Sinus, Nasal, Ear, Orbit

Question 1

what are the 3 external nasal muscles?

Answer 1

• procerus
• nasalis - 2 parts
• levator labii superioris alaeque nasi
• all innervated by facial n.
• supplied by facial a. and ophthalmic a.

Question 2

what are all of the components of the external nose?

Answer 2

• nasal bones
• lateral cartilage
• septal cartilage
• alar cartilage
• fibroareolar tissue
• external nares

Question 3

what features make up the lateral walls of the nasal cavity?

Answer 3

• superior, middle, and inferior nasal conchae
• superior, middle, and inferior nasal meatuses

Question 4

major sources of blood for the lateral nasal cavity

Answer 4

• ICA
  
  • ophthalmic a.
    
    • ethmoidal aa.
• ECA
  
  • facial a.
  • maxillary a.
    
    • sphenopalatine
      
      • lateral posterior nasal aa.

Question 5

major sources of blood for the nasal septum

Answer 5

• ICA
  
  • ophthalmic – ethmoidal arteries – anterior septal branches
• ECA
  
  • maxillary – sphenopalatine – posterior septal branches
  • facial – septal branch of superior labial artery

Question 6

innervation of the nasal cavity

Answer 6

• V-1 – anterior nasal septum and cavity
  
  • Anterior ethmoidal nerve
• V-2 – rest of the nasal septum and cavity
  
  • Sphenopalatine branch of V-2 via the sphenopalatine foramen
• CN I

Question 7

how does the nasal cavity communicate with the paranasal sinuses?

Answer 7

• opening of nasolacrimal duct
  
  • extends down into nasal cavity

Question 8

what are the paranasal sinuses?

Answer 8

• hollow chambers named for bones in which they reside
  
  • frontal sinus
  • ethmoid sinus (air cells)
  • maxillary sinus
  • sphenoid sinus

Question 9

how are the paranasal sinuses connected?

Answer 9

• frontal sinus - yellow
• maxillary sinus - orange
• ethmoid air cells - red and green
• semilunar hiatus - purple arrow
• maxillary hiatus (ostium) - blue circle
• they all drain into the nasal cavity

Question 10

how many drainage points are there in the paranasal sinuses?

Answer 10

5 sites of drainage

• drainage of the sinuses
  
  • maxillary hiatus
  • semilunar hiatus
  • sphenothemoidal recess
• drainage of the orbit
  
  • lacrimal duct
• drainage of the ear
  
  • pharyngeal orifice of pharyngotympanic tube

Question 11

describe innervation of the external surface of the ear

Answer 11

• helix
  
  • lesser occipital n. (C2)
• external auditory meatus
  
  • auriculotemporal branch of the mandibular n. (V3)
• tragus
  
  • auriculotemporal branch of the mandibular n. (V3) and great auricular n. (C2, C3)
• lobule
  
  • great auricular n. (C2, C3)

Question 12

describe sensory innervation of the tympanic membrane

Answer 12

• CN V3
• X (outer)
• IX (inner)

Question 13

which 2 palate muscles can be used to help clear the ears?

Answer 13

tensor veli palatini and levator veli palatini

Question 14

describe innervation and blood supply of the middle ear - tympanic cavity

Answer 14

• CN IX
• CN VII
• branches of maxillary artery

Question 15

what do ossicles do in the middle ear?

Answer 15

transform vibrations in the air (external) to waves in fluid (internal)

Question 16

describe the 3 bones of the middle ear

Answer 16

• malleus
  
  • on tympanic membrane
• incus
  
  • middle bone
• stapes
  
  • pushes on the oval window
• causes pressure gradients inside the ear to create sound

Question 17

describe the internal ear

Answer 17

• cochlea
• semicircular canals
• innervated by CN VIII

Question 18

describe the external ear muscles, what innervates them, and what arteries supply them

Answer 18

• auricularis anterior
• auricularis superior
• auricularis posterior
• innervated by CN VII
• supplied by p. auricular and superficial temporal aa.

Question 19

what muscle closes the eyelid? and what nerve innervates it?

Answer 19

• orbicularis oculi m.
• CN VII

Question 20

what muscles elevate the eyelid? what is the innervation?

Answer 20

• levator palpebrae superioris m.
  
  • CN III
• superior tarsal m.
  
  • sympathetics from T1 spinal cord

Question 21

describe sympathetics to the superior tarsal m.

Answer 21

• preganglionic - T1
• postganglionic - superior cervical ganglia
• follow ICA toward targets

Question 22

describe the function, drainage, innervation, and vasculature of the lacrimal apparatus

Answer 22

• function
  
  • production of tears via lacrimal gland
• drainage
  
  • medial into lacrimal sac and then nasolacrimal duct
• innervation
  
  • greater petrosal - parasympathetic input that causes tears to be produced
  • V1 is strictly sensory
• vasculature
  
  • ophthalmic a.

Question 23

describe the layers of the eyeball

Answer 23

• sclera/cornea
  
  • cornea - V1 sensory; functions to refract incoming light
• choroid layer
  
  • ciliary m. - suspensory ligaments and lens
    
    • parasympathetic innervation (CN III)
  • iris
    
    • sphincter pupillae m. VM CN III
• retina - CN II; somatic sensory - sight
  
  • fovea centralis

Question 24

light traveling from a point very close needs ___ refraction to focus on retina.

light traveling from a distance needs ___ refraction to focus on retina.

Answer 24

• more
• less

Question 25

describe innervation of the ciliary m. and sphincter pupillae

Answer 25

* CN III visceral motor parasympathetic * arises from accessory oculomotor nucleus, synapses at ciliary ganglion, then travels to targets

Question 26

describe innervation of the dilator pupillae muscles and superior tarsal muscles

Answer 26

sympathetic

Question 27

what resutls when sympathetics to the head is interrupted?

Answer 27

Horner's syndrome * ptosis - droopy eyelid * anhydrosis - decreased sweating * miosis - constricted pupil PAM has Horn's

Question 28

describe the pupillary reflex

Answer 28

* consensual reflex * bilateral contraction of sphincter pupillae muscles * CN II - input; synpase at olivary pretectal nucleus * CN III - output; synapse at ciliary ganglion and heads to targets

Question 29

what is the primary action, secondary action, and innervation of the lateral rectus muscle?

Answer 29

* primary action: abduction * secondary action: none * innervation: CN VI

Question 30

what is the primary action, secondary action, and innervation of the medial rectus muscle?

Answer 30

* primary action: adduction * secondary action: none * innervation: CN III, inferior branch

Question 31

what is the primary action, secondary action, and innervation of the superior rectus muscle?

Answer 31

* primary action: elevation * secondary action: adduction and medial rotation * innervation: CN III, superior branch

Question 32

what is the primary action, secondary action, and innervation of the inferior rectus muscle?

Answer 32

* primary action: depression * secondary action: adduction and lateral rotation * innervation: CN III, inferior branch

Question 33

what is the primary action, secondary action, and innervation of the superior oblique muscle?

Answer 33

* primary action: depression and abduction * secondary action: medial rotation * innervation: CN IV

Question 34

what is the primary action, secondary action, and innervation of the inferior oblique muscle?

Answer 34

* primary action: elevation and abduction * secondary action: lateral rotation * innervation: CN III, inferior branch

Question 35

describe vasculature of the orbit

Answer 35

* ICA * ophthalmic a. - enters orbit via optic foramen * central artery of the retina

Question 36

name the 3 superficial orbit muscles, their innervation, and blood supply

Answer 36

* orbicularis oculi * corrugator supercilii * depressor supercilii * CN VII * facial and ophthalmic aa.