Ears

1. Ears 3.03 Remember the structures of the sensory system

2. Structures of the ears • 3 regions: • External ear • Middle ear • Also known as the tympanic cavity • Inner ear • Also known as the labyrinth 3.03 Remember the structures of the sensory system

3. Structures of the ears • External ear • Pinnaor auricle • Auditory canal or external auditory meatus • Ceruminous glands • Tympanic membrane 3.03 Remember the structures of the sensory system

4. Structures of the ears • Middle ear • Ossicles • Hammer or malleus • Anvil or incus • Stirrup or stapes • Eustachian tube 3.03 Remember the structures of the sensory system

5. Structures of the ears • Inner ear • Cochlea Contains fluid called Perilymph - performs the all-important function of converting mechanical sound energy into electrical impulses • Semicircular canals Contains Endolymph fluid required for maintenance of balance or equilibrium.  • Vestibule -chamber that lies between the cochlea and the semicircular canals.  3.03 Remember the structures of the sensory system

6. Pathway of Hearing External Auditory Canal Ossicles (malleus, incus & stapes) Tympanic Membrane Cochlea Auditory nerve

7. Ears Name the structures… p…. t……. Review 3.03 Remember the structures of the sensory system

8. 3.04 Functions and disorders of the ear 3.04 Understand the functions and disorders of the sensory system

9. Understanding the functions of the ear: Hearing 3.04 Understand the functions and disorders of the sensory system

10. Understanding the functions of the ear External ear • Pinna • External auditory canal • Contains cerumen = wax • Tympanic membrane 3.04 Understand the functions and disorders of the sensory system

11. Understanding the functions of the ear Middle ear Ossicles - can you name them? Eustachian tube - a tube that links the nasopharynx to the middle ear. 3.04 Understand the functions and disorders of the sensory system

12. Understanding the functions of the ear Inner ear structures Cochlea Semicircular canals 3.04 Understand the functions and disorders of the sensory system

13. Understanding the functions of the ear What are decibels? The decibel ( dB) is the unit used to measure the intensity of a sound. Near total silence - 0 dB A whisper - 15 dB Normal conversation - 60 dB A lawnmower - 90 dB A car horn - 110 dB A rock concert or a jet engine - 120 dB A gunshot or firecracker - 140 dB

14. Understanding the functions of the ear Review the pathway of hearing 3.04 Understand the functions and disorders of the sensory system

15. The central part of the eardrum is connected to a small bone of the middle ear called the malleus (hammer). As the malleus vibrates, it transmits the sound vibrations to the other two small bones or ossicles of the middle ear, the incus and stapes. As the stapes moves, it pushes a structure called the ovalwindow in and out. This action is passed onto the cochlea, which is a fluid-filled snail-like structure that contains the organ for hearing- called the Organ of Corti. From here the vibrations are picked up by the auditory nerve and transmitted to the temporal lobe of the cerebrum 3.04 Understand the functions and disorders of the sensory system

16. Healthy Hearing How do you protect your hearing? 3.04 Understand the functions and disorders of the sensory system

17. Understanding the functions of the ear Short bit of sound or clip from a longer recording. Sound Activity What is a sound byte? 3.04 Understand the functions and disorders of the sensory system

18. Disorders of the ear What instruments are used to examine the ear? What specialist studies the ears, nose, and throat? 3.04 Understand the functions and disorders of the sensory system

19. Disorders of the ear External otitis Discuss what you see in this picture? (Besides a Q-tip!) What causes external otitis? How can it be prevented? 3.04 Understand the functions and disorders of the sensory system

20. Ear Infections There are three main kinds of ear infections, which are called acute otitis media (AOM), otitis media with effusion (OME), and otitisexterna (Swimmer’s Ear). 3.04 Understand the functions and disorders of the sensory system

21. Disorders of the ear Normal tympanic membrane Otitis media Myringotomy Otitis media What is otitis media? Who is most at risk of having otitis media? Why? What are the treatment options? 3.04 Understand the functions and disorders of the sensory system

22. Otitis media Children are more likely than adults to get ear infections. Otitis media (OM) is the second most common disease of childhood, after upper respiratory infection (URI) An ear infection is most often a bacterial or viral infection that affects the middle ear. 3.04 Understand the functions and disorders of the sensory system

23. Treatment for OM Because ear infections often clear up on their own, treatment begins with managing pain and monitoring the problem. Ear infection in infants and severe cases in older patients may require antibiotic medications. 3.04 Understand the functions and disorders of the sensory system

24. Surgical treatments for OM Myringotomy- a surgical procedure in which a small incision is made in the eardrum. Tympanostomy tubes, are small tubes open at both ends that are inserted into the incisions in the eardrums during myringotomy. While the tubes are in place, they keep the incision from closing, keeping a channel open between the middle ear and the outer ear. This allows fresh air to reach the middle ear, allowing fluid to drain out, and preventing pressure from building up in the middle ear. The patient's hearing returns to normal immediately and the risk of recurrence diminishes. 3.04 Understand the functions and disorders of the sensory system

25. Disorders of the ear Otosclerosis • What is it? • Oto- sclerosis • What causes it? • Why is a stapedectomy useful in treating otosclerosis? 3.04 Understand the functions and disorders of the sensory system

26. Otosclerosis The term otosclerosis is derived from the Greek words for "hard" (scler-o) and "ear" (oto). It describes a condition of abnormal bone growth around the stapes bone. Caucasian, middle-aged women are most at risk. Approximately 60 percent of otosclerosis cases have a genetic predisposition. 3.04 Understand the functions and disorders of the sensory system

27. symptoms Gradual hearing loss is the most frequent symptom of otosclerosis. Other symptoms of the disorder can include dizziness, balance problems, or a sensation of ringing or hissing in the ears known as tinnitus. If the hearing loss is mild, the otolaryngologist may suggest a hearing aid to amplify sounds reaching the ear drum. 3.04 Understand the functions and disorders of the sensory system

28. Treatment A stapedectomy is a surgical procedure. The surgeon removes part or all of the immobilized stapes bone and replaces it with a prosthetic device. Modern-day stapedectomy has been performed since 1956 with a success rate of approximately 90 percent. 3.04 Understand the functions and disorders of the sensory system

29. Disorders of the ear Meniere’s disease What are the symptoms of Meniere’s disease? What causes these symptoms? How is it treated? 3.04 Understand the functions and disorders of the sensory system

30. Meniere’s disease Meniere's disease is a disorder of the inner ear that causes spontaneous episodes of vertigo — a sensation of spinning — fluctuating hearing loss, ringing in the ear (tinnitus), and sometimes a feeling of fullness or pressure in your ear. In most cases, Meniere's disease affects only one ear. 3.04 Understand the functions and disorders of the sensory system

31. Meniere's disease is caused by a dysfunction of the endolymphatic sac (semi-circular canals) in the inner ear. approximately 1 in every 1,000 people suffers from Meniere's disease. most common between 40 and 60 years old 3.04 Understand the functions and disorders of the sensory system

32. Treatment Although there is no cure, there is treatment that can help the patient manage some of the symptoms of Meniere's disease.  Medications for vertigo = motion sickness Diuretics to decrease fluid retention Dietary changes to decrease salt intake Middle ear injections - some middle ear injections may improve symptoms of vertigo Endolymphatic sac decompression - a small portion of bone is removed from the endolymphatic sac. A shunt is placed from the inner ear.

33. Disorders of the ear Tinnitus What is tinnitus? Tinnitus is a symptom, not a disorder. 3.04 Understand the functions and disorders of the sensory system

34. Tinnitus is the perception of sound within the ear in the absence of external sound. Tinnitus is not a disease, but a condition that results from a wide range of underlying causes: neurological damage (multiple sclerosis), ear infections, foreign objects in the ear, nasal allergies, wax build-up and exposure to loud sounds. In-ear earphones, whose sound enters directly into the ear canal without any opportunity to be deflected or absorbed elsewhere, are a common cause of tinnitus when volume is set beyond moderate levels. 3.04 Understand the functions and disorders of the sensory system

35. Disorders of the ear What is the difference between conductive hearing loss and sensory hearing loss? How can they be treated? Presbycusis What is presbycusis? Who is most likely to develop presbycusis? 3.04 Understand the functions and disorders of the sensory system

36. Presbycusis “presbycusis”, is the slow loss of hearing that occurs as people get older. Tiny hairs inside your ear help you hear. They pick up sound waves and change them into the nerve signals that the brain interprets as sound. Hearing loss occurs when the tiny hairs inside the ear are damaged or die - hair cells do not regrow. 3.04 Understand the functions and disorders of the sensory system

37. Hearing loss can be divided into two basic types: • Conductive hearing loss is caused by anything that interferes with the transmission of sound from the outer to the inner ear. • Sensory hearing loss is due to damage to the pathway that sound impulses take from the hair cells of the inner ear to the auditory nerve and the brain. 3.04 Understand the functions and disorders of the sensory system

38. Testing for hearing loss Rinne test Weber test Compare these two tests. How are they diagnostic? 3.04 Understand the functions and disorders of the sensory system

39. Hearing Test Both the Rinne and the Weber tests use metal tuning forks to provide a rough assessment of a patient's hearing. A tuning fork is a metal instrument with a handle and two prongs, or tines. Tuning forks will vibrate at a set frequency to produce a musical tone when struck. The vibrations produced can be used to assess a person's ability to hear different sound frequencies. 3.04 Understand the functions and disorders of the sensory system

40. Rhine Test Weber Test Weber tuning fork test helps determine a patient's hearing ability by bone conduction, using a vibrating tuning fork that is held at various points along the midline of the skull and face. It is useful when hearing loss is asymmetrical. •  In the Rinne test, the vibrating tuning fork is held against the skull, usually on the bone behind the ear (mastoid process) to cause vibrations through the bones of the skull and inner ear. It is also held next to, but not touching, the ear, to cause vibrations in the air next to the ear. The patient is asked to determine which sound is louder, the sound heard through the bone or through the air.

41. 3.04 Functions and disorders of the ear The End 3.04 Understand the functions and disorders of the sensory system