In human anatomy, the rhomboid minor is a small
skeletal muscle
Skeletal muscle (commonly referred to as muscle) is one of the three types of vertebrate muscle tissue, the others being cardiac muscle and smooth muscle. They are part of the somatic nervous system, voluntary muscular system and typically are a ...
of the back that connects the
scapula to the
vertebrae
Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spinal ...
of the
spinal column. It arises from the
nuchal ligament, the 7th
cervical and 1st
thoracic vertebrae
In vertebrates, thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In humans, there are twelve thoracic vertebra (anatomy), vertebrae of intermediate size between the ce ...
and intervening
supraspinous ligaments; it inserts onto the
medial border of the scapula, and is innervated by the
dorsal scapular nerve. It acts together with the
rhomboid major to keep the scapula pressed against the thoracic wall.
Anatomy
Origin
The rhomboid minor arises from the inferior border of the
nuchal ligament, from the
spinous processes of the vertebrae C7–T1, and from the intervening
supraspinous ligaments.
Insertion
It inserts onto a small area of the
medial border of the scapula at the level of the
scapular spine.
Innervation
It is innervated by the
dorsal scapular nerve (a branch of the
brachial plexus), with most of its fibers derived from the C5 nerve root and only minor contribution from C4 or C6.
[, p. 4]
Blood supply
The rhomboid minor receives
arterial blood supply from the
dorsal scapular artery.
Relations
It is located inferior to
levator scapulae, and superior to
rhomboid major.
It lies deep to
trapezius, and superficial to the long spinal muscles.
Variation
It is usually separated from the rhomboid major by a slight interval, but the adjacent margins of the two muscles are occasionally united.
['' Gray's Anatomy'' (1918), see infobox]
Actions/movements
Together with the rhomboid major, the rhomboid minor retracts the scapula when the trapezius is contracted. Acting as a synergist to the trapezius, the rhomboid major and minor elevate the medial border of the scapula medially and upward, working in tandem with the
levator scapulae muscle
The levator scapulae is a slender skeletal muscle
Skeletal muscle (commonly referred to as muscle) is one of the three types of vertebrate muscle tissue, the others being cardiac muscle and smooth muscle. They are part of the somatic nervous s ...
to rotate the scapulae downward. While other shoulder muscles are active, the rhomboid major and minor stabilize the scapula.
Additional images
References
External links
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{{Authority control
Muscles of the upper limb