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Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University 1
Dr.Hongqi Zhang (张红旗)Email: [email protected]
Systematic Anatomy
Nervous system
Spinal cord
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Spinal cord
BrainTelencephalonDiencephalonCerebellumBrain stem
1-Midbrain2-Pons3-medulla oblongata
Spinal cord
Central nervous system (CNS)
Position of the Spinal Cord
Position: Lies in vertebral canal, 45cm long approximately
Upper end: Continuous with medulla oblongata at foramen magnum
Lower end: at the lower border of L1 in adult at newborn at level of L3
Sexual difference: usually a little lower in female than in male
Clinic significance: anaesthesia done usually at below the L1
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Anaesthesia in the vertebral canal
L1
Draw cerebrospinal fluidFrom the vertebral canalFor lab examination
Lower endOf spinal cord
Needle puncture
SkinSubcutaneous fasciaSupraspinal lig.Interspinal lig.Yellow lig.
External feature:A long cylindrical structure & slightly flattened anteroposteriorly
Two enlargementsCervical enlargement corresponds to C4 -T1 of spinal cordLumbosacral enlargement corresponds to L2 to S3 of spinal cord
Filum terminale-only thin filamentConus medullarisCauda equina
External Features of Spinal Cord
Conus medullaris and cauda equina
Lumbosacral enlargement
Conus medullaris
Filum terminale
Cauda equina
External Features of Spinal Cord
Fissure and sulci1 - Anterior median fissure 2 - Posterior median sulcus3 - Anterolateral sulcus - connect with ant.root (motor)4 - Posterolateral sulcus - connect with post.root (sense)
Ant.root
Post.root
Spinal ganglion
Ant.branch
Post.branch
1
2
3
4
Segments of Spinal CordA portion of the cord that
gives rise to a pair of spinal nerve constitutes a segment.
There are 31 segments
8 cervical ss
12 thoracic ss
5 lumbar ss
5 sacral ss
1 coccygeal s
Segment - s
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Relationship of SC Segments to Vertebral body
In the third month of fetal life,the spinal cord occupies the entire length of the vertebralcanal.After that time,there are some
difference between spinal cord & vertebral canal in growth speed,that is, the vertebral canal grow faster than that of spinal cord,
At 3rd fetal month
Sc length = vertebral canal
Spinal cord
Vertebral canal
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Relationship of SC Segments to Vertebrae
At birthThe inferior ends is
below at the lower border of L1 in adult;at birth at level of L3, usually a little lower in female than in male.
But each spinal nerve have to come out from their corresponding intervertebral foramina.
After 3rd month At birth
Sc inf. end is higherThan that of canal
Sc inf. end isAt the level of L 1 at adult
L3
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
More high levelMore almost horizental.More lower levelMore obliquity
Relationship of SC Segments to Vertebral Numbers
Spinal segments Vertebral levels (spines)Upper cervical region (C1~C4) Lie opposite the corresponding vertebrae
Lower cervical and upper thoracic region (C5~8;T1-4)
One lower in number than corresponding vertebrae
Middle thoracic region (T5~T8) Two lower in number than corresponding vertebrae
Lower thoracic region (T9~T12) Three lower in number than corresponding vertebrae
Lumber segments T10~T12
Sacral and coccygeal segments L1
Spinal segments Vertebral levels (spines)
Upper cervical region (C1~C4) = C1 ~ C4Lower cervical and upper thoracic region (C5-8;T1~4)
-1 = C4 ~ T3
Middle thoracic region (T5~T8) -2 = T3 ~ T6
Lower thoracic region (T9~T12) -3 = T6 ~ T9Lumber segments = T10 ~ T12
Sacral and coccygeal segments = L1
Relationship of SC Segments to Vertebral Numbers
Internal structure of spinal cord
1 - Gray matter2 - White matter3 – reticular formation
1
2
3S
L
T
C
C‐cervical;T‐tharacic;L‐lumbar;S‐sacral Central canal
Fasciculus gracilis
Fasciculus cuneatus
Ant.root
Post.root
Spinal ganglion
Spinal n.
Lat.corticospinal tractLat. spinothalamic tract
Nucleus proprius
Motor neuron of ant.horn
Spinal pia matar
Spinal arachnoid
Spinal dura matar.
White matter
Gray matter
Internal structure of spinal cord
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Gray matter of Spinal CordLike a butterfly or letter “H”Consist of cell body,neuroglia and dendriteLocated around the central canal
Ant. horn (column)
Post. horn (column)
Post. gray commissures
Ant. gray commissures
Intermediate zone
Gray Matter of Spinal Cord
Anterior horn (column) Posterior horn (column)
Lateral horn (column) is present in the thoracic & upper lumber segmentsof the cord (T1-L3) only
Intermediate zone Ant. gray commissuresPost. gray commissures
Gray Matter of Spinal CordPosterior horn (column): 1- Marginal layer 2- Substantia gelatinosa
Situated at the apex of posterior horn throughout the length of spinal cord. Receives fibers are associated with the senses cord.
3- Nucleus propriusSituated anterior to the substantia gelatinosa throughout the length of spinal cord. Concerns the sensations of pain and temperature
1
2
3
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Posterior horn (column):Nucleus thoracicus (lable A)
Situated at the base of posterior horn and extending from segments C8~L3. Associated with proprioceptive endings
A
Gray Matter of Spinal Cord
Intermediate zone Intermediolateral nucleus (labeled 1) Extends from segments
T1~L3, Containing sympathetic preganglionic neurons Sacral parasympathetic nucleus : Extends from segments S2~S4,
Containing parasympathetic preganglionic neurons
Intermediomedial nucleus (labled A): Throughout the whole length of spinal cord.Associated with receiving viscera afferent information
1
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Anterior horn (column): Two groups of nuclei
1-Medial nuclear group: present in most segments of spinal cord, innervating axial (trunk) muscles2-Lateral nuclear group: present only in cervical and lumbosacral enlargements, innervating limb skeletal muscles
12
Anterior horn (column): labeled with red color three kinds of neurons (motor neuron 2)
α- motor neuron: large multipolar neuron, innervates skeletal muscles, producing contraction of muscles
γ- motor neuron: smaller multipolar neuron, innervates intrafusal muscle fibers of neuromuscular spindles, regulating muscular tonus
Interneuron —Renshaw’s cell: negative feedback
Rexed’s laminaPosterior horn is formed by laminaⅠ to Ⅵ;
Intermediate zone is corresponding to lamina Ⅶ;
Anterior horn is composed laminae Ⅷ and Ⅸ;
lamina Ⅹ is the gray matter around the central canal.
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
laminae nucleiⅠ Posterior marginal nucleusⅡ Substantia gelatinosa
Ⅲ Ⅳ Nucleus propriusⅤ Reticular nucleusⅥ Base of posterior columnⅦ Thoracic nucleus
Intermediomedial mucleusIntermediolateral nucleus
Sacral parasympathetic nucleus
Ⅷ Ⅸ Medial motor neuron columnLateral motor neuron column
Ⅹ gray matter around central canal
Important Subdivision of Spinal Cord Gray Matter
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
White matter of spinal cordOrganizationNerve fiber (tract)Around the grey matterThree partsAnt. Funiculus (A.F)Lat. Funiculus (L.F)Ascending & descending fiberPost. Funiculus (P.F)Ascending fiber onlyWhite commissureAnt.commissure of WM
Post.commissure of wm
A.F
P.F
L.F
WM‐white matter
White Matter of Spinal Cord
White matter contains three kinds of fibers: ascending, descending and fasciculus proprius
Ant. funiculus
Lat. funiculus
Post. funiculus
Ant. white commissure
Post. white commissure
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Fiber tract:in CNS, fiber bundle which has similar origin, terminal, course and function.Ascending tract:to conduct the sensory impulse from the trunk and limbs to the brain.Descending tract.to convey the motor information from central nervous system to the trunk and limbs.
White matter of spinal cord
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Nomenclature : Course: pyramid tractOrigin and terminal : Corticospinal tract.
Spinothalamic tractAppearance of the tract: Fasciculus gracilisGeneral: lateral corticospinal tract.Fasciculus proprius: both origin & termination of the fascisulus are in the spinal cord.with two direction (ascending & descending), the function take part in different segment reflex.
White matter of spinal cord
Major Ascending or sensory Tracts
Fasciculus gracilis
Fasciculus cuneatus
Pos. spinocerebellar tract
Ant. spinocerebellar tract
Spinothalamic tract
Lat.Spinothalamic tract(rough tonch)Ant.Spinothalamic tract(pain,temperature,sensation)
Red color means important
Fasciculus gracilis
Fasciculus cuneatus
Fasciculus gracilis and fasciculus cuneatus
Spinothalamic tract
From pain and temperatureAnd some touch receptors
Lateral and anterior spinothalamic tract
Summary-ascending tractsTract Site of origin Funiculu
s Termination Function
Fasciculus gracilis
Spinal ganglia below segment T5
Posterior Gracile nucleus
Conscious proprioceptive (vibratory sense, and muscle joint sense) and fine touch sensation of trunk and limbs
Fasciculus cuneatus
Spinal ganglia above segment T4
Cuneate nucleus
Posterior spinocerebellartract
Homolateral nucleus thoracicus
Lateral Cerebellum Unconscious proprioception from limbs and trunk
Anterior spinocerebellartract
Contralateral Laminae Ⅴ~Ⅶ
LateralSpinothalamictract
Laminae Ⅰ, Ⅳ~Ⅶ
Lateral Dorsal thalamus
Pain, temperature and crude touch sensation of trunk and limbs
anteriorSpinothalamictract
anterior
Descending TractsLateral corticospinal tract
Anterior corticospinal tract
Rubrospinal tract
Vestibulospinal tract
Reticulospinal tract
Medial longitudinal fasciculus
Tectospinal tract
Fasciculus proprius
Red color means important content
Lateral corticospinal
tract
Anterior corticospinal
tract
Coranal section of cerebrum
horizental section of cerebrum
horizental section of midbrain
horizental section of pons
horizental section ofmedulla ablongata
horizental section ofspinal cord
Lateral and anterior corticospinal tract
Summary - descending tractsTract Site of origin Funiculus Termination Function
Lateral corticospinal
Cerebral cortex Lateral Laminae (Ⅳ~Ⅸ)anterior hornMotor neurons &interneurons
Voluntary movementof skeletal muscle of trunk and limbsAnterior
corticospinalCerebral cortex Anterior
Rubrospinal Red nucleus Lateral Laminae (Ⅴ~Ⅶ)anterior hornMotor neurons& interneuron(for flexor)
Facilitates activity of flexor muscles
Vestibulospinal Homolateral vestibular nuclei
Anterior Laminae (Ⅶ~Ⅷ)anterior hornMotor neurons& interneuron(for extensor)
Facilitates activity of extensor muscles
Reticulospinal Reticular formation
Anterior & lateral
Laminae (Ⅶ~Ⅷ) Control Voluntary movement of skeletal muscle of trunk & proximal extremity
Summary - descending tractsTract Site of origin Funiculus Termination Function
Medial longitudinal fasciculus
Vestibular nuclei
Anterior Laminae (Ⅶ~Ⅷ)Anterior horn cell
Coordinate of head and eye movement
Tectospinal Superior colliculus
Anterior Laminae(Ⅵ~Ⅷ) Reflex head turning
Fasciculus proprius
Spinal cord Anterior, lateral & posterior
Spinal cord Intrinsic reflex mechanism of spinal cord
Main functions of spinal cord Conduction of excitations
bridge; brain - periphery Sensory impulse to brainMotor impulse to periphery
ReflexSomatic reflex (skeletal m contration)superficial and deep reflexTendon (stretch reflex ) arcFlexor reflexAbdominal reflexVisceral reflex (sm,cardiac m,gland)Defecation reflexCarotid reflex
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Spinal cord transverse section lesionComplete spinal cord transection results in the immediate Loss of all neural function below the level of the lesion.thereis a complete lose below the level of the lesion of :
All somatic sensationAll motor functionAll visceral sensationAll reflex activityAll muscle tone,etc
Spinal shock: last for 1~6 weeks
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
sensation
motor
Right:deep sensation,limb paralysisLeft :superficial sensation disfunction
Hemisection of the spinal cord (brown-sequard syndrome)
Injured main sensory fasiculus:
1-Fasciculus gracilis
2-Fasciculus cuneatus
3-Spinothalamic tract
12
3
3
Injured motor fasiculus:
4 - Lat.corticospinal tract
5 - Ant.corticospinal tract
4
5
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Hemisection of the spinal cord
Brown-sequard syndromeResult in:The ipsilateral motor neuron paralysis below the level of lesion
Resulted from damage to the ipsilateral corticospinal tract.Loss of the ipsilateral deep sensation (proprioceptive,vibratroy
and two–point discrimination sense)below the level of lesion .resulted from damage to the fasciculus gracilis and fasciculuscuneatus.Loss of the contralateral superficial sensation (pain & thermal
Sense)below the level of lesion. resulted from damage to thelateral spinothalamic tract.
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Lesion of anterior horn of the spinal cord
It causes ipsilateral lower motor neuron paralysis in the segments of the lesion (resulting from damage to lower motor neurons)such as infantile paralysis (Poliomyelitis).
Motor neuron
Usually it is caused by poliomyelitis virus
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Meningocele cleft spine
Meningocele
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
FIGURE 3.1.3At upper thoracic and all cervical levels the dorsal funiculus is further subdivided, as shown here This view also shows the named sulci, fissures and septi, as well as the course taken by entering and departing axons.
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
answer 9 1 -intermediolateral cell column2 - dorsal funiculus3 - lateral funiculus4 - ventral funiculus
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
FIGURE 3.1.4Most of the structures labeled on these slides are ones you have identified in earier views of this module. Try to reconcile the appearance of the structure here with that in views of the brain's surface. All the sections, except the 3 spinal cord ones, are clickable. Clicking on one leads you to enlarged view of the section.
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Copy Right‐ Hongqi ZHANG‐Department of Anatomy‐Fudan University
Hardworking
Harvest
The end!