Ear Flashcards

Explore the external, middle, and inner ear, including auditory ossicles, cochlear structures, vestibular organs, innervation, and blood supply.

Card 1 of 30Question

What are the three anatomical divisions of the ear?

The external ear, middle ear, and inner ear.

In This Section

1. What are the three anatomical divisions of the ear?

The external ear, middle ear, and inner ear.

2. What are the two principal sensory functions of the ear?

Hearing and equilibrium.

3. Which structures form the external ear?

The auricle and external acoustic meatus, extending to the tympanic membrane.

4. What is the principal function of the auricle?

To collect and direct sound waves toward the external acoustic meatus.

5. What type of cartilage forms most of the auricle?

Elastic cartilage, except in the lobule, which contains fibrofatty tissue.

6. Which bones contribute to the bony external acoustic meatus?

Primarily the tympanic and squamous parts of the temporal bone.

7. What is the tympanic membrane?

A thin membrane separating the external acoustic meatus from the middle ear cavity.

8. What are the two principal regions of the tympanic membrane?

The pars tensa and pars flaccida.

9. Which auditory ossicle attaches to the medial surface of the tympanic membrane?

The malleus, through its manubrium.

10. Where is the middle ear cavity located?

Within the petrous part of the temporal bone, between the tympanic membrane and inner ear.

11. What are the three auditory ossicles in lateral-to-medial order?

Malleus, incus, and stapes.

12. Which auditory ossicle is the smallest bone in the human body?

The stapes.

13. Which opening receives the footplate of the stapes?

The oval window, also called the fenestra vestibuli.

14. What is the function of the round window?

It permits displacement of cochlear fluid as the stapes moves at the oval window.

15. Which muscle attaches to the handle of the malleus?

The tensor tympani muscle.

16. Which nerve supplies the tensor tympani muscle?

A branch of the mandibular division of the trigeminal nerve (cranial nerve V3).

17. Which nerve supplies the stapedius muscle?

The facial nerve (cranial nerve VII).

18. What is the function of the pharyngotympanic tube?

To equalize air pressure between the middle ear and nasopharynx and permit middle ear drainage.

19. Which part of the pharynx communicates with the middle ear through the auditory tube?

The nasopharynx.

20. What are the two major components of the inner ear?

The bony labyrinth and membranous labyrinth.

21. What are the three major divisions of the bony labyrinth?

The vestibule, semicircular canals, and cochlea.

22. Which fluid fills the space between the bony and membranous labyrinths?

Perilymph.

23. Which fluid fills the membranous labyrinth?

Endolymph.

24. Which sensory structure within the cochlea detects sound vibrations?

The organ of Corti, located on the basilar membrane of the cochlear duct.

25. What are the three fluid-filled compartments of the cochlea?

The scala vestibuli, scala media, and scala tympani.

26. Which vestibular structures detect linear acceleration and head position relative to gravity?

The utricle and saccule.

27. Which vestibular structures detect angular acceleration of the head?

The cristae ampullares within the ampullae of the semicircular ducts.

28. Which cranial nerve transmits hearing and equilibrium information from the inner ear?

The vestibulocochlear nerve (cranial nerve VIII).

29. Which artery primarily supplies the membranous labyrinth?

The labyrinthine artery, usually arising from the anterior inferior cerebellar artery.

30. What is the anatomical difference between conductive and sensorineural hearing loss?

Conductive loss involves sound transmission through the external or middle ear; sensorineural loss involves the cochlea or auditory neural pathways.