Spinal Anatomy Flashcards
How many spinal vertebrae are there?
33
Spinal vertebrae are separated by intervertebral ___
Spinal vertebrae are separated by intervertebral DISCS
Vertebral ___ allows for passage and protection of the spinal cord
Vertebral FORAMEN allows for passage and protection of the spinal cord
___ process is on each side of the vertebra (laterally)
TRANSVERSE process is on each side of the vertebra (laterally)
___ process is located posteriorly
SPINOUS process is located posteriorly
What do we hope to feel when doing a spinal or epidural?
Spinous process
Spinous processes overlap to protect the spinal cord–T/F?
True
Lateral notches are known as intervertebral ___ and allow for the passage of ___
Lateral notches are known as intervertebral FORAMINA and allow for the passage of nerves
If intervertebral foramina or discs become damaged, pressure is exerted on nerves which can cause pain and parasthesias–T/F?
True
Pedicles have superior and inferior articular surfaces and lateral notches; when vertebrae are stacked, the notches and surfaces form the ___ joint
Pedicles have superior and inferior articular surfaces and lateral notches; when vertebrae are stacked, the notches and surfaces form the FACET joint
Regional variation of vertebrae–cervical and thoracic spinous processes are more ___; require more ___ (caudal/cephalad) angle for needle
Regional variation of vertebra–cervical and thoracic spinous processes are more ANGLED; require more CEPHALAD angle for needle
Regional variation of vertebrae–lumbar vertebrae are ___ (smaller/larger); there is ___ (more/less) overlap, making ___ (smaller/larger) gaps; ___ (easier/harder) placement of needles
Regional variation of vertebra–lumbar vertebrae are LARGER; there is LESS overlap, making LARGER gaps; EASIER placement of needles
Regional variation of vertebrae–sacral vertebrae are ___; lamina of last sacral vertebra is ___ (complete/incomplete) and bridged only by ___, known as sacral ___
Regional variation of vertebrae–sacral vertebrae are FUSED; lamina of last sacral vertebra is INCOMPLETE and bridged only by LIGAMENTS, known as SACRAL HIATUS
What is the bony process used to identify the sacral hiatus? What is this good for?
SACRAL CORNU is the bony process used to identify the sacral hiatus; this is good for CAUDAL BLOCKS
Scoliosis = ___ (anterior/posterior/lateral) curvature
Scoliosis = LATERAL curvature
Kyphosis = ___ (anterior/posterior/lateral) curvature
Kyphosis = POSTERIOR curvature
Lordosis = ___ (anterior/posterior/lateral) curvature
Lordosis = ANTERIOR curvature
Abnormal curvatures of the spine may interfere with the interlaminar ___–don’t always expect it to be directly anterior to the spinous process
Abnormal curvatures of the spine may interfere with the interlaminar FORAMEN–don’t always expect it to be directly anterior to the spinous process
The intervertebral disc between each vertebral body contains (3) ligaments–what are they?
- Supraspinous
- Intraspinous
- Ligamentum flavum
Supraspinous ligaments are ___ (weak/strong) cord like ligament; connect apices of spinous processes; major ligament of ___ and upper ___ regions
Supraspinous ligaments are STRONG cord like ligament; connect apices of spinous processes; major ligament of CERVICAL and upper THORACIC regions
Intraspinous ligaments are ___ (thick/thin); run between adjacent spinous processes; absent or poor quality in ___ region; can be extremely thin in ___ region
Intraspinous ligaments are THIN; run between adjacent spinous processes; absent or poor quality in CERVICAL region; can be extremely thin in LUMBAR region
Ligamentum flavum is ___ (thick/thin) on lateral edge, ___ (thick/thin) midline, like a V
Ligamentum flavum is THIN on lateral edge, THICK midline, like a V
What spinous ligament is the strongest?
Ligamentum flavum
Ligamentum flavum can be 3-5 mm thick at L__-__
Ligamentum flavum can be 3-5 mm thick at L2-3
Anterior and posterior longitudinal ligaments cover anterior and posterior portions of vertebrae–T/F?
True
Epidural space lies between ___ and ___ mater
Epidural space lies between LIGAMENTUM FLAVUM and DURA mater
Epidural space originates in the base of the ___ and ends in the sacral ___
Epidural space originates in the base of the CRANIUM and ends in the sacral SULCUS
Distance of epidural space from the skin varies with level and is loosely correlated with weight–T/F?
True
If using a midline lumbar approach, distance of epidural space from the skin is ___-___ cm, average ___ cm
If using a midline lumbar approach, distance of epidural space from the skin is 2.5-8 cm, average 5 cm
Spinal cord extends from ___ to ___ in adults, ___ in peds
Spinal cord extends from MEDULLA OBLONGATA to L2 in adults, L3 in peds
Layers of the spinal cord are known as ___
Layers of the spinal cord are known as MENINGES
What are the (3) layers of the meninges?
- Dura mater
- Arachnoid mater
- Pia mater
Which meninges layer holds the CSF?
Arachnoid mater
There are ___ pairs of spinal nerves
There are 31 pairs of spinal nerves
How many cervical spinal nerves are there?
8 cervical
How many thoracic spinal nerves are there?
12 thoracic
How many lumbar spinal nerves are there?
5 lumbar
How many sacral spinal nerves are there?
5 sacral
How many coccygeal spinal nerves are there?
1 coccygeal
Thoracic spinal nerves run along the ___ (superior/inferior) margin of the rib; where would you put a chest tube?
Thoracic spinal nerves run along the INFERIOR margin of the rib
Where would you put a chest tube? In the superior or inferior aspect of the rib?
You would put a chest tube in the SUPERIOR aspect of the rib (so you don’t damage thoracic spinal nerves)
Spinal nerve level always correlates with vertebrae–T/F?
FALSE–does NOT always correlate with vertebrae
C1 exits between base of ___ and ___
C1 exits between base of SKULL and ATLAS
C8 exits between C__-T__
C8 exits between C7-T1
Cervical spinal nerves correlate with vertebrae ___ (above/below); after T1, spinal nerves correlate with vertebrae ___ (above/below)
Cervical spinal nerves correlate with vertebrae BELOW; after T1, spinal nerves correlate with vertebrae ABOVE
Spinal cord is approximately 25 cm ___ (shorter/longer) than vertebral canal
Spinal cord is approximately 25 cm SHORTER than vertebral canal
Spinal cord is enlarged at C__-C__ and L__-S__
Spinal cord is enlarged at C5-C7 and L2-S3
because C4-T1 = brachial plexus
L2-S3 = lumbar and sacral plexus
Brachial plexus = ___ (what spinal levels?)
Brachial plexus = C4-T1
Lumbar and sacral plexus = ___ (what spinal levels?)
Lumbar and sacral plexus = L2-S3
Cauda equina = long roots of ___ and ___ nerves; extends from L__-S__
Cauda equina = long roots of lumbar and sacral nerves; extends from L1-S5
Spinal cord is divided into ___, ___, and ___ regions
Spinal cord is divided into DORSAL, LATERAL, AND VENTRAL regions
Dorsal region = entering ___ (sensory/motor) root
Dorsal region = entering SENSORY root
Ventral region = outgoing ___ (sensory/motor) root
Ventral region = outgoing MOTOR root
H-shaped central gray region contains neuronal cell ___ and ___ (myelinated/unmyelinated) fibers; it is surrounded by ___ (gray/white) matter containing fiber tracts
H-shaped central gray region contains neuronal cell BODIES and UNMYELINATED fibers; it is surrounded by WHITE matter containing fiber tracts
Grey matter is subdivided into ___ laminae of ___
Grey matter is subdivided into 12 laminae of Rexed
Grey matter AFFERENT tracts = __-__
Grey matter AFFERENT tracts = I-VI
Grey matter VENTRAL tracts = __-__
Grey matter VENTRAL tracts = VII-IX
Grey matter AFFERENT tracts receive ___ (sensory/motor) information from the periphery
Grey matter AFFERENT tracts receive SENSORY information from the periphery
Grey matter VENTRAL tracts are ___ (sensory/motor) neurons
Grey matter VENTRAL tracts are MOTOR neurons
Laminae ___ is very important to anesthesia; it is called ___
Laminae II is very important to anesthesia; it is called SUBSTANTIA GELATINOSA
Why is the substantia gelatinosa (laminae 2) very important to anesthesia?–because it receives input from ___ and ___ receptors
Because it receives input from pain and thermoreceptors
(2) classes of white matter–___ white and ___/___ white
Dorsal white and lateral/ventral white
White matter is highly ___
White matter is highly organized
Dorsal white matter is almost exclusively ___ (ascending/descending) ___ (sensory/motor) fiber tracts
Dorsal white matter is almost exclusively ASCENDING SENSORY fiber tracts
Lateral/ventral white matter is ___ (ascending/descending) ___ (sensory/motor) tracts
Lateral/ventral white matter is DESCENDING MOTOR tracts
Most lateral/ventral white matter cross over at some point–T/F?
True
Lateral/ventral white matter can do one of two things–1) ascend to the ___; 2) originate and terminate entirely within the ___
Lateral/ventral white matter can do one of two things–1) ascend to the BRAIN; 2) originate and terminate entirely within the SPINAL CORD [i.e: spinal reflexes]
What type of motor function involves an association tract that originates and terminates entirely within the spinal cord?
Reflexes
Sensory pathways = ___ (afferent/efferent); ___ (ascend/descend)
Sensory pathways = AFFERENT; ASCEND
Sensory pathways transmit (6) things?
- Pain
- Temperature
- Pressure
- Touch
- Vibratory sense
- Proprioception
Sensory receptors location–pain and temp receptors are located in the ___ and ___
Sensory receptors location–pain and temp receptors are located in the EPIDERMIS AND DERMIS
Sensory receptors location–pressure, touch, vibration, and proprioception are located in the ___
Sensory receptors location–pressure, touch, vibration, and proprioception are located in the DERMIS
(2) classifications of sensory receptors–___ceptors, ___ceptors
(2) classifications of sensory receptors–EXTRORECEPTORS and PROPRIOCEPTORS
Extroreceptors are located near surface of ___ and ___ mucosa
Extroreceptors are located near surface of SKIN and ORAL mucosa
Proprioceptors are located in ___ (superficial/deeper) skin layers, joint ___, ligaments, tendons, muscles, and periosteum
Proprioceptors are located in DEEPER skin layers, joint capsules, ligaments, tendons, muscles, and periosteum
What are the (2) main sensory tracts in the dorsal column?
- Medial lemniscal pathway
- Anterolateral pathway
Medial lemniscal pathway–carries signals upwards towards ___ in dorsal column tract; cross over at ___; carried through brainstem to ___ in medial lemniscus tract; to area of brain to interpret
Medial lemniscal pathway–carries signals upwards towards MEDULLA in dorsal column tract; cross over at MEDULLA; carried through brainstem to THALAMUS in medial lemniscus tract; to area of brain to interpret
Medial lemniscal pathway [review]–sensory signal enters through ___ (dorsal/ventral) root; ascends through dorsal column on ___ (same/opposite) side; arrives at ___ and crosses over (1st order to 2nd order synapse); ascends via medial lemniscus tract through ___ (2nd order neuron); arrives at ___ (2nd to 3rd order synapse) and then to area of brain to interpret (3rd order neuron)
Medial lemniscal pathway–sensory signal enters through DORSAL root; ascends through dorsal column on SAME side; arrives at MEDULLA and crosses over (1st order to 2nd order synapse); ascends via medial lemniscus tract through BRAINSTEM (2nd order neuron); arrives at THALAMUS (2nd to 3rd order synapse) and then to area of brain to interpret (3rd order neuron)
Anterolateral pathway originates in ___ (dorsal/ventral) horn to what (4) laminae?
Anterolateral pathway originates in DORSAL horn to laminae I, IV, V, VI [1,4,5,6]
Anterolateral pathway–immediately cross over in anterior ___ to ___ and ___ white columns
Anterolateral pathway–immediately cross over in anterior COMMISSURE to ANTERIOR AND LATERAL white columns
Anterolateral pathway–signals ascend to brain through associated tract–___ spinothalamic or ___ spinothalamic; go to ___ or ___, to area of brain to interpret
Anterolateral pathway–signals ascend to brain through associated tract–ANTERIOR spinothalamic or LATERAL spinothalamic; go to BRAINSTEM or THALAMUS, to area of brain to interpret
Anterolateral pathway [review]–sensory signal enters through ___ (dorsal/ventral) horn [1st order neuron]; immediately synapses in the ___ (dorsal/ventral) horn of ___ (grey/white) matter [Rexed laminae, 1st to 2nd order synapse]; crosses over at ___ level; ascends to ___ or ___ [2nd order neuron]; synapse in ___ or ___ [2nd to 3rd order synapse]; carried to area of brain for interpretation [3rd order neuron]
Anterolateral pathway [review]–sensory signal enters through DORSAL horn [1st order neuron]; immediately synapses in the DORSAL horn of GREY matter [Rexed laminae, 1st to 2nd order synapse]; crosses over at ENTRY level; ascends to BRAINSTEM or THALAMUS [2nd order neuron]; synapse in BRAINSTEM OR THALAMUS [2nd to 3rd order synapse]; carried to area of brain for interpretation [3rd order neuron]
Dorsal column medial lemniscus–fibers are ___ (small/large), ___ (myelinated/unmyelinated); conduction speed is __-__ m/sec; spatial orientation is ___ (low/high) with respect to origin; ___ (discrete/broad) types of mechanoreceptive sensations
Dorsal column medial lemniscus–fibers are LARGE, MYELINATED; conduction speed is 30-110 m/sec; spatial orientation is HIGH with respect to origin; DISCRETE types of mechanoreceptive sensations
Dorsal column anterolateral system–fibers are ___ (small/large), ___ (myelinated/unmyelinated); conduction speed is ___-___ m/sec; spatial orientation is ___ (low/high) with respect to origin; ___ (discrete/broad) spectrum of sensory modalities
Dorsal column anterolateral system–fibers are SMALL, MYELINATED; conduction speed is few-40 m/sec; spatial orientation is LOW with respect to origin; BROAD spectrum of sensory modalities (i.e.: pain, warmth, cold, crude, touch)
SNS preganglionic neurons are ___ fibers, ___ (small/large)
SNS preganglionic neurons are B fibers, SMALL
SNS preganglionic neurons originate in the intermediolateral grey horn between T__-L__/__
SNS preganglionic neurons originate in the intermediolateral grey horn between T1-L2/L3
SNS preganglionic neurons exit the spinal cord via the ___ (dorsal/ventral) nerve root
SNS preganglionic neurons exit the spinal cord via the VENTRAL nerve root white rami communicans
Series of paired segmental paravertebral ganglia form ___
Series of paired segmental paravertebral ganglia form SYMPATHETIC TRUNKS
Cervical ganglia are divided into ___, ___, and ___ ganglia
Cervical ganglia are divided into SUPERIOR, MEDIAL, AND INFERIOR ganglia
Stimulation of SNS fiber in the superior cervical ganglia causes ___iasis [contraction of the radial muscle of the iris], ___ (contraction/relaxation) of the ciliary muscle of the eye, ___ (constriction/dilation) of the blood vessels of the head
Stimulation of SNS fiber in the superior cervical ganglia causes MYDRIASIS [contraction of the radial muscle of the iris], RELAXATION of the ciliary muscle of the eye, CONSTRICTION of the blood vessels of the head
Damage to the superior cervical ganglia, central SNS damage, or injury to other cervical paravertebral ganglia causes ___osis, ___osis, ___osis…what is this known as?
Damage to the superior cervical ganglia, central SNS damage, or injury to other cervical paravertebral ganglia causes MIOSIS, PTOSIS, ANHYDROSIS…this is known as HORNER’S SYNDROME
The inferior cervical ganglia fuses with the first thoracic ganglia to form the ___ ganglia at C__-C__
The inferior cervical ganglia fuses with the first thoracic ganglia to form the STELLATE ganglia at C5-C6
What are the (4) stages of pain transmission?
- Transduction
- Transmission
- Modulation
- Perception
Some fibers in the dorsal horn give off branches that synapse with ___ neurons; these synapse with ___ (sensory/motor) neurons in the ___ (dorsal/ventral) horn; can cross over and travel up or down before synapsing; part of the reflex response to pain
Some fibers in the dorsal horn give off branches that synapse with INTERNUNCIAL [messenger] neurons; these synapse with MOTOR neurons in the VENTRAL horn; can cross over and travel up or down before synapsing; part of the reflex response to pain
Afferent nerves come from relatively limited areas of the skin, and there is some overlap–T/F?
True
T4 dermatome = ___
T4 dermatome = NIPPLE LINE
T6-7 dermatome = ___
T6-7 dermatome = XIPHOID PROCESS
T10 dermatome = ___
T10 dermatome = BELLY BUTTON
Nipple line = ___
Nipple line = T4
Xiphoid process = ___
Xiphoid process = T6-7
Belly button = ___
Belly button = T10
Motor pathways = ___ (afferent/efferent), ___ (enter/exit)
Motor pathways = efferent, exit
Motor pathways = info from brain to ___ (voluntary/involuntary) muscles, ___ and ___ muscles, and some ___
Info from brain to voluntary muscles, smooth and cardiac muscles, and some glands
___ tract supplies the voluntary muscles of the trunk and extremities
Corticospinal tract supplies the voluntary muscles of the trunk and extremities
Corticospinal tract originates in ___ (small/large), ___ (upper/lower) ___ (sensory/motor) neurons located in the ___
Corticospinal tract originates in large, upper motor neurons located in the precentral gyrus
Corticospinal tract travels from ___ through the internal capsule (anterior limb) through the midbrain to the ___
Corticospinal tract travels from precentral gyrus through the internal capsule (anterior limb) through the midbrain to the medulla
90% of corticospinal tracts cross in medulla, forming ___ of medulla
90% of corticospinal tracts cross in medulla, forming pyramids of medulla
Corticospinal tract is sometimes referred to as ___ tract
Corticospinal tract is sometimes referred to as pyramidal tract
After crossing from the lateral corticospinal tract, the nerves ___ (ascend/descend) the spinal cord and leave at the designated level; they enter the ___ (dorsal/ventral) gray horn and synapse with ___ (upper/lower) motor neurons
After crossing from the lateral corticospinal tract, the nerves DESCEND the spinal cord and leave at the designated level; they enter the VENTRAL gray horn and synapse with LOWER motor neurons
10% of corticospinal tracts that don’t cross continue down as the ___ (dorsal/ventral) corticospinal tract; then cross over before synapsing with lower motor neurons in the gray matter; travel in spinal nerves to innervate ___ (involuntary/voluntary) muscle
10% of corticospinal tracts that don’t cross continue down as the VENTRAL corticospinal tract; then cross over before synapsing with lower motor neurons in the gray matter; travel in spinal nerves to innervate INVOLUNTARY muscle
A few corticospinal tract neurons are located anterior to the precentral gyrus–T/F?
True
Corticospinal tract neurons located anterior to the precentral gyrus have ___ (stimulatory/inhibitory) effect on the lower motor neurons to prevent them from discharging excessively
Corticospinal tract neurons located anterior to the precentral gyrus have INHIBITORY effect on the lower motor neurons to prevent them from discharging excessively
Damage to corticospinal tract neurons located anterior to the precentral gyrus can cause lower motor neurons to ___ fire or fire ___
Damage to corticospinal tract neurons located anterior to the precentral gyrus can cause lower motor neurons to OVER fire (hyperreflexia) or fire SIMULTANEOUSLY (spasticity)
With upper motor neuron paralysis, reflexes are ___ (intact/damaged), suppressor fibers are ___ (stimulated/impeded), and ___(hyper/hypo) reflexia occurs
With upper motor neuron paralysis, reflexes are intact, suppressor fibers are impeded, and hyperreflexia occurs
Damage to lower motor neurons produces ___ type paralysis
Damage to lower motor neurons produces flaccid type paralysis
What (2) diseases affect the corticospinal tract?
- Cerebral palsy
- ALS
