LIFESCI 2 Lecture Notes - Lecture 20: Sound, Nociceptor, Mechanoreceptor
Document Summary
Sharks: magnetoreceptors, electro have these, sense magnetic poles, birds migrating mechanoreceptors and sounds, vibration intensity/frequency determines level of loudness/amplitude frequency = pitch, ears = messengers. Causes hair cells to move: organ of corti, hearing apparatus, hair cells (mechanoreceptors) Have cilia on top: tectorial membrane, basilar membrane. Supported between the two membranes form synapses w/ neuron axons ear functions in balance: where head is with respect to body, vertigo cannot perceive position. Allows for light to travel in to the lens lens made of connective tissue: convexity, focus point, cillary muscles, terminate w/ zonular fibers, elongating/shortening the lens. Ability to focus looking far elongated looking close - shortened light path cornea pupil lens changes direction to neural layer: accommodation looking at far. Contracted ciliary muscles iris: determines pupil size, dim light increase entry. Radial muscles stimulated, stretch out: bright light. Circular smooth muscles constrict flash too quick, too much light enters, is bounced back neural layer: retina, contains photoreceptors.
