What is sound ?
Vibrating objects vibrate air molecules which then stimulate auditory system
What is Amplitude ?
What is Frequency ?
What is Complexity ?
What is Audition ?
Ossicles (malleus, incus, stapes)
Vibration of the oval window sets in motion the fluid of the cochlea
What is the organ of Corti ?
The cochlea's internal membrane
The auditory receptor organ
Anatomy of the Ear
What is the Organ of Corti composed of?
Stimulation of hair cells triggers action potentials in the auditory nerve (branch of CN VIII - Vestibular - Cochlear)
What is the Basilar Membrane ?
Auditory receptros, hair cells, are mounted here
What is the Tectorial Membrane ?
Rests on the hair cells
What is Tonotopic ?
Organization of the organ of corti
Different frequencies produce maximal stimulation of hair cells at different points along the basilar membrane
What is the Auditory Pathway ?
Medial Geniculate Nucleus (Thalamus)
Primary Auditory Cortex
What is the Auditory Cortex ?
Primary auditory cortex = lateral fissure; temporal lobe
Tonotopic Organization to simple tones
Secondary areas respond best to complex tones
What is Conduction Deafness ?
Mechanical systems (Hearing Aid)
Ex. Punctured eardrum, loss of function of bones of middle ear
What is Nerve Deafness ?
Damaged receptros (Can not heal)
Ex. Exposure to loud sounds can damage hair cells
What are some age related Hearing loss ?
Usually deficit in hearing high frequencies
Elderly people often problems with 's' 'f' & 't'
What is Olfaction ?
Detects airborne chemicals
What is Gustation ?
Responds to chemicals in the mouth
What is Flavor ?
Food acts on both Olfaction & Gustation to produce flavor
What is ordorant ?
Shape of the molecule determines its smell
What is the Olfactory nerve ?
Information is carried via CN I
What is the track of the Olfactory System ?
Olfactory track -> Piriform Cortext (Primary olfactory cortex & amygdala) -> BOTH Limbic system & Orbitofrontal cortex (conscious perception of odors)
What is the Cribriform Plate ?
When we get hit in the head this cuts olfactory receptors
What are Taste Buds ?
Occur in clusters of 50
Located on Papillea (big bumps on tongue)
What are 5 primary tastes each with their own receptor ?
What taste don't have receptors ?
How is the info carried ?
VII - Facial
IX - Glossopharygeal
X - Vagus
What is the Gustatory Pathway ?
Ventral Posterior Nucleus (Thalamus)
Primary Gustatory Cortex ( near face region of postcentral gyrus)
What is Ansomia ?
Inability to smell
Most common cause is a blow to the head that damages olfactory nerves
What is Ageusia ?
Inability to taste
Rare due to multiple pathways carrying taste information
The five senses