Sensory Perception PDF

OpenStax: Ch 14 Unit 6: Sensory Perception What if you could taste colors and see music? Synesthesia is a perceptual phenomenon in which stimulation of one sensory or cognitive pathway leads to automatic, involuntary experiences in a second sensory or cognitive pathway....

OpenStax: Ch 14 Unit 6: Sensory Perception What if you could taste colors and see music? Synesthesia is a perceptual phenomenon in which stimulation of one sensory or cognitive pathway leads to automatic, involuntary experiences in a second sensory or cognitive pathway. Ideasthesia – Letters and numbers evoke colors General Senses = receptors found throughout the body, including joints and organs Special senses = specialized receptors found in the head (eyes, ears, mouth) Sensations & Receptors Sensation = feeling that occurs when a brain interprets a sensory nerve impulse Projection = the brain causes a feeling to stem from a source What do you think is going Sensory adaptation = sensory on in this picture? receptors stop sending signals when Sensory Deprivation is a technique initially they are repeatedly stimulated used by neuro-psychiatrists designed to deliberately reduce or completely remove stimuli from one or all of the senses. Receptor cells in the PERIPHERAL NERVOUS SYSTEM are activated by stimuli in the environment Receptor cells can be classified into types on the basis of three different criteria: cell type, position, and function Structural Receptor Types Free Nerve Endings - dendrites embedded in tissue as receivers Respond to pain and temperature Encapsulated - embedded in connective tissue to increase sensitivity (pressure and touch) Specialized - receptors in the retina of the eye Location-Based Receptor Types Exteroceptor - located near external environment (skin) Interoceptor - interprets stimuli from internal organs Proprioceptor - located near moving body parts, interprets position Functional Receptor Types Chemoreceptor - chemicals, mostly found in nose/mouth Osmoreceptor - respond to solutes in body fluids Thermoreceptor - temperature Mechanoreceptor - pressure, vibration, body position Nocireceptor - pain (chemicals released when tissue is damaged) Sense of Pain Visceral Pain - occurs in visceral tissues such as heart, lungs, intestine Referred pain - feels as though it is coming from a different part (heart pain may be felt as pain in arm or shoulder) Acute Pain - originates from skin, usually stops when stimulus stops (needle prick) Chronic Pain - dull aching sensation How can you measure pain in babies and young children? Face, Legs, Activity, Cry, Consolability scale or FLACC scale Pain Differences Opioids 2019 An overview of how opioids work to block pain and why they become less effective the longer you use them. 1. Nerve sends signal 2. Opioids slow/block signal 3. Limbic system (emotions) and reward pathway are stimulated Special Senses Olfactory (smell) Gustatory (taste) Hearing & Equilibrium Sight Sense of Smell (Olfactory) Odor --> Receptor Cell --> Olfactory bulb --> Olfactory Tract --> All part of the LIMBIC SYSTEM (behavioral and emotional responses) Why do smells trigger memories? Olfactory Bulb on Sheep Brain Taste Sensations Imagine the taste of: Sweet Strawberries Cheetos Sour Banana Bitter French Fries Chocolate Salty Savory (Umami) Umami - a savory taste, is one of the five basic tastes, together with sweet, sour, bitter and salty. A loanword from the Japanese umami can be translated "pleasant savory taste". Bacon, cheddar and beef all have umami, and together they “synergize the umami effect.” Toss in sautéed mushrooms and you’ve struck an umami mother lode. Umami, he says, “alters our perception of other tastes, making salt, saltier, sweet sweeter, and bitter and sour less biting.” It is a taste that can’t be duplicated with any of the other four tastes. Do we all experience taste in the same way? Genetics may play a role in whether you like certain foods. Does cilantro taste like soap to you? Sense of Hearing External Ear Auricle (pinna) - outer ear Auditory Canal (external auditory meatus) - opening to the eardrum Ear movement is common in many mammals, including cats, dogs and horses, and usually serves to swivel the ear towards the direction of a sound. A group of muscles called the auriculares are responsible for this movement. Ear wiggling is considered a VESTIGIAL trait - a trait that no longer functions but is part of our evolutionary past. The Interactive Ear Middle Ear (tympanic cavity) malleus Eardrum (tympanum) incus Auditory Ossicles - malleus, incus, stapes - transmit vibrations and amplify the signal stapes Auditory Tube (eustachian tube) - connects the middle ear to the throat - helps maintain air pressure Why do children get tubes put in their ears? Inner Ear Semicircular Canals = sense of equilibrium (Utricle and Saccule) Cochlea = snail-shaped, sense of hearing Organ of Corti = contains hearing receptors, hair cells detect vibrations Steps in Hearing 1. Sound waves enter external auditory canal 2. Eardrum vibrates 3. Auditory ossicles (malleus, incus, stapes) amplify vibrations 4. Stapes hits oval window and transmits vibrations to cochlea 5. Organs of corti contain receptor cells (hair cells) that deform from vibrations 6. Impulses sent to the vestibulocochlear nerve 7. Auditory cortex of the temporal lobe interprets sensory impulses 8. Round window dissipates vibrations within the cochlea Why do we lose our hearing? Inside the cochlea are special neurons called HAIR CELLS. Loud noises damage these fibers. As you age, hair cells become damaged (loud music can speed this process along). Older people usually can’t hear frequencies that Hearing Test on Youtube younger people can hear. stereocilia EXTERNAL MIDDLE INNER Malleus, Incus, Stapes Vestibulocochlear nerve Tympanic Cavity Color the structures of the ear. Cochlear Implants A cochlear implant receives sound from the outside environment, processes it, and sends small electric currents near the auditory nerve. The brain learns to recognize this signal and the person experiences this as "hearing". 8 month old reacts to cochlear implant Sense of Equilibrium Static Equilibrium - maintain stability and posture Dynamic Equilibrium - balance during sudden movement Cerebellum - interprets impulses from the Walking on two legs is harder than you semicircular canals and think… maintains overall balance Robot Fails  OTOSCOPE Otolaryngology (pronounced oh/toe/lair/in/goll/oh/jee) Otolaryngologists are physicians trained in the medical and surgical management and treatment of patients with diseases and disorders of the ear, nose, throat (ENT), and related structures of the head and neck. They are commonly referred to as ENT physicians. Disorders of Sensory Systems 1. Synesthesia 2. Anosmia 3. Tinnitus 4. Anhidrosis (inability to sweat) 5. Congenital Analgesia (CIP) Mutations in genes prevents nerve impulses from pain receptors (nociceptors) from sending signals to the brain. Hereditary (Congenital) Deafness Occurs in 1 of every 1000 to 2000 newborns Syndromic Pendred Syndrome Usher Syndrome A SYNDROME is a disease that has more than one feature or symptom. A person with Usher syndrome also has vision problems Hereditary (Congenital) Deafness A specific mutation results in hearing Non-syndromic loss; can be recessive (80%) or dominant (20%). Recessive inheritance, can you identify the “carriers?” Deafness can also be caused by PRENATAL Infections from “ToRCH” organisms Toxoplasmosis Rubella Cytomegalovirus (CMV) Herpes Postnatal infections can also cause deafness Meningitis Streptococcus Listeria Influenza Presbycusis = age related hearing loss -diminished hearing sensitivity -poor speech comprehension in noisy environments -slowed central processing of acoustic information -high frequencies are more difficult to hear Fun Fact: Many vertebrates such as fish, birds and amphibians do not suffer presbycusis in old age as they are able to regenerate their cochlear sensory cells, whereas mammals including humans have It is estimated that 30-40% of people lost this regenerative ability. over the age of 65 have presbycusis Careers Related to Hearing Audiologist Speech-Language Pathologist Sign Language Interpreter Teacher: Deaf & Hearing Impaired Sensory Perception: The Eye The Structure of the Eye and Accessory Organs EYELID - Covers and protects the eye, thin skin Skin will not protect you from intense radiation, that’s why we use special goggles in a tanning bed EYELASHES - fine hairs that function to protect the eyes from dust and debris. Trichiasis - inversion of the eyelashes, which can irritate the eye CONJUNCTIVA is a covering around the eye and under the eyelids. PINK EYE - also known as CONJUNCTIVITIS (from bacteria, very contagious) Extrinsic Eye Muscles - move the eye 5 1 3 4 6 2 LACRIMAL GLANDS produce tears, which drain into the nasal cavity via the LACRIMAL DUCT. TEARS function is to moisten and lubricate the eye surface, and it has enzymes that kill bacteria. CANALICULI! Outer Tunic of the Eye Cornea - transparent dome that focuses light Cornea transplants can be done to replace damaged or diseased corneas. Your corneas can be donated if you have signed on to be an organ donor. Keratoconus is an eye condition in which the normally round cornea thins, causing a cone-like bulge to develop. Source: NPR http://n.pr/1a1oSx6 Outer Tunic of the Eye Sclera – continuation of cornea, going toward the back of the eye (white of the eye) Unlike other primates, human beings have eyes with a distinct color contrast between the white sclera and the colored iris. Outer Tunic of the Eye Optic Disk Optic Nerve – exits at optic disk and transmits information from the eye to occipital lobe of the brain. During Prohibition, methanol poisoning was the main cause of blindness. Wood Inflammation of the optic nerve can alcohol or “spirits” cause optic neuritis, or sudden vision contained a chemical loss. It is common in those with multiple that would damage the sclerosis. optic nerve. Vision loss may not be permanent. Middle Tunic of the Eye Choroid – contains blood vessels Ciliary Body – holds the lens in place Lens – focusing Iris – colored portion of the eye Pupil – opening for light to enter Aqueous humor – liquid surrounding the lens Eye Color Melanin is a brownish pigment that adds color to your hair, eyes, and skin. Caucasian babies are born with very little melanin in the eyes, so they appear blue. When exposed to sunlight, melanin levels rise and the eyes can change color. Brown is the world’s most common eye color. Heterochromia - one eye is a different color than the other Mila Kunis PUPILS - dilate or constrict to adjust light entering eye Fun Fact: - When you are looking at someone you love, your pupils dilate, and they do the same when you are looking at someone you hate. Inner Tunic Retina - visual receptor cells Fovea Centralis - region of the sharpest vision, also called the macula Optic Disc – where nerve fibers leave the eye, creating the blind spot Vitreous Humor – supports internal parts, fluid within the eye The Retina - has PHOTORECEPTORS, which are sensors for light. Rods = monochromatic (b&w) Cones = color vision R.O.Y.G.B.I.V Rainbows are seen after rain because light is passing through water droplets. This separates the white light into the individual colors of the spectrum Humans have three different color sensitive cone cells (red, green, blue). Dogs only have yellow and blue.  Vitreous Humor Fovea Centralis (macula) = the center of focus Aqueous Humor How Does the Eye Work? Accommodation = Lens changes shape to facilitate focusing. Images are then projected to the back of the eye (focal points). The lens reverses the image (objects are seen upside-down) Zonules of Zinn - connect ciliary body to lens - can change the shape of the lens - also called suspensory ligaments Information from retina passes through the optic nerve, crosses at the chiasma, and is sent to the occipital lobe of the brain. The brain is responsible for interpreting those images. We have difficulty interpreting images that are upside down Which one is the real mona lisa? Problems with the Eyes Cataracts - Clouding of the lens leads to a clinical condition known as CATARACTS. Treatment is to remove the lens and replace it with an artificial one, called an intraocular lens (IOL) Problems with the IRIS and PUPIL The function is to constrict or dilate the pupil (opening) to allow light in. Therefore, it regulates the amount of light passing to the visual receptors of the eye. ANIRIDIA = a condition where a person is born without an iris Onchocerciasis, also known as river blindness, is a disease caused by infection by a parasitic worm. Symptoms include severe itching, bumps under the skin, and blindness. Color Blindness A genetic trait that affects boys more than girls. The location of the gene is on the X chromosome. FLOATERS occur when the vitreous substance clumps and casts shadows on the retina. Floaters don’t actually move, the eye just tries to track them. Retinal Detachment A retinal detachment occurs when the retina is pulled away from its normal position. Blindness can occur if it is not treated right away. Symptoms flashing lights; new floaters; a shadow in the periphery of your field of vision; a gray curtain moving across your field of vision. Glaucoma -pressure from vitreous humor damages the optic nerve and can lead to blindness. Can be managed with medication. Hyperopia = farsightedness You can see distant objects fine, but close objects appear blurry Presbyopia is the loss of ability to see close objects or small print, age-related. Myopia = nearsightedness You can see near objects fine, but distant objects appear blurry ASTIGMATISM is when the cornea has an irregular shape. Part of the field of view is out of focus. Most vision problems are treated with glasses or contact lenses. Both change the focal point of the light entering the eye. Surgery is also an option