Paranasal sinuses

Dr Sachintha Hapugoda ◉ and Dr Maxime St-Amant ◉ et al.

The paranasal sinuses usually consist of four paired air-filled spaces. They have several functions of which reducing the weight of the head is the most important. Other functions are air humidification and aiding in voice resonance. They are named for the facial bones in which they are located:

Variant anatomy

The paranasal sinuses are subject to marked variation between individuals and between sides in the same individual, regarding size (aeration) and bony septations. Total paranasal sinus agenesis is very rare ¹. Isolated frontal sinus agenesis, on the other hand, is common.

Quiz questions

References

Anatomy: Head and neck

Anatomy: Head and neck

skeleton of the head and neck
- cranial vault
  - scalp (mnemonic)
    - galea aponeurotica
  - sutures
    - calvarial
    - facial
      - frontozygomatic suture
      - frontomaxillary suture
      - frontolacrimal suture
      - frontonasal suture
      - temporozygomatic suture
      - zygomaticomaxillary suture
      - parietotemporal suture (parietomastoid suture)
      - occipitotemporal suture (occipitomastoid suture)
      - sphenofrontal suture
      - sphenozygomatic suture
      - spheno-occipital suture (not a true suture)
      - lacrimomaxillary suture
      - nasomaxillary suture
      - internasal suture
    - basal/internal
  - skull landmarks
    - nasion
    - glabella
    - bregma
    - vertex
    - lambda
    - inion
    - pterion
    - asterion
    - basion
    - opisthion
    - obelion
  - frontal bone
    - supratrochlear foramen
    - supraorbital foramen
  - temporal bone
  - parietal bone
    - parietal foramen
  - occipital bone
    - clivus
      - inferior median clival canal
        foveola pharyngica recess
    - occipital condyle
- skull base (foramina)
- facial bones
  - midline single bones
  - paired bilateral bones
- cervical spine
- hyoid bone
- laryngeal cartilages
muscles of the head and neck
- muscles of the tongue (mnemonic)
  - extrinsic muscles of the tongue
  - intrinsic muscles of the tongue
- muscles of mastication
- muscles of facial expression
  - occipitalis muscle
  - circumorbital and palpebral muscles
  - nasal muscles
  - buccolabial muscles
    - elevators, retractors and evertors of the upper lip
      - levator labii superioris alaeque nasalis muscle
      - levator labii superioris muscle
      - zygomaticus major muscle
      - zygomaticus minor muscle
      - malaris muscle
      - levator anguli oris muscle
      - risorius muscle
    - depressors, retractors and evertors of the lower lip
      - depressor labii inferioris muscle
      - depressor anguli oris muscle
      - mentalis muscle
    - compound sphincter
      - orbicularis oris muscle
      - incisivus superior muscle
      - incisivus inferior muscle
    - muscle of mastication:
      - buccinator muscle
- muscles of the middle ear
  - stapedius muscle
  - tensor tympani muscle
- orbital muscles
  - extraocular muscles
  - levator palpebrae superioris muscle
    - superior tarsal muscle
- muscles of the soft palate
- pharyngeal muscles
- suprahyoid muscles
- infrahyoid muscles
- intrinsic muscles of the larynx
- muscles of the neck
- accessory muscles of the neck
  - levator glandulae thyroideae muscle
deep cervical fascia
deep spaces of the neck
surgical triangles of the neck
- anterior triangle
- posterior triangle
  - occipital triangle
  - supraclavicular triangle
orbit
ear
paranasal sinuses
nose
oral cavity
pharynx
larynx
viscera of the neck
blood supply of the head and neck
- arterial supply
  - common carotid artery
- venous drainage
innervation of the head and neck
- cranial nerves
  - olfactory nerve (CN I)
  - optic nerve (CN II)
  - oculomotor nerve (CN III)
  - trochlear nerve (CN IV)
  - trigeminal nerve (CN V) (mnemonic)
    - trigeminal ganglion
    - ophthalmic division
      - tentorial nerve
      - frontal nerve
        
        supra-orbital nerve
        
        supratrochlear nerve
      - lacrimal nerve
      - nasociliary nerve
        
        small communicating branch to the ciliary ganglion
        
        short ciliary nerves
        
        long ciliary nerves
        
        infratrochlear nerve
        
        posterior ethmoidal nerve
        
        anterior ethmoidal nerve
    - maxillary division
    - mandibular division
  - abducens nerve (CN VI)
  - facial nerve (CN VII)
    - chorda tympani
    - nerve to stapedius
  - vestibulocochlear nerve (CN VIII)
  - glossopharyngeal nerve (CN IX)
    - Jacobson nerve
  - vagus nerve (CN X)
    - superior laryngeal nerve
      - external laryngeal nerve
      - internal laryngeal nerve
    - recurrent laryngeal nerve (inferior laryngeal nerve)
  - (spinal) accessory nerve (CN XI)
  - hypoglossal nerve (CN XII)
- parasympathetic ganglia of the head and neck
- greater occipital nerve
- cervical plexus
  - muscular branches
    - longus capitis
    - longus colli
    - scalenes
    - geniohyoid
    - thyrohyoid
    - ansa cervicalis
      - omohyoid (superior and inferior bellies separately)
      - sternothyroid
      - sternohyoid
    - phrenic nerve
      - accessory phrenic nerve
    - contribution to the accessory nerve (CN XI)
  - cutaneous branches
- brachial plexus
- pharyngeal plexus
lymphatic drainage of the head and neck

Article information

rID: 25381

System: Head & Neck

Section: Anatomy

Tag: refs

Synonyms or Alternate Spellings:

Paranasal sinus

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Cases and figures

Figure 1: annotated CTFigure 1: annotated CT

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Case 1: normal paranasal sinusesCase 1: normal paranasal sinuses

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