Neck Muscles

Question 1

Answer 1

M. omotransversarius

o Origin: distal part of scapular spine, then runs under m. sternocleidomastoideus

o Insertion: caudal border of ala atlantis

o Action: if limb is free: draws shoulder cranially; if limb is fixed: flexes neck laterally

Question 2

Answer 2

Intersectio Clavicularis

Question 3

Answer 3

:m. brachiocephalicus: From humerus to head and neck

:o m. cleidobrachialis

o originating: on distal cranial surface of humerus and crista humeri

o inserting: on clavicular intersection

o Action: If forelimb is fixed: unilateral contraction of the muscle moves head into the

lateral direction, bilateral contraction fixes head and neck (or bends downward). If limb is free (it’s in an elevated position), it will move forelimb cranially.

Question 4

Answer 4

m. brachiocephalicus: From humerus to head and neck

:m. cleidocephalicus
o Origin: on clavicular intersection o Insertion

m. cleidocervicalis: o Insertion: dorsal midline (raphe cervicis) over cranial half of neck

o Action: If forelimb is fixed: unilateral contraction of the muscle moves head into the lateral direction, bilateral contraction fixes head and neck (or bends downward). If limb is free (it’s in an elevated position), it will move forelimb cranially.

Question 5

Answer 5

m. brachiocephalicus: From humerus to head and neck

:m. cleidocephalicus
o Origin: on clavicular intersection o Insertion

m. cleidomastoideus: o insertion: mastoid part of temporal bone

o Action: If forelimb is fixed: unilateral contraction of the muscle moves head into the lateral direction, bilateral contraction fixes head and neck (or bends downward). If limb is free (it’s in an elevated position), it will move forelimb cranially.

Question 6

Answer 6

m. sternocephalicus: From sternum to head

o Origin: manubrium sterni

o Insertion: m. sternomastoideus: mastoid part of temporal bone

o Action: unilateral contraction draws head and neck to one side (latero-ventral flexion)

bilateral contraction draws head down

Question 7

Answer 7

m. sternocephalicus: From sternum to head

o Origin: manubrium sterni

o Insertion: m. sternooccipitalis: nuchal crest of occipital bone

o Action: unilateral contraction draws head and neck to one side (latero-ventral flexion)

bilateral contraction draws head down