Spinal Anatomy Flashcards
The spine has ___ vertebrae separated by intervertebral discs
33
The vertebral body is ____ and ____
Solid and cylinderical
2 pedicles join with 2 lamina to complete and arch known as
(oval shape) vertebral foramen
What is the purpose of the vertebral foramen?
Allows for passage and protection of spinal cord
What process is on each side laterally?
What process is posteriorly?
laterally - transverse process
posteriorly - spinous process
When feeling for a a spinal or epidural placement, what are we feeling for?
The spinous process
Why do the spinous process overlap?
To protect the spinal cord
There are lateral notches superiorly and inferiorly (larger), it creates a space known as ______, and allows for passage of _____.
intervertebral body
nerves
If the discs in-between the intervertebral lamina become damaged, pressure on the nerves can result in what?
pain and paresthesias
Pedicles have superior and inferior articular surfaces and lateral notches
When vertebrae are stacked the notches and surfaces form the ____
facet joint
guides and restricts the movement of the vertebral column
Cervical and Thoracic
Spinous processes are more ____
Require more ____ angle for needle
angled
cephalad
Lumbar
The vertebra are ____
Less overlap =
Allows for easier
Larger
Larger gaps
needle placement
Sacrum
This part of the vertebra is ____
Fused
Sacrum
Lamina of last vertebra is incomplete and bridged only by ligaments, what is this known as
Sacral hiatus
What is the bony process used to ID the sacral hiatus?
What is this good for?
Sacral Cornu
Caudal block
How many Cervical: Thoracic: Vertebral: Sacral: Coccygeal:
Cervical: 7 Thoracic: 12 Vertebral: 5 Sacral: 5 fused Coccygeal: 4 fused
Scoliosis –
Kyphosis –
Lordosis –
Scoliosis – lateral curvature
Kyphosis – posterior curvature
Lordosis – Anterior curvature
Is the interlaminar foramen always directly anterior to the spinous process
NO
What are the 3 ligaments that connect the spinous process (in order of how you hit them with a needle)
Supraspinous
Intraspinous
Ligamentum Flavum
Supraspinous Ligament
Weak or strong?
What does it connect?
Where is this a major ligament at?
Strong cord like ligament
Connects apices of spinous processes
Major ligament of cervical & upper thoracic regions
Intraspinous ligament Thin or thick? Where is it located? What is it like in the cervical region? What is it like in the lumbar region?
Thin
Runs between adjacent spinous processes
Absent or poor quality in cervical region
Can be extremely thin in Lumbar
Ligamentum Flavum
- Strongest or weakest?
- Where is it thin and thick at?
- How thick at L2-L3?
- Join the _____ through vertical extensions from adjacent lamina
- Paired flat ligaments between each lamina and overlap
- Creates appearance of a
- Strongest
- Thin on lateral edge, thick midline, like a V
- Can be 3-5 mm thick at L2-3
- Join the Vertebral arches through vertical extensions from adjacent lamina
- Paired flat ligaments between each lamina and overlap
- Creates appearance of a contiguous ligament
Where is the epidural space located?
Lies between ligamentum flavum and dura mater
Where does the epidural space originate and end?
Contiguous from base of cranium to sacral sulcus
What is the distance of the epidural space from the skin?
Varies with level and loosely correlated with weight (heavier they are, the deeper it is)
Midline Lumbar approach 2.5-8 cm, average 5 cm
What are the contents of the epidural space?
veins, fat, lymphatics, segmental arteries, and nerve roots
Epidural veins are _____, form a plexus being most predominantly _____, become engorged during ____&_____
valveless
Lateral
Pregnancy & obesity
What is the depth of the epidural space at
Cervical:
Thoracic:
Lumbar:
Cervical: 1.5-2mm
Thoracic: 3-5mm
Lumbar: 5-6mm
The spinal cord extends from the medulla oblongata to where in adults vs Peds?
Adults: L2
Peds: L3
The spinal cord has 3 layers of meninges, what are they in order from posterior to anterior
Dura Mater
Arachnoid Mater
Pia Mater
Which meningeal layer holds the CSF?
Arachnoid Mater
The spinal cord has \_\_\_ pairs of spinal nerves Cervical: Thoracic: Lumbar: Sacral: Coccygeal:
31 pairs Cervical: 8 Thoracic: 12 Lumbar: 5 Sacral: 5 Coccygeal: 1
Thoracic nerves run along what margin of the rib?
Where would you want to place a chest tube?
Inferior
Superior aspect of the rib
The level of spinal nerve does not always correlate with vertebra.
Where does the 1st nerve exit?
Where does C8 exit?
Cervical correlate with vertebrae ___, after T1 correlates with vertebrae ____.
Base of skull and atlas
Between C7 and T1
below
above
The spinal cord is approx _____ shorter than the vertebral canal
25 cm
Where is the spinal cord enlarged at?
C5-C7 and L2-L3
C4-T1 – brachial plexus
L2-S3 – lumbar and sacral plexus
What is the Cuada Equine?
Where does it extend?
Long roots of lumbar and sacral nerves
Extends from L1-S5
Dorsal root contains _____ fibers
Ventral root contains _____ fibers
Sensory (dorsal entering sensory)
Motor (ventral outgoing motor)
The spinal cord contains ___ shaped central grey region. What does it contain?
H-shaped
Neuronal cell bodies and unmyelinated fibers
The spinal cord is surrounded by ____ matter. What does it contain?
white matter
Fiber tract
Grey matter is subdivided into:
What are the afferent and efferent tracts?
12 Laminae of Rexed
Afferent I-VI (receives sensory information from the periphery)
Efferent VII-IX (Ventral tracts - motor neurons)
In the grey matter, the _____ is very important to anesthesia. What is it called?
Laminae II
Substanca Gelatinosa
What is dorsal white matter?
Almost exclusively ascending sensory fiber tracts
What are lateral and ventral white matter?
Descending motor tracts
Can do two things:
Ascend to the brain
Association tract originate and terminate entirely within the spinal cord (reflexes)
What do sensory (afferent/ascending) transmit?
Transmit pain, temp, pressure, touch, vibratory sense, and proprioception
Where are sensory afferent receptors located?
Epidermis & Dermis = pain and temp
Dermis = Pressure, touch, vibration, proprioception
What are 2 classifiactions of sensory receptors?
Extroceptors –> near surface of skin and oral mucosa (why kids put things in their mouth)
Proprioceptors –> Deeper skin layers, joint capsules, ligaments, tendons, muscles, and periostium
There are 2 main sensory tracts, what is the Dorsal Column-Medial Lemniscus
Carries signals ______ in dorsal column tract
Cross over at _____
Carried through ___ in medial lemniscus tract
To area of brain to ____
upwards towards the medulla
medulla
brainstem to thalamus
interpret
(look at slide 29)
There are 2 main sensory tracts, what is the Anterolateral Pathway
Originate in dorsal horn to ____ where they synapse
____ cross over in anterior commissure to anterior and lateral white columns
Ascend to brain through associated tract
Anterior spinothalmic or lateral spinothalmic
Go to brainstem or thalmus
To area of brain to interpret
Laminae I, IV, V, VI
Immediately
(look at slide 31)
Where do IV and Neuraxial opioids work?
Substancia Gelatinosa
Dorsal Column-Medial Lemniscus: Fibers: Conduction Speed: Spatial Orientation: Types of mechanoreceptive sensations:
Fibers: Large/mylinated
Conduction Speed: 30-110 m/sec (fast)
Spatial Orientation: high respect to organ
Types of mechanoreceptive sensations: discrete
Anterolateral System: Fibers: Conduction Speed: Spatial Orientation: Types of mechanoreceptive sensations:
Fibers: smaller/mylinated
Conduction Speed: Few – 40 m/sec (slow)
Spatial Orientation: low respect to origin
Types of mechanoreceptive sensations: broad
What sensations does the anterolateral sensation transmit?
Pain Thermal (hot and cold) Crude touch and pressure Tickle and itch sensation Sexual sensation
Sympathetic Nervous System \_\_\_\_\_\_ neurons What type of fibers? Where does it originate? Where does it exit the spinal cord?
Series of _____ segmental paravertebral ganglia form sympathetic trunks
Preganglionic Neurons
Small B fibers
Originate in the intermediolateral gray horn between? T1-L2/L3
Exit the spinal cord via the ventral nerve root
(White rami communicans)
Paired
What is the cervical ganglia divided into?
superior, medial, and inferior ganglia
What does stimulation of the SNS in the superior ganglia cause?
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 causes:
Miosis (small pupil)
Ptosis (drooping eyelid)
Anhydrosis (lack of sweating)
HORNERS SYNDROME
The inferior cervical ganglia fuses with first thoracic to form what?
Stellate Ganglia
C5-C6
What are the 4 stages of pain transmission?
Transduction
Transmission
Modulation
Perception
Pain and temp pathway
need to read book to understand this…
Spinal reflex arc
need to read book to understand this…
Dematomes:
T4
T6/T7
T10
T4 - nipple line
T6/T7 - Xiphoid process
T10 - Belly Button
Dermatomes: Hand
C6
C7
C8
C6 - thumb
C7 - index/middle finger
C8 - ring/pinky finge
Motor pathways:
Motor/Efferent (Exit) transmits info from brain to…
voluntary muscles, smooth and cardiac muscles and some glands
Motor pathways:
Corticospinal tract supplies the…
voluntary muscles of the trunk and extremities
Where does the corticospinal tract originate?
Originates in large, upper motor neurons locate in the precentral gyrus
Corticospinal tract:
Damage can cause lower motor neurons to..
Overfire – Hyperreflexia
Fire simultaneously – spasticity
Corticospinal tract:
With upper motor neuron paralysis..
Reflexes intact
Suppressor fibers impeded
Hyperreflexia occurs
Corticospinal tract:
Damage to lower motor neurons produce..
flaccid type paralysis
What disease effect the corticospinal tract?
Cerebal Palsy and ALS
