spinal cord function/dysfunction Flashcards
(32 cards)
what is rams
Inanatomy, a branch, such as a branch of a blood vessel or nerve
what are ascending and descending tracts defined as
Ascending tract – sending info/impulses TO THE BRAIN
Descending tract – sending info/impulses FROM THE BRAIN
what are layers of meninges
3 layers:
Tough, outer dura mater
Delicate, thin, middle layer: arachnoid mater
Very thin, inner layer, which closely follows brain surface: pia mater
what are the layers of dura matter in brain
2 layers in the brain
Outer periosteal layer
Inner meningeal layer
where do layers of dura separate in brain
Dural partitions
Intradural venous sinuses
what similarities do spinal and brain meninges have
3 layers; outer dura, middle arachnoid, then a sub-arachnoid space containing CSF, finally pia
what differences do spinal and brain meninges have
Only one layer of dura – continuous with the inner meningeal layer of dura at the foramen magnum.
Denticulate ligaments– triangular-shaped extensions of pia which stretch across the sub-arachnoid space
anchoring the cord within the vertebral foramen
Epidural space exists – containing fat and venous plexi.
when do meninges end
Spinal cord ends at L2. This is the conus medullaris
Subarachnoid space ends at S2 – so arachnoid and pia mater end at S2
where do nerve roots end
The nerve roots continue past meninges. These are named the cauda equina
where does Pia end
Pia continues and is anchored to coccyx by the filum terminale
where is lumbar puncture performed and what’s it used for
A lumbar puncture is performed after L2
Why perform a lumbar puncture?
Diagnosis
Drug administration
In what situation would you avoid a lumbar puncture
in the presence of raised ICP. Why?
Because of coning of the cerebellar tonsils (tonsillar herniation)
what are names and locations of enlargements of the spinal cord
There are 2 enlargements to the spinal column
C5-T1: Cervical enlargement – Brachial plexus
L1-S3: Lumbosacral enlargement – LS plexus
how does relationship of nerve to vertebrae change down the spinal cord
First 7 nerves in cervical column originate above the vertebrae.
From C8 downwards nerves originate below the vertebrae (C8 nerve origin belowC7)
in what level of the spinal cord do vertebrae number and nerve number nit match
Cervical (7 vertebrae, 8 nerves)
Coccygeal (4/5 vertebrae, 1 nerve)
what is shape and parts of grey matter in spinal cord
Grey matter is ‘H’ shaped:
Anterior Horn
Dorsal Horn
Intermediate Horn
what’s in grey and white matter
Grey matter is where the cell bodies are; white matter is where the axons are
what are functions and origins of each part of grey matter
Anterior horn
Cell bodies of the motor neurones
Develops from the basal plate
Dorsal horn
Cell bodies of sensory neurones/ interneurons
Develops from the alar plate
Intermediate horn
Cell bodies of the preganglionic sympathetic neurones
Thoraco-lumbar region of the spinal cord
what are 2 major pathways in somatic sensory perception
Dorsal columns-medial lemniscal pathway
Spinothalamic
Where do neurones from upper and lower limb synapse
Neurones from the upper limb synapse ascend in the cuneate fasciculus
Neurones from the lower limb ascend in the gracile fasciculus
what are 2 neurone types which exit via ventral root
Somatic and autonomic motor neurones
where do sympathetic nerves originate from
The intermediate horn
what are the two orders of neurones in the corticospinal tract
Upper motor neurone
Cell body in the motor cortex in lamina V
Axons travel in the lateral and ventral corticospinal tracts to synapse with LMN.
Lower motor neurone
Cell body in the ventral horn
Axon travels out of the ventral root to effector
describe in detail path of UMNs
UMNs start in the motor cortex: Pass through the corona radiata Through the internal capsule Through the peduncles at the midbrain To the medullary pyramids Here, 80% of the UMNs decussate
