muscles of the upper limb MP Flashcards
Rhomboid major
origin
Spinous processes of the T2 to T5 vertebrae
Rhomboid major
Insertion
Medial border of the scapula
Rhomboid major
action
Retracts (retract=draw bak) the scapula, rotates it to depress the glenoid cavity.
also fixes the scapula to the thoracic wall.
Rhomboid major
INNERVATION
Dorsal
scapular nerve
Rhomboid minor
Origin
spinous processes of C7–T1
Rhomboid minor
insertion
Medial border of scapula
Rhomboid minor
Actions
Retracts and rotates scapula,
fixes scapula to thoracic wall
Rhomboid minor
INNERVATION
Dorsal
scapular nerve
Levator scapulae
Origin
transverse processes of C1 - C4 vertebrae
Levator scapulae
Insertion
Superior part of medial border of scapula
Levator scapulae
Actions
Elevates scapula and tilts
its glenoid cavity inferiorly by rotating scapula
Levator scapulae
INNERVATION
Dorsal scapular
and cervical
(C3 and C4)
nerves
Serratus anterior
Origin
upper 8-9 ribs
Serratus anterior
Insertion
medial margin of the scapula
Serratus anterior
Actions
Protracts (protract= draw out/lengthen ) and stabilizes scapula
Rotates scapula upward, and
pulls it anterior
toward thoracic wall
Serratus anterior
INNERVATION
long thoracic (C05-C07)
Pectoralis minor
Origin
Third to fifth ribs, near their costal cartilages
Pectoralis minor
Insertion
coracoid process of the scapula
Pectoralis minor
Actions
Depresses scapula
& stabilises it (by drawing it inferiorly and anteriorly against the thoracic wall
Pectoralis minor
INNERVATION
Medial pectoral
nerve
Subclavius
Origin
Junction of first rib and
costal cartilage
Subclavius
Insertion
inferior surface of middle third of clavicle)
Subclavius
Actions
depresses clavicle
Subclavius
INNERVATION
Nerve to
subclavius
Trapezius
Origin
- external occipital protuberance,
- nuchal ligament,
- medial superior nuchal line,
- spinous processes of vertebrae C7-T12
Trapezius
Insertion
- lateral third of the clavicle,
- acromion process, and
- spine of scapula
Trapezius
Actions
rotation,
retraction,
elevation,
depression of scapula
Trapezius
Innervation
Spinal root of accessory nerve (cranial nerve XI)
and cervical nerves (C3 and C4)
Sternocleidomastoid (SCM)
Origin
Manubrium
sterni and medial portion of the clavicle
Sternocleidomastoid (SCM)
Insertion
Mastoid process of the temporal bone,
superior nuchal line
Sternocleidomastoid (SCM)
Actions
Tilts head to one side, i.e., laterally flexes and rotates head so face is turned superiorly toward opposite side; acting together, muscles flex neck
Sternocleidomastoid (SCM)
Innervation
Spinal root of cranial nerve CN XI and C2-C3
Omohyoid
Origin
Upper border of the scapula
Omohyoid
Insertion
inferior border of Hyoid bone
Omohyoid
Actions
depresses, move backwards, n fixes hyoid
bone
Omohyoid
Innervation
C1-C3 from ansa cervicalis (a loop of nerves that are part of the cervical plexus)
Pectoralis major
Origin
4 origins 1. Medial half of clavicle; 2. sternum; 3. superior six costal cartilages; 4. aponeurosis of external abdominal oblique (extra info on doc)
Pectoralis major
Insertion
Intertubercular (bw tubercles) groove of humerus
Pectoralis major
Actions
- Clavicular head: flexes the humerus.
- Sternocostal head: extends the humerus.
- As a whole, adducts and medially rotates the humerus.
- It also draws the scapula anteriorly and inferiorly
Pectoralis major
Innervation
Lateral and medial pectoral nerves