SpecialSenses.ppsx

Happy Veterinary Technician Week!!  https://youtu.be/kMU0GzbD6SQ Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Sense Organs Chapter 10 Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Learning Objectives  List the four...

Happy Veterinary Technician Week!!  https://youtu.be/kMU0GzbD6SQ Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Sense Organs Chapter 10 Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Learning Objectives  List the four general types of stimuli that can trigger a response from sensory receptors.  List and describe the visceral senses.  Differentiate between superficial and central temperature sensors.  List and describe the processes that contribute to nociception.  Describe the structure of the taste buds.  List and describe the special senses.  Describe the structures and functions of the components that make up the ear and the eyeball.  Describe the processes that contribute to the sense of equilibrium.  Describe the structures of the conjunctiva and eyelids. Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Fluid that helps protect the brain and spinal cord? A. Cerebral B. Synovial C. Pleural D. Transcellular Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Fluid that helps protect the brain and spinal cord? A. Cerebral B. Synovial C. Pleural D. Transcellular Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. This section of the brain is divided into halves and lobes Diencephalon B. Brain stem C. Cerebrum D. Cerebellum A. Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. This section of the brain is divided into halves and lobes Diencephalon B. Brain stem C. Cerebrum D. Cerebellum A. Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Functional cell of the nervous system is called? Epithelial B. Squamous C. Neuron D. Somatic A. Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Functional cell of the nervous system is called? Epithelial B. Squamous C. Neuron D. Somatic A. Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. General types of stimuli 1. Mechanical stimuli o 2. Thermal stimuli o 3. (e.g., hot and cold) Electromagnetic stimuli o 4. (e.g., touch, hearing, balance) (e.g., vision) Chemical stimuli o (e.g., taste and smell) Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. General Senses Sense What Is Sensed Type of Stimulus Visceral sensations Hunger, thirst, holloworgan fullness Chemical, mechanical Touch Touch and pressure Mechanical Temperature Heat and cold Thermal Pain Intense stimuli of any type Mechanical, chemical, or thermal Proprioception Body position and movement Mechanical Table 14-1 Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Visceral sensations Most are vague and poorly localized  Sensations of hunger and thirst  Also include visceral stretch receptors in GI tract and urinary system  Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Touch and Pressure  Tactile sense: sensation of something being in contact with the surface of the body  Pressure: sensation of something pressing on the body surface ◦ Different touch and pressure receptors produce sensations of light contact, deep pressure, vibration, or hair movement Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Temperature  Superficial temperature receptors - in the skin ◦ Detect upward or downward changes in skin temperature  Central temperature receptors - in the hypothalamus ◦ Monitor the temperature of the blood  CNS can activate mechanisms (e.g., sweating, piloerection) to correct hypothermia or hyperthermia Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Pain  Nociceptors - pain receptors  Pain receptors are widely distributed inside and on the surface of the body ◦ Not present in the brain  May be simple free nerve endings or more specialized structures that detect mechanical forces, temperature, etc.  https://youtu.be/5j9Syov0AAw Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Proprioception  Sense of body position and movement  Stretch receptors in skeletal muscles, tendons, ligaments, and joint capsules sense movements of limbs, positions of joints, the state of contraction of muscles, and the amount of tension being exerted on tendons and ligaments Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Special Senses Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Taste  Gustatory sense  Chemical receptors: taste buds in oral cavity ◦ Papillae - small elevated structures on the tongue ◦ Also found in the lining of the mouth and pharynx Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Smell  Olfactory sense  Very important in most nonhuman animals  Olfactory cells and supporting cells in epithelial patches in nasal passages Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Smell Hairlike processes project up from olfactory cells into the mucous layer that covers the nasal epithelium  Odor molecules dissolve in the mucus and contact the sensory processes  ◦ Nerve impulses are generated, travel to the brain, and are interpreted as particular smells. Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc.  http://www.pbs.org/wgbh/nova/nature/dog s-sense-of-smell.html  https://youtu.be/p7fXa2Occ_U  https://youtu.be/-9TThJgBBew  https://youtu.be/FLH36ML8IEU Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Hearing  Auditory sense  Converts vibrations of air molecules into nerve impulses  Most structures of the ear are located in the temporal bones of the skull Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Hearing External ear - acts as a funnel to collect sound wave vibrations and direct them to the eardrum  Middle ear - amplifies and transmits the vibrations from the eardrum to the inner ear  Inner ear - contains the sensory receptors that convert the mechanical vibrations to nerve impulses, along with receptors for the equilibrium sense  Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. External Ear  Pinna: elastic cartilage and skin  External auditory canal: membrane-lined tube Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. External Ear  Tympanic membrane: thin connective tissue membrane ◦ Tightly stretched across the opening between the external auditory canal and the middle ear cavity ◦ Sound wave vibrations strike the tympanic membrane and cause it to vibrate Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Middle Ear  Three ossicles (small bones) link the tympanic membrane with the cochlea of the inner ear ◦ Act as a system of levers that transmit sound wave vibrations from the tympanic membrane to the cochlea  Eustachian tube connects the middle ear cavity with the pharynx ◦ Equalizes air pressure on the two sides of the tympanic membrane Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Middle Ear Ossicles  Malleus: outermost bone; attached to tympanic membrane  Incus: middle bone  Stapes: medial-most bone; attached to membrane that covers the oval window of the cochlea Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Inner Ear  Cochlea: shellshaped spiral cavity in the temporal bone  Organ of Corti: fluid-filled portion that makes up the receptor organ of hearing Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Inner Ear  Organ of Corti ◦ Runs along the cochlear duct on the basilar membrane ◦ Consists of hair cells (hearing receptors), supporting cells, and the tectorial membrane Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Hearing  Sound wave vibrations cause the tympanic membrane and ossicles in the middle ear to vibrate. ◦ Causes vibration of fluid around the cochlear duct ◦ https://youtu.be/T8lKKlnnC6M Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Hearing  Fluid vibration causes the cochlear duct to move ◦ Causes the tectorial membrane and the hair cells of the organ of Corti to rub against each other ◦ Generates nerve impulses that travel to the brain and are interpreted as sound  Different frequencies of sound wave vibrations stimulate different areas along the length of the organ of Corti Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Hearing Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Equilibrium  Mechanical sense - helps maintain balance by keeping track of the position and movements of the head  Involves equilibrium receptors and information from the eyes and proprioceptors  Receptors are located in the vestibule and semicircular canals in the inner ear Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Proprioception is the sense of? A. Balance B. Taste C. Hearing D. Body position Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Proprioception is the sense of? A. Balance B. Taste C. Hearing D. Body position Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Pain receptors are called? A. B. C. D. Nociceptors Gusatory Optic nerve Gyrus Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Pain receptors are called? A. B. C. D. Nociceptors Gusatory Optic nerve Gyrus Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Receptor for hearing is? Cochlea B. Oval window C. Organ of Corti D. Tympanic membrane A. Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Receptor for hearing is? Cochlea B. Oval window C. Organ of Corti D. Tympanic membrane A. Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Vision Most components of the eye function to help form an accurate visual image, not detect it.  Photoreceptors that detect the image and generate visual nerve impulses are in a single layer of cells in the retina.  https://youtu.be/9lF7F9XYCRE  https://www.youtube.com/watch?v=-ss -nmT7oAA  Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Eyeball Layers  Outer fibrous layer  Middle vascular layer  Inner nervous layer Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Eyeball Outer Fibrous Layer Cornea and sclera  Cornea: transparent; admits light to interior of the eye ◦ Arrangement of collagen fibers; no blood vessels  Sclera: "white" of the eye ◦ Dense fibrous connective tissue  Limbus: junction of the cornea and the sclera Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Eyeball Middle Vascular Layer  Choroid: between the sclera and the retina ◦ Pigment and blood vessels ◦ In most animals, choroid forms the tapetum - highly reflective area in the rear of the eye Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Tapetum lucidium https://www.youtube.com/watch?v=faeY7xf3ryE Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Eyeball Middle Vascular Layer  Iris: pigmented muscular diaphragm ◦ Controls amount of light that enters the posterior part of the eyeball ◦ Pupil: opening at center of iris Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Eyeball Middle Vascular Layer  Ciliary body: ringshaped structure behind the iris ◦ Muscles that adjust shape of the lens to allow near and far vision Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Eyeball Inner Nervous Layer  Retina ◦ Lines the back of the eye ◦ Avascular ◦ Contains the sensory receptors for vision, the rods and cones Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Compartments of the Eyeball Aqueous compartment   Subdivided by the iris into anterior and posterior chambers Contains a clear watery fluid: aqueous humor ◦ Produced in the posterior chamber by cells of the ciliary body Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Compartments of the Eyeball Vitreous compartment   Contains a clear gelatinous fluid called vitreous humor Vitreous humor fills the whole back of the eyeball behind the lens and ciliary body Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Lens  Layers of fibers  Elastic and biconvex  Front surface is in contact with aqueous humor; back surface is in contact with vitreous humor  Helps focus a clear image on the retina Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Lens  Accommodation: process by which the shape of the lens is changed to allow close-up and distant vision ◦ Relaxation of ciliary muscles causes tension on suspensory ligaments; flattens the lens ◦ Contraction of ciliary muscles releases tension on the suspensory ligaments Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Retina Multilayered  Lines most of the vitreous compartment  1.Pigment layer 2.Photoreceptor layer 3.Bipolar cell layer 4.Ganglion cell layer 5.Layer of nerve fibers Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Retina Optic Disc: site where nerve fibers on the inside surface of the retina converge and leave the eye to form the optic nerve  Photoreceptor cells: neurons with modified dendrites  ◦ Rods - more sensitive to light ◦ Cones - more sensitive to color and detail Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Extraocular Structures  Conjunctiva: thin transparent membrane ◦ Covers the front portion of the eyeball and lines the interior surfaces of the eyelids  Conjunctival sac: space between the bulbar and palpebral portions of the conjunctiva Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Extraocular Structures  Eyelids: upper and lower folds of skin lined by the thin, moist conjunctiva  Lateral and medial canthus: corners where the eyelids come together  Tarsal glands: produce waxy substance that helps prevent tears from overflowing onto the face Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Extraocular Structures  Nictitating membrane: third eyelid of domestic animals located medially between eyelids and eyeball ◦ T-shaped plate of ◦ cartilage covered by conjunctiva Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Extraocular Structures  Lacrimal apparatus: ◦ structures that produce and secrete tears and drain them away from the surface of the eye  Nasolacrimal duct Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Review  List the four general types of stimuli that can trigger a response from sensory receptors.  List and describe the visceral senses.  Differentiate between superficial and central temperature sensors.  Describe the structure of the taste buds.  List and describe the special senses.  Describe the structures and functions of the components that make up the ear and the eyeball.  Describe the processes that contribute to the sense of equilibrium.  Describe the structures of the conjunctiva and eyelids. Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc.