Muscles Of The Neck Flashcards
Superior attachment of the platysma muscle
inferior border of mandible and tissues of lower face
Inferior attachment of the platysma muscle
fascia covering pectoralis major and deltoid muscles
Platysma nerve supply
cervical branch of facial nerve
Action of platysma muscle
1- tenses skin as in shaving the neck or easing a tight collar
2- depresses mandible and corners of mouth as in expression of sadness or fright
A paired muscle in the superficial layers of the anterior portion of the neck; passes obliquely across the side of the neck; thick and narrow at its central part, but broader and thinner at either end
SCM
Origin of SCM
Anterior and superior manubrium and superior medial third of clavicle
Insertion of SCM
Lateral aspect of mastoid process and anterior half of superior nuchal line
SCM nerve supply
Spinal accessory nerve (lateral roots C1-5)
SCM action:
1- flexes and laterally rotates cervical spine
2- protracts head when acting together
3- extends neck when neck already partially extended
Anterior neck muscles / strap muscles
- Suprahyoid muscles
2. Infrahyoid muscles
region above (superior) the hyoid bone in the neck
Suprahyoid
Suprahyoid muscles
- digastric
- stylohyoid
- geniohyoid
- mylohyoid
Infrahyoid muscles
- sternothyroid
- sternohyoid
- thyrohyoid
- omohyoid
A group of four pairs of muscles in the anterior part of the neck above the hyoid bone
Suprahyoid muscles
O: mastoid process mandible
I: intermediate tendon (hyoid bone)
N: anterior belly - mandibular division (V3);
posterior belly - facial nerve (CN VII)
Digastric
O: styloid process
I: greater cornu of hyoid bone
N: facial nerve
Stylohyoid
O: symphysis menti
I: hyoid bone
N: C1 via hypoglossal nerve
Geniohyoid
O: mylohyoid line of mandible
I: median raphe
N: mylohyoid nerve from mandibular nerve
Mylohyoid
- elevate the hyoid when mandible is fixed
2. opens the jaw when the hyoid is fixed
Digastric
elevate the hyoid during swallowing
Stylohyoid
carry hyoid bone and the tongue upward during deglutition
Geniohyoid
raises oral cavity floor, elevates hyoid, depresses mandible
Mylohyoid
it has two bellies; connected by a tendon, which attaches to the body of the hyoid bone.
Digastric
a slender muscle, lying in front of, and above the posterior belly of the digastric muscle.
It is perforated, near its insertion, by the tendon of the Digastric muscle
Stylohyoid
a narrow muscle situated superior to the medial border of the mylohyoid muscle
Geniohyoid
It forms, with its fellow of the opposite side, a muscular floor for the cavity of the mouth
Geniohyoid
flat and triangular, and is situated immediately above the anterior belly of the digastric muscle; forms a muscular floor for the cavity of the mouth
Mylohyoid
A group of four pairs of muscles in the anterior part of the neck below the hyoid bone.
Infrahyoid muscles
O: sternum
I: thyroid cartilage
N: ansa cervicalis from the cervical plexus(C1-3)
Sternothyroid
O: sternum
I: hyoid bone
N: ansa cervicalis from the cervical plexus(C1-3)
Sternohyoid
O: thyroid cartilage
I: hyoid bone
N: C1
Thyrohyoid
O: superior border of scapula
I: hyoid bone
N: ansa cervicalis from the cervical plexus(C1-3)
Omohyoid
a thin, narrow muscle attaching the hyoid bone to the sternum
Sternohyoid
shorter and wider than the Sternohyoid, beneath which it is situated
Sternothyroid
a small, quadrilateral muscle appearing like an upward continuation of the Sternothyroid
Thyrohyoid
a muscle at the front of the neck that consists of two bellies separated by an intermediate tendon
Omohyoid
The inferior belly of the Omohyoid divides the posterior triangle of the neck into
upper or occipital triangle
lower or subclavian triangle
The superior belly of the omohyoid divides the anterior triangle into
upper or carotid triangle
lower or muscular triangle
Infrahyoid muscle action
depress the hyoid bone and larynx during swallowing and speaking
Broad thin subcutaneous sheet of muscle, superficial to the external jugular vein (EJV) and the main cutaneous nerves of the neck
Platysma
