Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
32 Cards in this Set
- Front
- Back
|
1. How does the temporal bone relate to the facial nerve?
|
It transmits if from the cranial cavity to its extracranial distribution
Serves as site of origin of a number of important facial nerve brances |
|
|
2. What are the three major parts of the temporal bone?
|
1. Petrous
-anteromedially directed prism-shaped portion of temporal bone 2. Tympanic 3. Squamous |
|
|
3. What are the three major surfaces of the petrous part?
|
1. Anterior
-forms the posterior part of the lateral portion of the middle cranial fossa 2. Posterior -contain internal acoustic meatus 3. Inferior -forms apex of mastoid process |
|
|
4. What is near the apical end of the anterior face of the petrous pyramid?
What is lateral to this impression? What seperates the anterior and posterior faces? |
Impression for the trigeminal ganglion
Foramen called the hiatus for the greater petrosal nerve Superior petrosal margin **marked by a sulcus for the superior petrosla dural venous sinus |
|
|
5. What does the internal acoustic meatus contain?
What is the stylomastoid foramen? |
Transmits facial and vestibulocochlear nerves and labyrinthine artery into temporal bone
External opening of the facial nerve canal |
|
|
6. Where is the carotid canal?
What will this transmit? |
Anterior to the jugular foramen
Internal carotid artery and its pericarotid sympathetic plexus superiorly and then anteromedially toward petrous apex **from here they ascend into cavernous sinus |
|
|
7. What transmits the tympanic branch of the glossopharyngeal nerve into the middle ear (tympanic) cavity?
|
Small aperture on the plate of bone that separates the jugular foramen posteriorly from the carotid canal anteriorly
|
|
|
8. What does the tympanic part of the temporal bone form?
What forms the flat lateral portion of the external acoustic meatus? What does this help to form internally? |
Anterior wall, floor, and part of the posterior wall of the external acoustic meatus
Squamous part of the temporal bone Lateral part of middle cranial fossa |
|
|
9. What is the external ear composed of?
|
1. Laterally projecting sound collecting auricle (pinna)
2. Sound transmitting external acoustic meatus |
|
|
10. Where does the deeper portion of the external meatus end?
Which walls are the longest? Which part of the tympanic membrane is farthest removed from the surface? |
Medially at the obliquely placed tympanic membrane
Inferior and anterior walls (b/c tympanic membrane slopes medially superiorly to inferiorly and posteriorly to anteriorly) Anteroinferior part |
|
|
11. What is the sensory innervation of the anterior wall of external acoustic meatus and the anterior part of the external surface of the tympanic membrane?
What is the sensory innervation of the posterior wall of external meatus, posterior part of the outside of the tympanic membrane, deeper part of auricle and skin over mastoid process? Where does this nerve arise from and run? |
Auriculotemporal branch of mandibular V
Auricular branch of the vagus nerve Arises from vagus as it exits jugular foramen Rune laterally through temperoal bone to emerge just posterior to the external meatus **Picks up some fibers of facial and glossopharyngeal nerves |
|
|
12. What does the sound conducting ossicular apparatus of the middle ear contain?
|
1. Malleus
2. Incus 3. Stapes 4. Their articulations 5. Tensory tympani muscle 6. Stapedius muscle |
|
|
13. What does the middle ear communicate w/?
|
Anteromedially through auditory tube w/ nasopharynx
Posterolaterally w/ mastoid antrum and its budded-off mastoid air cells |
|
|
14. What is the lateral or tympanic walls of the middle ear formed by?
What attaches to the lateral wall? |
Tympanic membrane
1. Circumference -> inner end of bony external acoustic meatus and its central apex (umbo) 2. Inner aspect -> malleus |
|
|
15. What do the lateral process and anterior process of the malleus serve as?
What is the manubrium of the malleus attached to? What extends from the lateral process of the malleus? |
Axis of rotation of the malleus
Inner surface of tympaic membrane Anterior and posterior mallear folds that divide into small upper pars flaccida and a larger lower pars tensa |
|
|
16. Where is the thin roof of the tympanic cavity?
As a result of this positioning what can middle ear infections (otitis media) produce? Where is the floor or jugular wall of the middle ear cavity? |
Above the middle cranial fossa
Middle cranial fossa or temporal lobe abscess Below to the bulbous upper end of the internal jugular vein w/in the jugular foramen |
|
|
17. What is another name for the posterior wall of the middle ear cavity and why?
How is the inside of the mastoid process in appearance? |
Mastoid wall b/c its above where the tympanic cavity communicates w/ the mastoid antrum (air-filled space of mastoid process)
Honeycomb b/c many small mastoid air cells bud off the mastoid antrum **middle ear infection can easily spread into the mastoid air cells to cause mastoiditis |
|
|
18. What does the lower part of the posterior wall of the middle ear cavity contain?
Where does the chorda tympani enter the middle ear cavity? |
Descending portion of the facial canal w/ its contained facial nerve
Through the lower part of its posterior wall |
|
|
19. What forms the lower portion of the anterior or carotid wall of the tympanic cavity?
How is the upper and lower end of the auditory tube? What muscle has part of its origin from the lateral wall of the auditory tube? |
Carotid canal
Upper tympanic end of auditory tube is bony Lower nasopharyngeal end is cartilaginous Tensor veli palatini muscle |
|
|
20. How is the auditory tube functionally?
What does opening the tube allow for? What happens if this mechanism is impeded by swollen mucosa due to pharyngeal or middle ear inflammatory process? |
Closed
**open by contracting tensor veli palatini muscle (as in swallowing) Allow the pressure in them middle ear cavity to be equilibrated to the external atmospheric pressure Prevent pressure equalization producing middle ear pain when atmospheric pressure increases or decreases |
|
|
21. What is the origin of the tensor tympani muscle?
Insertion? Innervation? Function? |
O: aperture at tympanic end of auditory canal
**course is lateral across tympanic membrane I: Upper end of manubrium of malleus IN: mandibular division of trigeminal nerve (exits foramen ovale) F: medial pull on manubrium and the attached tympanic membrane **dampen osscilations of malleus when there is high intensity sounds |
|
|
22. What forms the medial or labyrinthine wall of the tympanic cavity?
What is high on this wall? What is below this? |
Outer aspects of bony internal ear
1. High on wall -> prominence of lateral semicricular canal 2. Prominence of the facial canal 3. Vestibular (oval) window 4. Promontory (rounded protuberance) 5. Cochlear (round) window |
|
|
23. What does the vestibular (oval) window articulate with?
What does the secondary typmainc (round window) membrane do? |
Articulates w/ stapes footplate and communicated w/ bony vestibule
Membrane closes cochlear window and communicated w/ basal turn of cochlea **also permits pressure waves (produced in inner ear) to be dissipated back into typmanic cavity |
|
|
24. What is the base or footplate of the stapes attached to?
What does the incus do? What is it attached to? |
Vestibular window by annular ligament
Connects the malleus to the stapes 1. Body articulates w/ head of malleus -> synovial incudomallear joint 2. Short process attaches to floor of opening into mastoid antrum 3. Long process articulates w/ head of stapes -> synovial incudostapedial joint |
|
|
25. Where is the stapedius muscle?
What is the course of this muscle? Where does it insert (attach)? What innervates it? |
In a tiny bony prominence w/in the bend which the facial canal makes
Runs forward I: posterior aspect of head stapes IN: branch of facial nerve |
|
|
26. What is the function of the stapedius muscle?
What nerve limbs does this stapedial reflex have? |
Contracts: damps movements of anterior part of stapes footplate into inner ear
Contraction is reflex response to loud sounds detected by the cochlea **protect sensitive inner ear hair cells from mechanical damage from high intensity sound VIII nerve afferent limb and VII nerve efferent limb |
|
|
27. What is hyperacusis?
|
When patient complains that moderate intensity sounds (which others find tolerable) are irritating
Facial nerve injury proximal to its stapedial branch |
|
|
28. What is conductive deafness?
|
Type of deafness caused by a diminished ability of the ossicles to conduct sounds from the tympanic membrane to the internal ear
Can also be caused by diseases which damp the ossicular movement |
|
|
29. From where does the chorda tympani arise?
What is its course? |
From the facial nerve in the lower part of its descending course (not far above the stylomastoid foramen)
1. Enters tympanic cavity through posterior wall 2. Pass anteriorly bwt neck of malleus laterally and long process of incus medially 3. Reach petrotympanic fissure where exist anterior wall |
|
|
30. How can the chorda tympani nerve be damaged?
What happens as a result of nerve damage? |
Middle ear disease or during ear surgery
1. Loss of taste to anterior 2/3 of tongue 2. Loss of parasympathetic secretomotor innervation to submandibular and sublingual salivary glands |
|
|
31. What is the sensory innervation of the mucosa of the middle ear cavity, mastoid air cells, and upper auditory tube?
Where does this nerve arise from? What is its course? |
Tympanic branch of glossopharyngeal nerve
Arise for CN IX as it exits the jugular foramen 1. Enters middle ear through floor 2. Ascends onto surface of promontory **provides major input to the tympanic plexus |
|
|
32. What type of fibers does the tympanic branch of IX contain?
|
Both sensory and parasympathetic preganglionic nerve fibers into tympanic plexus
Parasympathetic fibers provide secretomotor innervation to parotid gland |
