ear cavity

Question 1

ear

Answer 1

receptor organ for hearing and equilibrium

Question 2

what are the 3 main regions of the ear

Answer 2

1. external ear: functions in hearing, transference of sound to ear
2. middle ear: hearing, connects to nasal cavity
3. internal ear: participates in hearing and equilibrium

Question 3

describe the components of the external ear

Answer 3

-auricle: elastic cartilage: gathers and directs sound waves to external acoustic meatus
-external acoustic meatus short cannal running medially from the auricle to the tympanic membrane (eardrum) and conducting sound waves
-tympanic membrane: forms the boundary between the external ear and the middle ears. eardrum
– covered with thin skin internally and a mucous membrane of the middle ear
– moves in response to air vibrations
– movements transmit to auditory ossicles

Question 4

innervation of the ear

Answer 4

-auriculotemporal nerve V3
-small area: CN X
-internal ear: CN IX vestibulocochlear nerve

Question 5

middle ear
-describe the tympanic membrane

Answer 5

narrow, filled with air, lines by a mucous membrane
-location: petrous portion of temporal bone
-2 parts:
tympanic cavity proper: directly internal to the tympanic membrane
epitympanic recess: superior to the membrane

Question 6

middle ear:
the tympanic membrane connects with the nasopharynx by:

Answer 6

pharyngotympanic tube (anteromedially)
-and posteriorly with the mastoid antrum

Question 7

middle ear internal ear ossicles

Answer 7

-malleus, incus, and scapes

Question 8

middle ear muscles
muscles, innervation, and function

Answer 8

-dampen or resist movements of the ossicles
-strapedius: origin from the wall of ear to stapes
-tensor tympani muscle: from wall of ear and inserts to malleus and tempanic membrane
-innervation: chorda tympani nerve (branch VII) plexus

Question 9

pharyngotympanic tube

Answer 9

connects the tympanic cavity to the nasopharynx where it opens posterior to the inferior nasal meatus
-structure: posterolateral 1/3 is bony, the rest is cartilaginous, lined with a mucous membrane
-function: equalize pressure in the middle ear with atm to allow free movement of tympanic membrane

Question 10

inner ear contains

Answer 10

vestibulocochlear organ: sound reception and balance

Question 11

vestibulocochlear nerve

Answer 11

-passes through the internal acoustic meatus and divides near the lateral end of the meatus
-cochlear nerve: hearing
-vestibular nerve: equilibrium

Question 12

sound transmission
1. sound waves enter through the

Answer 12

external ear and vibrate the tympanic membrane

Question 13

sound transmission
2. vibrations are transmitted through

Answer 13

ossicles of the middle ear

Question 14

sound transmission
3. base of stapes:

Answer 14

vibrates in the oral window (between stapes and cochlea), which transmits amplified energy to the fluids of the cochlea

Question 15

sound transmision
4. vibration from the stapes are transmitted through:

Answer 15

the perilymph chamber to the cochlear duct where the hair cells of the cochlear nerve are transmitted

Question 16

sound transmission
5. vibrations are dissipated back:

Answer 16

into the middle ear cavity at the round window, releasing their remaining energy into the air of the tympanic cavity

Question 17

ear innervation
-motor

Answer 17

-Trigeminal V3: tensor tympani muscle
-facial nerve VII: skin stapedius muscle

Question 18

ear innervation
general sensory:

Answer 18

-trigeminal V3: skin of external ear
-facial nerve VII: skin of external ear
-glossopharyngeal nerve IX: mucosa of the tympanic cavity, pharyngotympanic tube, and internal surface of tympanic membrane
-vagus nerve X: skin posterior to the ear and external acoustic meatus

Question 19

ear innervation
-special sense

Answer 19

-vestibulocochlear nerve VIII: hearing and equilibrium

Question 20

vertebral arteries
supply:
branches:
origin:
converge:

Answer 20

-supply: posterior brain
-branches: subclavian artery
-origin: arch of aorta
converge: basilar artery (base of brain), and posterior cerebral artery (posterior cerebrum)

Question 21

arteries of head and neck
most common:
end and divides:

Answer 21

common carotid arteries
ends and divides: branch under the maxilla

Question 22

branches of common carotid artery

Answer 22

-external carotid artery: supply most structures external to the cranium by sending multiple branches to target organs
internal carotid artery: no branches in the neck, supply the orbits and most of the brain- front

Question 23

internal carotid artery

Answer 23

-paired arterial branches of the common carotid artery
-supplies: orbits and most of the cerebrum
-anterior cerebral arteries
-middle cerebral arteries
-opthalmic arteries

Question 24

external carotid artery branches

Answer 24

-superior thyroid
-lingual
-facial
-occipital
-posterior auricular
-ascending pharyngeal
-superficial temporal
-maxillary

Question 25

external carotid artery branches maxillary branch and divisions

Answer 25

-to internal neurocranium, masticatory muscles, and nasal cavity -divisions: -lower teeth -upper teeth -superior oral cavity (middle meningeal artery): enters foramen spinosum and is on the surface of the dura mater

Question 26

carotid body and carotid sinus location and innervation

Answer 26

at the bifurcation of the common carotid artery into internal and external branches innerv: glossopharyngeal nerve CN IX

Question 27

carotid body

Answer 27

mass of tissue with chemoreceptors: that monitor oxygen and carbon dioxide levels

Question 28

carotid sinus

Answer 28

area in the wall of the artery with baroreceptors, monitor blood pressure

Question 29

1. internal jugular vein

Answer 29

drain almost all of the blood via dural sinuses, anterior face, cervical viscera, and deep muscles of the neck

Question 30

2. external jugular vein

Answer 30

drain parts of the scalp and face

Question 31

the internal and external jugular vein join before the

Answer 31

subclavian vein

Question 32

carotid sheath

Answer 32

wraps jugular vein and carotid artery -protective CT

Question 33

dural sinuses

Answer 33

drain the brain between two layers of dura mater

Question 34

what are the two layers of dura mater

Answer 34

-periosteal: closest to bone -meningeal: brain

Question 35

blood drains to what part of the vein: exit:

Answer 35

posterior brain exit: internal jugular vein at jugular foramen

Question 36

covernus sinus

Answer 36

lateral to sella turcica, receives blood from opthalmic veins -innervatin: internal carotid, carotid plexus, III, IV, V1, V2 and VI

Question 37

cranial meninges

Answer 37

protect brain, form arteries, vains, and sinuses, enclose subarachnoid space with CSF 1. dura mater 2. arachnoid mater 3. pia mater 4

Question 38

extradural hemmorage:

Answer 38

blood torn from branches of middle meningal artery, on the outside of dura mater

Question 39

dura border hematoma:

Answer 39

breakage of vein, creates a space at dura-arachnoid junction, results from a blow to head

Question 40

subarachnoid hemmorage:

Answer 40

breakage of vein, into the subarachnoid space -results from a ruptured aneurysm and head trauma