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Flashcards in Exam II: Back II Deck (35):

Thoracolumbar Fascia

surrounds the deep muscles of the back
superiorly, continuous with deep fascia of the neck
“deep” to serratus posterior muscles
medially, attaches to the spines of the vertebrae
laterally, attaches to the transverse processes
inferiorly, attaches to lower border of 12th rib and iliac crest


Deep Muscles of the Back Group

1. Superficial extrinsic
2. Intermediate extrinsic
3. Spinotransversales (superficial intrinsic)
4. Erector spinae (intermediate intrinsic)
5. Transversospinal (deep intrinsic)


Splenius capitis

Splenius capitis

Origin: nuchal ligament and spinous processes C7-T3
Insertion: Mastoid process and Superior nuchal line
Innervation: posterior rami of middle cervical nerves/spinal nerves
Action: draw head backward together, extending neck; individually laterally flex and rotate head to one side (same side rotation)


Splenius cervicis

Splenius cervicis
Origin: Spinous processes T3-T6
Insertion: Transverse processes C1-C3
Innervation: posterior rami of lower cervical nerves/spinal nerves
Action: draw head backward together, extending neck; individually laterally flex and rotate head to one side (same side rotation)



Iliocostalis: ribs
1. Lumborum
Origin: sacrum, spinous processes of lumbar and lower two thoracic vertebrae (ribs) and their supraspinous ligaments, and the iliac crest (sacrum to ribs)
Insertion: angles of the lower six or seven ribs

2. Thoracis
Origin: angles of the lower six ribs to ribs (muscle that go from ribs to ribs)
Insertion: angles of the upper six ribs and the transverse process of C7

3. Cervicis
Origin: angles of ribs 3-6
Insertion: transverse processes of C4-6



Longissimus: transverse processes

1. Thoracis
Origin: blends with iliocostalis in lumbar region and is attached to transverse processes of L1-5
Insertion: transverse process of T1-12 and just lateral to the tubercles of the lower 9-10 ribs

2. Cervicis
Origin: transverse processes of T1-5
Insertion: transverse processes of C2-6

3. Capitis
Origin: transverse processes of T1-5 and articular processes of lower C3-C7
Insertion: posterior margin of the mastoid process (attach to skull)



Spinalis: spinous processes; attaches spines to spines

1. Thoracis
Origin: spinous processes of T10 or 11 to L2
Insertion: spinous processes of T1-8 (varies)

2. Cervicis
Origin: lower part of ligamentum nuchae and spinous process of C7 (sometimes T1 to T2)
Insertion: Spinous process of C2 (axis)

3. Capitis
Origin: usually blends with semispinalis capitis
Insertion: with semispinalis capitis


Spinotransversales (superficial intrinsic)

Splenius capitis and Splenius cervicis


Erector spinae (intermediate intrinsic)

Iliocostalis (lumborum, thoracis, and cervicis)
Longissimus (thoracis, cervicis, and capitis)
Spinalis (thoracis, cervicis, and capitis)

Function: side bending


Transversospinal (deep intrinsic)

Semispinalis (thoracis, cervicis, and capitis)
Rotatores (lumborum, thoracis, and cervicis)



Semispinalis: C4-T10

1. Thoracis
Origin: transverse processes of T6 to T10
Insertion: spinous processes of T1-4 and C6-7

2. Cervicis
Origin: tranverse processes of T1-6
Insertion: spinous processes of C2-5

3. Capitis
Origin: transverse processes of T1-6/7 and C7 and articular processes of C4-6
Insertion: medial area between the superior and inferior nuchal lines of occipital bone



Origin: posterior sacrum, aponeurosis of erector spinae, posterior superior iliac spine, sacro-iliac ligaments, mammillary processes of lumbar vertebrae, transverse processes of thoracic vertebrae, and articular processes of lower four cervical vertebrae (C4-C7)

Insertion: base of spinous processes of all vertebrae from C2-L5

N: posterior rami of spinal nerves

A: unilateral contraction rotates to contralateral side; stabilizes vertebrae during local movements of vertebral column


Rotatores (short and long)

Function: attaches transverse processes to spines and runs 1-2 segments; best developed in thoracic region

Origin: transverse processes of lumbar vertebrae
Insertion: spinous processes of lumbar vertebrae

Origin: transverse processes of thoracis vertebrae
Insertion: spinous processes of thoracic vertebrae

Origin: articular processes of cervical vertebrae
Insertion: spinous processes of cervical vertebrae

A: may function as organs of proprioception, stabilize vertebrae and help with extension


Rotation of Vertebrae

Whole point rotate vertebral column:
1. Transversospinalis: semispinalis (thoracis, cervicis, capitis), multifidus, rotatores (lumborum, thoracis, and cervicis)
2. Spinotransversalis: splenius capitis and splenius cervicis (both individually rotate the head to one side while also turning the vertebrae to the same side)

Muscle cannot act on same level from spinous to transverse process
- Contracts and pull transverse
- Rotate vertebral body to same side

Muscle from transverse process to spinous process- move vertebral body in contralateral rotation (opposite side)


Segmental Back Muscles

Postural muscles/assist with posture
ALL are innervated by dorsal rami
1. Interspinales- between spinous processes
2. Intertranversarii- between transverse processes
in the thoracic region are modified to form the levator costarum

Accessory Respiratory Muscles:
Levatores costarum
Origin: Transverse processes of C7-T11
Insertion: Rib below origin
Action: Elevate ribs


Suboccipital Muscles

Muscles give you a headache
Deep to all muscle we have talked about: Trapezius, Splenius capitus, Semisplenalis, etc.
Suboccipital muscles include: rectus capitis posterior major and minor and obliquus capitis superior and inferior


Rectus capitis posterior major and minor

Rectus capitis posterior major
Origin: spinous process of C2
Insertion: lateral portion of occipital bone below inferior nuchal line
Innervation: posterior ramus of C1
Function: extension of head; rotation of face to same side as muscle

Rectus capitis posterior minor
Origin: spinous tubercle of C1
Insertion: medial portion of occipital bone below inferior nuchal line
Innervation: posterior ramus of C1
Function: extension of head


Obliquus capitis superior and inferior

Obliquus capitis superior
Origin: transverse process of C1
Insertion: occipital bone between superior and inferior nuchal lines
Innervation: posterior ramus of C1
Function: extension of head and bends it to the same side

Obliquus capitis inferior
Origin: spinous process of C2
Insertion: transverse process of C1
Innervation: posterior ramus of C1
Function: rotation of face to same side


Suboccipital Triangle

Obliguus capitis inferior: transverse process of C1 to C2; inferior border
Obliguus capitis superior: C1 to inferior nuclei; lateral border
Rectus capitis posterior major: spinous process of C2 up to skull; medial border
Retus capitis posterior minor: C1 up to inferior nuclei


Spinal Cord: General Information

Part of the CNS
Occupies the vertebral canal and segmented
In infants the spinal cord extends into the sacrum
In adults the cord extends from the cranial border of the atlas to L2
Level of termination is slightly more superior in flexion
Cervical enlargement: C5-T1
Lumbosacral enlargement: L1-S3
Tapers to conus medullaris (L2)- end of spinal cord
Cauda Equina (dorsal and ventral roots exiting)- nerve roots
Filum terminale (extension of spinal cord to coccyx)- anchors
31 pairs of spinal nerves: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal


External and Internal Surfaces of the Spinal Cord

External surface:
Anterior median fissure
Posterior median sulcus
Posterolateral sulcus

Internal surface:
Central canal (contains CSF)
White matter (spinal cord tract/info coming and going)
Gray matter (where cell bodies/synapses are)


Myotomes: Rhomboids and Latissimus Dorsi

Latissimus Dorsi: C6-8
Rhomboids: C5 and C6


Dura Mater

Thick/dense inelastic membrane
Attached around the foramen magnum and bodies of 2nd & 3rd cervical vertebrae
Tubular extensions enclose roots of the spinal nerves
End of dural sac is S2, but terminal cord like extension, filum terminals extern extends to the coccyx


Arachnoid Mater

Delicate membrane
Not attached to dura mater
Spider web like
Ends at S2
Avascular- gets nutrients from CSF


Pia Mater

Vascular membrane
Denticulate ligaments- connect spinal cord to dura mater
Filum terminlae internum
Directly adherent to the spinal cord


Multiple Spaces Between Meninges

Epidural space
Between vertebrae and dura
Contains epidural fat, internal vertebral venous plexus
Between ligamentum flavum and dura mater

Subdural space
Between dura and arachnoid
Contains only serous fluid
Potential space
Ends at S2

Subarachnoid space
Between arachnoid and pia
Contains CSF, blood vessels, and connective tissue
Ends at S2


Lumbar Cistern

The lumbar cistern is a space (subarachnoid) below the spinal cord that contains CSF
Spinal cord ends at L2
Dural sac ends at S2
Forms lumbar cistern- sample CSF
enlargement of the subarachnoid space between the conus medullaris of spinal cord (about vertebral level L2) and inferior end of subarachnoid space and dura mater (about vertebral level S2); occupied by the posterior and anterior roots constituting the cauda equina, the terminal filum, and cerebrospinal fluid; site for lumbar puncture and spinal anesthesia



Pregnant women before birth
Layers the needle passes through: skin, subcutaneous fat, supraspinous ligament, interspinous ligament, ligamentum flavum, then in epidural space
Inject needle into the epidural space just past the ligamentum flavum
Anesthesia injected into the sacral hiatus


Blood Supply to the Spinal Cord

Vertebral artery: anterior spinal artery and posterior spinal arteries

Segmental arteries: anterior radicular, posterior radicular, segmental medullary arteries

Longitudinal artery: anterior and 2 posterior arteries coming from vertebral artery and run the entire length of the spinal cord and connected to feeder arteries
Aorta with feeder arteries that branch off
Radicular arteries coming off rootlets


Venous Drainage

1. Spinal Cord: intervertebral veins, spinal veins, and internal venous plexus
Two main veins instead of 3: anterior and posterior and drain back into intervertebral veins
From there they drain from internal vertebral plexus in epidural space (blue)

1. Vertebral Column: external Spinal Venous Plexus and Basivertebral Veins
Take path of least resistance
Basivertebral veins also drain vertebral bodies
Can move anteriorly or posteriorly
These veins are valveless so they go to where there is least resistance
Azygos veins- vein running up the right side of the thoracic vertebral column draining itself towards the superior vena cavae


Iliocostalis, Longissimus, and Spinalis: Moore's

O: Arises by broad tendon from posterior part of iliac crest, posterior surface of sacrum, sacro-iliac ligaments, sacral and inferior lumbar spinous processes, and supraspinous ligament

Iliocostalis- fibers run superiorly to angles of lower ribs and cervical transverse processes
Longissimus- fibers run superiorly to ribs between tubercles and angles to transverse processes in thoracic and cervical regions and to mastoid process of temporal bone
Spinalis- run superiorly to spinous processes in upper thoracic region and to cranium

N: posterior rami of spinal nerves

A: acting bilaterally, extend vertebral column and head as back is flexed, control movement by gradually lengthening their fibers; acting unilaterally, laterally flex vertebral column


Semispinalis: Innervation and Action

Innervation: posterior rami of spinal nerves

Action: extends head, thoracic, and cervical regions of vertebral column and rotates them contralaterally



O: Superior surfaces of spinous processes of cervical and lumbar vertebrae

I: Inferior surface of spinous processes of vertebrae superior to vertebrae of origin

N: Posterior rami of spinal nerves

A: Aid in extension and rotation of vertebral column



O: Transverse processes of cervical and lumbar vertebrae

I: Transverse processes of adjacent vertebrae

N: Posterior and Anterior rami of spinal nerves

A: Aid in lateral flexion of vertebral column; acting bilaterally, stabilizes vertebral column


Levatores costarum

O: Tips of transverse processes of C7 and T1-T11

I: Pass inferolaterally and insert on rib between its tubercle and angle

N: Posterior rami of C8-T11 spinal nerves

A: Elevate ribs, assisting respiration; assist with lateral flexion of vertebral column