THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -A normal trachea (windpipe) has many rings made of cartilage (a strong and flexible tissue). These rings are C-shaped and support the trachea but also allow it to move and flex when your child breathes. Complete tracheal rings are a birth defect in these rings that causes them to be O-shaped instead of C-shaped.

Detailed explanation-2: -The cricoid cartilage is a hyaline cartilage ring which fully encircles the trachea and composes the inferior-most boundary of the laryngeal skeleton.

Detailed explanation-3: -In the trachea, or windpipe, there are tracheal rings, also known as tracheal cartilages. Cartilage is strong but flexible tissue. The tracheal cartilages help support the trachea while still allowing it to move and flex during breathing.

Detailed explanation-4: -C-shaped cartilaginous rings reinforces the anterior and lateral sides of the trachea to protect and maintain the airway open. (The cartilaginous rings are incomplete because this allows the trachea to collapse slightly to allow food to pass down the esophagus.)