Nerves And Vessels Of The Back And Spinal Cord

Front 1

Describe Spinal Nerves

Back 1

exit the vertebral column (spine) through intervertebral foramina

initially arise from the spinal cord as bilateral pairs of rootlets that converge to form two nerve roots

Front 2

Name the Spinal Nerve Regions and Numbers

Back 2

31 Spinal Nerves:
8 Cervical Nerves
12 Thoracic Nerves
5 Lumbar Nerves
5 Sacral Nerves
1 Coccygeal Nerve

Front 3

Describe the Ventral Nerve Root

Back 3

consists of motor (efferent) fibers passing from nerve cell bodies in the anterior horn of spinal cord gray matter to effector organs located peripherally

Front 4

Describe the Dorsal Nerve Root

Back 4

consists of sensory (afferent) fibers from cell bodies in the spinal sensory or posterior (dorsal) root ganglion, DRG, that extend peripherally to sensory endings and centrally to the posterior horn of spinal cord gray matter.

Front 5

Describe the Dorsal Primary Rami of Spinal Nerves

Back 5

supply nerve fibers to the synovial joints of the vertebral column, deep muscles of the back, and the overlying skin in a segmental pattern.

As a general rule, the posterior rami remain separate from each other (do not merge to form major somatic nerve plexuses).

Front 6

Describe the Ventral Primary Rami of Spinal Nerves

Back 6

supply nerve fibers to the anterior and lateral regions of the trunk and the upper and lower limbs.

The anterior rami that are distributed exclusively to the trunk generally remain separate from each other, also innervating muscles and skin in a segmental pattern

in relationship to the innervation of the limbs, the majority of anterior rami merge with one or more adjacent anterior rami, forming the major somatic nerve plexuses

Front 7

Greater Occipital Nerve Origin

Back 7

posterior ramus of spinal nerve C2

Front 8

Greater Occipital Nerve Course

Back 8

Emerges inferior to obliquus capitis inferior and ascends to posterior scalp

Front 9

Greater Occipital Nerve Distribution

Back 9

Skin over neck and occipital bone

Front 10

Suboccipital Nerve Origin

Back 10

Posterior ramus of spinal nerve C1

Front 11

Suboccipital Nerve Course

Back 11

Runs between cranium and C1 vertebra to reach suboccipital triangle

Front 12

Suboccipital Nerve Distribution

Back 12

Muscles of suboccipital triangle

Front 13

Spinal Accessory Nerve Origin

Back 13

CN XI
arises from the nucleus of the spinal accessory nerve, a column of anterior horn motor neurons in the superior five or six cervical segments of the spinal cord

Front 14

Spinal Accessory Nerve Course

Back 14

joins the CN X temporarily as they pass through the jugular foramen, separating again as they exit.
descends along the internal carotid artery, penetrates and innervates the sternocleidomastoid, and emerges from the muscle near the middle of its posterior border.
crosses the posterior cervical region and passes deep to the superior border of the trapezius to descend on its deep surface, providing multiple branches to the muscle. Branches of C2–C4 join the spinal accessory nerve in the posterior cervical region, providing these muscles with pain and proprioceptive fibers.

Front 15

Spinal Accessory Nerve Distribution

Back 15

supply somatic motor fibers to the sternocleidomastoid and trapezius muscles

provide muscles of the posterior cervical region with pain and proprioceptive fibers.

Front 16

Dorsal Root (Spinal) Ganglion

Back 16

Each dorsal root contains a spinal ganglion, where the cell bodies of sensory neurons are found.

The dorsal and ventral roots of the same segment join to form a spinal nerve, which soon divides into dorsal and ventral primary rami.

Front 17

List the major segmental arteries of the trunk

Back 17

Posterior intercostal arteries in the thoracic region

Subcostal and lumbar arteries in the abdomen

Iliolumbar and lateral and medial sacral arteries in the pelvis

Front 18

Describe the Internal Vertebral Venous Plexus

Back 18

epidural venous plexuses

communicate with external plexus through the intervertebral foramina.

densest anteriorly and posteriorly and relatively sparse laterally

consists of valveless anastomoses between anterior and posterior longitudinal venous sinuses.

Front 19

Describe the External Vertebral Venous Plexus

Back 19

communicate with internal plexus through the intervertebral foramina.

densest anteriorly and posteriorly and relatively sparse laterally