Superficial Back Flashcards
Surface Landmarks of Superficial Back
External occipital protuberance Vertebral prominens (C7) Fold of trapezius Spine of Scapula Medial border of scapula Intrinsic back muscles L4 Vertebra Iliac crest Posterior superior iliac spines
What does the axial skeleton include?
Skull
Sternum
Ribs
Vertebral column
What does the appendicular skeleton include?
Upper limb and pectoral girdle
Lower limb and pectoral girdle
Osteology - Skull
Temporal bone
- Mastoid Process
Occipital bone
- External occipital protuberance
- Superior nuchal line
- Inferior nuchal lineOsteology - Vertebral Column
33 vertebrae Support body weight Posture Locomotion Protection of spinal cord and spinal roots
What is the typical vertebrae composed of?
Body (except C1) Vertebral Arch - Laminae and Pedicles Processes - Spinous (1), Transverse (2), and Articular (4)
Osteology - Clavicle
Medial (Sternal) end - SC joint
Lateral (Acromial) end - AC joint (an attachment of trapezius)
Conoid Tubercle - Attachment of coracoclavicular ligament
Groove for Subclavius
What is the only bony attachment to the scapula?
Clavicle
Name the superficial back muscle attachments of the scapula
Superior angle - levator scapulae
Medial border - rhomboids
Inferior angle - latissimus dorsi
Spine and acromion - trapezius
Osteology of the Humerus
Head Neck (surgical and anatomical) Greater tubercle Lesser tubercle Intertubercular groove
How many cervical vertebrae are there?
7
How many thoracic vertebrae?
12
How many Lumbar vertebrae?
5
How many sacral vertebrae?
5
Fused into single, immobile structure called the sacrum
How many coccygeal vertebrae?
4 (or 3-5)
Fused into a single, immobile structure called the coccyx
3 Vertebral Arch Ligaments
Supraspinous ligament
Interspinous ligaments
Ligamentum Flacum
Ligamentum Nuchae
Occipital protuberance to spinous process of C7
Role of Ligamentum nuchae
Postural (aids extensors)
Keeps trapezius from bowing during contraction
Thoracolumbar Fascia
Deep fascia of the back
Invests the intrinsic back muscles
Separates the intrinsic from the extrinsic muscles
Functions of Intrinsic Muscles
Postural
Movement of the Spine
Functions of Extrinsic Muscles
Attach pectoral girdle to the axial skeleton
Movement of the humerus
Are the serratus posterior superior and inferior muscles intrinsic or extrinsic?
Extrinsic
When does innervation of muscles occur?
Early in development.
Muscles are innervated by spinal nerves from cord segments where they first began to develop.
Superficial layer of extrinsic muscles
Trapezius
Latissimus dorsi
Deep layer of extrinsic muscles
Levator scapula
Rhomboid minor
Rhomboid major
Intermediate back muscles (we still consider these muscles as extrinsic)
Serratus posterior superior
Serratus posterior inferior
What do dorsal rami innervate?
Vertebrae and joins
“True” or intrinsic back muscles
Skin of the back
What do ventral rami innervate?
All other skeletal muscle
Dermatome Segements
Origin of the Trapezius
External occipital protuberance
Ligamentum nuchae
Spinous processes of C7-T12 vertebrae
Insertion of the Trapezius
Spine of scapula
Acromion process
Lateral third of clavicle
Innervation of Trapezius
Spinal branch of the Accessory Neve (CN 11)
Movements of Trapezius
The fibers of this large muscle are oriented in three directions; thus multiple movements.
Elevation of scapula
Retraction of scapula
Depression of the scapula
The spinal portion of CN XI is comprised of:
motor fibers from the ventral rami of the C2-C6 spinal cord segments
What foramen does CN XI use to enter the cranium?
Foramen Magnum
What foramen does CN XI use to exit the skull?
Jugular foramen along with CN IX and X
Where can you find CN XI in dissection?
Midpoint of the posterior border of the SCM as it passes posteroinferiorly
Origin of Latissimus Dorsi
Spinous processes of T7-12 vertebrae
Inferior portion of ribs 9-12
Thoracolumbar fascia
Posteromedial half of the iliac crest
Insertion of the Latissimus Dorsi
Medial floor of the intertubercular groove (on anterior surface of the humerus)
Innervation of the Latissimus Dorsi
Thoracodorsal nerve (C6, 7, 8) - branch of the posterior cord of the brachial plexus
Movements of the Latissimus Dorsi
Extension of the arm
Adduction of the upper limb
Internal (medial) rotation of the arm
Moves trunk forward when the humerus is fixed
Intertubercular groove
Tendon long head of biceps brachii
Latissimus dorsi
Pectoralis major
Teres major
Thoracodorsal nerve
Ventral rami C6, 7, 8
Innervates Latissimus
Located on the deep side of the latissimus
Will enter the muscle in the middle of the muscle belly
Origin of Levator Scapulae
Transverse processes of C1-C4
Insertion of Levator Scapulae
Superior angle of the scapula
Innervation of Levator Scapulae
Dorsal Scapular Nerve (C5) - branch of the C5 ventral rami
Movements of Levator Scapulae
Elevation of the scapula
Rotation of the glenohumeral joint
Origin of Rhomboid Minor
Spinous processes of C7-T1
Ligamentum nuchae
Insertion of Rhomboid Minor
Medial border of scapula at (maybe a little above) the spine
Innervation of Rhomboid Minor
Dorsal Scapular Nerve (C5)
Movements of Rhomboid Minor
Retraction
Rotation
Origin of Rhomboid Major
Spinous processes of T2-T5
Insertion of Rhomboid Major
Medial border of scapula below the spine
Innervation of Rhomboid Major
Dorsal Scapular Nerve (C5)
Movement of Rhomboid Major
Retraction
Rotation
Dorsal Scapular Nerve
C5 ventral ramus
Innervates levator scapulae, rhomboid minor, rhomboid major
Functions of Serratus Posterior Muscles (superior and inferior)
Attach vertebrae to ribs
Aid in respiration
Attachment of SP Superior
From - nuchal ligament and spinous processes of C7 to T3 vertebrae
To - 2nd and 4th ribs
Innervation of SP Superior
T2 to T5 intercostal nerves
Vascular Supply of SP Superior
T2 to T5 posterior intercostal arteries
Attachment of SP Inferior
From - spinous processes of T11 to L2 vertebrae
To - 8th to 12th rib
Innervation of SP Inferior
T9 to T12 intercostal nerves
Vascular Supply of SP Inferior
T9 to T11 posterior intercostal arteries
T12 subcostal artery
The trapezius, levator scapulae, and the rhomboids are vascularized by branches of the ______ trunk
Thyrocervical trunk
What are the branches of the thyrocervical trunk?
Inferior thyroid artery
Ascending cervical artery
Transverse Cervical artery
Suprascapular artery
The transverse cervical artery divides into:
superficial and deep branch
The superficial branch of the transverse cervical artery vascularizes:
Sternocleidomastoid
Trapezius
The deep branch of the transverse cervical artery vascularizes:
levator scapula
rhomboid muscles
Describe the variation in vasculature of the Thyrocervical trunk/Subclavian
In approx. 70% of individuals, an artery named the dorsal scapular artery is a direct branch off the subclavian artery that vascularizes the levator scapula and rhomboids
In approx. 30% of individuals, the deep branch of the transverse cervical is a branch of the thyrocervical trunk
Vascularization of Trapezius
Superficial branch of transverse cervical (branch of thyrocervical trunk)
Artery runs deep to the muscle with CN XI
Vascularization of the Deep layer of extrinsic muscles (rhomboids and levator scapulae)
Dorsal scapular artery or deep branch of transverse cervical
See slides for vasculature variation
The axillary artery gives rise to the ____ artery
suscapular artery
The subscapular artery divides into the ____ and _____ arteries
Circumflex scapular and thoracodorsal arteries
Thoracodorsal Artery
Continuation of the subscapular branch of axillary artery
Supplies latissimus dorsi
Travels with thoracodorsal nerve
Superficial Back Anastamoses
Dorsal scapular artery
Suprascapular artery
Subscapular artery (thoracodorsal artery)
