Oral Region, Nose, Paranasal Sinuses, and Ear

Question 1

What is included in the oral region?

Answer 1

• oral cavity
• teeth
• gingivae (gums)
• tongue
• palate
• region of the palatine tonsils

Question 2

What does the mouth consist of?

Answer 2

• oral vestibule
• oral cavity proper

Question 3

• What is the space between the teeth and lips/cheeks?
• What is the space internal to the teeth and gums?

Answer 3

• oral vestibule
• oral cavity proper

Question 4

• What does the palate form?
• What consists of the anterior (concave) two thirds of the palate?
• What consists of the posterior third of the palate?

Answer 4

• the floor of the nasal cavity, the roof of the oral cavity
• hard palate
• soft palate

Question 5

• What is the hard palate filled with?
• What is the hard palate formed by?
• What is the hard palate covered by?

Answer 5

• filled w/ tongue when it is at rest
• formed by: palatine processes of maxillae, horizontal plates of palatine bones
• covered by thick mucosa that overlies numerous mucus-secreting palatal glands

Question 6

• What is the soft palate composed of?
• What do the muscles of the soft palate do?

Answer 6

• mucosa, mucosa-secreting palatal glands, 5 muscles contributing to its movements
• the muscles close of the nasopharynx when during swallowing

Question 7

• What palate is filled with the tongue at rest?
• Which palate is important when we eat/swallow food?

Answer 7

• hard palate
• soft palate

Question 8

• What are the 2 different bones that form the hard palate?
• What helps with airflow in the palate?
• What can be a big problem with sleep apnea due to it becoming enlarged and making it difficult to breathe while sleeping?

Answer 8

• palatine process of the maxilla (paired); palatine bone (paired)
• choana
• uvula

Question 9

What allows for the connection between the ear and the oral cavity?

Answer 9

eustachian tube

Question 10

What are the muscles of the soft palate and what are they innervated by?

Answer 10

• tensor veli palatini: CN V3 (n. to medial pterygoid via otic ganglion)
• levator veli palatini: CN X (pharyngeal branch)
• palatoglossus: CN X (pharyngeal branch)
• palatopharyngeus: CN X (pharyngeal branch)
• musculus uvulae: CN X (pharyngeal branch)

Question 11

What opens the auditory/eustachian tube when swallowing?

Answer 11

tensor veli palatini

Question 12

What is the function of the tensor veli palatini?

Answer 12

• tenses soft palate
• opens mouth of pharyngotympanic(eustachian) tube during swallowing and yawning

Question 13

What is the function of the levator veli palatini?

Answer 13

elevates soft palate during swallowing and yawning

Question 14

What is the function of the palatoglossus muscle?

Answer 14

• elevates posterior part of tongue
• draws soft palate onto tongue

Question 15

What is the function of the palatopharyngeus muscle?

Answer 15

• tenses soft palate
• pulls walls of pharynx superiorly, anteriorly, and medially during swallowing

Question 16

What is the function of the musculus uvulae?

Answer 16

• shortens uvula
• pulls uvula superiorly

Question 17

• What are masses of lymphoid tissue?
• Where are these located?
• Each (…) lies in a (…) bounded by the palatoglossal and palatopharyngeal arches of the tongue

Answer 17

• palatine tonsils (“the tonsils”)
• one on each side of the oropharynx
• tonsil; tonsillar sinus

Question 18

What is the tonsillar sinus bounded by?

Answer 18

palatoglossal and palatopharyngeal arches and the tongue

Question 19

• What supplies blood to the palate?
• What is the sensory innervation of the hard palate?
• What is the sensory innervation of the soft palate?

Answer 19

• greater palatine arteries (br. of descending palatine arteries)
• nasopalatine and greater palatine nn (CN V2)
• lesser palatine nerves (CN V2)

Question 20

• What is a strong, muscular organ (one of the strongest muscles in the body)?
• What does this muscle consist of?
• What are ^ innervated by?

Answer 20

• tongue
• intrinsic skeletal mm arranged in 4 different planes
• hypoglossal nerve (CN XII)

Question 21

The tongue consists of intrinsic skeletal muscles arranged in 4 different planes, what are they?

Answer 21

• superior longitudinal muscle fibers
• inferior longitudinal muscle fibers
• transverse muscle fibers
• vertical muscle fibers

Question 22

• What is the function of the intrinsic tongue muscles?
• What are they innervated by?

Answer 22

• change the shape of the tongue?
• hypoglossal n (CN XII)

Question 23

What are the different extrinsic tongue muscles and what are they innervated by?

Answer 23

• genioglossus: CN XII
• hyoglossus: CN XII
• styloglossus: CN XII
• palatoglossus: CN X + pharyngeal plexus

Question 24

• What is the function of the extrinsic tongue muscles?
• All extrinsic tongue muscles are innervated by (…) except for (…) which is innervated by (…)

Answer 24

• change the position of the tongue
• CN XII, except for palatoglossal m which is innervated by CN X

Question 25

- What is the function of the genioglossus muscle? - What is the function of the palatoglossus muscle?

Answer 25

- depresses/protrudes tongue - elevates posterior tongue/depresses palate

Question 26

What muscles retract the tongue during swallowing, pushing the bolus of food up against the palate as it is pushed posteriorly into the oropharynx ?

Answer 26

- hyoglossus m - styloglossus m

Question 27

What muscle can be considered both a muscle of the tongue and a muscle of the palate because it is innervated by the CN X rather than CN XII?

Answer 27

palatoglossus muscle

Question 28

- What is the function of the hyoglossus muscle? - What is the function of the styloglossus muscle?

Answer 28

- depresses/retracts tongue - retracts tongue/draws it up for swallowing

Question 29

How can you test the function of the hypoglossal nerve (CN XII)?

Answer 29

have pt protrude and laterally deviate their tongue

Question 30

- The surface of the tongue is characterized by small (...) which is divided into four types. - What are the four types?

Answer 30

- lingual papillae four parts: - filiform - fungiform - circumvallate - foliate

Question 31

- What are the numerous slender projections that lack taste buds that give the tongue its rough or furry feel (has mechanical function)? - What are large mushroom-shaped papillae scattered on the dorsum of the tongue's surface that possess taste buds and are difficult to see grossly?

Answer 31

- filiform - fungiform

Question 32

- What are larger papillae that lie in a row just anterior to the sulcus terminalis and possess taste buds? - What lie along the sides of the tongue and are rudimentary in humans and possess taste buds?

Answer 32

- circumvallate - foliate

Question 33

- Taste buds contain (...) - They are primarily located on the (...) of the tongue - They are also more sparsely scattered in the (...)

Answer 33

- taste receptor cells - dorsum of the tongue - epiglottis, palate, pharynx

Question 34

The papillae of the tongue have what functions?

Answer 34

- taste (taste buds) - mechanical function

Question 35

- What part of the tongue is considered the pharyngeal tongue? - What part of the tongue is considered the oral tongue? - Where are there more tastebuds?

Answer 35

- posterior 1/3 - anterior 2/3 - Anterior tongue

Question 36

- What provides taste (special sense) innervation to the anterior 2/3 of the tongue? - What provides general somatic (touch, pressure, temperature) sensation to the anterior 2/3 of the tongue?

Answer 36

- chorda tympani n (facial n) - lingual nerve (mandibular n - CN V3)

Question 37

- What provides taste (special sense) sensation to the posterior 1/3 of the tongue? - What provides general somatic (touch, pressure, temperature) to the posterior 1/3 of the tongue?

Answer 37

- glossopharyngeal n (CN IX) - glossopharyngeal n (CN IX)

Question 38

What plays a minor role in taste as it helps innervate the epiglottis?

Answer 38

vagus n (CN X)

Question 39

- What are the motor nerves of the tongue? - What do they innervate?

Answer 39

- vagus n (CN X) - palatoglossus n - hypoglossal n (CN XII) - all other mm of the tongue

Question 40

- What are the sensory nerves of the tongue? - What sensation do they provide?

Answer 40

- internal laryngeal n (CN X) - taste - glossopharyngeal n (CN IX) - general and special senses - lingual n (CN V) - general sensory - chorda tympani (CN VII) - special sensory

Question 41

- What are hard, conical structures set in the dental alveoli of the upper and lower jaws that are used in mastication and assisting in articulation of speech? - How many do children have?

Answer 41

- the teeth - 20 pimary teeth

Question 42

- When does the first tooth in children usually erupt? - The last tooth?

Answer 42

- 6-8 months - 20-24 months

Question 43

Eruption of the permanent (secondary) teeth, normally (...) in each jaw (3 molars, 2 premolars, 1 canine, and 2 incisors on each side), usually is complete by the (...), except for the third molars (wisdom teeth), which usually erupt during the (...)

Answer 43

- 16 - midteens - late teens or early 20s

Question 44

- What supplies blood to the maxillary (upper) and mandibular (lower) teeth? - What vein(s) drain this region and into what? - What innervates the maxillary and mandibular teeth?

Answer 44

- superior and inferior alveolar arteries (br. of maxillary artery) - superior and inferior alveolar veins; drain into pterygoid venous plexus - superior and inferior alveolar nn (br. of CN V2 and CN V3) which form superior and inferior dental plexuses

Question 45

The (...) are composed of fibrous tissue covered with mucous membrane, which is firmly attached to the alveolar processes of the mandible and maxilla and the necks of the teeth

Answer 45

gingivae (gums)

Question 46

- The buccal gingivae of the mandibular molar teeth are supplied by the (...) - The lingual gingivae of all mandibular teeth are supplied by the (...). - The palatine gingivae of the maxillary premolar and molar teeth are supplied by the (...) and the palatine gingivae of the incisors by the (...). - The labial and buccal aspects of the maxillary gingivae are supplied by the (...)

Answer 46

- buccal nerve (br. of CN V3) - lingual nerve - greater palatine nerve - nasopalatine nerve - anterior, middle, and posterior superior alveolar nerves

Question 47

- What are air-filled extensions of the respiratory part of the nasal cavity into cranial bones (and are names in according to the bones they are located in)? - What cranial bones do these extend into?

Answer 47

- paranasal sinuses - frontal, ethmoid, sphenoid, and maxilla

Question 48

What are the functions of the paranasal sinuses?

Answer 48

- lighten weight of the facial skeleton - warming air - humidifying inspired air - add resonance to the voice - drain mucus secretions into the nasal cavities

Question 49

What helps drain paranasal sinuses of mucus?

Answer 49

- sneezing - blowing nose - gravity - action of epithelial cilia

Question 50

The (...) surround the nose and orbits and are lined with respiratory epithelium (pseudostratified columnar epithelium with cilia)

Answer 50

paranasal sinuses

Question 51

- What provides sensory innervation to the frontal sinus? - What provides sensory innervation to the ethmoid sinus? - What provides sensory innervation to the sphenoid sinus? - What provides sensory innervation to the maxillary sinus?

Answer 51

- CN V1 - CN V1 and CN V2 - CN V2 - CN V2

Question 52

What is the blood supply to the sinuses? - frontal sinus - ethmoid sinus - sphenoid sinus - maxillary sinus

Answer 52

- anterior ethmoidal aa - ethmoidal aa - pharyngeal aa - infraorbital and alveolar aa

Question 53

What is the drainage of the frontal sinus?

Answer 53

frontal sinus drains via the frontonasal duct into the semilunaris hiatus

Question 54

What is the drainage of the ethmoid sinus?

Answer 54

- anterior ethmoid drains into semilunaris hiatus - middle ethmoid drains into ethmoid bulla - posterior ethmoid drains into superior meatus

Question 55

What is the drainage of the sphenoid sinus?

Answer 55

sphenoid sinus drains into sphenoethmoidal recess above superior concha

Question 56

What is the drainage of the maxillary sinus?

Answer 56

maxillary sinus drains into semilunar hiatus

Question 57

Which sinuses empty into the semilunaris hiatus?

Answer 57

- frontal - ethmoid - maxillary

Question 58

What drains tears into the inferior meatus, which is located beneath the inferior concha; thus your nose “runs” when you cry?

Answer 58

nasolacrimal duct

Question 59

- What does the nasal region include? - What happens in this region? - What does the nasal cavity contain and what are they responsible for?

Answer 59

- nose, nasal cavity, paranasal sinuses - air is filtered, humidified, and warmed before entering respiratory tract - specialized olfactory mucosa responsible for the sense of smell

Question 60

- What portion of the external nose is bony and is composed of paired nasal bones and the frontal processes of the maxillae? - What portion of the external nose is cartilaginous and is formed by the major and minor alar cartilages and a variable number of accessory cartilages (and vomer)?

Answer 60

- superior portion - inferior portion

Question 61

- What does the nasal cavity extend from? - What are the walls of the nasal cavity covered with? - What is involved in the sense of smell, is present on the superior part of the nasal septum and superior conchae?

Answer 61

- the vestibule of the nose to the choanae - respiratory epithelium - olfactory epithelium

Question 62

- What does the dorsum of the nose extend from? - What part of the nose is pierced by two piriform openings and the nares (nostrils, anterior nasal apertures)?

Answer 62

- its superior angle, the root of the nose, to the apex of the nose - inferior surface of the nose

Question 63

What are the nares bounded by laterally and separated by?

Answer 63

- laterally bound by the alae (wings) of the nose - separated from each other by the nasal septum

Question 64

- The cartilaginous part of the nose consists of how many cartilages? - What are they? - Which cartilages are free and movable? What do they do?

Answer 64

- 5 main cartilages - 2 lateral cartilages, 2 alar cartilages, and a septal cartilage - U-shaped alar cartilages; they dilate/constrict the nares when the muscles acting on the nose contract

Question 65

What are the boundaries of the nasal cavity? (roof, floor, anterior, posterior)

Answer 65

- roof: cribriform plate - floor: hard palate (maxilla, palatine bones) - anterior: nasal bone, nasal cartilage - posterior: choana (opening to nasopharynx)

Question 66

The floor of the nasal cavity is the (...) of the mouth

Answer 66

roof

Question 67

- What does the nasal cavity open posteriorly into and through? - What is firmly bound to the periosteum and perichondrium of the supporting bones and cartilages of the nose? - The inferior two thirds of the nasal mucosa is the (...) area, and the superior one thirds is the (...) area

Answer 67

- posteriorly into the nasopharynx through the choanae - nasal mucosa - respiratory area; olfactory area

Question 68

The olfactory area is specialized mucosa containing the (...); sniffing draws air to the area. The central processes of the olfactory receptor neurons in the olfactory epithelium unite to form nerve bundles that pass through the (...) collectively constituting the (...) and enter the (...)

Answer 68

- peripheral organ of smell - cribriform plate - olfactory nerve - olfactory bulb

Question 69

The cell bodies of the (...) are located in the olfactory part of the nasal mucosa, or olfactory area, in the roof of the nasal cavity and along the nasal septum and medial wall of the superior nasal concha

Answer 69

olfactory receptor neurons

Question 70

- What causes laminar nasal airflow? - What causes turbulent nasal airflow?

Answer 70

- quiet inspiration - sniffing

Question 71

(...) is unusual for a sensory nerve in that it lack a discrete sensory ganglion.

Answer 71

CN I

Question 72

- Olfactory fibers pass through foramina in the (...) of the ethmoid bone - They enter the (...) in the anterior cranial fossa - The olfactory fibers then synapse with (...) in the olfactory bulb - The axons from these cells form the (...), which conveys the impulses to the brain - Where is the olfactory center located? - If the cribriform plate is damaged, what can this create a passage way for?

Answer 72

- cribriform plate - olfactory bulb - mitral cells - olfactory tract - temporal lobe - pathway for infection/things to spread into brain, CSF leak

Question 73

- What nerve is associated with olfaction? - What is the fiber type? - Where is its cranial exit? - Where is its lesion site? - What would be the clinical deficits/findings?

Answer 73

- olfactory n (CN I) - special sensory - cribriform plate of ethmoid bone - fracture of cribriform plate - anosmia (loss of smell), cerebrospinal rhinorrhea

Question 74

What is the halo sign associated with?

Answer 74

CSF rhinorrhea

Question 75

What is anosmia (loss of smell) associated with?

Answer 75

fracture of cribriform plate tearing olfactory nerve bundles

Question 76

What is the GSA and special sense innervation of the nasal cavity?

Answer 76

- GSA: CN V1 and CN V2 - special sense: CN I via olfactory nn through cribriform plate

Question 77

- Nerve supply of the postero-inferior half of two thirds of nasal mucosa is by (...) - The antero-superior part of the nasal mucosa is supplied by the (...)

Answer 77

- CN V2 (nasopalatine n, br. of greater palatine n) - anterior ethmoidal nerves from CN V1

Question 78

What arteries supply the medial and lateral walls of the nasal cavity?

Answer 78

- sphenopalatine a - posterior ethmoidal aa - greater palatine a - superior labial a - lateral nasal br. of facial a

Question 79

- On the anterior part of the nasal septum is an area rich in capillaries (...) where all five arteries supplying the septum anastomose. This area is often where profuse bleeding from the nose occurs - A rich plexus of veins drains deep to the nasal mucosa into the (...) veins

Answer 79

- Kiesselbach area - sphenopalatine, facial, and ophthalmic

Question 80

- The nasal cavity is supplied by blood via 3 main arteries, what are they? - What is the common site for anterior nose bleed? - What is the source of a posterior nosebleed?

Answer 80

**branches:** - maxillary a. via sphenopalatine a + br. - facial a. via superior labial a - ophthalmic a via ethmoidal aa - common site: Keisselbach's plexus - source: sphenopalatine a

Question 81

- What nasal cavity arteries come off ICA? - What about ECA?

Answer 81

- ophthalmic a - facial a., maxillary a.

Question 82

What are the 3 parts of the ear?

Answer 82

- external ear - middle ear - internal ear

Question 83

- What does the external ear consist of? - What is the middle ear (tympanic cavity) enclosed within and what does it contain? - The internal ear is what part of the ear and is contained within what?

Answer 83

- auricle, external acoustic meatus - enclosed w/in temporal bone; contains ossicles (bones of middle ear) - neurologic part of the ear; contained w/in petrous portion of the temporal bone

Question 84

What is a vestibulocochlear organ and allows for equilibrium and hearing?

Answer 84

internal ear

Question 85

What parts of the ear are mainly concerned with the transference of sound to the internal ear?

Answer 85

external and middle ear

Question 86

What part of the ear contains the organ for equilibrium as well as hearing?

Answer 86

internal ear

Question 87

- What separates the external ear from the middle ear? - What joins the middle ear to the nasopharynx?

Answer 87

- tympanic membrane (eardrum) - pharyngotympanic (auditory) tube

Question 88

What is housed mostly in the petrous portion of the temporal bone ("hard as a rock")?

Answer 88

ear compartments

Question 89

What are the 3 main portions of the temporal bone?

Answer 89

- petrous apex - internal acoustic meatus - foramen lacerum

Question 90

- What part of the ear funnels and conducts sound to the tympanic membrane? - When is a pearly grey, transparent partition separating the external and middle ear? - What should you be able to see when looking in the external ear? - What can you sometimes see in the external ear? - The canal is slightly curved so what do you have to do to the ear to be able to best view the tympanic membrane through an otoscope?

Answer 90

- external ear - tympanic membrane - umbo, malleus, and long limb of the incus - chorda tympani n - pull up on the helix to straighten it out

Question 91

- What innervates the auricle part of the ear? - What innervates the external auditory canal? - What innervates the middle ear?

Answer 91

- auriculotemporal n (CN V3), greater auricular n (C2, C3), lesser occipital n (C2, C3), some CN X and CN VII - auriculotemporal n, CN X - CN IX

Question 92

What can cause referred pain in the ear and what can it cause?

Answer 92

any tumors, infection, or inflammation along the distribution of the different nerves that innervate the ear and can cause the brain to confuse the irritant for otalgia

Question 93

Referred otalgia pathways can be from which nerves?

Answer 93

- CN V3 (mandibular n) **anterior 2/3 tongue, inferior oral cavity, palate, lower teeth, mandible (TMJ), salivary glands - CN VII **nasal mucosa, posterior ethmoid sinus, sphenoid sinus, soft palate - CN IX **posterior 1/3 tongue, tonsillar fossa, inferior nasopharyngeal space, retropharyngeal space - CN X **supraglottic larynx, lower pharynx, epiglottis

Question 94

(...) is an air-filled cavity encased by the petrous bone and communicates with the nasopharynx through the eustachian tube (pharyngotympanic tube)

Answer 94

tympanic cavity

Question 95

What are the contents of the middle ear?

Answer 95

- auditory ossicles (malleus, incus, stapes) - tendons of the stapedius m (CN VII) and tensor tympani m (CN V3) - chorda tympani n (CN VII) - tympanic plexus (CN IX) to lesser petrosal n

Question 96

- What does the chorda tympani n innervate? - What does the lesser petrosal nerve innervate?

Answer 96

- anterior 2/3 of the tongue - parotid glands

Question 97

- The (...) serve as a mechanical way to amplify the vibrations of the tympanic membrane and transmit said vibrations to the oval window which is overlaid by the base of stapes - The amplification is caused by the (...) having a much larger area than the oval window, this amplifies sound ~10-15% - The ossicles themselves amplify sound through (...) - This amplification is important as the force is moving from an (...) into a (...) - This is also known as moving from (...) impedance to (...) impedance

Answer 97

- ossicles - tympanic membrane - leverage - air cavity (tympanic cavity) - fluid cavity (vestibulocochlear organ) - low (air) to high (fluid)

Question 98

- Describe conductive hearing loss

Answer 98

- missing bones/bone damage

Question 99

- What muscles in the tympanic cavity serve to dampen loud sounds? - Which muscle pulls on the malleus thus tensing the tympanic membrane, decreasing the vibrations to the ossicles? - Which muscle pulls on the stapes, decreasing the vibrations onto the oval window?

Answer 99

- tensor tympani m, stapedius m - tensor tympani m - stapedius m

Question 100

Which muscle is not attached to the tympanic membrane directly but is attached to the malleus that pulls on the tympanic membrane?

Answer 100

tensor tympani m

Question 101

What are the different sound dampening reflex (also is anticipatory)?

Answer 101

- afferent limb (cochlear division of CN VIII) - efferent limb (CN VII to stapedius m - consensual)

Question 102

(...) causes tensor tympani m. to contract which causes (...) hearing while (...) as well as vibrations which are from (...) tensing

Answer 102

- Yawning - dampened - yawning - tensor tympani m.

Question 103

What are the eustachian tube functions? Describe each

Answer 103

**ventilation** - regulation of pressure (atmospheric vs middle ear); tensor veli palatini m opens eustachian tube, swallowing and yawning open it **protection** - E.T. closed at rest to protect secretions and sound pressure from nasopharynx **drainage** - mucociliary clearance of middle ear secretions into nasopharynx

Question 104

The inner ear consists of the (...) which is encased in the petrous portion of the temporal bone

Answer 104

vestibulocochlear organ

Question 105

- What does the vestibulocochlear organ consist of? - What innervates the inner ear? (2 division) - What does the bony labyrinth consist of?

Answer 105

- a bony labyrinth and membranous labyrinth - CN VIII (vestibular division for balance, cochlear division for hearing) - vestibule, cochlea, semicircular canals

Question 106

The bony labyrinth is filled with (...) which resembles (...) (high in Na, low in K)

Answer 106

- perilymph - extracellular fluid

Question 107

What foramen does CN VIII go through?

Answer 107

internal acoustic meatus

Question 108

- What are the different parts of the membranous labyrinth? - The membranous labyrinth is filled with (...) which resembles (...) (low in Na, high in K)

Answer 108

- saccule and utricle; cochlear duct, semicircular ducts - endolymph - intracellular fluid

Question 109

- The membranous parts of the vestibule are the (...) and the (...) and are referred as (...) organs - These otolithic structures are located in the (...) of the (...) - (...) are attached to a thick mucoidal fluid which is attached to (...) - This structures detect (...)

Answer 109

- Utricle - Saccule - otolithic - maculae - utricle and saccule - Otoliths - hair cells - linear acceleration

Question 110

- Horizontal acceleration (x axis, i.e. walking) is detected by the (...) (hair cell-otolith structure on the floor of the utricle) - (...) also detects head tilt - Vertical acceleration (y axis, i.e. jumping) is detected by the (...)(hair cell-otolith structure on the wall of saccule)

Answer 110

- utricle - utricle - saccule

Question 111

- The hair cells of the vestibule have a (...) and (...) which are located in the utricle, saccule, cochlear duct, and semicircular ducts - If the (...) bend towards the kinocilium, there will be an (...) in action potentials - If the (...) bend away from the kinocilium, there will be a (...) in action potentials - This is important because your brain uses this information to interpret (...)

Answer 111

- kinocilium - stereocilia - stereocilia - increase - stereocilia - decrease - what direction you are accelerating in (forward, backward, etc)

Question 112

- What are three loops that connect the utricle? - What type do you have? - What do these detect?

Answer 112

- semicircular canals - anterior, posterior, lateral canals - angular acceleration

Question 113

- The semicircular canals are (...) to each other, being they are at right angles to each other - What does this allow for? - (...) is in the horizontal plane (shaking head no) - (...) are in the vertical plane (nodding head yes, and tilting head)

Answer 113

- orthogonal - allows for detection of angular acceleration in 3 axes - lateral - anterior and posterior

Question 114

- Balance relies on three sensory components, what are they? - If one of these components is removes (...) is dramatically affected - Standing on one leg is not too hard but once you close your (...) it gets very hard - Vertigo happens when the (...) is affected

Answer 114

- visual input, vestibular input, somatosensory input (touch, proprioception) - eyes - vestibular input

Question 115

- (...) transmits movement of the tympanic membrane to the oval window causing (...) in the perilymph - The pressure waves come from the oval window to the (...), the waves then travel through the (...) - The waves finally reach the (...) which is inferior to the oval window, there the waves transmit their energy through the round window into the (...) where it dissipates in air

Answer 115

- stapes - hydraulic pressure waves - scala vestibuli - scala tympani - round window - tympanic cavity

Question 116

- What is situated between the scala vestibuli and scala tympani? - What is this filled with?

Answer 116

- cochlear duct - filled with endolymph

Question 117

- What is the sensory organ of the cochlear duct? - Where is it located?

Answer 117

- organ of Corti - located in basilar membrane

Question 118

When pressure waves course through the perilymph they distort the (...) where it causes hair cells attached to the tectorial membrane to bend, sending off action potentials to (...)

Answer 118

- basilar membrane - CN VIII

Question 119

- The (...) has different degrees of flexibility along the cochlear duct allowing for detection of varying frequencies/pitch along the membrane - The base the membrane is less flexible and thus (...) are able to distort the membrane here but not (...) - Towards the apex of the membrane, it is more flexible allowing (...) to cause action potentials

Answer 119

- basilar membrane - high pitch frequencies - lower pitch sounds - low pitched sounds