Muscles of the Back

Question 1

Muscles of superficial layer

Answer 1

trapezuis and latissimus dorsi

Question 2

muscles of deep layer

Answer 2

levator scapulae
rhomboideus major
rhomboideus minor

Question 3

trapezius covers the

Answer 3

upper half of the back from both sides

Question 4

origin of trapezius

Answer 4

1. back of skull : from protuberance and superior nuchal line
2. back of neck : from ligamentum nuchae and spine of 7th cervical vertebra
3. back of thorax : from spine of all thoracic vertebrae supraspinous ligaments

Question 5

insertion of trapezius

Answer 5

V shaped insertion

1. upper fibres : inserted to clavicle
2. middle fibres : inserted to acromion and upper lip of crest of spine of scapula
3. lower fibres : inserted into rough tubercle on crest of spine of scapula (near the root)

Question 6

insertion of trapezius is surrounded by

Answer 6

V shaped origin of deltoid

Question 7

nerve supply of trapezius

Answer 7

motor: spinal root of accessory nerve

sensory : cervical nerve number 3 & 4

Question 8

action of trapezius

Answer 8

1. maintains level of shoulder
2. upper fibres elevate shoulder girdle
3. upper and lower fibers rotate scapula so glenoid cavity looks upward
4. middle fibres act with rhomboid to retract scapula and brace the shoulder

Question 9

paralysis of trapezius leads to

Answer 9

shoulder drop

Question 10

latissimus dorsi

Answer 10

flat muscle that covers lower half of back down to iliac crest

Question 11

origin of latissimus dorsi

Answer 11

fleshy fibres from:

1. posterior third of outer lip of iliac crest
2. spines of lower 6 thoracic vertebrae
3. thoraco-lumbar fascia
4. outer surface of lower 4 ribs
5. few fibres from dorsal aspect of scapula

TRIVS

Question 12

insertion of latissimus dorsi

Answer 12

into floor of bicipital groove

Question 13

nerve supply of latissimus dorsi

Answer 13

thoraco-dorsal nerve

Question 14

action of latissimus dorsi

Answer 14

1. extension, medial rotation, and adduction of arm
2. act with sternocostal part of pectoralis major, pulls trunk upward
3. attaches to ribs and helps in violent expiration like coughing

Question 15

upper border of latissimus dorsi crosses over

Answer 15

inferior angle of scapula and has triple relation to teres major
it lies behind it then curves below it then goes in front of it.

Question 16

the latissimus dorsi fuses with ______ to form

Answer 16

teres major to form posterior axillary fold

Question 17

triangle of auscultation is located

Answer 17

medial to lower part of scapula

Question 18

boundaries of triangle of auscultation

Answer 18

above: trapezuis
below: latissimus dorsi
laterally: scapula

Question 19

floor of triangle of auscultation is formed by

Answer 19

1. rhomboideus major

2. sixth and seventh ribs and space in between

Question 20

_______ are heard clearly from triangle of auscultation

Answer 20

breath sounds

Question 21

lumbar triangle

Answer 21

just above iliac crest and site of hernia

Question 22

boundaries of lumbar triangle

Answer 22

below: iliac crest
medially: latissimus dorsi
laterally: external oblique muscle

Question 23

floor of lumbar triangle is formed by

Answer 23

internal abdominal oblique and tranversus abdominis muscles

Question 24

levator scapulae origin

Answer 24

from transverse processes of upper 4 vertebrae

Question 25

insertion of levator scapulae

Answer 25

into dorsal surface of scapula above root of spine

Question 26

nerve supply of levator scapulae

Answer 26

nerve to rhomboids (dorsal scapular nerve) C5

fibres from c3 and c4

Question 27

action of levator scapulae

Answer 27

1. acts with upper fibres of trapezius to elevate shoulder girdle
2. rotates scapula so that glenoid cavity look downwards
3. retracts scapula

Question 28

rhomboideus minor origin

Answer 28

ligamentum nuchae, spines of 7th cervical and 1st thoracic vertebrae

Question 29

rhomboideus minor insertion

Answer 29

into dorsal surface of scapula, opposite root of spine

Question 30

nerve supply of rhomboideus minor

Answer 30

nerve to rhomboids (dorsal scapular nerve, C5)

Question 31

action of rhomboideus minor

Answer 31

1. rotates scapula so glenoid cavity faces downwards

2. retracts scapula and braces shoulder back

Question 32

rhomboideus major origin

Answer 32

from spines of 2,3,4,5 thoracic vertebrae and their supraspinous ligaments

Question 33

rhomboideus major insertion

Answer 33

into dorsal surface of scapula from root of spine to inferior angle

Question 34

nerve supply of rhomboideus major

Answer 34

nerve to rhomboids (dorsal scapular nerve C5)

Question 35

action of rhomboideus major

Answer 35

1. rotates scapula so glenoid cavity faces downwards

2. retracts scapula and braces shoulder back