scutum

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The scutum (plural: scuta) is a sharp bony spur that is formed by the superior wall of the external auditory canal and the lateral wall of the tympanic cavity. It forms the lateral margin of Prussak space.

Related pathology

acquired cholesteatoma: it is usually the first bony structure to be eroded by the enlarging cholesteatoma

History and etymology

The name scutum derives from the Latin word for shield.

Anatomy: Head and neck

skeleton of the head and neck
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
    - suboccipital triangle
  - supraclavicular triangle
orbit
- bony orbit
- orbital spaces
  - extraconal
  - myofascial cone
  - intraconal
  - ocular globe
    - conjunctiva
    - cornea
    - sclera
    - uvea
      - iris
      - ciliary body
      - choroid
    - ora serrata
    - vitreous body
      - Cloquet's canal
    - lens
  - optic nerve-sheath complex
    - fovea
- orbital septum
- naso-orbitoethmoid region
- eye movements
- orbital blood supply
- orbital nerve supply
- lacrimal apparatus
  - lacrimal gland
  - nasolacrimal drainage apparatus
ear
paranasal sinuses
nose
oral cavity
pharynx
larynx
- supraglottic space
- glottis
- subglottic space
  - true vocal cords
    - anterior commissure of the larynx
viscera of the neck
blood supply of the head and neck
- arterial supply
  - common carotid artery
- venous drainage
  - internal jugular vein (mnemonic)
    - jugular bulb
      - asymmetrically large jugular bulb
    - pharyngeal vein
    - common facial vein
      - angular vein
        supraorbital vein
        
        supratrochlear vein
    - lingual vein
    - superior thyroid vein
    - middle thyroid vein
  - external jugular vein (mnemonic)
    - posterior auricular vein
    - retromandibular vein
      - superficial temporal vein
      - (deep/internal) maxillary vein
        pterygoid venous plexus
    - facial vein
    - anterior jugular vein
    - posterior external jugular vein
    - suprascapular vein
    - transverse cervical vein
  - cavernous sinus
  - facial-cavernous anastomoses
  - anterior condylar confluence
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)
    - vestibular ganglion (Scarpa's ganglion)
  - 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
- third 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
embryological development of the head and neck
- branchial apparatus

Siehe auch:

und weiter:

flaccid portion of tympanic membrane

Assoziationen und Differentialdiagnosen zu scutum:

erworbenes

Cholesteatom

Wikipedia • CC BY-SA 3.0

Related pathology

History and etymology

Related Radiopaedia articles

Anatomy: Head and neck

Siehe auch:

und weiter: