Ascending Tracts
Part 1
Gray matter - collection of neuronal bodies
White matter - collection of myelinated axons
Different types of white matter
tracts - run up and down
association fibers - runs anterior to posterior
commissures - runs from left to right
What are tracts?
bundles of axons which have a common origin and termination
whcih are present in the CNS in cephalocaudal axis
(connects upper part to lower part)
Ascending tracts -
takes information
from the lower part
of the CNS to the
upper part
sensory system
Descending tracts -
takes information
from the upper part
of teh CNS to the
lower part
motor system
Ascending Tracts 1
, Association fibers - bundles of axons that connect the CNS
anteroposteriorly. eg. connects the frontal lobe to the
occipital lobe
Commissures - white matter connecting the right and left part
of the CNS
Corpus callosum - this is the
largest commissure and it
connects the right cerebral
hemisphere with the left
cerebral hemisphere
Receptors -biological transducers that convert stimulus energy
into electrochemical energy of action potential
eg. if you touch something with your hand, the touch
stimulus will be converted to action potentials which will
pass along the axons to the CNS
rods and cones - unique apparatus which can convert visible
light energy into action potential in the optic nerve. i.e.
photoreceptors
The motor nerve will go to the effector system. The effector
system can be either a muscle or a gland.
Ascending Tracts 2
, Organization of fibers in the spinal cord
The ventral and dorsal roots are pure. This means they are not
mixed. The dorsal roots has only sensory fibers and the
ventral roots has only motor fibers
The spinal nerve trunk, ventral ramus and dorsal ramus are all
mixed. This means that they have both sensory and motor fibers
In the spinal cord, there are 3 major white matter areas:
dorsal
column/dorsal
fasciculus
lateral column
anterior column
Ascending Tracts 3
, 🧠 tracts either run in the dorsal column, the lateral
column or the anterior column
dorsal column - only
ascending tracts
lateral column - both
ascending and descending
tracts
anterior column - both
ascending and descending
tracts
The tracts in the dorsal column are heavily myelinated
Ascending Tracts 4
Part 1
Gray matter - collection of neuronal bodies
White matter - collection of myelinated axons
Different types of white matter
tracts - run up and down
association fibers - runs anterior to posterior
commissures - runs from left to right
What are tracts?
bundles of axons which have a common origin and termination
whcih are present in the CNS in cephalocaudal axis
(connects upper part to lower part)
Ascending tracts -
takes information
from the lower part
of the CNS to the
upper part
sensory system
Descending tracts -
takes information
from the upper part
of teh CNS to the
lower part
motor system
Ascending Tracts 1
, Association fibers - bundles of axons that connect the CNS
anteroposteriorly. eg. connects the frontal lobe to the
occipital lobe
Commissures - white matter connecting the right and left part
of the CNS
Corpus callosum - this is the
largest commissure and it
connects the right cerebral
hemisphere with the left
cerebral hemisphere
Receptors -biological transducers that convert stimulus energy
into electrochemical energy of action potential
eg. if you touch something with your hand, the touch
stimulus will be converted to action potentials which will
pass along the axons to the CNS
rods and cones - unique apparatus which can convert visible
light energy into action potential in the optic nerve. i.e.
photoreceptors
The motor nerve will go to the effector system. The effector
system can be either a muscle or a gland.
Ascending Tracts 2
, Organization of fibers in the spinal cord
The ventral and dorsal roots are pure. This means they are not
mixed. The dorsal roots has only sensory fibers and the
ventral roots has only motor fibers
The spinal nerve trunk, ventral ramus and dorsal ramus are all
mixed. This means that they have both sensory and motor fibers
In the spinal cord, there are 3 major white matter areas:
dorsal
column/dorsal
fasciculus
lateral column
anterior column
Ascending Tracts 3
, 🧠 tracts either run in the dorsal column, the lateral
column or the anterior column
dorsal column - only
ascending tracts
lateral column - both
ascending and descending
tracts
anterior column - both
ascending and descending
tracts
The tracts in the dorsal column are heavily myelinated
Ascending Tracts 4
