HTHSCI 1H06 Lecture Notes - Lecture 2: Thalamus, Endolymph, Inferior Colliculus

• School: McMaster University
• Department: Health Sciences
• Course: HTHSCI 1H06
• Professor: Peter Helli

Document Summary

Vagus nerve (x) sensory fibers in the ear. Controls stapedius muscle which puts tension on the bones of the middle ear to reduce the amount of sound when it"s really loud. The ear: external ear extends from the oracle, allows for sounds to funnel into the ear, middle ear behind tympanic membrane. External auditory canal contains wax that trap foreign bodies: seruminous glands in the skin produce ear wax, bad smell repels insects. Thin skin firmly attached to periosteum of bone closer to middle ear. Eardrum (tympanic membrane) connective tissue with skin on the outside, mucus membrane on the other side cone shaped. Mechanical relay of vibrations of the tympanic membrane are relayed to oval window membrane where they set up a series of vibrations in the fluid of the inner ear. Muscles in ear dampen vibrations from tympanic membrane to oval window: stapedius (cn vii) attached to stapes.