Back Axilla & Upper Limb Flashcards
What are the components of the axial skeleton?
Skull
Vertebral column
Sternum
Ribs
What are the components of the appendicular skeleton?
Pectoral girdle
- clavicle
- scapula
Upper limbs
Pelvis
Lower limbs
What are the components of the shoulder girdle?
Bones: scapula and clavicle
Acromioclavicular, sternoclavicular, physiological scapulothoracic joint: allows movement of the scapula on the posterior thoracic wall
What are the components of the shoulder joint?
Bones: glanoid fossa of scapula, head of humerus, clavicle
Allows movement of the humerus and thus the upper limb
What are axioms?
Every muscle that crosses a joint will act on that joint
-a direction of movement may be the function of more than one muscle, although only one muscle may be the primary mover
What is Hilton’s law?
Nerves that supply a joint will also supply the muscles that move the joint, and the skin over the joint
- Generally, each muscle is innervated by a single spinal nerve, and injury to that nerve will affect only that muscle
Each muscle has a major arterial supply but could also receive blood supply from other arteries (collateral blood supply). Thus, blockage of the major artery to a muscle may NOT adversely effect the muscle because of collateral blood supply
What are the two types of superficial back muscular groups?
a) superficial appendicular /extrinsic group
b) superficial respiratory or intermediate extrinsic group
Both groups of extrinsic muscles are innervated by “named” branches of ventral rami of spinal nerves via the brachial plexus and receive their blood supply from branches of major arteries
Explain superficial appendicular/extrinsic group as back muscles
Superficial axial skeleton to appendicular skeleton
- Connect Axial skeleton to appendicular skeleton
- Functions primarily in movement of the upper limbs- move the SCAPULA or the HUMERUS
-Arranged in two layers-
1st layer- trapezius, latssimus dorsi
2nd layer- levator scapulae, rhomboid major and minor
Explain superficial respiratory or intermediate extrinsic group
These serve more likely a proprioceptive role than motor function
Consists of a thin layer of muscles made up of:
- Serratus posterior superior
- Serratus posterior inferior
What is the function of the Trapezius muscle?
Assists in rotating the scapula during abduction of humerus above horizontal; upper fibers elevate, middle fibers adduct, and lower fibers depress the scapula
What is the innervation of the trapezius muscle?
Accessory nerve (motor) cervical spinal nerves C3 and C4 (proprioception)
What is the blood supply of the trapezius muscle?
Superficial branch of transverse cervical artery
What is the function of the latissimus dorsi?
Extends, adducts and medically rotates humerus
What is the innervation of the latissimus dorsi?
Thoracodorsal nerve (C6-C8)
What is the blood supply of the latissimus dorsi?
Thoracodorsal artery
What is the function of the levator scapula?
Elevates scapula
What is the innervation of the levator scapulae?
C3 to C4 and dorsal scapular nerve
What is the blood supply of the levator scapulae?
Transverse and ascending cervical arteries
What is the function of the rhomboid major?
Retracts (adducts) and elevates scapula
What is the innervation of the rhomboid major?
Dorsal scapular nerve (C4-C5)
What is the blood supply of the rhomboid major?
Deep branch of transverse cervical artery/ or dorsal scapular artery
What is the blood supply of the rhomboid minor?
Deep branch of transverse cervical artery/ or dorsal scapular artery
What is the innervation of the rhomboid minor?
Dorsal scapular nerve(C4-C5)
What is the function of the rhomboid minor?
Retracts (adducts) and elevates scapulae
What are the intermediate (respiratory)extrinsic group of back muscles?
Serratus posterior superior
Serratus posterior inferior
What is the function of the serratus posterior superior?
Elevates ribs II - IV
What is the innervation of the serratus posterior superior?
Anterior rami of upper thoracic (intercostal ) nerves T2 to T5
What is the blood supply of the serratus posterior superior?
Segmental supply through intercostal arteries
What is the function of the serratus posterior inferior?
Depresses ribs IX to XII and may prevent lower ribs from elevating when diaphragm contracts
What is the innervation of the serratus posterior inferior?
Anterior rami of lower thoracic (intercostal) nerves T9 to T12
What is the blood supply of the serratus posterior inferior?
Segmental supply through intercostal arteries
What is the role of dorsal Ramus nerves for back muscles?
Branches to skin of back and deep/intrinsic muscles of the back
What is the function of ventral Ramus nerves?
Gives off lateral and anterior branches of nerves
Superficial appendicular and intermediate back muscles are EXTRINSIC back muscles innervated…
By ventral rami of spinal nerves
Where is the thoracolumbar fascia located?
Deep investing membrane throughout most of the posterior thorax & abdomen
What is thoracolumbar fascia formed by?
It is formed by longitudinal and transverse fibers from various muscles that bridge the aponeurosis of internal oblique and transversalis muscles
It is continuous with the deep fascia of the neck
What are the 3 layers of the thoracolumbar fascia?
Consists three layers anterior, middle and posterior
- the anterior and middle layers insert into the transverse processes of the vertebral column
- Posterior layer inserts onto the tips of the spinous process processes, hence it is indirectly continuous with the interspinous ligaments
It covers the paravertebral deep muscles of the back
What are deep muscles?
Deep= true= intrinsic back muscles
Attached to elements of the axial skeleton
What are the functions of deep back muscles?
Functions in movement of the back proper and maintenance of upright posture
Innervated by dorsal rami of spinal nerves and receive segmental blood supply from branches of the aorta and vertebral arteries
Where are the deep ( intrinsic) back muscles located(nerves from dorsal rami)?
They extend from pelvis to cranium
- Enclosed by deep fascia (thoracolumbar)
- Grouped in layers
- Superficial layer (splenius group)
- Interm3diate layer (erector spinal group)
- Deep layer (transversospinales group)
What is the function of the splenus capitis?
Acting bilaterally: extend neck
What is the innervation of the splenus capitis ?
Posterior rami of cervical spinal nerves
What is the blood supply(segmental) of the splenus capitis?
Deep cervical, occipital
What is the function of the spinal cervicis?
Acting unilaterally: laterally flexes and rotates the same side
What is the innervation of splenius cervicis?
Posterior rami of cervical spinal nerves
What is the blood supply(segmental) of the blood supply?
Deep, cervical, occipital
What is the function of spinalis capitis?
Acting bilaterally: extend vertebral column and head; as back is flexed, control movement by gradually lengthening their fibers
Acting unilaterally: laterally flexes vertebral column
What is the function of the spinalis cervicis?
Acting bilaterally: extend vertebral column and head; as back is flexed, control movement by gradually lengthening their fibers
Acting unilaterally: laterally flexes vertebral column
What is the function of the spinalis thoracis?
Acting bilaterally: extend vertebral column and head; as back is flexed, control movement by gradually lengthening their fibers
Acting unilaterally: laterally flexes vertebral column
What is the innervation(segmental) of the spinalis capitis?
Posterior rami of spinal rami
What is the innervation of the spinalis cervicis?
Posterior rami of spinal nerves
What is the innervation of the spinalis thoracis?
Posterior rami of spinal nerves
What is the blood supply(segmental) of the spinalis capitis ?
Vertebral, deep cervical occipital, transverse cervical, posterior intercostal, subcostal, lumbar and lateral sacral arteries
What is the blood supply of the spinalis capitalis?
Vertebral, deep cervical occipital, transverse cervical, posterior intercostal, subcostal, lumbar and lateral sacral arteries
What is the blood supply (segmental) of the spinalis thoracis ?
Vertebral, deep cervical occipital, transverse cervical, posterior intercostal, subcostal, lumbar and lateral sacral arteries
