Session 1: Session slides

Question 1

what is the function of the semicircular canals (ducts) and how do they differ?

Answer 1

• The semicircular canals detect rotational movements of the head:

*Anterior: Detects vertical plane movements (e.g., nodding).
*Lateral: Detects horizontal movements (e.g., turning the head left or right).
*Posterior: Detects side-to-side tilts (e.g., moving head toward shoulder).

• Function: Filled with endolymph, these canals send signals to the brain when hair cells in the cristae (within the ampullae) bend in response to head movement.

Question 2

What are the cristae within the ampullae, and what do they do?

Answer 2

• Location: Each ampulla is an enlarged region at the base of the semicircular canals.
• Function: The cristae are sensory organs that detect angular acceleration (rotation). Movement of endolymph stimulates hair cells in the cristae, which send signals about head movement to the brain.

Question 3

What is the role of the utricle and saccule in the vestibular system?

Answer 3

• Utricle: Detects horizontal acceleration and head tilts (e.g., moving forward or backward).
• Saccule: Detects vertical movements (e.g., jumping or
  moving in an elevator).
• Both are part of the otolith organs and send information to the brain about linear head movements and tilt.

Question 4

What does the vestibulocochlear nerve (VIII cranial nerve) do?

Answer 4

• Function: Transmits sensory information for both balance (from the vestibular system) and hearing (from the cochlear system) to the brain.
• Vestibular Division: Carries balance information from the semicircular ducts, utricle, and saccule.
• Cochlear Division: Carries sound information from the cochlea to the brain.

Question 5

What is the function of the vestibular duct in the cochlea?

Answer 5

Transmits pressure waves through the cochlea, aiding in the detection of sound by sensory cells.

Question 6

What is the function of the cochlear duct in the cochlea?

Answer 6

Houses the organ of Corti, the sensory organ for hearing, where hair cells convert sound vibrations into electrical signals.

Question 7

What is the tympanic duct, and how does it work with the vestibular duct?

Answer 7

Works with the vestibular duct to conduct sound vibrations, creating wave motion that stimulates hair cells for sound detection.

Question 8

What is the role of the cochlea in hearing?

Answer 8

• Location: The spiral-shaped part of the inner ear.
• Function: Converts sound vibrations into neural signals that are sent to the brain via the cochlear nerve, playing a crucial role in hearing.