Muscles of the Neck and Back Flashcards
Which muscle divides the anterior and posterior anatomical triangles of the neck?
Sternocleidomastoid
2 groups of muscles that move hyoid bone
- Suprahyoid muscles
- Infrahyoid muscles
Suprahyoid muscles
- Digastric
- Mylohyoid
- Stylohyoid
- Geniohyoid
Action of suprahyoid muscles
Elevate hyoid and larynx during swallowing
Infrahyoid muscles
- Thyrohyoid
- Sternothyroid
- Sternohyoid
- Omohyoid
Action of infrahyoid muscles
Depress hyoid and larynx during swallowing and speech
2 muscle groups of the body wall
- Anterolateral muscle wall
- Posterior muscle wall
What does the fascial covering of the neck and back attach to medially?
- Ligamentum nuchae
- Tips of spinous processes
- Supraspinal ligament of entire vertebral column
- Median crest of sacrum
2 broad groups of muscles of the back
- Extrinsic muscles
- Intrinsic muscles
2 groups of extrinsic back muscles
- Superficial
- Intermediate
Superficial extrinsic back muscles
- Trapezius
- Latissimus dorsi
- Levator scapulae
- Rhomboid major
- Rhomboid minor
Origin, insertion and action of trapezius
- Descending part (superior fibres)
> O = medial 1/3 of superior nuchal line, external occipital protuberance, nuchal ligament
> I = lateral 1/3 of clavicle
> A = draws scapula superomedially, extension + lateral flexion of head + neck, rotation of head - Transverse part (middle fibres)
> O = spinous processes + supraspinous ligaments of T1-4
> I = medial acromial margin, superior crest of spine of scapula
> A = draws scapula medially - Ascending part (inferior fibres)
> O = spinous processes + supraspinous ligaments of T4-12
> I = latera apex of medial end of scapular spine
> A = draws scapula inferomedially
Motor innervation of trapezius
Accessory nerve (CNXI)
Origin, insertion and action of latissimus dorsi
- Origin
> Vertebral part = spinous processes of T7-12, thoracolumbar fascia
> Iliac part = posterior 1/3 of crest of ilium
> Costal part = ribs 9-12
> Scapular part = inferior angle of scapula - Insertion = intertubercular sulcus of humerus
- Action = arm internal rotation, adduction + extension (+ assists respiration)
Innervation of latissimus dorsi
Thoracodorsal nerve (C6-8)