Back and Spinal Cord Flashcards
How many vertebrae are there, and how are they divided into groups?
7 cervical
12 thoracic
5 lumbar
5 sacral (fused)
3-5 coccygeal (fused)
Name the 8 parts of a vertebra
Body
Pedicles
Transverse process
Lamina
Spinous process
Vertebral foramen/canal
Intervertebral notch/foramen
Articular facet
Which part of a vertebra is most anterior, which is most posterior?
Anterior: Body
Posterior: Spinous process
What lies in the vertebral foramen?
Spinal cord
What lies in the intervertebral foramen?
The transverse process of the below vertebra
What type of joint occurs between bodies of adjacent vertebrae? How many do we have?
Sympheses
24
What type of joint occurs between articular facets of adjacent vertebrae?
Zygapophyseal
What specific name is given to:
C1
C2
C7
Atlas
Axis
Prominens
Name 3 distinguishing features of cervical vertebrae
Smallest body
Bifid spinous process
Two holes (transverse foramen) which are postereolateral to body as well as ventral foramen
Name 2 distinguishing features of thoracic vertebrae
Spinous process sits downwards
Transverse processes are 90 degrees to one another
Name 4 distinguishing features of lumbar vertebrae
Largest body
Transverse processes are 180 degrees to each other
Prominent transverse process
Articular processes
What type of joint is between vertebrae?
Vertebral discs
Type of secondary (symphesis) cartilaginous joint
What type of joint is between spinous processes?
Facet joint
Name the 2 parts of an IV disc
Anulus fibrosus
Nucleus pulposus
What type of cartilage is found in an IV disc?
Fibrous cartilage (annulus fibrosus)
What is a slipped disc? What can it lead to?
Protrusion of the nucleus pulposus through the annulus fibrosis
It can impinge on emerging spinal nerves
What direction does nucleus pulposus tend to herniate?
Posterolateral
Name the 5 ligaments of the vertebra
Supraspinous ligament
Ligamentum flavum
Interspinous ligament
Anterior longitudinal ligament
Posterior longitudinal ligament
What does the ligamentum flavum connect
Lamina of adjacent vertebrae
What does the anterior longitudinal ligament connect
Connects anterior spinal column
What does the posterior longitudinal ligament connect
Inside of vertebral canal
What does the supraspinous ligament connect
Apices of spinous processes
What does the interspinous ligament connect
Spinal processes
What shape is a foetal spinal curve vs adult?
C vs double S
How does the cervical curvature develop?
When baby lifts head
How does the lumbar curvature develop?
When baby stands and walks
What is an exaggerated inward curve of the spine called?
Lordosis
What is an exaggerated, forward rounding of the upper back called?
Kyphosis
What is abnormal lateral curvature of the spine called?
Scoliosis
What restricts movements of the thoracic region?
Attachment of the ribs
What determines the restriction of movement of the vertebral column
The orientation of the vertebral articular facet joints
What movements are permitted by cervical vertebra? Thoracic? Lumbar?
Cervical - rotation
Thoracic - lateral flexion/rotation
Lumbar - flexion/extension
What term describes the fact that only a small amount of movement occurs at each individual joint, but it increases as successive vertebrae simultaneously move?
Summation
When posterior vertebral muscles on the left and right side contract bilaterally, what movement occurs? What if they move unilaterally?
Flexion/extension
Roation/lateral flexion
What’s the main muscle of the back?
Erector spinae muscles
What’s are the major anteriorly situated muscles that act on the vertebral column
Sternocleidomastoid in neck
Anterior abdominal wall muscles - obliques, transverse abdominis, rectus abdominis
Limb muscles (if immobilised)
When trunk flexors and extensors contract simultaneously, what happens?
Increase intra-abdominal pressure. It aids things like coughing, defecation, giving birth, lifting etc
Where is the vertebral prominence bony surface landmark found?
Spinous process of C7
What level is the spine of scapula found
Spine of T3
What level is the inferior angle of scapula found?
T7
What level is the summit of iliac crest found?
L4
What does a lumbar puncture obtain and what can it diagnose? Why else might it be used?
Cerebrospinal fluid
e.g. meningitis, bleeding in the brain
Anaesthetic purposes, e.g. epidural anaesthesia
At what level is a lumbar puncture performed in an adult and child?
Between spinous processes of L3 and L4 in adults
Between L4 and L5 in child
Why are lumbar punctures performed between L3-L4 in adults?
It’s below the spinal cord so less risk of causing nerve damage
Which interspinous distance is greatest - cervical, thoracic, lumbar?
Lumbar - bears the most weight so needs most space for thickest discs
When carrying out a lumbar puncture the patient is normally requested to flex their lumbar spine.
How does this aid access of the needle between the L3 and L4 vertebrae?
Increases the space between spinal processes, so easier to insert needle
Why is a lumbar puncture performed at a slightly lower level in a child (between L4 and L5) compared to an adult (between L3 and L4)?
Because their spinal cord extends down to a lower level in the spinal column compared to adults. Their cord grows slower than their column, so it’s harder to avoid damage.
In adults, we don’t typically do LPs between L4-L5 because it’s easier to access the CSF without risking damage by hitting nerve roots and causing cauda equina, and L3-L4 has more space. There’s also more bony landmarks.
What 3 things can cause IV discs to herniate?
Excessive pressure
Degeneration of discs
Ligament weakening
A transverse CT scans of a cervical vertebrae looks like…
:D
The foramen look like the eyes of a smiley face
Where does the spinal cord begin? Where does it end?
Occipital bone of the skull
IV disc between L1-L2
The distal end of the spinal cord forms the _____ and terminates in a fibrous extension called _____, the tip of which is called ____
Conus medullaris
Cauda equina
Filum terminale
Where is the spinal cord enlarged? Why?
Cervical and lumbar
Enlargement of grey matter to supply limbs
Which spinal nerves form the cauda equina and from which structure do they emerge?
L2-L5 from conus medullaris
Where does the filum terminale attach inferiroly and what is its function?
Conus medullaris to stabilise spinal cord
Sectioning the spinal cord in which region causes immediate death?
Cervical
Name the 6 regions of the spinal cord
(Clue: 3 horns, what’s in the middle and 2 colours)
Anterior horn
Posterior horn
Lateral horn
Central canal
Area of white matter
Area of grey matter
What makes up grey matter of the spinal cord? What makes white matter?
Cell bodies - grey
Axons - white
Which end of a transverse spinal cord looks like w
Anterior ahs a deeper groove between horns
What type of nerve impulses are associated with anterior horn cells?
Motor
What type of nerve impulses are associated with posterior horn cells
Sensory
What nerve impulses are associated with lateral horn cells?
Interneurons
Name the 3 layers of meninges and their primary function
Dura mater
Arachnoid mater
Pia mater
Protect and cushion CNS
In adults, at what level does the dural sac terminate? What about the termination of the spinal cord
S2 - dural sac ends
L1-2 - spinal cord ends
What’s the space between the dura mater and arachnoid mater called? What do they form distally?
Subdural space
Dural sac
What’s the space between the arachnoid mater and pia mater? What does it contain?
Subarachnoid space
Cerebrospinal fluid
The space between the dura mater and vertebral bone is called what?
Epidural/extradural space
To which level does the arachnoid mater descend?
S2
Where does arterial blood supply to the spinal cord come from?
Spinal arteries arising from the aorta and its branches
What drains the vertebrae and spinal cord? Where is it found?
Vertebral venous plexus in the epidural space
What is a spinal nerve?
A mixed nerve carrying motor, sensory and autonomic signals between the spinal cord and the rest of the body
How many spinal nerves are there in the human body?
31 pairs (one on each side of the vertebral column)
What do somatic fibres supply?
Voluntary muscles and body wall structures, e.g. bones and joints
What do autonomic fibres supply?
Involuntary structures, e.g. organs, involuntary muscles and glands
Where do sympathetic nerve fibres emerge from? In which spinal segments are they?
Lateral horn cells
T1 - L2
Which levels can the grey ramus communicans be found? What about the white ramus communicans?
Grey - all levels of spinal cord
White - T1 to L2
The white ramus communicans carry ____ fibres from the ____ to the _____
The white ramus communicans carry SYMPATHETIC fibres from the SPINAL NERVE to the SYMPATHETIC
The grey ramus communicans carry ____ fibres from the ____ to the _____
The grey ramus communicans carry SYMPATHETIC fibres from the SYMPATHETIC GANGLION to the VENTRAL RAMUS
Is a white ramus communicans myelinated? What about grey?
White - myelinated
Grey - unmyelinated
What’s the alternate name for sympathetic chains?
Paravertebral ganglia
Define ganglion
Collection of nerve cell bodies
What 3 things can sympathetic fibres do?
- synapse in a chain ganglion at the same spinal level before exiting the chain (mainly to the skin).
- ascend and descend within the sympathetic chain before synapsing in a different ganglion to the one it lies next to and exiting the chain.
- run through the chain without synapsing and synapse instead in a prevertebral (preaortic) ganglion in
the abdomen (= splanchnic nerves to abdominal organs – “splanchnic” = organ).
What 2 places are parasympathetic nerves found?
Some cranial nerves
S2-4
Do parasympathetic nerves enter the sympathetic chain?
No
Which spinal cord levels give rise to the sympathetic nerves? What about parasympathetic nerves?
Sympathetic - thoracolumbar
Parasympathetic - crainosacral
Name 5 locations of large autonomic nerve plexuses
Cardiac (thorax)
Pulmonary
Coeliac (abdomen)
Superior hypogastric (abdomen)
Inferior hypogastric (pelvic)
The upper and lower limbs receive autonomic supply from which nerves?
Sympathetic ONLY
Name the 8 major pulse points
Carotid
Brachial
Radial
Ulnar
Femoral
Popliteal
Posterior tibial
Dorsalis pedis
What is lymph?
Plasma filtrate leaked from capillary beds due to high hydrostatic pressure
Where does lymph ultimately go? What’s it for (one normal, one pathology)?
Circulatory system
It’s important for immunity and cancer spread
Name the 6 major groups of lymph nodes
Axilla
Inguinal region
Pectoral
Bifurcation of trachea
Lumbar and pelvic
Cervical
Name 5 parts of a lymph node
Germinal centre
Follicle
Medulla
Paracortex
Cortex
What type of cells are found in lymphoid nodes?
Lymphocytes (B and T cell)
What process occurs in lymph nodes?
Filtering harmful substances
Define sentinel node
Lymph node where cancer spreads. If we suspect metastasis, we can remove a sentinel node and test it to look for metastasis
Efferent lymphatic vessels can lead to one of which two places?
Thoracic duct
Right lymphatic duct
Where does the thoracic duct commence, ascend and cross?
L1, at the cisterna chyli
Ascends on the vertebral bodies between the azygos vein and aorta on the right side, and posterior thoracic wall below T4
At T4 it crosses the vertebral column to the left side of the thoracic vertebral bodies and drains into the medial end of the left subclavian vein
Name the 4 main lymph nodes on face and neck
Parotid
Occipital
Supraclavicular
Submandibular
Also: Posterior auricular, tonsillar, cervical, submental
