Neuraxial: Anatomy

How many vertebrae are there? Name the numbers and sections

33 total (26 if fused are counted as 1)

• 7 cervical- smallest

• 12 thoracic

• 5 lumbar- largest

• 5 fused sacral= 1

• 4 fused coccygeal =1

How does the angle of the spinous process change through the spine?

Cervical- horizontal

Thoracic- caudal (downward pointing)

Lumbar- horizontal

Name the parts of the vertebrae

Body

Spinous process

Bony arch made of : 2 posterior lamina, 2 transverse processes, and 2 anterior pedicles

Name the major ligaments of the spine and where they are located

• Supraspinous

  • Connects the tips of the spinous processes from sacrum to T7

• Interspinous

  • Connects the posterior spinous processes & fills gap

• Ligamentum flavum

  • Connects the lamina of the adjacent vertebrae

• Ant/Post Longitudinal

  • Primary supportive ligaments of the vertebral column

  • Binds vertebral bodies and provides stability

Name the spinal cord coverings from inside to outside

• Pia mater - adherent to the spinal cord & nerves

• Arachnoid - between the pia & dura mater

• Dura mater - toughest outer membrane 

Where are the subrachnoid space and the epidural space located?

Subarachnoid- between the arachnoid and pia (contains CSF)

Epidural- potential space between dura and ligamentum flavum that ends at the sacral hiatus

How many nerves are located in the spine?

62 (31 pairs)

Anterior AKA ventral AKA motor (MVA)

Posterior AKA dorsal AKA sensory (PtSD)

What surface landmarks are often used to indentify location prior to neuraxial administration?

C7-T1: vertebral prominens

T7: inferior scapula

L4: iliac crest (intercristal line)

S2: posterior superior iliac spine

How much blood supply does the brain and spinal cord require

Spinal cord are similar to cerebral

• gray: 80cc/100gm/min

• white: 20cc/100gm/min

• Avg 50cc/100 gm/min

WHich arteries supply the spinal cordw ith bloo

1 anterior spinal artery

2 posterior spinal arteries

Plus radicular arteries

Trace the sensory dermatmes through the body. Which landmarks correspond with T10, T6, and T4?

T4- nipples

T6-xyphoid

T10- umbilicus

Name the action of the following myotomes

C5

C6

C7

C8

T1

L1-2

L3-4

L5-S1

L5

S1

Which myotome is associated with the follong deep tendon reflexes:

Biceps

Brachioradialis

Triceps

Quadriceps

Achiles tendon