​Chemoreceptors- CHEMICAL SENSES  

• Taste and smell (olfaction)  

• Their chemoreceptors respond to chemicals in aqueous solution (exteroreceptors) 

MORE CHEMICAL RECEPTORS

• Olfactory cilia 

• Increase receptive surface area 

• Covered with mucus or solvent 

• Cranial nerve I 

• The neurons are mitotic, very sensitive 

​taste bud- They are chemoreceptors  

• Taste Bud Types 

• In papillae on the tongue 

• Filiform 

• no taste buds 

• Fungiform 

• Scattered & tip & sides 

• Circumvallate 

• V at tongue back 

• Foliate papillae 

• Sides of tongue 

filiform papillae- ROUGH  

​Vestibule- 

• Central egg-shaped cavity of the bony labyrinth 

• Contains two membranous sacs 

1. Saccule is continuous with the cochlear duct OPENS INTO THE COCHLEA  

2. Utricle is continuous with the semicircular canals IMPORTANT IN BALANCE  

bony labyrinth- 

Series of bony cavities within the temporal bone  

Saccule- 

continuous with the cochlear duct, part of the VESTIBULE  

utricle- 

 continuous with the semicircular canals, part of VENTRICLE  

maculae-  

Both the saccule and the utricle house the equilibrium receptor regions AKA as maculae  

semicircular canals- 

• Three canals (anterior, lateral, and posterior) that each define two-thirds of a circle 

• Membranous semicircular ducts line each canal and communicate with the utricle 

• Ampulla of each canal houses equilibrium receptor region called the crista ampullaris 

• Receptors respond to angular (rotational) movements of the head 

Ampulla- 

A localized dilation of a canal or duct  

crista ampullariids- 

• each canal houses equilibrium receptor region called the crista ampullaris