Motor Systems Flashcards
Regulate contraction of the skeletal muscles to produce movement
Alpha LMN
Regulate the sensitivity of the muscle spindles for groups Ia and group II afferent modulation of alpha LMN excitability
Gamma LMN
Produce trophic factors to maintain the nerve-muscle association
Supporting cells (Schwann Cells) Myocytes
LMNs are found as clusters of neuron in the _______ represented as lamina IX of Rexed
Anterior ventral horn of spinal card
Trunk and neck muscles are found
Medially
Distal extremities are found
Laterally
Flexor Muscle Groups
Dorsally
Extensor Muscle Groups
Ventrally
Medial column derives from the general somatic efferent system
- Oculomotor nuclear
- Trochlear nucleus
- Abducens nucleus
- Hypoglossal nucleus
Lateral column derives from the special visceral efferent system
- Motor nucleus V
- Facial Nucleus
- Nucleus ambiguus
- Spinal accessory nucleus
Cortical neurons in the motor cortex (Area 4) and supplemental and premotor cortices (Area 6) send axons to the:
- Basal Ganglia
- Thalamus
- Red Nucleus
- Pontine Nuclei
- Cranial nerve motor nuclei on both sides
- Spinal cord ventral horn
Neurons of the sensory cortex (Areas 3, 1, 2) regulate incoming lemniscal sensory projections destined for
Conscious interpretation
Neurons in the frontal eye fields (Area 8) are responsible for
Coordinate voluntary eye movements and associated head movements
Area 8 project to the:
- Superior colliculus
- Horizontal and vertical gaze centers of the brain stem
- Interstitial nucleus of cajal
What tract arises mainly from the lateral portion of the primary motor cortex (area 4)
Corticobulbar Tract
CBT projection to hypoglossal nucleus are mainly
contralateral
CBT projection to spinal accessory are mainly
ipsilateral
What tract is mainiyl from the primary motor cortex (area 4) and the supplemental and premotor cortices (area 6)
Corticospinal Tract
What tract results in the lesions in contralateral spastic hemiplegia as long-term consequences
Rubrospinal Tract
What tract results in weakness of contralteral fine, dextrous hand and finger movements when there is isolation lesions in medullary pyramids
Corticospinal Tract
Lateral Vestibulospinal Tract terminates directly and mainly indirectly on ipsilateral alpha-and gamma-LMNs associated with
Extensor musculature
Proximal Musculature
Medial vestibulospinal tract provides inhibition of alpha-and gamma-LMNs controlling
Neck and Axial musculature
Mediates reflex and visual tracking influences for positioning the head with regard to visual input
Tectospinal Tract
Terminates directly and indirectly on alpha-and gamma LMNS associated with the axial musculature of the trunk (involved in rotational movement of the body around its central axis)
Interstitiospinal Tract
