Please enable JavaScript.

Coggle requires JavaScript to display documents.

Sense organs (Olfactory sensory (smell) (cells of the olfactory membrane:,…

- - - - replace receptors monthly
  - - - memory recall, more detailed in humans
    - - detectable olfactory chemicals that cause change in animals behavior
      - chemicals secreted by 1 animal that influences the behavior of another animal
      - mode of communication
      - purpose of pheromones: making trails or boundaries, recognizing individuals from the same herd or nest, marking location of food source, emitting alarms
- - - - dissolved substance contact gustatory hairs
      - receptor potential results in neurotransmitter release
      - nerve impulse formed in 1st order neuron
- - - - pinna: elastic cartilage covered skin
      - external auditory canal: tube of cartilage and bone leading into temporal bone
      - tympanic membrane (eardrum)
    - - 3 ear ossicles: malleus, incus, stapes
      - auditory tube leads to nasopharynx
    - - series of fluid filled membranous sacs and canals
      - contains mechanoreceptors (hair cells)
      - Bony labyrinth: set of tubelike cavities in temporal bone
      - cochlea
        
        3 fluid filled channels: scala vestibuli, scala tympani, and cochlear duct
        
        Tubular structure of the cochlea
        
        stapes pushes on fluid of scala vestibuli at oval window
        
        at helicotrema, vibration moves into scala tympani
        
        fluid vibration dissipated at round window which bulges
        
        the central structure is vibrated (cochlear duct)
  - - - Maintain the position of the body relative to the force of gravity
      - macula receptors w/in saccule and utricle
    - - maintains body position during sudden movement of any type rotation, deceleration or acceleration
      - crista receptors w/in ampulla of semicircular ducts
- - - - transparent
      - helps focus light (refraction)
      - 3 layers and nourished by tears and aqueous humor
      - Sclera: white of the eye
        
        dense irregular CT layer, collage, and fibroblasts
        
        provide shape and support
        
        at the junction of the sclera and cornea is an opening (scleral venous sinus)
        
        posteriorly pierced by optic nerve
    - - Choroid and ciliary body
        
        choroid: pigmented epithelial cells and blood vessels, provide nutrients to retina, and black pigment in melanocytes absorb scattered light
        
        ciliary body: consist of ciliary processes and ciliary muscle, which the muscle alters shape of lens
      - Iris and pupil: colored portion of eye
        
        hole in center is pupil
        
        function is to regulate amount of light entering eye
        
        muscles of the Iris
        
        constrictor papillae are innervated by parasympathetic fibers while dilator papillae are innervated by sympathetic
        
        response varies w/ different levels of light
      - lens
        
        lens held in place by suspensory ligaments
        
        focuses light on fovea
    - - The retina
        
        Posterior 3/4 of eyeball
        
        optic disc
        
        Rods- photoreceptors associated w/ black and white vision
        
        sensitive to light
        
        120 million rod cells
        
        distributed along periphery
        
        Cones: photreceptors associated w/ color vision
        
        functions best during day vision
        
        fovea of macula lutea
        
        Pathway of nerve signal in retina
        
        light penetrates retina
        
        rods and cones transduce light into action potentials
        
        rods and cones excite bipolar cells
        
        bipolar excite ganglion cells
        
        axons of ganglion cells form optic nerve leaving the eyeball
        
        to thalamus and then the primary visual cortex
  - - - Refraction: bending of light as it passes from 1 substance into a 2nd substance w/ a different density
    - - convex lens refract light rays towards each other
      - lens of eye is convex on both surfaces