Neck Dissection Anatomy

Question 1

platysma origin

Answer 1

fascia overlying the pectoralis major and deltoid muscle

Question 2

platysma insertion

Answer 2

1) depression muscles of the corner of the mouth,
2) the mandible, and
3) the SMAS layer of the face

Question 3

platysma function

Answer 3

1) wrinkles the the neck
2) depresses the corner of the mouth
3) increases the diameter of the neck
4) assists in venous return

Question 4

platysma present in midline?

Answer 4

no

Question 5

platysma fibers run in which direction relative to SCM

Answer 5

opposite

Question 6

SCM origin

Answer 6

1) medial third of the clavicle (clavicular head)

2) manubrium (sternal head)

Question 7

SCM insertion

Answer 7

mastoid process

Question 8

SCM nerve supply

Answer 8

CN XI

Question 9

SCM blood supply

Answer 9

1) occipital a. or direct from ECA
2) superior thyroid a.
3) transverse cervical

Question 10

SCM function

Answer 10

turns head toward opposite side and tilts head toward the ipsilateral shoulder

Question 11

omohyoid origin

Answer 11

upper border of the scapula

Question 12

omohyoid insertion

Answer 12

1) via the intermediate tendon onto the clavicle and first rib
2) hyoid bone lateral to the sternohyoid muscle

Question 13

omohyoid blood supply

Answer 13

inferior thyroid artery

Question 14

omohyoid function

Answer 14

1) depress hyoid

2) tense the deep cervical fascia

Question 15

omohyoid absent in what percentage of individuals?

Answer 15

10%

Question 16

omohyoid inferior belly lies superficial to what structures?

Answer 16

brachial plexus
phrenic nerve
transverse cervical vessels