Muscle
Occipitofrontalis
Moves the scalp and lifts the brows
High-yield
Both bellies receive facial nerve motor supply. Forehead movement is often relatively preserved in a unilateral supranuclear facial lesion, but this finding alone does not establish the cause of facial weakness.
Overview
A broad tendon sheet, the epicranial aponeurosis, connects the frontal and occipital muscle bellies across the scalp. The frontal belly lifts the eyebrows and produces horizontal forehead lines; the occipital belly draws the scalp backward.
Reference facts
- Origin
- Frontal belly: epicranial aponeurosis. Occipital belly: lateral superior nuchal region and adjacent mastoid region
- Insertion
- Frontal belly: eyebrow and forehead skin. Occipital belly: epicranial aponeurosis
- Action
- Lifts the eyebrows and wrinkles the forehead; retracts the scalp
- Innervation
- Frontal belly: temporal branches of CN VII. Occipital belly: posterior auricular branch of CN VII
- Blood supply
- Supraorbital and supratrochlear vessels anteriorly; occipital and posterior auricular vessels posteriorly, with superficial temporal contributions
Mnemonic
Read SCALP from superficial to deep: Skin, dense Connective tissue, Aponeurosis, Loose connective tissue, Pericranium.
Clinical correlation
A wound dividing the aponeurosis can gape under muscle tension. The loose tissue beneath it communicates with emissary veins, creating a possible route for infection to spread toward intracranial venous channels.
Frequently asked questions
What does the occipitofrontalis do?
Lifts the eyebrows and wrinkles the forehead; retracts the scalp.
What nerve innervates the occipitofrontalis?
Frontal belly: temporal branches of CN VII. Occipital belly: posterior auricular branch of CN VII.
Where does the occipitofrontalis attach?
Origin: Frontal belly: epicranial aponeurosis. Occipital belly: lateral superior nuchal region and adjacent mastoid region. Insertion: Frontal belly: eyebrow and forehead skin. Occipital belly: epicranial aponeurosis.
What is the blood supply of the occipitofrontalis?
Supraorbital and supratrochlear vessels anteriorly; occipital and posterior auricular vessels posteriorly, with superficial temporal contributions.