Human Anatomy Vol 1

UPPEB LIMB

Table 5.1r Attachments of muscles connecting the upper limb to the vertebral column (Figs 5.4 and 5.6)

Muscle

Trapezius

The right and left muscles

together form a trapezium that

covers the upper half of the back

(Fig. 5.4)

Latissimus dorsi

It covers a large area of

the lower back, and is

overlapped by the trapezius

(Fis. 5.6)

Levator scapulae

(Fig. 5.6)

Rhomboid minor

Rhomboid major

Muscle

Trapezius

Latissimus dorsi

Levator scapulae

Rhomboid minor

Rhomboid major

Origin from

. Medial one-third of superior nuchal line
. External occipital protuberance
. Ligamentum nuchae
. C7 spine
. I1-f 12 spines
. Corresponding supraspinous ligaments
. Posterior one-third of the outer lip of
iliac crest
. Posterior layer of lumbar fascia; thus
attaching the muscle to the lumbar and
sacral spines
. Spines ot f7-T12, Lower four ribs
. lnferior angle of the scapula
. Transverse processes ol C1 , C2
. Posterior tubercles of the transverse
processes of C3, C4
. Lower part of ligamentum nuchae
. Spines C7 and T1
. Spines of T2, T3, T4, T5
. Supraspinous ligaments

lnseftion into

. Upper fibres into the posterior border of
lateral one-third of clavicle
. Middle fibres, into the medial margin of
the acromion and upper lip of the crest

The Arteries of the Foreorm

. Lower fibres, on the apex of triangular
area at the medial end of the spine, with
a bursa interuening
The muscle winds round the lower
border of the teres major, and forms the
posterior fold of the axilla
The tendon is twisted upside down and is
inserted into floor of the intertubercular
sulcus

Superior angle and upper paft of medial

border (up to triangular area) of the scapula

Base of the triangular area at the root of the

spine of the scapula

Medial border of scapula below the root of

the spine

Table 5.2: Nerve supply and actions of muscles connecting the upper limb to the vertebral column

Nerve supply

. Spinal paft of accessory nerue is motor
. Branches from C3, C4 are proprioceptive

Thoracodorsal nerve (C6, C7, C8)

(nerve to latissimus dorsi)

. A branch from dorsal scapular nerve (C5)
. C3, C4 branches are proprioceptive
Dorsal scapular nerve (C5)
Dorsal scapular nerve (C5)

Actions

. Upper fibres act with levator scapulae, and elevate
the scapula, as in shruggtng
. Middle fibres act with rhomboids, and retract the
scapula
Upper and lower fibres act with serratus anterior, and
rotate the scapula fonrvards round the chest wall thus
playing an important role in abduction of the arm
beyond 90o (Fig. 5.9)
Steadies the scapula
Adduction, extension, and medial rotation of the
shoulder as in swimming, rowing, climbing, pulling,
folding the arm behind the back, and scratching the
opposite scapula
Helps in violent expiratory effort like coughing,
sneezing, etc.
Essentially a climbing muscle
Hold inferior angle of the scapula in place
Helps in elevation of scaPula
Steadies the scapula during movements of the arm
Retraction of scapula
Retraction of scapula

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