Spinal Cord Flashcards
Links the brain and the rest of the body
Extends from the Foramen Magnum to vertebrae L1-L2
Spinal Cord
Cone-shaped end of the Spinal Cord
Conus Medularis
The Spinal Cord is protected by? (3)
1) Vertebral Column
2) Cerebrospinal Fluid
3) 3 Meninges
* The Meninges that cover the Spinal Cord are continuous with thous covering the brain
The Pia Mater continues caudally (inferiorly, towards the tailbone/coccyx) beyond the Spinal Cord (Conus Medularis), and is refer to as?
Filum Terminale
*It passes through the dura to attach to the coccyx and helps anchor the Spinal Cord
The Vertebral Foramina (hole in each vertebrae between the vertebral bodies and the lamina) of each vertebrae in the Spine form the?
Protects the Spinal Cord
Vertebral Canal
Aka Neural Canal or Spinal Canal
Contained within the Subarachnoid space
A bundle of spinal nerves, all of which originate from the Conus Medularis
Cauda Equina
Latin for “horse’s tail”
The dura mater extends to S2, where it is known as?
The Dural Sheath
Located between the dura and the interior surface of the Neural Canal
Contains veins, arteries and fat
Epidural Space
*an “epidural” is an injection of medication, often an analgesic, into the epidural space
The Spinal Cord is suspended within the dura mater by many ligaments, which extend from the pia mater, called?
Denticulate Ligaments
*Named for their tooth like appearance, they are believed to stabilize the spinal cord against motion within the vertebral column.
The area of the Spinal Cord from which a pair of dorsal and ventral roots arise
Spinal Cord Segment
*Within the Cord itself, there are no distinct boundaries between these segments
The anterior (Ventral) and posterior (Dorsal) roots join together at the intervertebral foramen (a bony channel between adjacent vertebrae) to form?
A Spinal Nerve
*particularly vulnerable site to injury
The Dorsal (posterior) root carries?
Afferent (Sensory) Info
The Ventral (anterior) root carries?
*from the Spinal Cord to the muscles and viscera
Efferent (Motor) Info
Moving inferiorly down the Spinal Cord, the length of the nerve roots progressively…
Increases
The lumbar and sacral spinal nerve roots below the conus medularis form the?
Cauda Equina
*these nerve roots travel caudally prior to exiting the spinal column below the conus medularis at their respective foramina in the lumbar vertebrae and sacrum
The Spinal Cord has how many spinal nerves and corresponding segments?
*the names of the spinal nerves correspond to the names of the spinal cord segement from which they emerge
31
8 Cervical 12 Thoracic 5 Lumbar 5 Sacral 1 Coccygeal
Each of the first 7 cervical nerves leaves the vertebral canal…
Above the corresponding vertebrae
The 8th cervical nerve leaves the vertebral canal between?
The 7th cervical vertebrae and the 1st Thoracic vertebrae
*each of the subsequent nerves leaves below the corresponding vertebrea
Partially divides the Spinal Cord into right and left sides (2)
Anterior Median Fissure
Posterior Median Sulcus
Contains cell bodies of neurons, neuroglia, unmyelinated axons and the dendrites of interneurons and motor neurons
Grey Matter (of the Spinal Cord) (butterfly shape or "H")
A canal within the grey matter filled with Cerebrospinal Fluid
Runs longitudinally through the length of the entire Spinal cord
Contiguous with the ventricular system of the brain
The Central Canal (of the Spinal Cord)
The grey matter in the Spinal cord is divided into
Horns
The Ventral (anterior) horn contains the cell bodies of?
Lower Motor Neurons (LMN)
Lower Motor Neurons in the Cranial nerves (leaving the brain stem) innervate?
Muscles of the head
Lower Motor Neurons that leave the spinal cord innervate?
The Body
Collective term for the brainstem and spinal cord
Neuraxis
The 3 grey columns of the Spinal Cord
1) Anterior (horn) grey column
2) Posterior (horn) grey column
3) Lateral (horn) grey column
The lateral horn is present at how many levels (through how many segments) of the spinal cord? Specifically through?
14 levels of the SC
Specifically through levels T1-L2
All sympathetic Nervous System outflow is via the cell bodies of what level of the Spinal Cord, in the ventral horn?
T1-L2
*This is why the SyNS is also referred to as the thoracolumbar outflow
Lower Motor Neurons are motor neurons whose cell bodies are found in the? (2)
Ventral horn of the Spinal Cord
The Cranial nerve nuclei of the brain stem
All voluntary movement relies on Lower Motor Neurons which innervates skeletal muscle fibres and act as a link between?
Upper Motor Neurons and Muscles
Lower Motor Neurons that innervate extrafusal muscle fibers
Alpha Motor Neurons
Lower Motor Neurons that innervate intrafusal muscle fibers
Gamma Motor Neurons
Consists of myelinated and unmyelinated axons of sensory neurons, interneurons and motor neurons
White Matter (of the Spinal Cord)
Bundle of axons in the CNS
Tract
Ascending tracts, traveling towards the brain are?
Sensory
Descending tracts, traveling away from the brain are?
Motor
Most sensory tracts names begin with ___, indicating they begin in the Spinal Cord, and the name will end with the part of the brain where the tract leads
“Spino-“
Tracts whose names end in ____ are motor
“-spinal”
A condition where the space in the spinal (vertebral) canal narrows as a result of degenerative changes in the vertebrae as we age. These changes cause excessive bone growth (osteophytes), ligament hypertrophy and loss of disc height.
Most commonly seen in adults over 50.
Symptoms vary and include pain, muscle weakness, loss of bladder, bowel and sexual functions
Spinal Stenosis
- People with spinal stenosis find a bent forward position while walking or sitting down helps to decompress the area and relieve pain
- *In severe cases laminectomy is an option to relieve pressure off the nerves
