The Vertebral Column, Spinal Cord and Spinal Tracts (Neuro) Flashcards
What is the Vertebral column also known as? Where does it run to and from?
Spine or spinal column
Head to pelvis
How many vertebrae are there? What are the 5 types of vertebrae? How many of each is there?
33 vertebrae
Cervical-7
Thoracic-12
Lumbar-5
Sacral-5
Coccygeal-4
What do the sacral and coccygeal vertebrae fuse to form respectively? Where are they found?
Sacrum and Coccyx
In the Pelvis
What are the name for the two types of curvatures in the Vertebral column? What does each one mean?
Lordosis- Inwards curvature
Kyphosis- Outwards curvature
What are the three curvatures in the vertebral column?
Cervical lordosis
Thoracic kyphosis
Lumbar Lordosis
What 4 things can cause excessive lordosis or kyphosis?
- Poor posture
- Muscle weakness
- Anatomical abnormalities
- Injuries
What is the third type of curvature known as which is abnormal? What direction does it curve?
Scoliosis
Spine curves laterally
Name the structures of the vertebrae (Superior and lateral view)
a-Transverse process
b-Pedicle
c- Spinal Canal
d- Spinous process
e- body (anaterior) and laminae (posteriorly)
f- Intervertebral foramen
g- Spinous process
h- Articular process
i- Transverse process
Which part of the vertebrae is located most anteriorly? What does it support?
Body
Supports weight of vertebral column above it
What connects Vertebrae to each other?
Intervertebral discs
What structure stems posteriorly from the vertebral body? What does it form?
Pedicle
Forms lateral wall of spinal canal
What forms the posterior wall of the spinal canal? What stems from it?
Lamina
Spinous process
What is the spinal canal? What travels in it?
Hole formed by body, pedicle and lamina
Spinal cord travels in it
What protrusions are formed at the junction between the pedicle and lamina? What do they provide?
Transverse processes
Provide attachment for the muscles
What do the Transverse processes form in the cervical and thoracic spine respectively?
Cervical- Canal for vertebral arteries
Thoracic- Primary site of articulation with ribs
What are the articular processes? What do they provide?
Vertical protrusions
Provide a site of attachment for vertebrae above and below
Where do the spinal nerves leave the spinal cord? What is this space formed by?
Intervertebral foramina
Body and the pedicles of neighbouring vertebrae
What is Vertebrae C1 known as? What does it articulate with? What does it allow us to do?
Atlas
Occipital bone
Nod our heads
What shape is the atlas? What does it not have?
Ring shaped
Doesn’t have a spinous process and a vertebral body
What is vertebrae C2 known as? What does it allow us to do? What structure allows us to do this and what is the structure of this structure?
Axis
Rotate our head
Otonoid process
The body is a vertical protrusion
What is different about the body, the transverse process and the Spinous process in C3-C6? Why?
Smaller body- support less weight
Holes in transverse process- Transverse foramina allow vertebral arteries to pass through
Have a bifoid transverse process (two-pronged)
What three features makes C7 different to the other cervical vertebrae
Transverse foramen doesn’t transmit vertebral arteries
Doesn’t have a bifoud spinous process
Spinous process more prominent
How do the thoracic vertebrae change from superior to inferior? What extra structure do they contain? How is there spinous process different?
Increasingly larger
Articular surfaces for ribs
Longer sharper spinous process that faces downwards
Why are the lumbar vertebrae larger than the thoracic vertebrae? How do their transverse processes project? How do their spinous process compare to thoracic vertebrae?
Carry more weight
Laterally
Larger spinous process
What is the shape of the sacrum? Where in the pelvis is it located?
Large triangular shape
Central and posterior part of the pelvis
Where does the sacrum articulate with the pelvis?
Sacroiliac joints
What is the Sacral promontory? What attaches to the inferior aspect of the sacrum?
Anterior prominence at the top of the sacrum
Coccyx
Primary movements of the atlas, axial and cervical vertebrae respectively?
Atlas & axis- Rotation at atlanto-axial joint
Cervical (C3-C7)- Flexion, extension and lateral flexion
Primary movements of the Thoracic and Lumbar vertebrae respectively?
Thoracic- Rotation
Lumbar- Flexion, extension and lateral flexion
Primary movements of the sacral and coccygeal vertebrae?
None
What is between non fused vertebrae? What is it made of and what does this allow (3)?
Intervertebral discs
Fibrocartilaginous structure
Withstand compression, flexibility and movement
What is at the centre of the intervertebral discs?
What surrounds it? what is each made of?
Nucleus pulposus- geltinous
Annulus fibrosus- made of concentric rings
What separates intervertebral discs from the vertebral bodies? What is the combination of vertebrae and intervertebral discs called?
Thin layer of Hyaline cartilage
Secondary cartilaginous joint (Bone- hyaline cartilage- fibrocartilage- hyaline cartilage- bone)
What are spinal ligaments? (2) and function?
Several ligaments that help maintain upright posture and prevent hyperflexion and hyperextension injuries
What are the 5 spinal ligaments?
Anterior longitudinal ligament
Posterior longitudinal ligament
Ligamentum flavum
Interspinous ligament
Supraspinous ligament
Where do the anterior longitudinal ligaments and posterior longitudinal ligaments run respecively?
Anterior surfaces of vertebral bodies
Posterior surface of vertebral bodies but anterior to spinal canal
Where does the Ligamentum flavum run? What colour is it and why?
Inside of laminae
Yellow
High amount of elastin
Where do the interspinous and supraspinous ligament run respectively?
Interspinous- between spinous processes
Supraspinous- tips of the spinous processes
Name the structures
a- anterior longitudinal ligament
b- Ligamentum flavum
c- Posterior longitudinal ligament
d- Interspinous ligament
e- Supraspinous ligament
What is the name of the group of muscles that support the vertebral column? What do they form? What do they contribute towards and where can they be palpated?
Erector spinae
Either side of spinous processes
Maintaining upright posture
Either side of lumbar spine
What can result from repetitive compression of the intervertebral discs?
Weakening of annulus fibrosus causing posterior herniation of the nucleus pulposus and can narrow the intervertebral foramina
Called disc herniation
Where does the spinal cord terminate? What does this mean in terms of collecting cerebro spinal fluid?
L1/L2
Lumbar puncture can be performed as no damage to spinal cord
What leaves the spinal cord at every level and through where? How are these named?
Pair of spinal nerves through the intervertebral foramina
Named by the level that they leave at
Where do the spinal nerves leave their corresponding vertebrae in the cervical spine and the then the rest of the spine?
Cervical- above their corresponding vertebrae
Rest of spine- Below their corresponding vertebrae
What is the extra pair of spinal nerves in the cervical spine? How many pairs of nerves are there in the coccygeal spinal cord?
C8- exits below C7
Coccygeal spinal cord only has one pair
What level does the spinal cord taper off and into what shape? What is this shape called?
L1/L2 into a cone shape
Conus medullaris
What carries on around the vertebral column after the spinal cord terminates? Where does it carry on to?
Dura and arachnoid meninges
Carries on to the sacrum
What happens to the pia mater after the spinal cord terminates? What does it form? Where does it travel to?
Thickens to form a thin strand of fibrous tissue known as the filum terminale
To the coccyx
What happens to the remaining spinal nerves once the cord has terminated? What is it called?
They all leave the spinal cord and descend to their designated level
Cauda equina (Resembles a horse tail)
What are the two roots of each spinal nerve called? Why?
Dorsal and ventral roots
Stem from either the dorsal or ventral aspects of the spinal cord
What does the dorsal root carry? Where? Through what?
Sensory fibres
into spinal cord
Dorsal root ganglion
What does the Ventral root of the spinal cord carry (2)? What direction? How are they different from the dorsal roots?
Motor fibres and sympathetic fibres out of the spinal cord
Doesn’t have ganglion on it
Where is the grey matter found in the spinal cord What four structures does this form?
In the centre
Two dorsal horns and two ventral horns
What surrounds the central horns?
White matter
What forms the spinal nerve? What does it then divide into?
Dorsal and Ventral root
Dorsal and ventral ramus (rami plural)
What does each Rami contain (2)? Which ramus is larger? What does each rami supply?
Contain motor and sensory fibres
Ventral is larger
Dorsal rami supplies dorsal structures and ventral supplies ventral structures
2 examples of what the dorsal ramus sypplies
Skin of back and paraspinal muscles
In the ascending sensory pathways How many neurones are there what are they each called?
3
First, second and third order neurones
Where does each neurone carry information to and from in the ascending pathway? (3)
Receptor to CNS
CNS to thalamus
Thalamus to somatosensory cortex
How many order neurones are there in the descending motor tracts? Where does each one carry information to and from?
First order (UMN)- motor cortex to ventral horn
Second order (LMN) Spinal cord to target muscle
What do most neurones do during their pathway in the ascending or descending tracts?
What is this known as? Do they all do this at the same point?
Cross over to the contralateral side
Decussation
No decussate at different points
What are bundles of neurones organised into within the white matter of the cord? What are they known as?
Vertical columns
Spinal tracts
What spinal tracts are located most dorsally in the spinal cord? What information do they carry? (4)
Dorsal Columns Medial Lemniscus (DCML)
1. Fine touch
2. Two-point discrimination
3. Vibration
4. Proprioception
Where do the first order neurones travel in the DCML? What are the dorsal columns divided into on each side? What are they called and where are they located?
Along dorsal root to medulla
Fasciculus gracilis- Medial
Fasciculus Cuneatus- Lateral
What do the fasciculus gracilis and fasciculus cuneatus carry information for respectively? Where do they synapse in what structure?
Lower limbs and upper limbs
Gracile and cuneate nuclei in the medulla
What happens to the second order neurones within the medulla in the DCML? Where do they travel to? What is this part of the tracts called?
Decussate onto the other side
To the Thalamus (On the contralateral side)
Dorsal column
Where is the second synapse in the DCML? Where does the third order neurone travel to? through what structure?
In the thalamus
Travels to Primary somatosensory cortex in the parietal lobe
Via the internal capsule
Where are the Spinothalamic tracts located in the spinal cord? What fibres do they carry?
Antero-laterally
Sensory fibres
What do the spinothalamic tracts carry information about(3)? Where do they first synapse?
Crude touch, pain and temperature
within the Dorsal horn
Where do the Spinothalamic tracts decussate? Where does the second order neuron travel to?
In the Spinal cord after travelling one or two vertebral levels upwards
Travels to thalamus on contralateral side
Where is the second synapse in the spinothalamic tract? Where do the third order neurones travel through and to where?
Thalamus
Via internal capsule to the primary somatosensory cortex
Where are the Lateral corticospinal tracts located within the Spinal cord? What type of impulses do they carry?
Laterally
Motor impulses
What is the route of the First order neurones in the Lateral corticospinal tract? Where do the decussate?
Leave Motor cortex and pass through the internal capsule
Decussate at the level of the medullary pyramids
Continue contralaterally down the spinal cord
Where do the first order neurones synapsein the lateral corticospinal tract? Where do the LMN/ SON go?
Ventral horn of desired spinal cord level
Second order neurones leave the cord via the ventral root
What tracts are located most laterally in the spinal cord? What do they carry?
Anterior and Posterior spinocerebellar tracts
Carries unconscious proprioceptive information to the cerebellum
Which spinocerebellar tract decussates? Where?
Anterior spinocerebellar
Once at the level of entry into the spinal cord
and once as soon as it enters the cerebellum
Does the posterior spinocerebellar tract decussate? What level? What side does each tract reach the cerebellum on?
No it doesn’t- no level
Both reach it on the ipsilateral side
What syndrome is classified as damaged to one side of the spinal cord?
Brown-Sequard Syndrome
Name of joints that connects individual vertebrae together and allows movements between them?
Facet joints
Ligamentum flavum connects which parts of the vertebrae together?
Laminae
