Back Dissection

Question 1

Trapezius

Answer 1

Attachment (Proximal): Occipital bone, nuchal ligament, and spinous processes of lower cervical and all thoracic vertebrae

Attachment (Distal): Clavicle, acromion, and scapular spine

Innervation: CN XI (Accessory n.)

Action: Elevates (superior fibers), depresses (inferior fibers), and retracts (middle fibers) the scapula

Question 2

Latissimus dorsi

Answer 2

Attachment: Spinous processes of lower thoracic vertebrae, thoracolumbar fascia, iliac crest, and ribs

Attachment 2: Intertubercular sulcus of humerus

Innervation: Thoracodorsal n.

Action: Extends, adducts and medially rotates the arm

Question 3

Levator scapulae

Answer 3

Attachment: Transverse processes of cervical vertebrae

Distal Attachment: Medial border of scapula

Innervation: Dorsal scapular n.

Action: Elevates the scapula

Question 4

Rhomboid minor

Answer 4

Attachment: Spinous processes of lower cervical and upper thoracic vertebrae and nuchal ligament

Distal Attachment: Medial boarder of scapular near the scapular spine

Innervation: Dorsal scapular n.

Action: Retracts the scapula; holds scapula to thoracic wall

Question 5

Rhomboid major

Answer 5

Attachment: Spinous processes of upper thoracic vertebrae

Distal Attachment: Medial border of scapula from the level of the scapular spine to inferior angle

Innervation: Dorsal scapular n.

Action: Retracts the scapula; holds scapula to thoracic wall

Question 6

Serratus posterior superior

Answer 6

Attachment: Spinous processes of lower cervical and upper thoracic vertebrae

Distal Attachment: Superior border of upper ribs

Innervation: Intercostal nn.

Action: Elevate ribs; proprioception

Question 7

Serratus posterior inferior

Answer 7

Attachment: Spinous processes of lower thoracic and upper lumbar vertebrae

Distal Attachment: inferior border of lower ribs

Innervation: Intercostal nn.

Action: Depresses ribs; proprioception

Question 8

Splenius capitis

Answer 8

Attachment: Nuchal ligament and spinous processes of upper thoracic vertebrae

Distal Attachment: Occipital bone and mastoid process

Innervation: Posterior rami of spinal nerves

Action: Laterally flexes neck; rotates head to same side. Bilateral activation: extends head and neck

Question 9

Splenius cervicis

Answer 9

Attachment: Nuchal ligament and spinous processes of mid/upper thoracic vertebrae

Distal Attachment: Transverse processes of upper cervical vertebrae

Innervation: Posterior rami of spinal nerves

Action: Laterally flexes neck; rotates head to same side. Bilateral activation: extends head and neck

Question 10

Iliocostalis

Answer 10

Attachment: Broad tendon arising from posterior region of the sacrum

Distal Attachment: Ribs

Innervation: Posterior rami of spinal nerves

Action: As a group
(erector spinae): Extend the vertebral column and head (bilateral); laterally flex vertebral column (unilateral)

Question 11

Longissimus

Answer 11

Attachment: Broad tendon arising from posterior region of the sacrum and iliac crest

Distal Attachment: Ribs, transverse processes, mastoid process

Innervation: Posterior rami of spinal nerves

Action: As a group
(erector spinae): Extend the vertebral column and head (bilateral); laterally flex vertebral column (unilateral)

Question 12

Spinalis

Answer 12

Attachment: Spinous processes

Distal Attachment: Spinous processes

Innervation: Posterior rami of spinal nerves

Action: As a group
(erector spinae): Extend the vertebral column and head (bilateral); laterally flex vertebral column (unilateral)

Question 13

Semispinalis capitis

Answer 13

Attachment: Transverse processes of cervical and thoracic vertebrae

Distal Attachment: Occipital bone

Innervation: Posterior rami of spinal nerves

Action: Extends the head and upper spine (bilateral); rotates head to opposite side (unilateral)

Question 14

Rectus capitis posterior major

Answer 14

Attachment: Spinous process of C2

Distal Attachment: Occipital bone

Innervation: Suboccipital n.

Action: Extends neck, rotates head to same side

Question 15

Rectus capitis posterior minor

Answer 15

Attachment: Posterior arch of C1

Distal Attachment: Occipital bone

Innervation: Suboccipital n.

Action: Extends neck, rotates head to same side

Question 16

Obliquus capitis inferior

Answer 16

Attachment: Posterior arch of C2

Distal Attachment: Transverse process of C1

Innervation: Suboccipital n.

Action: Rotates atlanto‐occipital joint

Question 17

Obliquus capitis superior

Answer 17

Attachment: Transverse process of C1

Distal Attachment: Occipital bone

Innervation: Suboccipital n.

Action: Extends and laterally flexes neck

Question 18

Greater occipital nerve

Answer 18

Course and Function: passes through the semispinalis capitis and the suboccipital triangle; supplies sensory innervation to skin on the back of the head

Question 19

Vertebral artery

Answer 19

Course and Function: passes through the transverse foramen of C1 and all the way through to C6-ish where it meets the subclavian artery

Question 20

Cervical enlargement

Answer 20

Course and Function: C5 to T1, provides nerves to the upper limbs

Question 21

Lumbar Enlargement

Answer 21

Course and Function: L1 to S3, provides nerves to the lower limb

Question 22

Conus Medullaris

Answer 22

End of spinal cord b/t L1 and L2

Question 23

Cauda equina

Answer 23

collection of ventral and dorsal roots in the lower vertebral canal

Question 24

filum terminale

Answer 24

continuous with the pia mater; arises from the inferior tip of the conus medullaris and ends at S2, where it is encircled by the lower end of the dural sac

Question 25

ligamenta flava

Answer 25

connect the laminae of adjacent vertebrae