articulatio cricothyroidea The articulatio cricothyroidea is a ball joint, the joint head is formed by the medial portion of the lower horn of the thyroid glenoid and the outer wall of the cricoied .
Movements to be a frontal axis which right and left from a functional point of view a joint unit. by contraction of the muscle cricothyroideus thyroied the distance between the bottom and top cricoidring tighten, which the vocal cords and prolong be instituted. The latter are stretched between the shield cartilage and arythenoieden placed on the dorsal part of the cricoied.
The elastic joint capsule will slow rotation and cartilage from extreme positions back to the initial creation , once the action of the forces affecting stops.
articulatio cricoarythenoidea
The articulatio cricoarythenoidea is a eigewricht : the glenoid is formed by the concave under surface of the arythenoid, the joint head located in the lamina cricoidea, slopes down to bottom, outside and forward. Movements performed by rotation and translation . A combination of both movements gives a screw movement. The translation is a sliding motion along the axis of rotation for both articular surfaces passing to caudal, ventral and lateral . In translation, the arythenoieden lageraf diagonally forward or backward and upstream sliding. By the screw motion will processus vocalizations in phonation in the idle position to rotate medially, caudally and ventrally. The vocal cords will this movement during voice production, therefore, shorter than during rest, at least in the chest register.
The joint capsule of the articulatio arythenoidea is weak but is enhanced by the cricoarythenoideum posterius ligament, so that after the cessation of muscle actions on the arythenoied this cartilage can take back its neutral position.
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