Spinal Cord, Brainstem And Motor Fnx II (Obj. 1 and 2) Flashcards
Most fibers of the CBT terminate where?
- In the RETICULAR formation
- Near the Cranial Nerve Nuclei
CST Lesions can lead to what?
- Hyper-Tonia
- Hyper-Reflexia
- Clonus (Spasm)
- Muscle weakness
Rubro-Spinal Tract Characteristics
- Origin
- Decussation
- Descends
- Responsible for
- Originates in the RED Nucleus
- Decussates in the MIDBRAIN
- Descends in LATERAL Column (Funiculus)
- Responsible for Large Muscle MOVEMENT and some FINE motor movement
Cortico-Bulbar Tract Characteristics
- UMN of the CRANIAL Nerves
- Innervating the Face, Head, and Neck
- Contain ASSOCIATION Neurons
The Lateral CST supplies ____ while the Anterior CST supplies _____.
- All Levels of the Spinal Cord
2. Neck and Upper Limbs
What is thought to be the fxn of the Olivo-Spinal Tract?
- Involved into REFLEX movement
- Recent studies have called into question its existence
What % of Upper MN decussate in the Pyramidal System and where?
- 75% to 85%
- Decussate in the Pyramids
Red Nucleus Projections Stimulate ____ and Inhibit ____.
- Flexors
- Extensors (Anti-gravity)
Olivospinal tract originates where?
The Medulla in INFERIOR Olivary Nucleus
Reticular formation is a network of what?
- Nuclei w/in the Brainstem
- In both the PONS and the Medulla
What do the UMN form after decussation?
Forms the LATERAL Cortico-Spinal Tracts
Effects of Lesions to the Rubro-Spinal Tract
- Impairment of DISTAL Arm and Hand movement
- Intention Tremors
- May take over for injured CST in some animals
The Cortico-Spinal Tract is also known as the _____.
Pyramidal Tract
Lateral VST
- Major part of tract
- IPSILATERAL
- Upright posture and Balance
Anterior CS Tract Characteristics
- Made up of UNCROSSED fibers
- Cross near the level of Synapse with LMN’s
- Supply NECK and Upper Limbs
Medial VST
- Projects Bilaterally
- Controls LMN of CN 11
- Projects Indirectly to CN 6 and 3
Vestibulo-Spinal Tract Characteristics
- Originates
- Goal
- Descends
- Synapses
- In the Vestibular Nuclei in the Medulla
(Receives input from CN8) - Maintain BALANCE
- Descends in ANT. Column (Funiculus)
- Synapses w/ LMNs to EXTENSOR Muscles
(Upright Posture)
Where does the Pyramidal System upper MN originate?
Motor Cortices