Summary

This document covers sensory physiology, focusing on vision and photoreception in fish. It discusses variations in fish eye structures and functions, including light penetration, image forming, and transduction mechanisms.

Full Transcript

Chapters 9-10 : sensory Physiology Sensory Perception : Spatial scale & Signal dispersal fields from prey : e Vision and The Photoreception fish eye : variations in functions and structure : continuously grows throughout life . a body size Eye size correlates Designed for sensitiv...

Chapters 9-10 : sensory Physiology Sensory Perception : Spatial scale & Signal dispersal fields from prey : e Vision and The Photoreception fish eye : variations in functions and structure : continuously grows throughout life . a body size Eye size correlates Designed for sensitivity we Detection threshold clarity Acuity throughout life of vision sharpness RESOLUTION functions I capture the light 2 focus 3 Transform the image on the retina image Light Penetration and into neural + Signals integrate process by brain Spectrum factors Turbidity i depth Spectral changes Absorption : by water , preference for red light scattering , additional reflection : coastal water . Poor depth penetration Algae : Absorb . green blue and red is . reflected light Why are so many deep sea fishes red ? red fish only red at surface - a depth Black bic no red light pigmentation costs to fisheye components - eye is , on retina needs to Image forming I refraction : bending of light as it passes through different densities allows FOCUS hemispheric refract corned 2 Iris : control amount of light entering 3 Lens : Intraocular 4 Retina : light detection . 5 choroid : O2 delivery 6 Falciform process : Of delivery . focusing Transduction Sclerd : Eyeball , - Located the eye to nerve signals behind retina On top of retina connective +issue , structure , whites corned Retind Outermost transparent layer conjuctiva and for light Detection sciera Thin , transparent , laminar Thinner in fish Back of eye refraction little between cornea water + Overlayer - B/C of eyes Density between corned + water is small pigmented epithelium light after it passes photo receptors absorb . Lens (much more spherical than human must refract Spherical - light to focus light On for refraction bonyfish and in Slightly flattened in Distance between (near + far field lens lens) photo receptors detect light retina lamprey & elasmobranchs + . - retina varies vision Sclerd Outer layer . connective tissue agnathans fibrous sciera in cartilagenous sciera in chondrichthyans Inner . Teleosts have Sclerotic bones choroid Nuclei of highly vascularized reflects light passing through back retina reflective guanine crystals to reflect shine Layer (OPTIC NERVE Nerves . Nervous +issue in sharks + Send photo receptors optic lobe of brain for processing nocturnal fish Falciform process also vascularized but over retina . Eye oc demanding Eye . Root shift RETEMIRABLE : Enhance Of delivery to " O2 unloading