Special Senses TLOs

Question 1

Describe the events from sound waves to vibration of the tympanic membrane and auditory ossicles

Answer 1

Sound waves travels through air and reach the ear drum. From there a vibration is sent through the ossicles (malleus, incus and stapes) to be amplified

Question 2

Describe the events from from vibration of the stapes and basilar membrane to stimulation of hair cells of the
organ of corti: transduction

Answer 2

The staples vibrates the fluid filled cochlea and the basil membrane picks up this vibration as a specific frequency

Question 3

Describe the vestibular system

Answer 3

Made up of 2 sensors:

• Semicircular canals
• Otolith organs

Otolith organs produce depolarisation when cilia bend due to change in head orientation

Semicircular canals respond rotation accelerations due to the movement of the endolymph. Cruitial for steady gaze

Question 4

Describe the anatomy of Otolith Organs and Semicircular Canal

Answer 4

Otolith Organs:

• Otoliths
• Gelatinous cap
• Hair cells
• Vestibular nerve axons

Semicircular Canals:

Question 5

Describe the role of the Vesticulo-Occular reflex

Answer 5

To help maintain steady eye gaze

Question 6

What are the 5 difference taste categories?

Answer 6

• Salt
• Sour
• Sweet
• Unami
• Bitter

Question 7

Outline the mechanisms for detection of tastant molecules?

Answer 7

• Taste cells care polarised
• Tasted ions (salt, sour) –> depolarisation
• Tasted molecules (sweet, bitter, unami) –> 2 nd messenger mechanisms –> depolarisation & Ca release into cyotplasm
• Serotonin is released into synaptic cleft (neurotransmitter)