Name structures
e) what is contained in A?
f) What is the origin of fibres in C?
a) lateral horn /intermediate grey
b) rubrospinal tract from red nucleus
c) tectospinal tract (always in ventromedian fasciculus)
d) reticulospinal tracts (always in ventromedian fasciculus)
-comprised of the medial (pontine) and the lateral (medullary)
reticulospinal tract
medial: pontine reticulospinal tract
lateral: medullary reticulospinal tract
e)Cell bodies of pre-ganglionic sympathetic neurons
f)tectospinal tract originate from Superior colliculus (i.e. tectum)
Name structures
E) What is contained in A?
F)What is contained in B?
G) Which mixed spinal nerves contribute to C?
a) sympathetic trunk
b) Dorsal root ganglia
c)Brachial plexus
d) Ventral rootlets
e) In the sympathetic trunk itself (i.e. between the ganglia) there
are only preganglionic neurons of the sympathetic nervous system. Of
course the sympathetic ganglia contain both pre- and post-ganglionic fibres.
f) Cell bodies of sensory afferent neurons
g)C5-T1
E) what structure is A a continuation of?
F) What does C consist of?
G) What vertebal level is D?
Name structures
A) filum terminale
b) Anterior spinal artery
c) Cauda Equina
D) Conus Medullaris
E) Pia Mater
F) Ascending sensory fibres and descending motor fibres from below
vertebral level L2-L3
G) L2-L3
31 pairs of mixed spinal nerves
where are denticulate ligaments
function?
the lateral extensions of pia mater which are denticulate ligaments
attach from the cord to the dura and hold the spinal cord in position
in the vertebral canal
where is the conus medullaris found
found at vertebral level L2-L3, but contains the final spinal cord
levels (coccygeal and sacral)
cauda equina is made up of made of lots of ventral and dorsal rootlets
what is the filum terminale
extension of pia mater. at its caudal end it anchors the spinal cord
to the dura and coccyx
Ventral rootlets
contain motor fibres
what is true about the cauda equina
1. its located between vertebral levels L2 and S5
2 it carries proprioceptive information
3. it contains primary afferent fibres
4. it contains axons of LMN
ventral corticospinal tract on the right, not rubrospinal tract
corticospinal tract
Major pathway controlling voluntary pathway in humans is
corticospinal tract which originates in the primary motor cortex
before descending in the internal capsule and decussating at this
level of medulla.
Corticospinal neurons terminating at the C8 level controls finger movements.
lateral corticospinal tract
where does this tract decussate?
Lateral corticospinal tract travels down the spinal cord and
terminates in the ventral horn at the level specific to the muscles it innervates
decussates at the medulla (pyramidal decussation)
where is the rubrospinal tract
what is the function
voluntary movement of upper limb in some mammals, less important for
humans. Superceded by corticospinal tract in humans
where is the tectospinal tract
what is the function
Subconscious motor activities - involved in reflexive head orienting
responses to novel visual and auditory stimuli
Which two tracts involved in subconscious motor activities?
Tectospinal tract and reticulospinal
tracts involved in subconscious motor activities such as
reflex responding to novel stimulus and maintaining activity
in antigravity muscles
which are the pathways that are involved in unconscious motor responses
1. reticulospinal tract
2. tectospinal tract
3. vestibulospinal tract
dorsal root contains
sensory afferent fibres
ventral root contains
motor efferent fibres
dorsal root ganglia contains
the cell bodies of sensory afferent neurons (dorsal fibres)
mixed spinal nerve
contains both afferent and efferent fibres (dorsal and ventral
rootlets combine)
in mixed spinal nerve is the dorsal root ganglia
ventral horn
contains the cell bodies of the LMN
dorsal horn contains
the termination of the primary afferent fibres