Anatomy and Functioning of the Vestibular System and Taste Receptors - Prof. Douglas N. Is, Study notes of Biology

Download Anatomy and Functioning of the Vestibular System and Taste Receptors - Prof. Douglas N. Is and more Study notes Biology in PDF only on Docsity! 8 February Figure 7.40 Semicircular canals Three dimensions – “yes”, “no”, tilt to shoulder “Labyrinth” Figure 7.39 Ampulla – swellings in semicircular canals Houses cupula 3 of them (since there are 3 semicircular canals) Saculla and utricle Figure 7.41 With ampulla – cupula Supporting cells under hair cells w/ stereocilia Swelling is filled with fluid Stereocilia are bent by fluid movement during turning – resistance to fluid Figure 7.42 Hair cells Resting or constant velocity – base NT Stimulation (depolarization) - ↑ NT Inhibition (hyperpolarization) - ↓ NT Depends on which way stereocilia are bent Detects changes (we don’t feel the turn of the Earth) Figure 7.43 Utricle and saccule Hair cells embedded in gelatin-like material Contain calcium carbonite crystals – otolith Head position relative to gravity and acceleration or deceleration Otolith in gel gives gel greater mass to bend hairs Crystals can be dislodged in disease Vestibular System Information from hair cells → vestibular nerve → parietal lobe (also receives information from proprioceptors, sensory neurons from muscles, tendons) Feedback between parietal lobe, eye, eye movements Adjustments of posture Nystagmus Vestibular-occular reflex Fluid in head continues to turn while body is not Hair cells are bent still Eyes move as if still spinning Vestibular disease Person at rest – no change Nystagmus occurs Meniere’s disease