anatomy and physiology of sensory system ppt
The stereocilia are an array of microvilli-like structures arranged from tallest to shortest. You will have to identify these structures using both the sheep or cow eye and the models. Learning Objectives. You can estimate this distance (d, in mm) of your retinal structures by recording the distance when the image disappears (x), and measuring the distance between the cross and circle in the image (d). Merkel cells are located in the stratum basale of the epidermis. Check with your instructor to determine which way they want you to cut the eye in half. Therefore, as the frequency of a sound changes, different hair cells are activated all along the basilar membrane. 14.1 Sensory Perception - Anatomy and Physiology 2e - OpenStax Rotational movement of the head is encoded by the hair cells in the base of the semicircular canals. Sensory systems include organs, tissues, and cells that receive stimuli from the environment and send this information to the brain for processing. Chemical stimuli can be interpreted by a chemoreceptor that interprets chemical stimuli, such as an objects taste or smell. This complexity allows you to be aware of your surroundings and take appropriate actions. The highest concentration of bitter receptors appear to be in the posterior tongue, where a gag reflex could still spit out poisonous food. Additionally, pain is primarily a chemical sense that interprets the presence of chemicals from tissue damage, or similar intense stimuli, through a nociceptor. Other somatosensory receptors are found in the joints and muscles. We do not perceive the blind spot because the brain interpolates information to fill in the gaps. Bitter taste is similar to sweet in that food molecules bind to G proteincoupled receptors. Bulbous corpuscles are also known as Ruffini corpuscles, or type II cutaneous mechanoreceptors. The malleus is attached to the tympanic membrane and articulates with the incus. The three types of cone opsins, being sensitive to different wavelengths of light, provide us with color vision. As the head rotates in a plane parallel to the semicircular canal, the fluid lags, deflecting the cupula in the direction opposite to the head movement. Stand there and cover one eye without squinting. The inner ear is often described as a bony labyrinth, as it is composed of a series of canals embedded within the temporal bone. (Micrograph provided by the Regents of University of Michigan Medical School 2012). Deep pressure and vibration is transduced by lamellated (Pacinian) corpuscles, which are receptors with encapsulated endings found deep in the dermis, or subcutaneous tissue. An individual sensory modality represents the sensation of a specific type of stimulus. The eye is located within the orbit and surrounded by soft tissues that protect and support its function. 1_Digital Dots Adobe Photoshop Image Microsoft Photo Editor 3.0 Photo Sensory Overview Classification of Sensory System by Structural Complexity Sensory Receptors - Overview Sensory Transduction Complexity Range of Receptors 4 Types of . Each olfactory sensory neuron has dendrites that extend from the apical surface of the epithelium into the mucus lining the cavity. When a photon hits retinal, the long hydrocarbon chain of the molecule is biochemically altered. Whereas spinal information is contralateral, cranial nerve systems, with some exceptions, are mostly ipsilateral, meaning that a cranial nerve on the right side of the head is connected to the right side of the brain. There are several ways to slice through an eye. These modalities include pressure, vibration, light touch, tickle, itch, temperature, pain, proprioception, and kinesthesia. Muscles in the iris alter pupil size to vary light entering the eye. Therefore, the olfactory neurons are regularly replaced within the nasal epithelium, after which the axons of the new neurons must find their appropriate connections in the olfactory bulb. Once any sensory cell transduces a stimulus into a nerve impulse, that impulse has to travel along axons to reach the CNS. Professional fighters often experience anosmia because of repeated trauma to face and head. The retinal molecule has two isomers, (a) one before a photon interacts with it and (b) one that is altered through photoisomerization. sight, touch, hearing, taste, smell. Chapter 10: Sensory Physiology Author: Kindy Last modified by: Kindy Created Date: 10/3/1999 7:36:15 PM . Receptors can be classified structurally on the basis of cell type and their position in relation to stimuli they sense. Except where otherwise noted, textbooks on this site Finally, a proprioceptor is a receptor located near a moving part of the body, such as a muscle, that interprets the positions of the tissues as they move. Do you and your lab partner vary in your sensitivities? Specific molecules (odorants) bind to receptor proteins and activate neural electrical signals (action potentials). Similar to the smell test, list the concentrations of the two substances and circle the one where you can begin to taste the substance. The otolithic membrane moves separately from the macula in response to head movements. Resources Notes: Chapter 2: Tissues | Presentation Slides consent of Rice University. Rods are so sensitive to light that a single photon can result in an action potential from a rods corresponding RGC. Anatomy and Physiology Anatomy is the branch of science that deals with the structure (morphology) of body partsforms and organization. The odorantprotein complex binds to a receptor protein within the cell membrane of an olfactory dendrite. As the spinal nerve nears the spinal cord, it splits into dorsal and ventral roots. This article describes the anatomy and physiology of the sensory systems, examining structures associated with vision and hearing, equilibrium and sensation. Anatomy and physiology of the senses - PubMed The nasal epithelium, including the olfactory cells, can be harmed by airborne toxic chemicals. Perception is dependent on sensation, but not all sensations are perceived. The molecule that activates this receptor is the amino acid L-glutamate. The cochlea is attached to the stapes through the oval window. Protein fibers tether adjacent hairs together within each array, such that the array will bend in response to movements of the basilar membrane. The bony orbits surround the eyeballs, protecting them and anchoring the soft tissues of the eye (Figure 14.13). Why or why not? The anterior and posterior vertical canals are oriented at approximately 45 degrees relative to the sagittal plane (Figure 14.12). The fluid-filled tube, now called the scala tympani, returns to the base of the cochlea, this time travelling under the cochlear duct. The shape change of retinal in the photoreceptors initiates visual transduction in the retina. Stimuli from varying sources, and of different types, are received and changed into the electrochemical signals of the nervous system. If you have missed laboratory or class; complete the makeup work below. mucous membrane that lines the anterior surface of the eye and the posterior surface of the eyelid. The C-shaped curves of the auricle direct sound waves toward the auditory canal. The general senses of somatosensation for the face travel through the trigeminal system. If you answered YES!, then you have the dominant genotype for the PTC gene! The movement of two canals within a plane results in information about the direction in which the head is moving, and activation of all six canals can give a very precise indication of head movement in three dimensions. The Eustachian (or auditory) tube connects the middle ear cavity to the pharynx (it is an evolutionary descendant of pharyngeal pouches). Specific locations along the length of the duct encode specific frequencies, or pitches. Within the structure of the papillae are taste buds that contain specialized gustatory receptor cells for the transduction of taste stimuli. If you are redistributing all or part of this book in a print format, Relate damage in the spinal cord to sensory or motor deficits. At the fovea, the retina lacks the supporting cells and blood vessels, and only contains photoreceptors. The absorbance of rhodopsin in the rods is much more sensitive than in the cone opsins; specifically, rods are sensitive to vision in low light conditions, and cones are sensitive to brighter conditions. They alter the lens to aid focusing. By the end of this section, you will be able to: A major role of sensory receptors is to help us learn about the environment around us, or about the state of our internal environment. Other species and artificial technologies can detect other parts of this energy spectrum. In skeletal muscle tissue, these stretch receptors are called muscle spindles. Have the subject stand with their back to the whiteboard. Typically, spinal nerve systems that connect to the brain are contralateral, in that the right side of the body is connected to the left side of the brain and the left side of the body to the right side of the brain. The difference in visual acuity between the fovea and peripheral retina is easily evidenced by looking directly at a word in the middle of this paragraph. The middle ear consists of a space spanned by three small bones called the ossicles. Loss of the sense of smell can result in food tasting bland. This means that its receptors are not associated with a specialized organ, but are instead spread throughout the body in a variety of organs. HISTORICAL NOTE: The standard map of taste buds common in many lab manuals has been disproved by subsequent research (J. are licensed under a, Structural Organization of the Human Body, Elements and Atoms: The Building Blocks of Matter, Inorganic Compounds Essential to Human Functioning, Organic Compounds Essential to Human Functioning, Nervous Tissue Mediates Perception and Response, Diseases, Disorders, and Injuries of the Integumentary System, Exercise, Nutrition, Hormones, and Bone Tissue, Calcium Homeostasis: Interactions of the Skeletal System and Other Organ Systems, Embryonic Development of the Axial Skeleton, Development and Regeneration of Muscle Tissue, Interactions of Skeletal Muscles, Their Fascicle Arrangement, and Their Lever Systems, Axial Muscles of the Head, Neck, and Back, Axial Muscles of the Abdominal Wall, and Thorax, Muscles of the Pectoral Girdle and Upper Limbs, Appendicular Muscles of the Pelvic Girdle and Lower Limbs, Basic Structure and Function of the Nervous System, Circulation and the Central Nervous System, Divisions of the Autonomic Nervous System, Organs with Secondary Endocrine Functions, Development and Aging of the Endocrine System, The Cardiovascular System: Blood Vessels and Circulation, Blood Flow, Blood Pressure, and Resistance, Homeostatic Regulation of the Vascular System, Development of Blood Vessels and Fetal Circulation, Anatomy of the Lymphatic and Immune Systems, Barrier Defenses and the Innate Immune Response, The Adaptive Immune Response: T lymphocytes and Their Functional Types, The Adaptive Immune Response: B-lymphocytes and Antibodies, Diseases Associated with Depressed or Overactive Immune Responses, Energy, Maintenance, and Environmental Exchange, Organs and Structures of the Respiratory System, Embryonic Development of the Respiratory System, Digestive System Processes and Regulation, Accessory Organs in Digestion: The Liver, Pancreas, and Gallbladder, Chemical Digestion and Absorption: A Closer Look, Regulation of Fluid Volume and Composition, Fluid, Electrolyte, and Acid-Base Balance, Human Development and the Continuity of Life, Anatomy and Physiology of the Testicular Reproductive System, Anatomy and Physiology of the Ovarian Reproductive System, Development of the Male and Female Reproductive Systems, Changes During Pregnancy, Labor, and Birth, Adjustments of the Infant at Birth and Postnatal Stages. The eye is also divided into two cavities: the anterior cavity and the posterior cavity. PPT - Anatomy and Physiology PowerPoint Presentation, free download As one of the canals moves in an arc with the head, the internal fluid moves in the opposite direction, causing the cupula and stereocilia to bend. Watch this video to learn about Dr. Danielle Reed of the Monell Chemical Senses Center in Philadelphia, Pennsylvania, who became interested in science at an early age because of her sensory experiences. Patterns of signals are integrated in the cerebellum and parietal cortex. The stereocilia are tethered together by proteins that open ion channels when the array is bent toward the tallest member of their array, and closed when the array is bent toward the shortest member of their array. Find an individual taste bud and draw it in the space provided. Ch. 1 Introduction - Anatomy and Physiology | OpenStax Receptors are the cells or structures that detect sensations. Some structures are quite tough including the lens and sclera (in Latin, sclera means tough!). In the video, there is a brief image of a person sticking out their tongue, which has been covered with a colored dye. Similar to the olfaction tests, serial dilutions of basic chemicals can be used to test for variable sensitivity in subjects. covers outer layer of eye- closes to protect the eye and allow for sleep and rest. a. The tendon inserts obliquely into the superior surface of the eye. In addition, two separate clusters of hair cells the saccule and utricle are oriented to detect vertical and horizontal movements. A seventh muscle in the orbit is the levator palpebrae superioris, which is responsible for elevating and retracting the upper eyelid, a movement that usually occurs in concert with elevation of the eye by the superior rectus (see Figure 14.13). The opsins are sensitive to limited wavelengths of light. Follicles are also wrapped in a plexus of nerve endings known as the hair follicle plexus. Humans consistently recognize certain odorants (e.g. __________________, ______________________________________________________________________________________________________________________________________________, Color-blindness can be tested with an appropriate Standard Pseudoisochromatic plates (e.g. INTRODUCTION TO ANATOMY AND PHYSIOLOGY.ppt - Academia.edu By containing toxic alkaloids, the plant is less susceptible to microbe infection and less attractive to herbivores. One bitter taste receptor protein is encoded by the PTC gene, or TAS2R38 (discovered in 2003). A receptor cell is changed directly by a stimulus. At the uppermost tip of the cochlea, the scala vestibuli curves over the top of the cochlear duct. The large, fleshy structure on the lateral aspect of the head is known as the auricle. A particular body part's function depends on its structure. This first fiber in the pathway synapses on a thalamic cell that then projects to the visual cortex in the occipital lobe where seeing, or visual perception, takes place. Because the tectorial membrane only moves where the basilar membrane moves, the hair cells in this region will also only respond to sounds of this specific frequency. Retinal is a hydrocarbon molecule related to vitamin A. In this lab, we will explore the anatomy & physiology used for interpreting the environment both within and outside our bodies. Concentration 1: _____________ Concentration 2: _____________ Concentration 3: _____________ Concentration 4: _____________ Concentration 5: _____________. If you exhibit some degree of colorblindness, what type? LM 1600. vision, taste). Other monosaccharides such as fructose, or artificial sweeteners such as aspartame (NutraSweet), saccharine, or sucralose (Splenda) also activate the sweet receptors. There are at least 30 different genes coding for bitter taste receptors. This book uses the 6: Sensory Physiology - Biology LibreTexts Bulbous corpuscles are also present in joint capsules, where they measure stretch in the components of the skeletal system within the joint. The middle ear is connected to the pharynx through the Eustachian tube, which helps equilibrate air pressure across the tympanic membrane. Do you have the same acuity in both eyes? Sound is transduced into neural signals within the cochlear region of the inner ear, which contains the sensory neurons of the spiral ganglia. The olfactory receptor neurons are located in a small region within the superior nasal cavity (Figure 14.4). Conjunctiva. These new axons grow along the axons that are already in place in the cranial nerve. Using the plates are you able to detect the image present for the presented colors? Wavelengths of electromagnetic radiation longer than 720 nm fall into the infrared range, whereas wavelengths shorter than 380 nm fall into the ultraviolet range. This is because the fovea is where the least amount of incoming light is absorbed by other retinal structures (see Figure 14.15). Light falling on the retina causes chemical changes to pigment molecules in the photoreceptors, ultimately leading to a change in the activity of the RGCs. LM 412. In humans, from 100-200 different functional receptor proteins have been identified (there are over 1000 in rodents). For example, a molecule in food can serve as a ligand for taste receptors. sucrose), Bitter (various, common test is Ca2+), sour (H+), and umami (glutamate). Specifically, photons cause some of the double-bonded carbons within the chain to switch from a cis to a trans conformation. The inner surface of each lid is a thin membrane known as the palpebral conjunctiva. Common disorders of vision and hearing are also considered, including glaucoma, cataract, age-related hearing impairment and conductive hearing impairment. The stereocilia of the hair cells extend into a viscous gel called the otolithic membrane (Figure 14.11). The sensory system is a network of sensory nerves and tissues that enable the body to receive information about its surroundings. Such low frequency vibrations are sensed by mechanoreceptors called Merkel cells, also known as type I cutaneous mechanoreceptors. The group of axons called the olfactory tract connect to the olfactory bulb on the ventral surface of the frontal lobe. These cells release neurotransmitters onto a bipolar cell, which then synapses with the optic nerve neurons. The incus, in turn, articulates with the stapes. All of the other muscles are innervated by the oculomotor nerve, as is the levator palpebrae superioris. The auditory receptors for the ear (shown below) include the: Within the inner ear, the 3 semicircular canals are arranged at right angles to each other, and they contain hair cells and fluid similar to the cochlea. The iris is a smooth muscle that opens or closes the pupil, which is the hole at the center of the eye that allows light to enter. Are you very sensitive to tastes? Ask for help if you need it. Not surprisingly, dishes that contain meat are often described as savory. However, at the exact center of the retina is a small area known as the fovea. Alkaloids are nitrogen containing molecules that are commonly found in bitter-tasting plant products, such as coffee, hops (in beer), tannins (in wine), tea, and aspirin. Pressure, vibration, muscle stretch, and the movement of hair by an external stimulus, are all sensed by mechanoreceptors. (Micrograph provided by the Regents of University of Michigan Medical School 2012). The organs of Corti lie on top of the basilar membrane, which is the side of the cochlear duct located between the organs of Corti and the scala tympani. The center of the retina has a small indentation known as the fovea. Sour flavors are, essentially, the perception of acids in our food. Some sources will also refer to this structure as the pinna, though that term is more appropriate for a structure that can be moved, such as the external ear of a cat. Also, taste is often integrated as a perception with olfactory sensory input. This explains why some elderly people salt their food more than younger people do. Two types of somatosensory signals that are transduced by free nerve endings are pain and temperature. Sensory Systems: Anatomy, Physiology and Pathophysiology provides a comprehensive description of how human sensory systems function, with comparisons of the five senses and detailed descriptions of the functions of each of them. Nociceptive Pain. This region is referred to as the olfactory epithelium and contains bipolar sensory neurons. Humans have five special senses: olfaction (smell), gustation (taste), equilibrium (balance and body position), vision, and hearing. Measure the distance from the image to your eye. The photoreceptors (rods and cones) change their membrane potential when stimulated by light energy. Sensory System f Sensory Organs (Receptors) Monitor the internal and external environment Transmit signals from periphery to CNS for processing Critical for homeostasis f Types of Sensory Receptors Functional Types Based on modality (type of environmental change they sense) 1. Hearing, or audition, is the transduction of sound waves into a neural signal that is made possible by the structures of the ear (Figure 14.5). Anatomy and Physiology Environmental Science APES Welcome to Ms. Stephens' Anatomy & Physiology Class Email: astephensscience@gmail.com Class website: www.astephensscience.com Tutorial: Thursday (3:45-4:45) Announcements: The class website contains lesson plans, notes, and study links. An interoceptor is one that interprets stimuli from internal organs and tissues, such as the receptors that sense the increase in blood pressure in the aorta or carotid sinus. This will help to underscore the relationships between the different components. Hearing involves the signal transduction of mechanical waves into neural signals in the cochlea, within the inner ear. Dr. Reed discovered that she is a non-taster, which explains why she perceived bitterness differently than other people she knew. Anosmia may also be related to some presentations of mild depression, because the loss of enjoyment of food may lead to a general sense of despair. The extraocular muscles are innervated by three cranial nerves. The cochlear duct contains several organs of Corti, which transduce the wave motion of the two scala into neural signals. She recognized that her sense of taste was unique compared with other people she knew. Taste involves stimulation of receptor proteins on gustatory cells within taste buds. Because of this, many bitter foods that are normally ingested are often combined with a sweet component to make them more palatable (cream and sugar in coffee, for example). Taste buds are arranged along the tongue epithelium. The choroid is a layer of highly vascularized connective tissue that provides a blood supply to the eyeball. The extraocular muscles move the eye within the orbit. Corrective lenses: If you have contacts, keep them in, but if you wear glasses you may want to try the test with and without them to see just how much your corrective lenses improve your vision! The exact position of the head is interpreted by the brain based on the pattern of hair-cell depolarization. PTC tasting test kits provide material to survey the class. Can you label any structures if you use the above diagram as a guide? Color vision results from the interaction of 3 sub-types of cone photoreceptors. Smell is the one sensory modality that does not synapse in the thalamus before connecting to the cerebral cortex.
