1. Muscles and nerves of the head Flashcards
what are the 2 main muscle groups of the head and how is each innervated
- muscles of facial expression - facial n.
2. muscles of mastication (all insert into mandible) - trigeminal n. (mandibular br.)
what is the function of occipitofrontalis and how is this tested
- function: eyebrow elevation and forehead skin wrinkling
- test: raise eyebrows against resistance
what is the function of orbicularis occuli and how is this tested
- orbital part: forceful eyelid closure (surrounds orbital margin)
- palpebral part: unconscious light eyelid closure, e.g. blink, sleep (in eyelid)
- test: squeeze eyelid against resistance
what is the function of levator palpebrae superioris and how is this muscle innervated
- function: upper eyelid retraction
- innervation: occulomotor n. (CN III)
superior tarsal fibres: SNS on CN III
what is the function and innervation of orbicularis oris
- compression and protrusion of lips
- buccal n.
what is the function and innervation of buccinator
- flattens cheek (holds against teeth when chewing, preventing food pooling)
- buccal n.
name the 4 muscles of mastication and their respective functions
Mandible elevation at TMJ:
- temporalis (+ mandible retraction)
- masseter (most powerful elevator)
- medial pterygoid
Mandible depression at TMJ:
4. lateral pterygoid (+ protrusion and lateral mov. when acting unilaterally)
which nerve provides main sensory innervation of neck and scalp - via which branches?
trigeminal n. (CN V):
- opthalmic n: scalp (anterior to vertex), forehead and nose
- maxillary n: upper lip and cheekbones
- mandibular n. lower lip, chin and lateral head and scalp (anterior to ear)
what is the main arterial supply and venous drainage to the face
- facial artery (branch of ECA) and ICA branches
- facial vein (drains into IJV)
