Spinal Cord and Meninges Flashcards
What ligament runs down the anterior side of the vertebral canal?
Posterior longitudinal ligament
What ligament runs down the posterior side of the vertebral canal?
Ligamentum flavum
What causes an increase in size of the cervical and lumbosacral regions?
Brachial and lumbar plexus
Where does the spinal cord end?
L1/L2
What lies medially on both the anterior and posterior side?
Posterior median sulcus
Anterior median fissure
What are contained in the different horns of the spinal cord?
Lateral- autonomic and motor neurons
Ventral- Somatic motor
Dorsal- Interneurons
How many spinal nerves are there?
31 pairs
Where to spinal nerves emerge from?
Intervertebral foramen
How many nerves enter the different vertebral regions?
Cervical- 8
Thoracic- 12
Lumbar- 5
Sacral- 5
Coccygeal- 1
What are the different structures that develop from the spinal cord?
Dorsal/ventral rootlets
Dorsal/ventral roots
Spinal nerve
Dorsal ramus
Ventral ramus
What nerves are contained in the dorsal rootlets?
Sensory
What nerves are contained in the ventral root?
Motor
What nerves are contained in the dorsal ramus and ventral ramus?
Both
What three layers surround the spinal cord?
Dura mater
Pia mater
Arachnoid mater
Describe the dura mater
Outermost layer
Attached to inner surface of cranium
In the vertebral canal it is called the dural sac and is not attached to bone
Narrows extensively at lower border of S2 where it fuses with filum terminale
Covers roots of spinal nerves as they pass through the intervertebral foramina
Describe arachnoid mater?
Delicate avascular layer which lies deep to dura
Connects to pia via arachnoid trabeculae
Continuous with space around brain
Ends at S2
Contains CSF
Encloses the caudal equina as lumbar cistern
Describe pia mater?
Innermost layer
Very thin
Becomes filum terminale at inferior end of cord, attached to the coccyx
In the vertebral canal, triangular extensions of pia- denticulate ligaments- are attached to arachnoid mater
What is contained within the extra dural space?
Internal vertebral venous plexus
What two ways is the spinal cord supplied with blood?
3 longitudinal arteries- branch of subclavian and lies on cord
Numerous segmental arteries- branches of aorta enter via vertebral canal and invertebral foramen
What are the 3 longitudinal arteries?
2 posterior spinal arteries- arise from vertebral and posterior inferior cerebellar arteries
1 anterior spinal artery- arises from vertebral arteries
Where do the segmental arterial supply arise from?
Cervical- vertebral arteries
Thoracic- intercostal arteries
Lumbar- lumbar arteries
What do segmental arteries split into?
Radicular arteries
What are the arteries called if there is an anastomosis between the radicular and longitudinal arteries?
Segmental medullary artery
What artery runs into the vertebra?
Sulcus artery
