4: Back Angiology And Neurology Flashcards
Transection of the spinal cord at different levels and its effect
- C1-3: no function below head; respirator necessary for life
- C4-5: no function of limbs, respiration capable
- C6-8: loss of hand and variable upper limb function, possible use of wheelchair
- T1-9: paralysis of lower limbs
- T10-L1: some thigh function, may walk using leg braces
- L2-3: most lower limb function present, may walk using short leg braces
Five categories of structures that can be injuring, causing back pain
- Fibroskeletal structures
- Meninges
- Synovial joints
- Intrinsic back muscles
- Spinal nerves and nerve roots
What is considered fibroskeletal structures of the back
Periosteum, ligaments
Anterior and posterior spinal A’s: how are they formed?
By two branches of each vertebral A uniting in the midline (this is true for anterior and posterior spinal A’s)
What do sulcal A’s supply?
Anterior 2/3 of spinal cord
Another artery that can produce the posterior spinal A’s instead of the vertebral A
Posterior inferior cerebellar A
When the two vertebral arteries join in the cranial fossa, what artery is formed?
Basilar A
What does the inferior thyroid A supply?
Thyroid
Two muscles supplied by suprascapular A
Supraspinatus, infraspinatus
What nerve does the superficial branch of the transverse cervical artery travel with?
Spinal accessory N
What does the dorsal scapular A supply?
Levator scapulae, rhomboids
Path of the dorsal scapular A
Superior to scapula -> along medial border -> muscle innervation
What is the largest but shortest branch of the axillary A
Subscapular A
Muscle supplied by thoracodorsal A
Latissimus dorsi
What does the internal iliac broadly supply?
Pelvic viscera, gluteal region, perineum
What levels are equatorial branches and periosteal branches of spinal A’s found?
Every level of the vertebral column
What levels are spinal branches of spinal A’s found?
Every thoracic level
When are anterior and posterior segmental medullary A’s used in place of anterior and posterior radicular A’s
Sporadically near the C and L enlargements
Great anterior segmental medullary A
Much larger anterior segmental medullary A
Location of external vs internal vertebral venous plexuses
External: anteriorly and posteriorly on spinal column
Internal: in vertebral canal
What does the external vertebral venous plexus drain?
Basivertebral V’s
What does the internal vertebral venous plexus drain?
Anterior and posterior medullary and radicular V’s, basivertebral V’s
What do anterior and posterior medullary V’s drain and into what?
Anterior and posterior spinal V’s -> internal vertebral venous plexus
How many anterior and posterior spinal V’s are there?
Three each, typically freely communicating
Intervertebral V: drains what into what?
Internal vertebral venous plexus -> segmental V’s
Three segmental V’s
Lumbar, subcostal, posterior intercostal
How much of the vertebral canal does the spinal cord occupy?
About 2/3rds
Two things located in the epidural space
Internal vertebral venous plexus, epidural fat
Dural root sheath
Lateral tapering extension of dura mater surrounding anterior and posterior rootlets (contains arachnoid mater too)
Filum terminale externum
Filum terminale inferior to dural sac, travels through sacral hiatus and inserts on coccyx
Where is CSF located?
Subarachnoid space
What is in the lumbar cistern?
Cauda equina
Denticulate ligament
Lateral extension of fibrous pia mater at regular intervals between spinal roots to attach to dural sac, suspending the spinal cord
Filum terminale internum
Inferior continuation of pia mater after conus medullaris, eventually picks up layer of dura mater and becomes filum terminale externum
Two spinal cord enlargements
C4-T1, T11-S1
Path from spinal cord to rami
Spinal cord, spinal rootlets, spinal root, spinal nerve, spinal rami
How many pairs of spinal nerves are there
31
Recurrent meningeal branches
From anterior rami of whole spinal cord -> send sensory and sympathetic fibers to dura mater
What is cauda equina anyway?
A bundle of anterior + posterior roots from lumbosacral enlargement and medullary cone
