posterior neck triangle

Question 1

borders of posterior triangle

Answer 1

posterior border of SCM
anterior border of trapezius
middle 3rd of clavicle
occipital bone

Question 2

sections of posterior triangle

Answer 2

occipital
subclavian

Question 2

muscles of posterior triangle

Answer 2

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Sternocleidomastoid
Levator scapulae muscle
Scalene (anterior & middle)
Trapezius
Omohyoid (inferior belly)
(Spelnius capitus
Posterior scalene)

Question 2

sternocleidomastoid origin, insertion, action and innervation

Answer 2

origin: sternal head - manubrium of sternum, clavicular head - medial 3rd of clavicle
insertion: sternal head - lateral of superior nuchal line, clavicular head - lateral surface of mastoid process
action: draws head forward (both SCMs) or tilts head towards ipsilateral shoulder while turning face contralaterally (one SCM)
innervation: CN XI

Question 3

levator scapulae origin, insertion, action and innervation

Answer 3

origin: C1 - C4
insertion: scapula
action: elevates scapula
innervation: C3, C4 and dorsal scapular nerve C4 and C5

Question 4

anterior scalene origin, insertion, action and innervation

Answer 4

origin: C3-C6
insertion: rib 1 and scalene tubercle
action: elevates 1st rib
innervation: anterior rami of C3-C7

Question 5

middle scalene origin, insertion, action and innervation

Answer 5

origin: C4-C7
insertion: upper surface of rib 1
action: elevates 1st rib
innervation: anterior rami of C4-C7

Question 6

trapezius origin, insertion, action and innervation

Answer 6

origin: superior nuchal line
insertion: lateral 3rd of clavicle
action: Assists in rotating scapula during abduction of humerus; upper fibres elevate, middle adduct & lower depress scapula
innervation: CN XI spinal accessory

Question 7

what are the muscular branches of cervical plexus

Answer 7

phrenic nerve (C3, C4, C5)
ansa cervicalis (C1, C2, C3)
branches to preverterbral and verterbral muscles

Question 8

what are cutaneous branches of cervical plexus

Answer 8

C2: lesser occipital nerves
C2 and C3: greater auricular and transverse cervical nerves
C3 and C4: supravclavicular nerves