Orbit and nasal cavity

    Cards (36)

    • What is the function of the nose?
      filter dust entering the respiratory system
    • What is the blood supply for the nose??
      Branches from ophthalmic and maxillary arteries
      -Facial vein 
    • What is the nerve supply for the nose?
      -Olfactory nerve (CN I)
      -Ophthalmic (V1)
      Maxillary (V2)
    • What is the structure of the nose?
      • Comprised of bones and cartilage
      • Nasal bone -comprises the bridge of the bone
    • What is the structure nasal cavity?
      Lateral wall of the cavity has three projections:
      -Superior conchae
      -Middle conchae
      -Inferior conchae
    • What is the structure of the conchae??
      Superior and middle conchae arise from the ethmoid bone
      -Inferior concha is an individual bone
    • What are meatuses?
      Spaces beneath the conchae that increase the surface area and humidify inspired air
    • What is the olfaction nerve and what does it do?
      • Olfactory Nerve CNI
      • Special afferent sensory nerve
      • Arises from the cerebrum
      • Exits via cribriform plate (foramina)
    • Where are olfactory receptors found?
      • Line the epithelium in the roof and walls of the nasal cavity
      • Mucous allows gases to dissolve into the fluid which are then detected by the olfactory nerves
    • What are paranasal sinuses?
      Air filled extensions of the nasal cavity which can produce mucus
      • Used for humidification and trapping air
      • Makes skull lighter
    • Where do paranasal sinuses drain into?
      -Frontal sinuses drain through frontonasal duct into middle meatus
      -Anterior and middle ethmoidal cells drain into middle meatus
      -Maxillary sinuses drain into middle meatus.
      -Posterior ethmoidal cells drain into superior meatus
      -Sphenoidal sinuses drain into sphenoethmoidal recess.
    • What is the orbit?
      Bony structure that houses the eye
    • What 7 bones make up the orbit?
      • Frontal
      • Maxilla
      • Ethmoid
      • Lacrimal
      • Sphenoid
      • Zygomatic
      • Palatine
    • What are the openings into the orbit?
      -Optic canal
      • -CN II and ophthalmic artery
      -Superior orbital fissure
      • -CN III, IV, V1 & VI
      -Inferior orbital fissure
      • -CN V2
    • What is the structure of the eye?
      Suspended by muscles in the orbit
      • Divided into 3 chambers
      • Anterior
      • Anterior to iris
      • Aqueous fluid
      • Posterior
      • Posterior to iris
      • Aqueous fluid
      • Vitreous chamber
      • Largest chamber of the eye
      • Contains set amount of fluid
      • if fluctuation occur problems can occur (glycoma if pressure increase)
    • How does the visual field work?
      • Visual information received by the retina
      • Impulses carried through CN II (Optic nerve)
      • Lateral visual field is processed by contralateral portion of the occipital lobe
    • How does crossing over work?
      • Things are seen backwards and inverted
      • Visual cortex processes the information to “flip” the image
    • What is the optic Nerve?
      • Nerve CNI
      • Special afferent sensory nerve
      • Exits the skull through the optic canal
      • Develops as extension of the forebrain
      • Medial fibres decussate at the optic chiasm
    • Swelling of what nerve causes disturbance in vision?
      • Swelling of pituitary - causes disturbance in vision
      • Optic chiasm is directly above it which pushes it up towards the optic chiasm
    • What are the muscles used in movement of the eye?
      • 7 extraocular muscles:
      • Levator Palpebrae - helps opens eyelid
      • Superior Oblique - above the eye
      • Superior Rectus -
      • Medial Rectus
      • Lateral Rectus
      • Inferior Rectus
      • Inferior Oblique - below the eye
    • How does movement of the eye work?
      • Movements occur around 3 axes:
      • Vertical
      • ABduction (taking away from the midline) and ADduction (towards the midline)
      • Transverse
      • Elevation and depression
      • Anteroposterior
      • Internal rotation
      • External rotation
    • Label the diagram
      A) Frontal sinus
      B) Ethmoid cells
      C) Ethmoid bone
      D) Maxillary sinuses
      E) Posterior upper molars
    • Label the diagram
      A) Sphenoid
      B) Sphenoid
      C) Frontal bone
      D) Optic canal
      E) Ethmoidal foramina
      F) Ethmoid bone
      G) Zygomatic
      H) Maxilla
      I) Palatine
      J) Lacrimal
      K) lacrimal
    • What is the oculomotor nerve and what does it do?
      • CNIII
      • Exits through superior orbital fissure
    • What does the somatic motor nerve of CNII do?
      • Somatic Motor
      • General somatic efferent
      • Supplies extraocular muscles except superior oblique and lateral rectus
    • What does the parasympathetic nerve of CNIII do?
      • General visceral efferent via short ciliary nerves to ciliary body and sphincter pupillae
    • What are the Trochlear & Abducens Nerves?
      • CN IV - Supplies superior oblique 
      • CN VI - Supllies lateral rectus
    • What do Trochlear & Abducens Nerves do  ?
      • General somatic efferent and Exits via superior orbital fissure
    • What causes drooping eyelids?
      Injury to CN III
    • What is the lacrimal apparatus for??

      Crying
    • What are the components of the lacrimal apparatus and what do they do?
      • Recieves sensory and autonomic innervation
      • Lacrimal gland secretes lacrimal fluid
      • Lubricates, protects and provides nutrients for the eye
      • Lacrimal papilla collects fluid which moves to the lacrimal sac
      • Nasolacrimal duct then drains into the inferior meatus
      • nose runs when you cry
    • How is the lacrimal gland innervated?
      • Sensory innervation - Lacrimal nerve (branch of V1)
      • Parasympathetic innervation-Secretomotor function via facial nerve (CN VII)
      • Sympathetic innervation- Vasoconstrictive (sup. cervical ganglion, via internal carotid)
    • What is the trigeminal nerve?
      • CN V (1, 2 & 3)
    • What are the divisions of the trigeminal nerve?
      • Ophthalmic / V1
      • Exits cranium through superior orbital fissure
      • Maxillary / V2
      • Exits cranium through foramen rotundum
      • Mandibular / V3
      • Exits cranium through foramen ovale
      • Provides somatic sensory and somatic motor to structures developed from 1st pharyngeal arch.
    • What is the opthalamic nerve ?
      • CNV(1)
      • Exits the cranium via the superior orbital fissure
    • What are the divisions of the opthalamic nerve?
      • Lacrimal
      • Sensory innervation to lacrimal gland, conjunctiva and upper eyelid
      • Parasympathetic fibres to lacrimal gland
      • Frontal
      • Sensory innervation to upper eyelid, conjunctiva, forehead & scalp
      • Nasociliary
      • Sensory innervation to the eye, bridge of nose and mucous membranes of the paranasal sinuses
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