Deep Back Flashcards
Vertebral canal
Canal formed by vertebral foramina of vertebral bodies
- Houses spinal cord
Vertebral foramen
Hole formed by vertebral arch + posterior surface of vertebral body
Intervertebral foramen
Hole formed by superior + inferior notches of adjacent vertebrae
- Passage for spinal nerve roots + vessels
Epidural space
Extradural space separating dura mater from vertebrae
- Location for epidural anesthesia (epidurals)
- Filled with epidural fat + vessels
Dura mater spinalis
Outermost cover of spinal cord
- Tough, fibrous, elastic tissue
- Pierced by spinal nerves
- Forms spinal dural sac starting from margin of foramen magnum + adheres to coccyx by filum terminale externum
Arachnoid mater spinalis
Middle cover of spinal cord
- Delicate, fibrous, elastic
- Encloses CSF in subarachnoid space
- Not attached to DMS but pressed tightly against it by pressure from CSF
- Lumbar puncture occurs in subarachnoid space
- Dura-arachnoid space is not really a space but rather a weak cell layer
Pia mater spinalis
Innermost cover of spinal cord
- Consists of flattened cells w/ long equally flattened processes that closely follow all surface features of SC
- Also directly covers all roots of spinal nerves + blood vessels
- Inferior to conus medullaris, continues as filum terminale
Conus medullaris
Tapered end of spinal cord
- Typically L1-L2
- High as T12
- Low as L3
Cauda equina
Bundle of spinal nerve roots below conus medullaris
*Resembles horsetail
Filum terminale
Extends from conus medullaris + anchors spinal cord + dural sac
- Consists primarily of pia mater
- Internum: Inside dural sac
- Externum: Outside dural sac (takes on layers of arachnoid + dura)
Denticulate ligaments
Extension of pia mater midway on either side that suspends spinal cord in dural sac
*Runs longitudinally along either side of spinal cord
Posterior roots of spinal nerves
Contain sensory (afferent) fibers
Anterior roots of spinal nerves
Contain motor (efferent) fibers
Dorsal root ganglion
Cluster of cell bodies of sensory neurons
*also known as spinal ganglion
Posterior longitudinal ligament
Location:
- Longitudinal ligament in between vertebral body and spinal cord
Function:
- Prevent hyperflexion of spine + posterior herniation of IV discs
*weaker than anterior
Ligamentum flavum
- Pale, yellow elastic fibrous tissue connecting vertebral arches, laminae to laminae
- Forms alternating sections of the posterior wall of vertebral canal
Sacrum
5 fused sacral bones
- S1 landmark = sacral promontory
- Fused SPs = median sacral crest
- Fused APs = intermediate sacral crest
- Fused TPs = lateral sacral crest
- Sacral hiatus = inverted U-shape (absence of L4-L5 laminae + SPs)
- Sacral cornua = inferior AP
- 4 posterior + 4 anterior foramina
Transverse scapular ligament
Crosses suprascapular notch
Spinal accessory nerve (CN XI)
Innervates:
- Trapezius
Dorsal scapular nerve
Innervates:
- Rhomboid major
- Rhomboid minor
- Levator scapulae
Superficial branch of transverse cervical artery
Supplies:
- Trapezius
*Runs with spinal accessory nerve
Dorsal scapular artery
Supplies:
- Rhomboid major
- Rhomboid minor
Suprascapular artery + nerve
Location:
- Above + below transverse scapular ligament
Supplies:
- Supraspinatus
- Infraspinatus
- Teres minor
Vertebral artery
Location:
- Suboccipital triangle
Supplies:
- Suboccipital muscles
Deltoid (origin + insertion)
Origin:
- Lateral 1/3 clavicle
- Acromion
- Spine of scapula
Insertion:
- Deltoid tuberosity of humerus
Deltoid (function + innervation)
Function:
- Anterior - flex + medially rotate shoulder joint
- Middle - ABduct shoulder joint (to 90 degrees)
- Posterior - extend + laterally rotate shoulder joint
Innervation:
- Axillary nerve (C5) (C6)
Teres major (origin + insertion)
Origin:
- Inferior part of lateral border of scapula
- Posterior surface of inferior angle of scapula
Insertion:
- Medial lip of intertubercular sulcus of humerus
Teres major (function + innervation + vascularization)
Function:
- ADduct shoulder joint
- Medial (internal) rotation of shoulder joint
Innervation:
- Lower subscapular nerve (C5) (C6)
Vascularization:
- Thoracodorsal branch of the subscapular artery
- Posterior circumflex humeral artery
Teres minor (origin + insertion)
Origin:
- Middle part of lateral border of scapula
Insertion:
- Inferior facet of greater tubercle of humerus
Teres minor (function + innervation + vascularization)
Function:
- Laterally rotate shoulder joint
- Help hold humeral head in glenoid cavity
Innervation:
- Axillary nerve (C5) (C6)
Vascularization:
- Suprascapular artery
- Dorsal scapular artery
Biceps brachii, short + long heads (origin + insertion)
Origin:
- Short: Tip of coracoid process of scapula
- Long: Supraglenoid tubercle of scapula
Insertion:
- Radial tuberosity of radius
- Deep fascia of forearm via bicipital aponeurosis
Biceps brachii, short + long heads (function + innervation + vascularization)
Function:
- Supinate forearm
- Flex elbow joint in supinated position
- Flex shoulder joint (weak)
- Short head resists dislocation of shoulder
Innervation:
- Musculocutaneous nerve (C6) (C5)
Vascularization:
- Branches of brachial artery
Triceps brachii, long + lateral + medial heads (origin + insertion)
Origin:
- Long: Infraglenoid tubercle of scapula
- Lateral: Posterior surface of humerus, superior to radial groove
- Medial: Posterior surface of humerus, inferior to radial groove
Insertion:
- Proximal end of olecranon of ulna
- Fascia of forearm
Triceps brachii, long + lateral + medial heads (function + innervation + vascularization))
Function:
- Chief extensor of elbow joint
- Long head extends shoulder joint + resists dislocation of humerus (esp during ABduction)
Innervation:
- Radial nerve (C7, C8) (C6)
Vascularization:
- Deep brachial artery
- Superior ulnar collateral artery
Supraspinatus (origin + insertion)
Origin:
- Supraspinous fossa of scapula
Insertion:
- Superior facet of greater tubercle of humerus
Supraspinatus (function + innervation + vascularization)
Function:
- ABduction of shoulder joint (to 15 degrees)
- Act w/ other RC muscles
Innervation:
- Suprascapular nerve (C5) (C4, C6)
Vascularization:
- Suprascapular artery
Infraspinatus (origin + insertion)
Origin:
- Infraspinous fossa of scapula
Insertion:
- Middle facet of greater tubercle of humerus
Infraspinatus (function + innervation + vascularization)
Function:
- Laterally rotate shoulder joint
- Help hold humeral head in glenoid cavity (RC)
Innervation:
- Suprascapular nerve (C5) (C6)
Vascularization:
- Suprascapular artery
- Circumflex scapular arteries
Subscapularis (origin + insertion)
Origin:
- Subscapular fossa (most of anterior surface of scapula)
Insertion:
- Lesser tubercle of humerus
Subscapularis (function + innervation + vascularization)
Function:
- Medially rotate + ADduct shoulder joint
- Help hold humeral head in glenoid cavity (RC)
Innervation:
- Upper and lower subscapular nerves (C6) (C5, C7)
Vascularization:
1) Suprascapular artery
2) Axillary artery
3) Subscapular artery
Obliquus capitis superior (ID)
Lateral side of suboccipital triangle
*Smaller than inferior
Obliquus capitis inferior (ID)
Inferior side of suboccipital triangle
*Larger than superior
Rectus capitis posterior minor (ID)
Most medial, above rectus capitis major
Rectus capitis posterior major (ID)
Superior side of suboccipital triangle
*Lateral to the minor
Suboccipital triangle (borders)
Sides (clockwise starting at 12:00):
1) Rectus capitis posterior major
2) Obliquus capitis inferior
3) Obliquus capitis superior
Splenius capitis (origin + insertion)
Origin:
- Nuchal ligament
- SPs of C7-T3
Insertion:
- Mastoid process
- Lateral 1/3 superior nuchal line of occipital bone
Splenius capitis (function + innervation + vascularization)
Function:
- Unilateral = Lateral flexion neck + rotate head to side of active muscle
- Bilateral = Extend head + neck
Innervation:
- Dorsal rami of spinal nerves
Vascularization:
- Muscular branches of occipital artery
Omohyoid
Origin:
- Superior border of scapula
Insertion:
- Body of hyoid bone
Function:
- Depress hyoid
Innervation:
- Anterior rami of spinal nerves C1-C3
Vascularization:
- Superior thyroid artery
Which rami innervates the deep back muscles?
Posterior rami
3 groups of deep (intrinsic) back muscles
1) Erector spinae
2) Transversospinalis
3) Splenius
3 groups of erector spinae muscles (+ location)
1) Iliocostalis (outer)
2) Longissimus (middle)
3) Spinalis (inner)
3 groups of transversospinalis muscles (relative location + innervation)
Relative location:
1) Semispinalis (superficial)
2) Multifudus (deeper)
3) Rotatores (deepest)
* Connect btwn TPs to more superior SPs
Innervation:
- Dorsal rami of spinal nerves
2 groups of splenius muscles
1) Capitis
2) Cervicis
Erector spinae (function + innervation)
Bilateral function:
- Extend VC
- Extend head
- Control flexion of VC
Unilateral function:
- Lateral bend of VC
Innervation:
- Dorsal rami of spinal nerves
Suboccipital muscle innervation
Suboccipital nerve (C1 dorsal ramus) *Located in suboccipital triangle
Obliquus capitis superior (origin + insertion + innervation + vascularization)
Origin:
- TP of C1
Insertion:
- Lateral part of inferior nuchal line on occipital bone
Innervation:
- Suboccipital nerve (posterior ramus of spinal nerve C1)
Vascularization:
- Vertebral artery and descending branches of the occipital artery
Obliquus capitis inferior (origin + insertion + innervation + vascularization)
Origin:
- SP of C2
Insertion:
- TP of C1
- Meets up with the superior
Innervation:
- Posterior ramus of spinal nerve C1 (suboccipital nerve)
Vascularization:
- Vertebral artery and deep descending branches of the occipital artery
Rectus capitis posterior minor (origin + insertion + innervation + vascularization)
Origin:
- Posterior tubercle of C1
Insertion:
- Medial part of inferior nuchal line on occipital bone
Innervation:
- Posterior ramus of spinal nerve C1 (suboccipital nerve)
Vascularization:
- Vertebral artery
- Occipital artery (via the deep descending branch)
Rectus capitis posterior major (origin + insertion + innervation + vascularization)
Origin:
- Spinous process of C2
Insertion:
- Lateral part of inferior nuchal line on occipital bone
Innervation:
- Suboccipital nerve (posterior ramus of spinal nerve C1)
Vascularization:
- Vertebral artery and descending branches of the occipital artery
Quadrangular space (borders + contents)
Borders:
- Teres minor (inf)
- Teres major (sup)
- Long head of triceps (lat)
- Humerus (med)
Contents:
- Axillary nerve
- Posterior humeral circumflex artery (+vein)
Triangular space (borders + contents)
Borders:
- Teres minor (inf)
- Teres major (sup)
- Long head of triceps (med)
Contents:
- Circumflex scapular artery (+ vein)
Splenius cervicus (function + innervation)
Function:
- Unilateral: Lateral flexion and rotation of neck
- Bilateral: Extension of neck
Innervation:
- Dorsal rami of spinal nerves
Splenius cervicus (origin + insertion)
Origin:
- Spinous processes of T3 – T6 vertebrae
Insertion:
- Transverse processes of C1 – C3 vertebrae
Erector spinae (origin + insertion)
Origin:
- Iliac crest (posterior broad tendon)
- Sacrum (posterior surface)
- Sacro-iliac ligaments
- Spinous processes of sacral + inferior lumbar vertebrae
- Supraspinous ligament
Insertion:
- Iliocostalis - Superiorly to angles of lower ribs + cervical TPs
- Longissimus - Mastoid process + superiorly to ribs btwn tubercles + angles to thoracic + cervical TPs
- Spinalis - Superiorly to SPs in upper thoracic region + to cranium
What is the most commonly torn tendon of the rotator cuff?
Supraspinatus
What muscle is utilized up to 15 degrees abduction of the shoulder joint?
Supraspinatus
What muscle is utilized with 15-90 degrees abduction of the shoulder joint?
Deltoid
What muscles are utilized with abduction of the shoulder joint past 90 degrees?
- Trapezius
- Serratus anterior
Walk through steps of a lumbar puncture
1) ID L4 level (iliac crest)
2) Pierce skin
3) Supraspinous ligament
4) Infraspinous ligament
5) Ligamentum flavum
6) Epidural space
7) Dura/arachnoid mater
STOP!
*CSF in subarachnoid space
What are the four muscles of the rotator cuff?
- Supraspinatus
- Infraspinatus
- Teres minor
- Subscapularis
*SITS
Subclavius (origin + insertion)
Origin:
- 1st rib
Insertion:
- Bottom surface of the middle part of the clavicle.
Subclavius (function + innervation)
Function:
- Stabilise the clavicle during movements of the pectoral girdle
- Depress lateral end of the clavicle & pull it slightly anteriorly
Innervation:
- Nerve to subclavius
What defines the triangle interval?
- Teres major
- Long head of triceps
- Lateral head of the triceps
What are the contents of the triangle interval?
- Radial nerve
- Deep branch of brachial artery
What nerve innervates the suboccipital muscles?
Suboccipital nerve (C1 dorsal ramus)
What are the contents of the suboccipital triangle?
- Vertebral artery
- Suboccipital nerve (C1 dorsal ramus)
Where does the spinal cord terminate?
L1-L2
Do cervical nerves exit above or below the vertebra with the same number?
Above
- C8 exits between C7 + T1
Do thoracic and lumbar spinal nerves exit above or below the vertebra with the same number?
Below
Anterior longitudinal ligament
Location:
- Anterior to vertebral column
Function:
- Prevent hyperextension of spine + anterior herniation of IV discs
Which nerve root would a posterolateral herniation of the nucleus pulposus impinge upon?
Tranversing nerve root
How do the rotator cuff muscles stabilize the shoulder joint?
Form a musculotendoninous cuff around the GH joint
White matter
- Contains only tracks of myelinated + unmyelinated axons traveling to + from the brain
Gray matter
- Contains neuronal cell bodies + their dendrites, along with axons + central neuroglia
Where are the cell bodies of motor neurons that innervate skeletal muscle located?
- Ventral horn of the gray matter
