1. The central nervous system the spinal cord
Xiaoming Zhang
Department of Human Anatomy
School of Medicine
Zhejiang University

2. The Spinal Cord 1. External features: Location:
foramen magnum -- lower
border of first lumbar vertebra
Shape:
A long cylindrical structure
Enlargements:
cervical enlargement
lumbar enlargement
Conus medullaris
Filum terminale

3. main longitudinal fissure and sulci on surface:
Cauda equina
posterior lateral posterior median sulcus
anterior lateral anterior median
sulcus
Filum terminale
sulcus
fissure

4. It's a part of spinal cord, which is connected
Spinal segment:
It's a part of spinal cord, which is connected
with the rootlets of a pair of spinal nerve.
31 segments
8 cervical segments
12 thoracic segments
5 lumbar segments
5 sacral segments
1 coccygeal segments

5. Corresponding relationship between spinal segments and vertebrae
spinal segments correspond to vertebrae C1-C C1-C4
C5 ~ T8, T l~ T C4 - C7, C7 ~ T3
T5 ~ T T3 ~ T6
T9-T T6-T9
L1-L T10-T12
S l~S5,Co LI 

6. 2. Internal structure The central canal Gray matter: parts:
Lateral horn
(only extends from Tl
to L3 segments.)
gray commissure
(anterior and
posterior )
posterior horn
central canal
Intermediate
zone
Lateral horn
anterior horn
Gray matter
gray commissure

7. Main nuclei: anterior horn: medial group intermediate zone:
lateral group
intermediate zone:
intermediolateral nucleus
intermediomedial nucleus
posterior horn:
the nucleus
posteromarginalis
the substantial gelatinosa
the nucleus proprius:
the dorsal nucleus
(thoracic nucleus)
the nucleus
posteromarginalis
the substantia
gelatinosa
the nucleus proprius
the dorsal nucleus
(thoracic nucleus)
Intermediomedial
nucleus:
intermediolateral
nucleus
lateral group
medial group

8. The nuclei and the laminas
the nucleus
posteromarginalis
the substantia
gelatinosa
the nucleus proprius
the dorsal nucleus
(thoracic nucleus)
intermediolateral
nucleus
Intermediomedial
nucleus:
lateral group
medial group

9. White matter: parts: posterior funiculus lateral funiculus
posterior median sulcus
posterior lateral sulcus
lateral funiculus
anterior lateral sulcus
anterior white
commissure
anterior funiculus
anterior median
fissure

10. Main tracts (or fasciculi): long ascending tracts:
fasciculus gracilis: come from sacral,
lumbar and lower six thoracic nerves,
terminate upon nucleus gracilis
fascicules cuneatus: come from
cervical and upper six thoracic nerves,
terminate upon nucleus cuneatus.
*conduct the fine tactile (e.g.two-point
discrimination) and kinesthetic sense (e.g.position and movement and vibration)of the ipsilateral trunk and
limbs.
fascicules
cuneatus
fascicules
gracilis

11. lateral and anterior spinothalamic tracts: *in corresponding funiculus
thalamus
lateral and anterior spinothalamic
tracts:
*in corresponding funiculus
*arises from opposite nucleus
proprius
*terminate on thalamus
*conduct pain, thermal and
rough tactile sense of opposite
trunk and limbs
anterior
spinothalamic
tracts
anterior
spinothalamic
tracts
nucleus proprius

12. main long descending tracts lateral corticospinal tract:
*arises from opposite cerebral
cortex
*descends through lateral
funiculus of spinal cord
*terminate on ipsilateral
anterior horn (lateral group)
*controls the contraction of
skeletal muscles of ipsilateral
limbs
anterior corticospinal tract:
*controls the movement of
bilateral muscles of trunk
lateral
corticospinal
tract
anterior
corticospinal
tract

13. Other descending tracts: they are related to regulate muscle tonus
Fascicules gracilis
fascicules cuneatus
lateral
corticospinal
tract
Rubrospinal
tract
anterior
spinothalamic
tracts
Reticulospinal
tract
anterior
spinothalamic
tracts
vestibulospinal
tract
tectospinal tract
anterior corticospinal
tract

14. Functions:
To convey afferent impulses, which come from somatic and visceral receptors to the brain, and conduct efferent impulses from brain to effectors.
Related to reflexes

15. good bye！