Read the summary and the most important questions on Locomotor apparatus

• 1 Anatomy

  This is a preview. There are 1 more flashcards available for chapter 1
  Show more cards here

• 1.1 The ear

  This is a preview. There are 23 more flashcards available for chapter 1.1
  Show more cards here

• What are forms of mechanical energy?

  Sound (detected by cochlea)
  Gravity (detected by the vestibular organs)
  Rotational acceleration (detected by the vestibular organs)

• What characterises a sound?

  Frequency (pitch) --> 20Hz <> 20000 Hz normally
  Intensity (loudness) --> 120 dB normally

• Where is the parotid gland located?

  In front of the tragus of the external auditory canal

• Where does the facial nerve exit?

  The stylomastoid foramen, 1 cm deep to the tip of the tragus (tragal pointer)

• What are the fissures of Santorini?

  Small fenestrations through the cartilage within the anterior and inferior portions of the cartilaginous ear canal.
  
  Clinical relevance: Otitis externa can spread to the parotid gland through these fissures and may lead to sskull base osteomyelitis.

• Where is the temporomandibular joint located?

  Anterior to the bony canal

• Where is cerumen secreted?

  From glands in the skin of the cartilaginous canal

• Which nerve provides sensory innervation to the skin overlying the mastoid process and the pinna?

  The great auricular nerve (from nerve roots C2 and C3)

• Which nerves innervate the external auditory canal?

  Cranial nerves V (trigeminal), VII (facial), and X (vagus)

• Where do the three layers of the tympanic membrane originate from?

  Outer layer --> ectoderm --> squamous epithelium
  Middle layer --> mesenchyme --> fibrous (radial and circumferential)
  Inner layer --> endoderm --> cuboidal mucosal epithelium.