Anatomy - Spine Flashcards
What makes up the spinal column?
24 separate vertabrae + sacrum + coccyx
7 Cervical
12 Thoracic
5 Lumbar
5 fused Sacrum
3-4 fused Coccyx
How are the articular processes arranged in the thoracic vertabrae?
Superior - faces backward
Inferior - faces forward
Allows articulation between adjacent vertabrae
How are the articular processes arranged in the thoracic vertabrae?
Superior - faces inward
Inferior - faces outward
This arrangment limits rotation of lumbar spine
What is the name of the most anterior point on the sacrum?
Sacral promontory
What are the parts of the intervertebral disc called?
Outer - annulus fibrosus (fibrocartilaginous type I collagen)
Inner - nucleus pulposus (type II collagen)
Which spinal ligament runs on the anterior aspect of adjacent lamina?
Ligamentum flavum
Which spinal ligament holds the vertebral bodies of adjacent vertabrae together?
Anterior (stronger) and posterior longitudinal ligaments
Vertebral level: termination of dural sac
S2
Vertebral level: conus medularis
L1/2
What are the three dural layers?
Dura mater
Arachnoid mater
Pia mater
Which areas within the spinal column transmit light touch and vibration sensation?
Dorsal columns
Where is the spinothalamic tract located and what does it transmit?
Anterolaterally, transmitting sensation of sharp pain and temperature
Where is the corticospinal tract located and what does it transmit?
Posterior to the spinothalamic tract, transmitting motor fibres
Describe the findings in Brown-Séquard syndrome
Hemisection of the spinal cord leades to:
1. contralateral loss of pain and temperature beginning a few levels below the level of injury (due to how the spinothalamic tract decussates)
2. ipsilateral spastic paralysis, loss of light tough, vibration, proprioception
What is the common mechanism of injury causing a central cord syndrome?
Hyperextension injury of the neck
What are the upper limbs more affected than the lower limbs in a central cord syndrome?
Motor fibres supplying the upper limb run more centrally within the corticospinal tract, therefore more likely to be injured
Describe the blood supply of the spinal cord
Anterior spinal artery originates from the vertebral arteries
Two posterior spinal arteries originate from the posterior inferior cerebellar arteries
Multiple radicular arteries at multiple levels
Landmark for Lumpar Puncture
Iliac crests correspond to the supracrestal plane at L4
The spinal cord terminated at the conus at L1
LP is safe to perform at L3/4 or L4/5
Layers transversed by a LP needle
- Skin
- Subcutaneous tissue
- Supraspinous ligament
- Interspinous ligament
- Ligamentum flavum
- Epidural space (contains venous plexus)
- Dura mater
- Subdural space
- Arachnoid mater
- CSF (obtained for subarachnoid space)
What is cauda equina?
Syndrome consisting severe back and bilateral leg pain resulting from compression of the nerve roots at the cada equina
Failure to manage compression promptly may lead to irreversible loss of bowel, bladder and lower limb function
How many pairs of spinal nerves are there?
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal
What fascial layers would be encountered in the neck during an anterior cervical spinal decompression and fusion (ACDF)?
- Superficial fascia - platysma and fat
- Investing layer of the deep cervical fascia - enveloped entire neck including trapezius and SCM
- Carotid sheath - common carotid and the internal carotid arteries, internal jugular vein and vagus nerve
- Pretracheal layer - thyroid gland, trachea, oesophagus, “strap” muscles
- Prevertebral fascia - vertebral column and muscles
What type of joint is the intervertebral joints?
Secondary cartilaginous
What is the most important radicular artery providing additional blood supply to the spinal column?
Artery of Adamkiwicz
