Ear

• What is the function of the ear?

  Hearing and balance
• What is the anatomy of the ear?


  Outer: pinna , auricular canal

  Middle: tympanic membrane , tympanic cavity , ossicles , eustachian tube

  Inner: cochlea and vesitbular system
• What are the characteristics of the outer ear?


  Elastic cartilage covered with skin. Skin lying on cartilage/bone
• What are the characteristics of the middle ear?


  Tympanic avity , tympanic membrane (eardrum) , ossicles , eustachian tube
• How do we hear?

  Sound waves move the tympanic membranes (vibrates) which causes ossicles to move and oval window moves and the fluid perilymph/endolymph moves which activates the sensory cells int he organ of corti which generates the nerve impulses
• What is the organ of corti?

  Neurons with stereo cilia which when moved it touches the tectorial membrane which generates a wave impulse
• How are high pitch and low pitch sounds sensed?


  High pitch- hairy cells in bottom of cochlea

  
  

  Low pitch- hairy cells in the apex of the cochlea
• What is the vestibular system?


  the three fluid-filled semicircular canals and adjacent organs located next to the cochlea in each inner ear
• What are the sensory areas?

  Ampulla , utricle , saccule
• What is the role of the internal ear?


  Vestibular portion plays a role in balance/movement
• What is the function of the ampullary crista?

  Senses rotation movements
• How do we detect movement?

  Epithelium(supportive and sensory cells) , sensory neurons contain cilia , connected to axons which merge to form a nerve , sensory cells coverend in a gelatinous material (cupula) the liquid and gel move which move cilia. which sends impulses to sense rotation or tiliting of the head
• What do the utricle and saccule sense?


  Utricle- linear acceleration

  saccule- position of the head
• What is the function of the otoconia?


  sense linear acceleration and gravity to maintain balance , crystals of Caco3
• What is the position of the utricle and saccule?


  Utricle has sensory cilia facing up

  Saccule has sensory cilia perpendicular