Posterior Triangle Flashcards
1
Q
What are the boundaries of the Posterior triangle?
A
- Anteriorly, by the posterior edge of SCM
- Posteriorly by anterior edge of trapezius muscle
- BASE: middle of 1/3 clavicle
- APEX: the occipital bone just posterior to the mastoid process
2
Q
STERNOCLEIDOMASTOID MUSCLE STERNAL HEAD (4)
A
- ORIGIN: upper part of anterior surface of manubrium of sternum
- INSERTION: lateral 1/2 of superior nuchal line
- INNERVATION: accessory nerve [XI] and branches from anterior rami of C2 to C3 (C4)
- FUNCTION:individually tilt head towards shoulder on same side,
rotating head to turn face to pop side
- ACTING TOGETHER: draw head forwards
3
Q
STERNOCLEIDOMASTOID MUSCLE - CLAVICULAR HEAD (4)
A
- ORIGIN: superior surface of medial 1/3 of clavicle
- INSERTION: lateral surface of mastoid process
- INNERVATION: Accessory nerve (XI) and branches from C2-C3(C4)
- FUNCTION:
- Individual= tilt head towards shoulder on same side, rotating head turn face opposite side
ACTING TOGETHER: draw head forwards
4
Q
TRAPEZIUS(4)
A
- ORIGIN:
- superior nuchal line
- external occipital protuberance
- ligamentum nuchae
- spinous processes of vertebrae CVII to TXII - INSERTION:
- lateral 1/3 of clavicle
- acromion
- spine of scapula - INNERATION: motor accessory nerve (XI); proprioception - C3 AND C4
- . FUNCTION; assists scapula during abduction go humerus above horizontal
- upper fibers- elevate
- middle fibres= ADDUCT
- lower fibres = depress scapula
5
Q
Splenius Capitis (4)
A
- ORIGIN:
- lower half of ligament nuchal
- spinous processes of vertebrae CVII to TVI - INSERTION:
- mastoid process,
- skull below lateral 1/3 of superior nuchal line
3.INNERVATION: posterior rami middle cervical nerves
FUNCTION:
- together draw head backwards individually
- draw and rotate head to one side (turn face to same side)
6
Q
Levator scapulae (4)
A
- ORIGIN:Transverse processes of C1 TO C4
- INSERTION: upper part of medial border of scapula
- INNERVATION:C3,C4 and dorsal scapular nerve (C4,C5)
- FUNCTION: elevates the scapula
7
Q
POSTERIOR SCALENE
A
- ORIGIN: posterior tubercles of vertebrae CIV to CVI
- INSERTION: Upper part of medial border of scapula
- INNERVATION: anterior rami of C5 TO C7
- F: elevation rib II
8
Q
MIDDLE SCALENE:
A
- O: transverse processes of vertebrae CII to CVII
- I: upper surface of rib 1 between tubercle and groove for subclavian artery
- INNERVATION: anterior rami of C3-C7
- FUNCITON: elevation of rib 1
9
Q
Anterior scalene
A
- O: Anterior tubercles fo transverse processes of vertebra CIII TO CVI
- I: scalene tubercle and upper surface of rib I
- INN: anterior rami of C4 TO C7
- FUNCTION: el. rib 1
10
Q
OMOHYOID
A
- O: superior border fo scapula medial to scapula notch
- I: inferior border of body of hyoid bone
- INN: ansa cervicalis; anterior rami of C1 AND C3
- depress the hyoid bone
11
Q
What divides the posterior triangle and what subdivisions are formed
A
- Omohyoid muscle splits the posterior triangle of neck into 2
- OCCIPITAL TRIANGLE: larger, superior part
- SUBCLAVIAN TRIANGLE: contains distal portion of the subclavian artery
12
Q
What are the muscle contents of the posterior triangle?
A
- OMOHYOID MSUCLES: split into 2 bellies by tendon where the inferior belly crosses post triangle splitting to 2. Then cross underneath SCM to enter anterior triangle of neck
- VERTEBRAL MUSCLES: ( covered by prevertebral fascia) form the floor of the posterior triangle:
- spleius capitis
- levator scapulae
- anterior, middle and posterior scalene
13
Q
What are the vessel contents in the posterior triangle?
A
- EXTERNAL JUGULAR VEIN: in here it will join the subclavian vein
- SUBCLAVIAN , TRANSVERSE CERVICA, SUPRASCAPULAR VEINS AND ARTERIES
14
Q
Neve contents in the posterior triangle
A
- accessory nerve (CN XI)
- cervical plexus: forms the muscles of the floor of the post triangle
- phrenic nerve
- the trunks of the brachial plexus also cross floor of post triangle
