Posterior Triangle

Question 1

Floor of posterior triangle

Answer 1

prevertebral layer of deep cervical fascia
splenius capitis m
levator scapulae m.
-posterior scalene m.
-middle scalene m.
-anterior scalene m.
roots of brachial plexus

Question 2

Splenious capitis m attachment

Answer 2

-from the ligament nuchae and the spinous process of C7-T3 to occipital bone and mastoid process

Question 3

Levator scapulae m.

Answer 3

-Transverse process of C2-C4 to superior medical angle of scapula

Question 4

Posterior scalene m.

Answer 4

-Transverse process of C4-C6 to 2nd rib

Question 5

Middle scalene m.

Answer 5

-Transverse process of C4-C6 to 1st rib

Question 6

Anterior scalene m.

Answer 6

-Transverse process of C4-C6 to 1st rib

Question 7

Cercical Plexus

Answer 7

• Level of origin–Ventral rami of C2, C3, & C4 with contribuation from C1 and C5
• Sensory branches of plexus
• Cervical plexus block
• Motor branches of the plexus

Question 8

Sensory branches of the plexus

Answer 8

-Lesser occiptal (C2) sometimes C3
-Great auricular (C2,C3)
-Transverse cervical (c2, C3)
Supraclavicular (C3, C4)

Question 9

Deep cervical fascia

Answer 9

• 3 layers + carotid shealth
• —Investing layer, prevertebral layer, pretracheal layer
• functions—-supports organs, blood vessels…forms natural cleavage spaces, and allows movements of organs during swallowing and turning head

Question 10

Investing layer

Answer 10

-surrounds the entire neck deep to the superficial fascia
-splits to go both sides of superficial muscles (trap, SCM, strap m.)
Anterior part of neck will split to surround the submandibular gland & form capsule of parotid gland

Question 11

Prevertebral layer

Answer 11

• surrounds the vertebral column and muscles closely associated with it
• extends from hyoid to to thorax
• tubular sheath that surrounds deep back muscles
• base of skull to T3
• extends laterally as axiallary sheath
• forms floor of posterior triangle
• retropharyngeal space-potential space between the prevertrbarl fascia & teh fascia of pharynx

Question 12

Pretracheal layer

Answer 12

• very thin layer in the anterior part of the anterior triangle
• surrounds the trachea, esophagus, & thyroid gland
• helps form the visceral compartment
• blends laterally with carotid sheath

Question 13

Roof of the posterior triangle

Answer 13

• deep cervical fascia
• superficial cervical fascia containing superficical veins and nerves
• platysma m
• skin

Question 14

Sensory branches of plexus (cervical plexus)

Answer 14

• exit from posterior part of SCM -nerve point

- joined by post ganglionic sympathetics

Question 15

Lesser occipital

Answer 15

• C2–sometimes C3

- Supplies the skin of the neck and scalp posterosuperior to the auricle

Question 16

Greater auricle

Answer 16

• C2, C3
• travels superomedically across the SCM with the external jugular vein..aka.. goes up the SCM in the middle with the external jugular
• Supplies the skin inferior to the auricle, over the parotid gland and posterior part of auricle

Question 17

Transverse cervical

Answer 17

• C2, C3
• goes across the SCM-crossses it horizontally
• supplies the skin over the anterior triangle

Question 18

Supraclavicular

Answer 18

• C3, C4
• Originates as a single trunk but divides into 3 branches
• –medial branch, intermediate branch, lateral branch
• supplies the skin over the clavicle & the superior wall of the chest and anterolateral part of the shoulder

Question 19

Motor branches of cervical plexus

Answer 19

• Ansa cervicalis

- Phrenic nerve

Question 20

Ansa cervicalis

Answer 20

• C1, C2, C3
• superior ramus—-C1, C2
• inferior ramus—-C2, C3
• branches of ansa cervicalis supply the strap muscles of neck (sterohyoid, sternohyoid, superior and inferior bellies of omohyoid)
• C1 fibers of plexus which contribure to the superior ramus of the ansa cervicalis supply the thyrohoid and geniohyoid muscles only

Question 21

Phrenic nerve

Answer 21

• C3, C4, C5
• motor supply to the diagram–sole motor nerve to it
• also supplies the pericardium and part of the pleura
• damage to the nerve will cause paralysis to 1/2 of the diaphragm of affected side
• sensory to the central part of the diaphragm

Question 22

C2 sensory nerves

Answer 22

-lesser occipital, great auricular, transverse cervical

Question 23

C3

Answer 23

-great auricular, transverse cervical, supraclavicular—3 branches-lateral, intermediate, medial

Question 24

C4

Answer 24

-supraclavicular

Question 25

Spinal Accessory nerve

Answer 25

• cranial nerve XI
• motor supply to the trapezius and SCM
• courses obliquely across the posterior triangle dividing it into two equal halves