ANATOMY

Detailed explanation-1: -The orbicularis oculi muscle closes the eyelids and assists in pumping the tears from the eye into the nasolacrimal duct system. The orbital section of the orbicularis oculi is more involved in the voluntary closure of the eyelid, such as with winking and forced squeezing.

Detailed explanation-2: -The Orbicularis Oculi The Orbicularis Oculi muscle opens and closes the eyelids thus allowing us to blink, wink or squint in bright sunlight.

Detailed explanation-3: -The medial rectus muscle pulls the eye inwards and the lateral rectus outwards. The superior rectus is responsible for upwards movements of the eye and in the opposite direction, the inferior rectus muscle mostly pulls the eye downwards.

Detailed explanation-4: -Therefore, the orbicularis oculi muscle plays a vital role in facial expression and various ocular reflexes such as frowning, squinting, and eye closure. There is a palpebral portion that can be contracted actively and passively. There is an upper and lower section of the palpebral fibers.

Detailed explanation-5: -The orbicularis oris muscle contributes to the form and shape of the lips. Contraction of this muscle closes and protracts the lips (Fig. 2.13). The position and movement of the lips is acted upon by several mimetic muscles that elevate and depress the lips.