PHS 4300 Lecture Notes - Lecture 7: Motor Neuron, Internal Carotid Artery, Flaccid Paralysis

• School: University of Ottawa
• Department: Physiology
• Course: PHS 4300
• Professor: Joanne Savory

Document Summary

Corticobulbar projections: controls upper and lower facial motoneurons: lower face: innervation from fibers contralaterally (only crosses over, upper face: innervation from fibers ispilaterally, eg. Damage to facial nerve since this nerve travels through narrow bone canal under the ear, swelling or compression can lead to nerve inhibition, damage or nerve death; can be caused by stroke, tumour, lyme disease. If no specific cause is known, paralysis is identified as bell"s palsy. The brain uses 20% of the cardiac output at rest; neurons die after 5 minutes without blood (compared to. 20 mins for heart and 6 hours for skeletal muscles); brain is supplied by vertebral and internal carotid arteries; circle of willis is a mechanism to always allow blood flow even if arteries are completely obstructed. A blood-brain barrier exists to protect from toxics and amino-acids (eg. glutamate, which is excitatory and.