Exam 2: Muscles of Head, Neck, and Trunk Flashcards
Naming of Muscles
- actions
- body regions
- attachments
- fiber oreientation
- shape/size
- muscle head/tendons of origin
Epicranius
-composed of the occipitofrontalis muscle and an epicranial aponeurosis (flattened tendon)
Frontal Belly of Occipitofrontalis
-elevates eyebrows and wrinkles skin of forehead
Occipital Belly of Occipitofrontalis
-retracts scalp slightly
Orbicularis Oculi
- closes the eyes
- wink, blink, squint
Orbicularis Oris
- closes and purses lips
- kiss, pucker
Zygomaticus Major
- elevates corner of mouth
- smile
Depressor Anguli Oris
- depresses corner of mouth
- frown
Buccinator
- pulls cheeks against teeth when chewing
- some trumpet players stretch this out
Platysma
- tenses skin of neck, and depresses lower lip
- pout
Masseter
- elevates and protracts mandible
- muscle of mastication
Temporalis
- elevates and retracts mandible
- muscle of mastication
Medial Pterygoid
- elevates mandible and moves mandible side to side
- muscle of mastication
Lateral Pterygoid
- elevates mandible and moves mandible side to side
- muscle of mastication
Genioglossus
-protracts (protrudes) tongue
Styloglossus
- retracts tongue
Hyoglossus
-depresses tongue
Sternocleidomastoid
- each rotates head to one side, together: flex the head/neck
- attaches to sternum, clavicle, and mastoid process
- posterior neck muscle
Splenius Capitis
- each rotates head to one side, together: extend the head/neck
- head bandage
- posterior neck muscle
- Sternocleidomastoid and Slenius Capitis work together to rotate head but they perform opposite functions regarding flexing or extending the neck
Digastric
- elevates hyoid
- depresses mandible
- suprahyoid muscle
- anterior neck muscle
Stylohyoid
- elevates hyoid bone
- suprahyoid muscle
- anterior neck muscle
Mylohyoid
- elevates hyoid and raises floor of mouth
- suprahyoid muscle
- anterior neck muscle
Geniohyoid
- elevates hyoid bone
- suprahyoid muscle
- anterior neck muscle
Sternohyoid
- depresses hyoid
- infrahyoid muscle
- anterior neck muscle
Omohyoid
- depresses hyoid
- infrahyoid muscle
- anterior neck muscle
Sternothyroid
- depresses thyroid cartilage (not bone)
- infrahyoid muscle
- anterior neck muscle
Thyrohyoid
- depresses hyoid and raises thyroid cartilage
- infrahyoid muscle
- anterior neck muscle
Superficial Back Muscles
-move the scapula and humerus
Quadratus Lumborum
- together: extend lumbar vertebral column
- unilaterally: each laterally flexes vert column
- deep back muscle
Erector Spinae Group of Muscles
- Extend vertebral column
- Consists of:
a. Iliocostalis: lateral
b. longissimus: intermediate
c. spinalis: medial - deep back muscles
Superficial Thorax Muscles
-move upper limb, not ribs
Deep Thorax Muscles
-respiration muscles
Diaphragm
- contraction pulls the central portion down, increasing vertical dimensions of thorax
- deep thorax muscle
External Intercostals
- elevate ribs during inhalation
- fibers run inferomedially
- deep thorax muscle
Internal Intercostals
- depress ribs during exhalation
- fibers run inferolaterally
- deep thorax muscle
External Abdominal Oblique
- bilaterally flex vertebral column andcompress abdominal wall
- unilaterally: lateral flexion of vertebral column
- fibers run inferomedially
- similar to external intercostals
Internal Abdominal Oblique
- bilaterally: flex vertebral column and compress abdominal wall
- unilaterally: lateral flexion of vertebral column
- fibers run inferolaterally
- similar to inferior intercostals
Transversus Abdominus
- bilaterally: flex vertebral column and compress abdominal wall
- unilaterally:laterally flexes vertebral column
Rectus Abdominus
- flex vertebral column and compress abdominal wall
- straight fibers
Muscles of the Pelvic Floor and Perineum
- close inferior opening of pelvis
- support the pelvic organs - assist with defecation, voluntary part of urination, and childbirth
