Somatic and Special Senses Chapter 10 Introduction Sensory

Somatic and Special Senses Chapter 10

Introduction • Sensory Receptors- detect environmental changes and trigger nerve impulses that travel on sensory pathways into the CNS for processing and interpretation http: //michaeldmann. net/pix_4 b/gust_receptors. gif

2 large types of sensory receptors • 1. Somatic senses: touch, pressure, temperature, and pain • 2. Special senses: smell, taste, hearing, equilibrium, and vision http: //www. medicalook. com/systems_images/Somatic_senses. gif

Receptors and Sensations • Receptors are distinct to a type of environmental change • This selective response distinguishes the senses • 5 kinds

1. Chemoreceptors • Stimulated by changes in the chemical concentration of substances

2. Pain Receptors • Stimulated by tissue damage https: //courses. cit. cornell. edu/psych 396/student 2006/the_biology_of_pain/receptor 2. jpg

3. Thermoreceptors • Stimulated by changes in temperature http: //resource. rockyview. ab. ca/t 4 t/bio 30/images/m 1/b 30_m 1_022_l. jpg

4. Mechanoreceptors • Stimulated by changes in pressure or movement http: //bdml. stanford. edu/twiki/pub/Haptics/Project. Overview/mechanoreceptors. jpg

5. Photoreceptors • Stimulated by light energy http: //thebrain. mcgill. ca/flash/d/d_02_m/d_02_m_vis_1 a. jpg

Sensation • Sensation-a feeling that occurs when the brain interprets sensory impulses • Impulse is read depending on what area of the brain receives it • One area may be sound and one area may be touch

http: //www. drugabuse. gov/sites/default/files/slide 4. gif

Projection • Projection-process where the cerebral cortex causes a feeling to stem from a source • It allows a person to pinpoint the region of stimulation (eyes & ears)

Sensory Adaptation • Sensory adaptation-sensory receptors stop sending signals when they are repeatedly stimulated • Can only be triggered if stimulus strength changes again • Think smell (phasic)

http: //www. cyndan. com. au/Portals/0/Media/F/Farm%20 Mate%20 cow. jpg

Somatic Senses • 1. Sensory Nerve Fibers – Common in epithelial tissues – Are associated with touch and pressure http: //www. exploringnature. org/graphics/anatomy/sensory%20 organs. jpg

• 2. Meissner’s Corpuscles – Small masses of connective tissue – Located in hairless portions of the skin (lips, fingertips, palms, soles, nipples, external genitalia) – Interpret light touch http: //www. exploringnature. org/graphics/anatomy/sensory%20 organs. jpg

• 3. Parcinian Corpuslces – Large structures of connective tissue – Located in deep tissue layers like ligaments and tendons – Respond to heavy pressure

Temperature Senses • 1. Warm Receptors - nerve endings that respond to warmer temperatures (sensitive above 77°, unresponsive above 113°F) • 2. Cold Receptors - nerve endings that respond to colder temperatures (sensitive between 50°F and 68°F)

http: //herkules. oulu. fi/isbn 9514259882/html/graphic 22. png

Sense of Pain • These protect the body because tissue damage stimulates them • Usually unpleasant and signals the person to remove the stimulation • Pain is persistent and doesn’t go away • Four types

1. Visceral Pain • Occurs in visceral tissues such as heart, lungs, intestine http: //wehelpwhathurts. homestead. com/visceral-somatic_referral_patterns_resize_smaller. jpg

2. Referred Pain • Feels as though it is coming from a different part (heart pain may be felt as pain in arm or shoulder) • Caused from Nerves passing through the same area http: //www. merckmanuals. com/media/home/figures/NEU_referred_pain. gif

3. Acute Pain • Originates from skin, usually stops when stimulus stops (needle prick) https: //courses. cit. cornell. edu/psych 396/student 2006/the_biology_of_pain/receptor 2. jpg

4. Chronic Pain • Dull aching sensations http: //criticalscience. com/wp-content/uploads/2011/08/pain-map_alphachimp_com. jpg

Regulation of pain • Pain is interpreted by the Cerebral Cortex in the brain. • Three types of neuropeptides that inhibit pain: serotonin, enkephalins, endorphins. • Natural brain chemicals can be mimicked by drugs such as morphine.

Morphine http: //recoverylife. com/resources/gallery_photo/morphine 60. jpg

Special Senses • Smell: olfactory organs • Taste: taste buds • Hearing equilibrium: Ears • Sight: Eyes

http: //www. exploringnature. org/graphics/anatomy/poster_special_senses_small. jpg

Sense of Smell • The sense of smell is associated with complex sensory structures in the upper region of the nasal cavity http: //www. umm. edu/graphics/images/en/8689. jpg

Olfactory Receptors • Chemoreceptors that are stimulated by chemicals that are dissolved in liquid • Aid in food selection because smell and taste are closely related http: //www. yalescientific. org/wp-content/uploads/2011/05/fulllengths-olfaction-2. jpg

Olfactory Organs • Contain the olfactory receptors which are masses that cover the upper parts of the nasal cavity http: //www. medicalook. com/systems_images/Olfactory_sense. gif

Olfactory Receptor Cells • Bipolar neurons surrounded by epithelial cells • Covered in cilia which have receptor proteins that the odor chemicals bind to http: //openwetware. org/images/b/ba/Olfactory_System_2. jpg

Olfactory Bulbs • Receive the nerve impulses from the receptor cells (located in the brain) http: //lynlaukimdak. wikispaces. com/file/view/42. jpg/219698964/42. jpg

Olfactory Tracts • Located inside the olfactory bulbs and interpret the nerve impulses Smell Video http: //www. medicalook. com/systems_images/Olfactory_sense. gif

10. 6 Sense of Taste (258 -260) http: //1. bp. blogspot. com/_JUf. Bb. Vl. Jk-s/TOB 1 pd-Zq. VI/AAAABh. M/Bo. Q 04 m. SXNWI/s 1600/tongue. jpg

The special organs of taste; papillae http: //thesalience. files. wordpress. com/2013/05/taste-buds-fungiform-papillae-vallate-papilla-gustatory-hairs-stratified-squamous-epithelium-of-tongue-taste-fibers-of-cranial-nerves. jpg

Gustatory cells; 50 to 150 receptor cells

The chemical must dissolve in the watery fluid surrounding the taste buds that are produced by the salivary glands. http: //oldenaplesperio. com/wp-content/uploads/2013/05/salivary-glands. jpg

1. Sweet—table sugar 2. Sour—lemon 3. Salty—table salt 4. Bitter—caffeine or quinine http: //www. zecuppa. com/images/primary-tastes. jpg

It detects monosodium glutamate (MSG), used as a flavor enhancer in many prepared foods http: //insidescoopsf. sfgate. com/files/2013/03/umami. BUB. jpg

10. 7 Sense of Hearing (260 -264) http: //www. mhhe. com/biosci/esp/2001_saladin/folder_structure/in/m 4/s 5/assets/images/inm 4 s 5_1. jpg

Auricle (pinna)—outer ear; External Auditory meatus http: //www. infovisual. info/03/img_en/049%20 External%20 middle%20 internal%20 ear. jpg

malleus, incus, stapes - transmit vibrations and amplify the signal http: //upload. wikimedia. org/wikipedia/commons/b/b 0/Illu_auditory_ossicles. jpg

Eustachian tube; Connects the middle ear to the throat; Helps maintain air pressure http: //3. bp. blogspot. com/-Ac. DUn. UFGUAQ/T 2 P-q. Sz. Tfb. I/AAAAAE 0/Uo. Qm. O 3 y. By 9 M/s 1600/Middle-Ear-Pressure 2. gif

Labyrinth, semicircular canals, cochlea, round window, and organ of Corti http: //www. brainhq. com/media/49/download/middle-inner-ear_0. jpg

Labyrinth: communicating chambers and tubes Osseous Labyrinth and Membranous Labyrinth Perilymph and Endolymph (fluids within the labyrinth) http: //www. positivehealth. com/img/image-article/Issue%20166/Articles/Inner%20 Ear. gif

Semicircular Canals: sense of equilibrium http: //www. daviddarling. info/images/semicircular_canals. jpg

Cochlea: sense or hearing http: //upload. wikimedia. org/wikipedia/commons/thumb/a/a 6/Cochlea. svg/490 px-Cochlea. svg. png

Organ of Corti: contains hearing receptors, hair cells detect vibrations http: //www. nature. com/nature/journal/v 405/n 6783/images/405130 aa. 2. jpg

Hair cells http: //www. neurophys. wisc. edu/auditory/johcfig 2. jpg

10. 8 Sense of Equilibrium (264267) http: //classes. midlandstech. edu/carterp/Courses/bio 110/chap 09/Slide 17. JPG

It senses the position of the head and maintains stability and posture http: //people. emich. edu/pbogle/PHED_200/overheads/ch 10_art/10_11. jpg

It balances the head during sudden movements; Semicircular canals http: //faculty. spokanefalls. edu/Inet. Share/Auto. Webs/Gary. B/AP%20242/Unit%204/Anatomy%20 of%20 the%20 ear-Equilibrium_files/slide 0007_image 011. jpg

It interprets impulses from the semicircular canals and maintains overall balance and stability http: //nh-chs-anatomy. pbworks. com/f/1390421610/Cerebellum-6%5 B 1%5 D. jpg