different planes so that angular acceleration in any direction can be detected

Different planes so that angular acceleration in any

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different planes so that angular acceleration in any direction can be detected o Ampullae are swollen chambers at the end of canals Protrude cilia of another group of cells Saccule, utricle, and semicircular canals are collectively referred to as the vestibular apparatus. Chemoreceptors: Taste, Smell, pH Contain membrane proteins that can bind to particular ligands in the extracellular fluid Becomes depolarized and produces action potentials Important in monitoring the chemical composition of the blood and cerebrospinal fluid Taste detects and analyzes potential food Perception of taste (gustation) is a combo of physical and psychological factors Sweet, sour, salty, bitter, umami (meat, cheese, broth) Tastebuds: chemosensitive, epithelial, afferent neurons Tastebuds occur in the epithelium of the tongue within papillae Onion shaped betweeon 50-100, each cell has finger like projections called microvilli that pokes through the top called the taste pore Salty and sour tastes act directly through ion channels o Salty (na+, influx depolarizing the membrane), receptor cell releases neurotransmitter and active sensory neuron which sends impulse to brain o Sour (H+) o Increased conc of protons that can also depolarize the membrane when they diffuse through ion channels Sweet, bitter and umami bind to G protein receptors Activation of these G protein receptors stimulates a single signaling pathway that leads the release of neurotransmitter to activate a sensory neuron and send an impulse to the brain Smell Olfaction involves chemoreceptors at the upper portion of the nasal passages Dendrites end in tassels of cilia, project into nasal mucosa, axons project directly into the cerebral cortex pH Peripheral chemoreceptors: aortic and carotid bodies, sensitive primarily to plasma pH
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Central chemoreceptors in the medulla oblongata of the brain: sensitive to pH of cerebrospinal fluid Vision Photoreceptors: capture of light energy o Can be used to determine both direction and distance of an object Vertebrate eye o Sclera: white part. Tough connective tissue o Light enters the eye through the transparent cornea, focuses light o Iris: colored portion of the eye o Light passes through the pupil to the lens, completes the focusing of the light onto the retina Attached by the suspensory ligament to the ciliary muscles Vertebrate retina has 2 kinds of photoreceptor cells o Rods: black and white vision o Cones: sharpness and high visual acuity Most cones are located in the central region of the retina, fovea Eye forms the sharpest image Rods are almost absent in fovea
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o o Photopigment in rods is the rhodopsin Consists of protein opsin bound to a molecusin of cis-retinal produced from vitamin A, carotene o Photopigment in cones is the photopsin Cis-retinal bound to protein w/ a slightly diff amino acid sequence Differences in the light absorbing properties of the photopsins
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