Neuro Anatomy 2 Flashcards
How many pairs of nerves are there in the spine?
31
What level is the caudal equina at?
L2
Is there more nerves at the top or the bottom of the spine?
Top due to arms and head
What is a nerve plexus?
Group of intersecting nerves
What is the difference between grey and white matter?
Grey= Outside of the brain, contains nerves (axons, dendrites etc.) White = Inside, myelinated
What are the posterior nerve roots?
Afferent - sensory nerve root (dorsal horn cells)
Finish in the posterior horn
What are the anterior nerve roots?
Efferent - motor (ventral horn)
Finish in the Ventral horn
Nerve cells inside the spinal cord are called?
Nuclei
Nerve cells outside the spinal cord are called?
Ganglion
What do ascending tracts carry?
Sensory neurons
What do descending tracts carry?
Motor neurons
What is an interneuron?
Transmits from one to another
Inhibitory or excitatory
What are the three main spinothalamic pathways?
Lateral and ventral spinothalamic tracts
Corticospinal tract
What does the lateral spinothalamic tract do?
Pain and temperature
What does the ventral spinothalamic tract do?
Touch and pressure
What does the corticospinal pathway do?
Motor cortex to the spine (Finishes in the anterior horn cells)
Why do stroke patients struggle with movement?
Some of the neurone in the somatosensory cortex have gone, no descending impulses and therefore no activation of motor fibres
Name the 4 major plexuses of the ventral rami
Cervical, brachial, lumbar and sacral
What does the GTO do?
Percieve the stretch and contraction of the muscle
What do muscle spindles do?
Detect stretch
Describe why spasticity happens
No descending impulses to tell the muscles to relax
What are a group of muscle fibres innervated by one single motor neurone called?
A motor unit
