Olfaction and the auditory system Flashcards
What are the 4 functions of the nasal cavity
- Warms and humidifies the inspired air
- Removes and trap pathogen from the inspired air
- Responsible for a sense of smell
- Drains and clears the paranasal sinuses and lacrimal ducts
What are the divisions in the superior part of the respiratory tract
Olfactory region –> located at the apex of the nasal cavity
Vestibule –> The area surrounding the anterior external opening to the nasal cavity
Respiratory region –> lined by ciliated pseudostratified epithelium, with mucus-secreting goblet cells.
What are the olfactory regions composed of?
- Supporting cells
- Basal cells
- Receptor cells
What is the gland that is located in the olfactory epithelium? (also its function)
Bowman gland
So they trap and dissolve odiferous substances for the interpretation of smell.
What is the substance that the bowman gland produces
- Produces a gel-forming mucin
- Lysozyme (breaks down bacterial cells walls
- IgA (immune role)
- Amylase (breaks down starch)
- Odorant-binding protein
- Increase the aqueous solubility of hydrophobic odorants
How do we sense a smell?
- Olfactory receptors
->Through the olfactory nerve - Olfactory bulb
->Through the olfactory tract - Primary olfactory cortex (temporal lobe)
-> Orbitofrontal cortex (secondary cortex in the frontal lobe)
-> Hippocampus (olfactory memory)
Features of olfactory pathway
has 2 neurons only
don’t have synapse in the thalamus
Where are both the piriform and orbitofrontal cortexes located in the brain?
Piriform cortex –> temporal lobe
orbitofrontal –> frontal lobe
What are the anatomy terminology and the function of the external ear?
Auricle /Pinna
- It’s a cartilage that covered with skin
- direct sound wave to the inner ear
Anatomy of the external ear
Helix (#耳外位)
Antihelix (#中骨位)
lobule (#bottom of the ear)
Concha (# bed of the ear/凹位 in the middle)
External acoustic meatus (EAM) (#the hole of the ear)
Tragus (#凸位 close to the ear)
Antitragus (#凸位 close to the lobule)
what does the outer ear region include?
Auricle to the tympanic membrane through the external acoustic meatus
What is within the middle ear region?
extends from the tympanic membrane to the oval window
- contain auditory ossicles (malleus, incus and stapes)
- contain pharyngotympanic tube that conveys with nasopharynx
What is within the region of the inner ear?
It’s within the petrous part of the temporal bone
Contains:
- cochlear
- vestibular apparatus
- internal acoustic meatus (VIII)
Sensory innervation of the ears (3 parts)
Outer ears:
- auriculotemporal (CN V3)
- auricular branch of (CN X)
- Posterior auricular branch of Facial (CN VII)
Middle ear:
- Glossopharyngeal (CN IX)
Inner ear:
- Vestibulocochlear (CN VIII)
What is auditory ossicles, and what does it compose of?
connection from the tympanic membrane to the internal ear
- malleus
- incus
- stapes
