Physiology of balance (2).pptx

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1. Physiology of balance Done by Athira

2. Vestibular system Semicircular canal Saccule Utricle

3. 1. Crista 2. Maculae Peripheral receptors:

4. Structure of Crista :

5. CUPULA-gelatinous mass extend from surface of Crista to ceiling of ampulla, only to be displaced to one or other side like swing door. Gelatinous mass consists of polysaccharide & contain canals-cilia of sensory hair cells project.

6. Hair cells are of two types . Type I cells Type II cells

7. Structure of Macula: two parts: (i)sensory neuroepithelium (ii) an otolithic membrane

8. Physiology of vestibular system: Peripheral, which is made up of membranous labyrinth (semicircular ducts, utricle and saccule) and vestibular nerve. Central, which is made up of nuclei and fibre tracts in the central nervous system to integrate vestibular impulses with other systems to maintain body balance.

9. Semicircular canal

10. Posterior semicircular canal-head tilt right to left

11. Superior semicircular canal-head nods up and down

12. Lateral semicircular canal-head shakes side to side in a no motion

13. Vestibulo-ocular reflex – nystagmus

14. VERTIGO AND DIZZINESS * Disorientation in space causes vertigo or dizziness * arise from disorders of any of the three systems: vestibular, visual or somatosensory. * Normally, the impulses reaching the brain from the three systems are equal and opposite. * If any component on one side is inhibited or stimulated, the information reaching the cortex is mismatched, resulting in disorientation and vertigo.

15. Motion sickness * characterized by nausea, vomiting, pallor and sweating during travel . * arise from the mismatch of information reaching the vestibular nuclei and cerebellum from the visual, labyrinthine and somatosensory systems. * It can be controlled by the usual labyrinthine sedatives.

16. THANK YOU