Week 2 Flashcards
Discuss the trochlear nerve
- Exits midbrain (Trochlear nucleus) caudal to the inferior colliculus
- Innervates the superior oblique muscle of the contralateral eye
- Only CN to exit from the dorsal surface of the brainstem
What is the primary cause of damage to the trochlear nerve?
Trauma.
Central damage causes deficit in contralateral eye. Distal injury causes deficit in ipsilateral eye.
Discuss the Ventral Trigeminothalamic Tract
- All sensation from head
- Primary neurons in Trigeminal ganglion of CN V
- Secondary neurons in Trigeminal Nucleus of brainstem
- Wired to contralateral VPM of thalamus.
What is the exception about VTT proprioception of the jaw?
Its primary neurons are in the brainstem proper.
What are the 2 features shared by spinal and cranial sensory pathways?
- Primary neurons are outside the spinal cord/brainstem.
2. They cross the spinal cord at some point. Taste is the exception to this.
Discuss the definition of UMNs and LMNs in relation to the corticospinal/bulbar tracts.
Corticospinal and Corticobulbar tracts: UMNs are located in Primary Motor Cortex and LMNs are found in the ventral horns of the spinal cord and the various motor nuclei of the brainstem, respectively.
Which cranial nerves are purely sensory?
1,2,and 8.
Which cranial nerves are purely motor?
3,4,6,11 and 12
Which cranial nerves are mixed?
5,7, 9, and 10
Which cranial nerves carry parasympathetic innervation?
3,7,9, and 10
Differentiate GVEs from SVEs
General Somatic Efferent) Voluntary innervation to skeletal muscle derived from the somites g. SVE = (Special Visceral Efferent ) Motor fibers innervating skeletal musculature derived from the branchial gill arches
What is the primary blood supply to the medulla?
Vertebral Arteries
What does the PICA supply? Blockage?
Dorsal lateral medulla; Wallenberg’s syndrome
What does the anterior spinal artery supply? Blockage?
Ventral spinal cord and medial medulla; See drawing
What does the posterior spinal artery supply?
Dorsal medulla; see drawings
