Neuro anatomy Flashcards
Name the four columns of the spinal cord grey matter.
Dorsal horn
Ventral horn
Intermediate column
Lateral horn
What is the dorsal horn?
A column of the spinal cord which contains neurons that receive somatosensory information from the body, which is then transmitted via ascending pathways to the brain
What is the ventral horn?
A column of the spinal cord that mainly contains motor neurons that exit the spinal cord to innervate the skeletal muscle
What is the intermediate column?
A column of the spinal cord that contains neurons that innervate visceral and pelvic organs.
What is the lateral horn?
A column of the spinal cord that contains neurons that innervate visceral and pelvic organs.
What are the ascending tracts?
Neural pathways by which sensory information from the peripheral nerves is transmitted to the cerebral cortex (also known as somatosensory pathways).
Ascending tracts are divided into what two types of tract?
Conscious and unconscious tracts.
What are conscious tracts?
A type of ascending tract in the spinal cord grey matter comprised of the dorsal column-medial lemniscal pathway and the anterolateral system.
What are unconscious tracts?
A type of ascending tract in the spinal cord grey matter comprised of the spinocerebellar tracts
What are the descending tracts?
Pathways by which motor signals are sent from the brain to lower motor neurones. The LMNs then directly innervate muscles –> movement.
How are the descending tracts subdivided?
Pyramidal tracts and extrapyramidal tracts
What are the pyramidal tracts?
Descending (motor) tracts which originate in the cerebral cortex and carry motor fibres to the spinal cord and brain stem.
–> voluntary control of muscles
What are the extrapyramidal tracts?
Descending (motor) tracts which originate in the brain stem and carry motor fibres to the spinal cord.
–> involuntary and automatic control of muscles (e.g. tone, balance, posture, locomotion)
What is an upper motor neuron and why?
All neurons within the descending (motor) system.
Because there are no synapses within the descending pathways. Where the descending tracts terminate, the neurones synapse with a lower motor neurone.
Where is the cell body of an upper motor neurone?
The cerebral cortex or brain stem.
