Bio 155 Quiz 3 topic 10

List the anatomical components and their functional characteristics for the outer ear

1. Auricle or Pinna:The pinna is the only visible part of the ear (the auricle) with its special helical shape. It is the first part of the ear that reacts with sound. The function of the pinna is to act as a kind of funnel which assists in directing the sound further into the ear. 2. Auditory Canal: Once the sound waves have passed the pinna, they move two to three centimetres into the auditory canal before hitting the eardrum, also known as the tympanic membrane. The function of the ear canal is to transmit sound from the pinna to the eardrum. 3. Tympanic Membrane: The tympanic membrane, or eardrum, is a thin layer of cone-shaped tissue that separates the outer ear from the middle ear. It facilitates hearing by transmitting sound vibrations from the air to the bones in the middle ear.

List the anatomical components and their functional characteristics for the middle ear

1. Malleus: receives vibrations from the tympanic membrane and transmits this to the incus 2. Incus:eceives vibrations from the malleus, to which it is connected laterally, and transmits these to the stapes, medially. 3. Stapes:The stapes transmits sound vibrations from the incus, another little bone in the middle ear, to the oval window adjacent to the inner ear 4. Tensor Tympani Muscles:role is to dampen loud sounds, such as those produced from chewing, shouting, or thunder 5. Eustachian tubes: to ventilate the middle ear space, ensuring that its pressure remains at near normal environmental air pressure. The secondary function of the Eustachian tube is to drain any accumulated secretions, infection, or debris from the middle ear space. 6. Oval Window (stapes) and Round Window:. As the stapes footplate moves into the oval window, the round window membrane moves out, and this allows movement of the fluid within the cochlea, leading to movement of the cochlear inner hair cells and thus hearing.

List the anatomical components and their functional characteristics for the inner ear

1. Osseous Labyrinth: bony canal filled with perilymph, contain membrane tubes and chambers 2. Cochlea: receives sound in the form of vibrations, which cause the stereocilia to move. The stereocilia then convert these vibrations into nerve impulses which are taken up to the brain to be interpreted. - Scala Vestibuli: a perilymph-filled cavity inside the cochlea of the inner ear that conducts sound vibrations to the cochlear duct. - Scala Tympani:is one of the perilymph-filled cavities in the inner ear of the human. It is separated from the cochlear duct by the basilar membrane, and it extends from the round window to the helicotrema, where it continues as vestibular duct. 3. Semicircular Canals: contain semicircular ducts 4. Vestibule: contains utricle and saccule 5. Membranous Labyrinth: filled with endolymph -Cochlea: * Chochlear duct: Organ of Corti (hair cells, tectorial membrane) transmits hearing signals to brain via cochlear portion of auditory nerve

Define Presbycussis. What are the two main forms and causes?

Age related hearing loss ( 3 most common chronic ailment in elderly) 1. Conduction{maybe treatable}: problems with conduction sound vibrations (fused ear bones, reputed ear drum, ear wax. These forms are easily corrected with surgery or hearing aids 2. Nerve Deafness: damage to hair cells or cochlear nerve. this damage is regarded as more permanent but cochlear implants can be used

Define the components of the osseous and membraneous labyrinths

Osseous: bony canals, filled with perilymph, contain membrane tubes and chambers - cochlea (scali vestiboli and scala tympani) - semicircular canal - vestibule Membranous: filled with endolymph - cochlea: cochlear duct; organ of corti (hair cells, tectorial membrane), transmits hearing signals to brain via cochlear potion of auditory nerve

Explain how the semicircular canals and utricle/saccule function in dynamic and static equilibrium situations

The semicircular canals are responsible for maintaining the dynamic equilibrium of the body. Dynamic equilibrium lets us know the direction in which our head is moves in three-dimensional space and also gives us information about rotation. The information about the dynamic equilibrium is detected in the semicircular canals which are attached to the vestibule. Static equilibrium helps us to detect the positioning of our head relative to gravity, that is it helps us realize which way the head is tilted. The horizontally positioned utricle and the vertically positioned saccule are the two sensory chambers present in the vestibule of the inner ear. The utricle and saccule are responsible to help maintain the static equilibrium of the body.

Explain why ear vestibular function is important to overall health

Your balance system helps you stand, walk, run, and move without falling. Your eyes, inner ear, and muscles and joints send signals to your brain. These signals help you stay balanced. This system of signals is your vestibular system.

Explain briefly, the function of the cochlea, semicircular ducts and utricle/saccule

cochlea: receives sound in the form of vibrations, which cause the stereocilia to move. The stereocilia then convert these vibrations into nerve impulses which are taken up to the brain to be interpreted. semicircular ducts: -cristi ampullaris(hair cells) -dynamic equilibrium: angular acceleration -vestibular portion of auditory nerve Utricle/saccule: - macula (hair cells) with otoliths - static equilibrium - vestibular portion of auditory nerve (motion sickness: utricle/saccule vs confliction visual signals)

Explain how the organ of court is simulated and transmits hearing signals to the brain

hairs cells vibrate according to tonal quality of sound Hair cell vibration send nerve signals to temporal lobes of brain

Define tinnitus

persistent ringing in the ears Variety of causes: -infection or tumor in CNS High blood pressure, diabetes Migranes medication Depending on cause it be cured if severe, can result in sleep disturbances, irritability and depression

Discuss the difference between conduction deafness and nerve deafness (think about anatomy and function in your answer)

risk factors for conduction: -occuoation (chronic exposure to sound noises) - smoking nerve: -middle ear effection