12/3/2010

Departemen Anatomi

 Contain receptors for & awareness of head position & movement  Divided into : I. External  receives & directs sound waves from external environment II.  tranforms sound waves into mechanical vibrations III. : o Mechanical vibration converted to nerve impulses & relayed to brain to be interpreted as sound o Contain vestibular organs that function in balance

1 12/3/2010

 / pinna consist of : ◦ Irregular plate of elastic cartilage, surrounded by thick pericondrium ◦ Skin with a few small ◦ & ◦ Sheets of skeletal muscle  External auditory meatus : ◦ An open S-shaped course ◦ Lined by keratinized stratified squamous epith. ◦ Ceruminous gland :  Secretory cells : cuboidal to collumnar  Produced cerumen ( a waxy material that prevents drying of skin lines meatus)

 Auditory : ◦  M. tensor tymphani ◦ ◦  M. stapedius   Lined by mucous membrane with a simple squamous epith.  Tympanic membrane : ◦ 3 layers :  Outer : stratified squamous epith  Middle : 2 layers of collagenous fibers  Inner : a simple squamous epith ◦ Inner surface attaches to malleus

2 12/3/2010

 Auditory tube / eustachian tube : ◦ 4 cm long ◦ Connect anterior part of tympanic cavity with nasopharynx ◦ Wall of auditory tube :  1/3 near tympanic cavity supported by compact bone with simple columnar epith  2/3 medial supported by J-shaped elastic cartilage with ciliated pseudostratified columnar epith.

 Consist of : 1. Periboney labyrinth / osseosa labyrinth  filled with 2.  filled with  Periboney & membranous labyrinth major components : a. Vestibular labyrinth  contain sensory element for equlibrium b.  contain sensory stuctures for hearing  Perilymph : ◦ Resembles extracellular fluid ( ↑ sodium ions, ↓ potassium ions) ◦ Production site : unknown  Endolymph : ◦ Resembles intracellular fluid ( ↑ potassium ion, ↓ sodium ions ) ◦ Produced by striae vascularis (an area of cochlear duct)

3 12/3/2010

 Consist of 3 semisicular canals    Most membranous labyrinth lined by simple squamous epith  Sensory epithelium : ◦ Stratified epith , found in spesific region of membranous labyrinth ◦ In semisircular canal  cristae ampularis ◦ Utricle  macula utriculi ◦ Saccule macula sacculi ◦ 3 type cells : cells type I & II, supporting (sustentacular) cells

4 12/3/2010

 Type I hair cells : ◦ Flask-shaped with narrow apical region ◦ Rounded base contain nucleus ◦ Apical membrane bears 50- 100 large, non motile microvilli, known as “hair”. ◦ : a single, eccentrically placed cilium, present on apical surface  Type II hair cells Similar to type I, but the cells are collumnar  Supporting / sustentacular cells : ◦ Columnar shaped ◦ Function unknown ◦ At periphery  planum semilunatum (simple columnar layer, lacks hair cells )

 Microvilli of hair cells in cristae embeded in gelatinous structure called cupula cristae ampullaris  Microvilli of hair cells in maculae embeded in viscous proteoglycan, forms otholitic membrane. Numerous crystalline bodies / suspended in this layer

5 12/3/2010

 Consist of : ◦ Outer portion of compact bone ◦ A central membranous part  Osseous cochlea : ◦ Mediolus ◦ Spiral lamina  & ◦

 Cochleal canal divided by basilar & vestibular membrane into : 1. Upper scala vestibuli  perilymph 2. Scala media  endolymph 3. Lower scala tympani  perilymph  Striae vascularis : ◦ Pseudostratified columnar epith ◦ Contain basal & marginal cells ◦ Marginal cell may elaborte in endolymph

6 12/3/2010

7 12/3/2010

 : ◦ Specialized cells on scala media that transform vibrations of basilar membrane to nerve impulse ◦ Supporting cells  a tall columnar, consist of : 1. Inner & outer pillar cells 2. Inner & outer phalangeal cells 3. Border cells 4. Cells of hensen 5. Cells of claudius

8 12/3/2010

1. Histologi Dasar, 8 th Edition, L. Carlos Junquira MD, Jose Carneiro MD, Robert O. Kelley PhD, EGC, 1995. 2. Essentials of Human Histology, 2 nd Edition, William J. Krausse PhD, Little Brown & Company (Inc), 1996. Pp 3. Atlas Histologi Manusia, 6th Edition, Mariano S. H. di Fiore, EGC, 1992.

9