What's That Sound?
Which part of the ear vibrates when sound waves hit it?
A) Eardrum
B) Broccoliorli
C) Cochlea
D) Vitaminus
...What is the Eardrum?
FOLLOW-ALONG NOTES)
Outer ear: collects and directs sound ( parts = auricle & ear canal)
Middle ear: amplifies vibrations (parts = ossicles, oval window, Eustachian tube)
Inner ear: converts vibrations to signals and maintains balance (parts = cochlea, Organ of Corti, vestibule, semicircular canals)
Hair cells in the Organ of Corti detect vibrations and create nerve signals
Cochlear branch of vestibulocochlear nerve --> brainstem --> thalamus --> auditory cortex
Basilar membrane: different regions respond to different pitches (base = high pitched noise, apex = low pitched noise)
Raise your hand when you can no longer hear the sound.
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What animal shell does the cochlea look the most like?
A) Turtle Shell
B) Crab Shell
C) Snail Shell
D) Armadillo Shell
...What is Snail Shell
FOLLOW ALONG NOTES)
Sound waves travel through the air, and then they enter the external auditory canal. Next, they reach the tympanic membrane (eardrum), causing vibrations, which are amplified by ossicles (malleus → incus → stapes). The stapes pushes on the oval window, transmitting vibrations into the inner ear fluids. Those fluid waves travel through the scala vestibuli and scala tympani. The basilar membrane vibrates at specific locations depending on pitch. Hair cells in the Organ of Corti bend, converting that mechanical energy to electrical signals. Those signals travel through the cochlear branch of the vestibulocochlear nerve (CN VIII). Then the nerve signals reach the cochlear nuclei in the medulla, where they travel to the superior olivary complex (sound localization) and continue to the inferior colliculus in the midbrain (auditory reflexes). They then travel to the medial geniculate nucleus of the thalamus and finally reaches the primary auditory cortex in the temporal lobe for sound perception and interpretation
Overall pathway: Air → ear canal → eardrum → ossicles → oval window → cochlea hair cells → CN VIII → brainstem → thalamus → auditory cortex
Distinguish between static and dynamic equilibrium. Describe the equilibrium organs (probably edit this?)
What even is Equilibrium?
Equilibrium: It isn’t just one sense, it’s two senses. Two equilibriums that come from two different organs.
How many senses equilibrium and why?
2 senses
Static vs Dynamic equilibrium
Static equilibrium: Sense position of the head, maintains balance, stability, and posture when the head and body is still.
Dynamic equilibrium: And when the head and body are in motion or rotate in any way or form, the organs that aid in dynamic equilibrium, detect such motion and aid in maintaining balance.
Organs in static equilibrium
Organs in dynamic equilibrium
The equilibrium pathway starts from where and ends in where
a.) inner ear / cerebral cortex
b.) brain stem / thalamus
c.) vestibular nerve / thalamus
d.) brainstem vestibular nuclei / cerebral cortex
a.) inner ear / cerebral cortex
The pathway an equilibrium signal follows starts in the vestibular nerve (CN VIII), moves to the Brainstem Vestibular Nuclei, then the Thalamus, and finally ends in the cerebral cortex