The corrugator supercilii (Coiter's muscle) is a small narrow muscle at the inner extremity of the eyebrow, just beneath the occipito-frontalis and occularis palpebrarum muscles. It originates from the nasal prominence and the orbital portion of the orbicularis oculi muscle and inserts in the skin of the eyebrow. This muscle is innervated by the facial nerve (VII cranial nerve) and supplied by the facial artery. The corrugator supercilii draws the eyebrows downward and inward, producing wrinkles on the forehead. It is often called the ' frowning muscle'. Research Corrugator Supercilii
The occipito-frontalis is a broad musculo-fibrous layer that cover the episkull. It consists of two thin layers of muscle. The occipital portion, sometimes called the occipitalis muscle, is quadrilateral in form and about an inch and a half in length. It originates from the occipital bone, covers the back of the skull and inserts in the galia aponeurotica. The frontal portion, sometimes called the frontalis, is also quadrilateral in form. It is broader and its fibres are longer. It originates from the galea aponeurotica, covers the forehead and inserts in the skin of the eyebrows and nose. The frontalis and occipitalis portions of the muscle are joined together by a thin, flat intermediate tendon called the galia aponeurotica. It is located above the occipito and frontalis muscle and covers the top of the skull. The occipito-frontalis muscle is innervated by the facial nerve and is supplied by the occipital artery. The galia aponeurotica works with the occipito- frontalis muscles to move the scalp. The frontalis muscle elevates the eyebrows
and draws the scalp forward. The occipitalis muscle draws the scalp backward. Research Occipito-Frontalis
The orbicularis palpebrarum refers to the palpebral portion of the orbicularis oculi (sphincter oculi) muscle. The orbicularis oculi is a broad, thin, ring shaped layer of muscle that covers the eyelid and the surrounding orbit. Because of its shape it is classified as a sphincter muscle. The muscle is composed of three parts: the palpebral portion, the orbital portion, and the lachrimal portion. The palpebral portion covers the eyelid. It originates from the palpebral ligament, passes over each eyelid and inserts in the palpebral raphe. The orbital portion of the muscle surrounds the orbit, extending from the bottom of the forehead down to the front of the cheek. It originates from the frontal process of the maxilla, encircles the orbit, and inserts near its point of origin. The upper fibres of the orbital portion blend with the occipito-frontalis and corrugator supercilli. The lachrimal portion (tensor tarsi; Horner's muscle; Duverney's muscle) originates from the lachrimal crest inside of the bridge of the nose and passes across the lachrimal sac to insert with the palpebral portion of the muscle. This muscle is innervated by the facial nerve and supplied by the angular artery and branches of the temporal artery. The three portions work together to narrow the eye, thus causing the eye to close or blink. Research Orbicularis Palpebrarum
The pyramidalis nasi, or procerus muscle, is a thin sheath of muscle placed over the nasalbone between the eyes. Its origin is with the fascia covering the lower part of the nasalbone (bridge of the nose) and it is inserted into the frontalis portion of the occipito-frontalis muscle and the skin over the lower part of the forehead between the two eyebrows. It is innervated by branches of the facial nerve (VII cranial nerve) and supplied by branches of the facial artery. The muscle draws the eyebrows down and together causing wrinkles across the bridge of the nose. It is used when expressing anger, pain, or frowning or concentrating. Research Pyramidalis Nasi
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Corrugator Supercilii
