The zona orbicularis acts like a buttonhole on the femoral head and assists in maintaining the contact in the joint.
The zona orbicularis assists in maintaining the contact in the joint by acting like a buttonhole on the femoral head.
As a result of the orbicularis oculi weakness, patients may suffer from exposure keratopathy (damage to cornea) from the inability to close the eyes tightly.
The main muscles, in the upper eyelid, that control the opening and closing are the orbicularis oculi and levator palpebrae superioris muscle.
For example: compression to the facial nerve causes a lesion and the set of axons that innervates the orbicularis oris (mouth muscle) degenerate.
This time though, only 50% of the set of axons that innervate the orbicularis oris successfully reinnervate the original site.
As time progresses, it spreads to the whole lid, then to the orbicularis oris muscle around the lips, and buccinator muscle in the cheekbone area.
Four such muscles that were activated were the orbicularis oculi, zygomaticus, the corrugator, and levator.
