  1. The atrioventricular cushions form from the cardiac jelly and play a crucial role in the development of the atrioventricular valves and septa.
  2. The cushions initially appear as swellings in the cardiac jelly and later fuse to form the atrioventricular valves and the membranous part of the interventricular septum.
  3. Abnormalities in the development of the atrioventricular cushions can lead to congenital heart defects, such as septal defects and valve malformations.
  4. The atrioventricular cushions also contribute to the formation of the atrioventricular node, which is responsible for the coordinated contraction of the atria and ventricles.
  5. The proper formation and development of the atrioventricular cushions are essential for the efficient pumping and circulation of blood through the mature heart.

Review Questions

  • Explain the role of the atrioventricular cushions in the development of the heart's structures.
    • The atrioventricular cushions are crucial for the formation of the atrioventricular valves and septa, which are essential components of the mature heart's structure. The cushions initially appear as swellings in the cardiac jelly and later fuse to form these vital structures. Abnormalities in the development of the atrioventricular cushions can lead to congenital heart defects, underscoring their importance in the proper formation and function of the heart.
  • Describe the relationship between the atrioventricular cushions and the cardiac jelly during heart development.
    • The atrioventricular cushions form from the cardiac jelly, which is the gelatinous extracellular matrix that fills the space between the myocardium and endocardium during early heart development. The cardiac jelly provides the structural and signaling cues necessary for the formation and growth of the atrioventricular cushions, which then go on to play a critical role in the development of the atrioventricular valves and septa. The interplay between the cardiac jelly and the atrioventricular cushions is essential for the proper patterning and morphogenesis of the mature heart.
  • Evaluate the clinical significance of understanding the development of the atrioventricular cushions in the context of congenital heart defects.
    • Comprehensive knowledge of the atrioventricular cushions and their role in heart development is crucial for understanding the etiology of various congenital heart defects. Abnormalities in the formation or patterning of the atrioventricular cushions can lead to structural malformations, such as septal defects and valve abnormalities. By elucidating the mechanisms underlying the development of the atrioventricular cushions, researchers and clinicians can better identify the genetic and environmental factors that contribute to these congenital heart defects. This knowledge can inform the development of more effective diagnostic tools, preventive strategies, and targeted treatments, ultimately improving patient outcomes and quality of life.