H and N

Question 1

Origin and insertion of the muscles of mastication (temp)

Answer 1

temporalis is a fan shapped muscle has three fibrers. anterior intermediate and posteriormost fibers.

Temporalis : O : Floor of temporal fossa
• Temporal fascia
insertion : Tip, anterior border,
and medial surface of
coronoid process
• Anterior border of
ramus of mandible
nerve supple : mandibular branch of trigeminal nerve.

Question 2

masseter

Answer 2

The masseter (Greek: masseter = a chewer) is a thick
quadrilateral muscle covering the lateral surface of the ramus
of the mandible including its coronoid process. The condylar
process is left uncovered.

Origin : Zygomatic arch adjoining
part of zygomatic process of
maxilla
insertion : Lateral surface of
ramus of mandible
• Coronoid process
nerve supply : mandibular nerve

Question 3

lateral pterygoid

Answer 3

It is a short, thick conical muscle with its apex pointing
backwards. It passes backwards and slightly laterally from
the roof and medial wall of the fossa to the neck of the
mandible.

Origin • Upper head from
infratemporal surface and
crest of greater wing of
sphenoid
• Lower head from lateral
surface of lateral pterygoid
plate
Insertion : • Pterygoid fovea on
anterior surface of
neck of mandible
• Articular disc and
capsule of TMJ
nerve supply : mandibular division of trigeminal nerve.

Question 4

medial pterygoid

Answer 4

The medial pterygoid is a thick quadrilateral muscle and
consists of two heads: superficial and deep.

O : • Superficial head from
tuberosity of maxilla
• Deep head from medial
surface of lateral pterygoid
plate
I : Medial surface of angle
adjoining ramus of
mandible
NS : mandibular division of trigeminal nerve.

Question 5

sternocleidomastoid

Answer 5

ORIGIN
• STERNAL HEAD: Superolateral part of front of Manubrium Sterni.
(Tendinous)
• CLAVICULAR HEAD: medial ⅓rd of superior surface of the clavicle.
(Musculotendinous)
INSERTION
• Lateral surface of MASTOID PROCESS, by a thick tendon.
• Lateral half of SUPERIOR NUCHAL LINE OF OCCIPITAL BONE, by a thin
aponeurosis.
NERVE SUPPLY
• MOTOR: spinal accessory nerve.