Download Anatomy of the Central Nervous System by Camille

Muscle/Nerve Cross Talk:
Impact on
Voluntary Muscle Action
OBJECTIVES
I. Coordination of signaling for agonist and antagonistic muscle action
II. Complexity of layered control over voluntary muscle movement
Goals
concepts
1) Basic gross and micro anatomical structure of muscle movement
2) CNS signaling for monosynaptic & polysynaptic reflex muscle action
3) Coordinated CNS signaling of excitatory and inhibitory neurons
4) Cortical origin of voluntary muscle action
5) Influence of sensory input and learning on voluntary muscle action
Goals
How is the
Cerebral cortex
involved in
skeletal muscle
movement?
C5-T1 : Upper limb
L4-S3 : Lower limb
Skeletal Muscle
related Neurology
How are
motor units recruited
to control
fine movement?
Skeletal Muscle
related Neurology
How are
Motor axons
Arranged
in the spinal cord?
Extension
Flexion
Proximal
Distal
Skeletal Muscle
related Neurology
How is muscle action
Compartmentalized in the
upper and lower limbs?
Upper Limb
Extension:
Radial N.
Flexion:
Musculocutaneous N.
Lower Limb
Extension:
Flexion:
Tibial N.
Femoral N.
Skeletal Muscle
related Anatomy
How does the primary mover
differ from
Synergistic muscles
In Muscle action?
Skeletal Muscle
related Anatomy
How do
agonist and antagonist muscles
work coordinately?
Skeletal Muscle
related Anatomy
What skeletal muscle receptors
Send signals about
Proprioception
to the CNS?
Skeletal Muscle
related histology
How do
muscle spindle and
Golgi tendon organ signals
To the
alpha motor neuron
differ?
Skeletal Muscle
related histology
What is a
reflex?
[gastric distension>increased intestinal peristalsis]
[appendicitis>muscle rigidity]
http://photo.accuweather.com/photogallery/details
/photo/22464/Lightning+Strike+over+Desert
Involuntary
Muscle action
What action
induces the monosynaptic
knee jerk reflex?
Knee Jerk Reflex
Monosynaptic reflex loop
through spinal cord
Involuntary
Skeletal Muscle action
What afferent signal
is activated In the
monosynaptic
reflex arc?
Involuntary
Skeletal Muscle action
What neurons
signal the
muscle spindle
intrafusal fibers
to contract?
Involuntary
Skeletal Muscle action
What is the difference
between a
Monosynaptic and a
polysynaptic reflex?
Involuntary
Skeletal Muscle action
How do signals from the
golgi tendon organ
Affect
agonist and antagonist
muscles?
Involuntary
Skeletal Muscle action
What is the role of The
Cerebral cortex In
voluntary muscle action?
Cerebral Cortex
Corticospinal Tract
(Pyramidal Tract)
] Fiber Decussation
Motor cortex control of
voluntary muscle action
How are the cell bodies
for motor axons
in the cerebral cortex
characterized?
Motor cortex control of
voluntary muscle action
How do
muscle spindles and
golgi tendon organs
impact voluntary muscle movement?
voluntary
Skeletal Muscle action
What
extra-pyramidal influences
are exerted over
voluntary muscle action?
Complex neural influence
over
Voluntary muscle action
Where do
Extra-pyramidal pathways
And muscle proprioceptors
interact?
Neural regulation of
muscle action
Why Do our runners
reflexively pull
the hot coffee cup
From Their lips ?
Complex neural influence
over
muscle action
Complexity of Muscle/Nerve Cross Talk in
Skeletal Muscle Action
Summary of
basic neurology, anatomy and histology
 Larger areas of motor cortex are dedicated to muscles that are used for fine movements.
 Fine movements are associated with small motor units while gross movements are
associated with larger motor units.
 Location, Location, Location! of a lesion will determine what impact it has on muscle
movement.
 Muscle spindles & Golgi tendon organs are receptors for proprioception and regulate
muscle length and muscle tension respectively.
Control of
muscle movement
Complexity of Muscle/Nerve Cross Talk in
Skeletal Muscle Action
Summary of
basic muscle movement
 Reflex movement can involve monosynaptic (without interneurons) or polysynaptic
(with interneurons) synapses.
 Skeletal muscle movement is regulated by coordinated signaling of excitatory and
inhibitory neurons.
 Upper motor neurons in the motor cortex signal lower motor neurons in the spinal cord
via the corticospinal tract.
 Muscle movement is influenced by extra-pyramidal pathways, sensory input &
learning .
Control of
muscle movement
Questions?
Acknowledgments