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  2. 2. Five General Senses: Hearing Sight Touc Smell Tast e h
  3. 3. TASTE Physiology of Taste Activation Taste buds -located inTaste oral cavity (most in tongue in saliva, To be tasted, first must be dissolvedpapillae) each taste bud has 40-100 epithelial cells made of 3 major diffuseSensations make contact with types.into the pore and gustatory hairs which trigger Sweet at tip of tongue 1. Supporting Cells:to elicit action potentials in neurotransmitters separate and insulate Salty & sour on the 2. Receptor Cells: deal with taste seconds & these fibers. Adapt rapidly 3-5 sides stem cells, they give rise to new 3. Basal cells: 1-5 minutes completely in like cellsBitter in the back Taste Transduction Process in which stimulus energy is converted into a nerve
  4. 4. SMEL L STRUCTURE Pathway PHYSIOLOGY - In order to smell the substance must be in a - Detects chemicals infrom bulb down tract gaseous state - Send impulses solution - Olfactory Epithelium: soluble to dissolve in olfactory -Must be water Located on roof -Thalmus -> Frontal Lobe or Hypothalmus of nasal cavity and elicit emotional responses toepithelium interpret - Contain olfactory receptor cells with open ion Bind to-odor to protein receptors which columnar supporting cellsanosmias (without channels that send - Imablances include action potentials to - Covered byfrom head injuries; unicinate fits olfactory bulb smells) mucous to trap air born molecules (olfactory hallucinations)
  5. 5. SIGHT Accessory Structures Eyebrows -Shade the eyes; Prevent perspiration into eye Eyelids Palpabrae- protects eye; Levatorpal pebrae superioris raises eyelid; Eyelashes trigger blinking Conjunctiva- Mucous membrane over eyelids and anterior surface of eyeball (white part); Vascular, when irritated eyes are blood shot
  6. 6. VISION PHYSIOLOGY Photoreception Wavelength & Color- Eyes respond to visible light spectrum; Progresses from red to violet Photoreceptors are modified neurons; Outer segment connected to inner, in straight lines and blocked by Refraction & lenses- Light travelsinner connects to cell body which has synaptic endings. non transparent objects Light reflects or bounces off a surface; Rods- Sensitive to low of light reaching our Reflection accounts for most light, best at night eyes; as light Cones- Require high light, provides color changes mediums it can bend or refract. Focus- Your lens refracts the light to your focal point which projects on your retina Images are upside down & reversed Myopia (near sighted) Hyperopia (farsighted) Astigmatism (unequal curvature of lens leading to blur)
  7. 7. HEARIN G Middle Ear Outer Inner EarEar (tympanic cavity) Auricle or Pinna: ear composed of elastic Three areas: direct sound waves to -Small air filled mucus lined cavity cartilage & skin to -Behind eye socket & contains receptor information Outer ear -Between eardrum & bony external auditory 2 Major divisions canal wall with two openings oval (vestibular) ) round (cochlear) curved External auditory meatus: middle ear -Bony (osseous & labyrinth Short window -Contains pharyngotympanic (auditory tube) running tube from ear to ear Series -Membranous Labyrinth-drum. of sacs and ducts inner auricle nasopharynx & helps equalize from middle ear to Tympanic membrane ( to drum ) boundary containing endolymph fluidear help conduct sound pressure between vibrations. outer & middle ear -Otitis Media – middle ear inflammation
  8. 8. SOUND & MECHANISM HEARING Sound – a disturbance of pressure Transmission Frequency – measurement of offurrences of a Sound waves unit of time repeated event per move through the air, membranes, bones, fluids is a wavelength - Distance between two crests to reach receptor is expressed in hertz - Frequencycells in the organ of corti. Vibrations excite is 20-20,000 Hz - Range for humans hair cells which send messages to cochlear related - Amplitude or height of wave is nerve to and brings the impulses to the brain intensity for processing - Loudness is measured in decibles.
  9. 9. IMBALANCES OF HEARING Deafness – any hearing loss Conduction deafness- When something hampers sound conduction to fluids of inner ear Sensorinerual- Damage to neural structures of cochlear hair cells. Tinnitus- Ringing of ear; Symptom of pathology and not disease1st symptom of cochlear nerve degeneration. Meniere’s Syndrome- Affects semicircular & cochlear canals. Causes vertigo, nausea, vomiting.
  10. 10. EQUILIBRIUM -Responds to head movement without awareness -Receptors of inner ear are divided into two parts: Static Sensory receptors for static are the maculae Found in saccules and utricle Monitor position of head in space, control posture Dynamic Receptor for dynamic are the crista ampullaris; Excited by head movement but major stimuli are rotatory. These areas are at work when twirling or feeling ill on a boat
  11. 11. TOUCH In contrast, the other sense, touch, is a somatic sense which does not have a specialized organ but comes from all over the body, most noticeably the skin but also the internal organs. Touch includes mechanoreception (pressure, vibration and proprioception), pain (nociception) and heat (thermoception), and such information is carried in GSA and GVE.