anterior triangle of the neck Flashcards
what muscle forms the posterior border of the anterior triangle of the neck ?
sternocleidomastoid
what are the boundaries of the anterior triangle of the neck?
anterior border - imaginary midline of the neck
posterior boundary - anterior border of SCM
base - mandible
what are the divisions of the anterior triangle of the neck?
submental
submandibular
carotid
muscular
what is the platysma?
a thin layer that covers the anterior and lateral surfaces of the neck
what muscle group is platysma classified as part of?
classified as a muscle of facial expression
what is the function of platysma?
acts to tighten the skin of the neck
what nerve innervates platysma?
CN 7 (facial nerve)
where do the internal and external jugular veins lie?
external jugular vein - anterior to SCM (in posterior triangle of the neck )
internal jugular vein- posterior to SCM (in anterior triangle of the neck)
where does the facial vein drain into?
into the internal jugular vein
what vein does the internal jugular vein join with and what vein do these two veins form?
the internal jugular vein joins w/ the subclavian vein to form the brachiocephalic vein (one on either side)
what is the cervical plexus formed from?
the anterior rami of C1-C4
what is the function of the cervical plexus?
the nerves from the cervical plexus give motor supply to some of the muscles of the anterior triangle and the sensory nerves supply the skin of the neck
how do the motor branches from the cervical plexus supply the supra and infra hyoid muscles of the neck?
the motor branch form a loop of nerve tissue (ansa cervicalis) to supply some of the supra and infrahyoid muscles
the ansa cervicalis contains nerve fibres from where?
C1-C3
where does the ansa cervicalis sit?
on the anterior surface of the carotid sheath
where does the hyoid bone lie?
between the mandible and the larynx
what muscles attach to the hyoid bone?
suprahyoid muscles and infra hyoid muscles
what is the general function of the supra hyoid muscles?
generally act to raise the hyoid bone
what are the supra hyoid muscles?
mylohyoid
digastric
stylohyoid
geniohyoid
describe digastric muscle
digastric has two muscle bellies that are divided by a small tendon that passes through a loop of connective tissue that is attached to the hyoid bone
where does the anterior belly of digastric attach?
the mandible
where does the posterior belly of digastric attach?
the mastoid process of the temporal bone
where does stylohyoid attach?
to the styloid process of the temporal bone
where does mylohyoid attach?
to the mylohyoid line of the mandible
what muscles forms a diaphragm in the floor of the oral cavity?
mylohyoid
what muscle lies deep to mylohyoid?
geniohyoid
where does geniohyoid attach?
to the inferior genial tubercle of the mandible