Developmental aspects of ANS choroid (supplies blood) During youth, ANS impairments are usually ciliary body (controls lens due to injury shape) iris In old age, ANS efficiency declines, partially (colored part of the eye). due to structural changes at preganglionic (Pupil controls amount of light entering the eye.) axon terminals 3. Sensory- the retina Pigmented layer absorbs light and stores vitamin A Neural layer has photoreceptors and transmits signals Section 3: Special Senses Optic disc is your blind spot due to lack of photoreceptors Eye and Vision Photoreceptors (rods: operate in 70% of all sensory receptors are in the eye dim light and provide indistinct, Nearly half of the cerebral cortex is involved fuzzy, non-color peripheral vision, in processing visual information cones: operate in bright light and Most of the eye is protected by a cushion of provide a high-acuity color vision) fat and the bony orbit Internal cavity is filled with humors fluid Lens separate internal cavity into anterior Structure of the eye and posterior segments Eyebrows- shade the eye and protect it Taste from perspiration Receptor organs are taste buds Eyelids (palpebrae)- protect the eye Taste sensations anteriorly, eyelashes initiate reflex Sweet- sugars, saccharin, alcohol, and blinking some amino acids Conjunctiva- transparent membrane that Sour- hydrogen ions produces a lubricating mucous secretion Salt- ions Lacrimal apparatus- lacrimal glands and Bitter- alkaloids such as quinine and ducts that connect to the nasal cavity and nicotine produce tears Umami- amino acids glutamate and Extrinsic eye muscles aspartate 6 strap-like extrinsic eye muscles that enable the eye to follow moving Taste is 80% smell objects Thermoreceptors, mechanoreceptors, 4 rectus muscles provide nociceptors in the mouth also influence movement to the eye taste 2 oblique muscles move the eye Temperature and texture enhance or laterally and rotate the eye detract from taste Structure of the eyeball Smell Wall of eyeball contains three layers Organ of smell is the olfactory epithelium in 1. Fibrous- outer most layer that the roof of the nasal cavity contains the sclera and cornea Olfactory receptor cells-bipolar neurons 2. Vascular- middle pigment layer and with radiating olfactory cilia contains three regions-
Developmental aspects of ANS During youth, ANS impairments are usually due to injury In old age, ANS efficiency declines, partially due to structural changes at preganglionic axon terminals Section 3: Special Senses Eye and Vision 70% of all sensory receptors are in the eye Nearly half of the cerebral cortex is involved in processing visual information Most of the eye is protected by a cushion of fat and the bony orbit Structure of the eye Eyebrows- shade the eye and protect it from perspiration Eyelids (palpebrae)- protect the eye anteriorly, eyelashes initiate reflex blinking Conjunctiva- transparent membrane that produces a lubricating mucous secretion Lacrimal apparatus- lacrimal glands and ducts that connect to the nasal cavity and produce tears Extrinsic eye muscles 6 strap-like extrinsic eye muscles that enable the eye to follow moving objects 4 rectus muscles provide movement to the eye 2 oblique muscles move the eye laterally and rotate the eye Structure of the eyeball Wall of eyeball contains three layers 1. Fibrous- outer most layer that contains the sclera and cornea 2. Vascular- middle pigment layer and contains three regions- choroid (supplies blood) ciliary body (controls lens shape) iris (colored part of the eye). (Pupil controls amount of light entering the eye.) 3. Sensory- the retina Pigmented layer absorbs light and stores vitamin A Neural layer has photoreceptors and transmits signals Optic disc is your blind spot due to lack of photoreceptors Photoreceptors (rods: operate in dim light and provide indistinct, fuzzy, non-color peripheral vision, cones: operate in bright light and provide a high-acuity color vision) Internal cavity is filled with humors fluid Lens separate internal cavity into anterior and posterior segments Taste Receptor organs are taste buds Taste sensations Sweet- sugars, saccharin, alcohol, and some amino acids Sour- hydrogen ions Salt- ions Bitter- alkaloids such as quinine and nicotine Umami- amino acids glutamate and aspartate Taste is 80% smell Thermoreceptors, mechanoreceptors, nociceptors in the mouth also influence taste Temperature and texture enhance or detract from taste Smell Organ of smell is the olfactory epithelium in the roof of the nasal cavity Olfactory receptor cells-bipolar neurons with radiating olfactory cilia
11%20Peripheral%20Nervous%20System%20Notes%20filled%20in.docx