anatomy and physiology of sensory system ppt anatomy and physiology of sensory system ppt

Check with your instructor to determine which way they want you to cut the eye in half. Watch this video to learn more about a transverse section through the brain that depicts the visual pathway from the eye to the occipital cortex. The three ossicles are the malleus, incus, and stapes, which are Latin names that roughly translate to hammer, anvil, and stirrup. Because these axons pass through the retina, there are no photoreceptors at the very back of the eye, where the optic nerve begins. 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. Therefore, our low-light vision isin essencein grayscale. 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. 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. A branch may also turn into the posterior (dorsal) column of the white matter to connect with the brain. 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). The main sensory modalities can be described on the basis of how each is transduced. They are the superior rectus, medial rectus, inferior rectus, and lateral rectus. Body parts form a well-organized unitthe human organism. Dr. Reed discovered that she is a non-taster, which explains why she perceived bitterness differently than other people she knew. Sour flavors are, essentially, the perception of acids in our food. Another way that receptors can be classified is based on their location relative to the stimuli. If you think that you can see colors in the dark, it is most likely because your brain knows what color something is and is relying on that memory. The sclera accounts for five sixths of the surface of the eye, most of which is not visible, though humans are unique compared with many other species in having so much of the white of the eye visible (Figure 14.15). The fluid-filled tube, now called the scala tympani, returns to the base of the cochlea, this time travelling under the cochlear duct. The unit of Hertz measures the frequency of sound waves in terms of cycles produced per second. The first half of the pathway is the projection from the RGCs through the optic nerve to the lateral geniculate nucleus in the thalamus on either side. At the uppermost tip of the cochlea, the scala vestibuli curves over the top of the cochlear duct. Such stretch receptors can also prevent over-contraction of a muscle. As the fluid waves move through the scala vestibuli and scala tympani, the basilar membrane moves at a specific spot, depending on the frequency of the waves. The standing sound wave generated in the cochlea by the movement of the oval window deflects the basilar membrane on the basis of the frequency of sound. The specific response depends on which molecule is binding to the receptor. The humors are fluids filling the anterior and posterior chambers of the eye. Can you label any structures if you use the above diagram as a guide? Without moving your eyes off that word, notice that words at the beginning or end of the paragraph are not in focus. In addition to describing anatomy and function, the book also provides insight as to how sensory information is processed in the brain to provide the basis for . These cells release neurotransmitters onto a bipolar cell, which then synapses with the optic nerve neurons. She recognized that her sense of taste was unique compared with other people she knew. The general senses of somatosensation for the face travel through the trigeminal system. The stereocilia of the hair cells extend into a viscous gel called the otolithic membrane (Figure 14.11). Connections between the body and the CNS occur through the spinal cord. As a result, a large part of the neural function of the eyes is concerned with moving the eyes and head so that important visual stimuli are centered on the fovea. https://openstax.org/books/anatomy-and-physiology-2e/pages/1-introduction, https://openstax.org/books/anatomy-and-physiology-2e/pages/14-1-sensory-perception, Creative Commons Attribution 4.0 International License, Dermis, cornea, tongue, joint capsules, visceral organs, Pain, temperature, mechanical deformation, Epidermaldermal junction, mucosal membranes, Papillary dermis, especially in the fingertips and lips, Deep pressure, high-frequency vibration (around 250 Hz), Wrapped around hair follicles in the dermis, Describe different types of sensory receptors, Describe the structures responsible for the special senses of taste, smell, hearing, balance, and vision, Distinguish how different tastes are transduced, Describe the means of mechanoreception for hearing and balance, List the supporting structures around the eye and describe the structure of the eyeball, Describe the processes of phototransduction. The first two tastes (salty and sour) are triggered by the cations Na+ and H+. Perception is dependent on sensation, but not all sensations are perceived. Now, she studies the genetic differences between people and their sensitivities to taste stimuli. An individual sensory modality represents the sensation of a specific type of stimulus. Eventually, patterns of ganglion cells signals are integrated within the brain (in the occipital cortex) to generate the perception of complex images. The most obvious omission from this list is balance. We recommend using a The semicircular canals are three ring-like extensions of the vestibule. Finally, vision involves the activation of photoreceptors. Nociceptive Pain. 3 285-296 doi: 10.1083/jcb.201003144). Stimuli in the environment activate specialized receptor cells in the peripheral nervous system. 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. sodium ions), Various neurons that respond to physical movements, Neurons responding to stretch and contraction of muscles & tendons. The chemical senses are taste and smell. Pressure, vibration, muscle stretch, and the movement of hair by an external stimulus, are all sensed by mechanoreceptors. Frequencies as low as 20 Hz are detected by hair cells at the apex, or tip, of the cochlea. Listing all the different sensory modalities, which can number as many as 17, involves separating the five major senses into more specific categories, or submodalities, of the larger sense. The anterior cavity is the space between the cornea and lens, including the iris and ciliary body. Information is integrated along the brain stem and in the temporal cortex. a. Middle ear - contains 3 ossicles, anchored between tympanum & oval window. Anatomy And Physiology Of Lens PowerPoint PPT Presentations - PowerShow When the pressure waves from the scala move the basilar membrane, the tectorial membrane slides across the stereocilia. PPT Chapter 10: Sensory Physiology - Medical University of South Carolina A cross-sectional view of the cochlea shows that the scala vestibuli and scala tympani run along both sides of the cochlear duct (Figure 14.7). The vagus nerve connects to taste buds in the extreme posterior of the tongue, verging on the pharynx, which are more sensitive to noxious stimuli such as bitterness. The odorantprotein complex binds to a receptor protein within the cell membrane of an olfactory dendrite. 6.3: Somatosensation The Eustachian (or auditory) tube connects the middle ear cavity to the pharynx (it is an evolutionary descendant of pharyngeal pouches). Proprioceptive Sensations- relating to the physical state of the body (position, tendons, muscles, equilibrium) Visceral Sensations- sensations from the internal organs Deep Sensations- come from the deep tissues (fascia, muscles, and bone) 4 Detection and Transmission of Tactile Sensations Interrelaitons Among the Tactile Sensations of Touch, When you eat something salty, the salt crystals dissociate into the component ions Na+ and Cl, which dissolve into the saliva in your mouth. Below, list the micromolar concentrations of mint and circle the one where you can begin to smell the mint. Some bitter molecules depolarize gustatory cells, whereas others hyperpolarize gustatory cells. Raised bumps called papillae (singular = papilla) contain the structures for gustatory transduction. Photoreceptors in the eyes, such as rod cells, are examples of (c) specialized receptor cells. However, cones cannot react to low-intensity light, and rods do not sense the color of light. b. Merkel disks - attached to nerve endings of the epidermis. Movement of the eye within the orbit is accomplished by the contraction of six extraocular muscles that originate from the bones of the orbit and insert into the surface of the eyeball (Figure 14.14). The moving otolithic membrane, in turn, bends the sterocilia, causing some hair cells to depolarize as others hyperpolarize. Also, taste is often integrated as a perception with olfactory sensory input. 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). Free Nerve Endings Direct stimulation of sensory neurons the sensory neuron is also the receptor dendrites of sensory neurons 1. The essential component is neurons, the major functional cells in nervous tissue. Using the plates are you able to detect the image present for the presented colors? Uploaded on Jan 02, 2020 James P Dunbar + Follow tion visceral pain pain transmission noxious stimuli referred visceral pain Mechanical, chemical, or thermal stimuli beyond a set threshold will elicit painful sensations. Rotation of the eye by the two oblique muscles is necessary because the eye is not perfectly aligned on the sagittal plane. Do you have the same acuity in both eyes? Some travel to the cerebrum, specifically to the primary olfactory cortex that is located in the inferior and medial areas of the temporal lobe. The inner ear is often described as a bony labyrinth, as it is composed of a series of canals embedded within the temporal bone. There are four types of papillae, based on their appearance (Figure 14.3): circumvallate, foliate, filiform, and fungiform. Photoreceptors in the eyes, such as rod cells, are examples of (c) specialized receptor cells. Like sweet and bitter, it is based on the activation of G proteincoupled receptors by a specific molecule. Like taste, the sense of smell, or olfaction, is also responsive to chemical stimuli. Conjunctiva. The eyelids, with lashes at their leading edges, help to protect the eye from abrasions by blocking particles that may land on the surface of the eye. The organ of Corti, containing the mechanoreceptor hair cells, is adjacent to the scala tympani, where it sits atop the basilar membrane. Structure of Sensory Receptor Sensations can be produced mainly by very simple kinds of receptors or complex sense organs receptors for General Senses are relatively simple A. Photoreceptor cells have two parts, the inner segment and the outer segment (Figure 14.16). The stapes is then attached to the inner ear, where the sound waves will be transduced into a neural signal. A particular body part's function depends on its structure. Others project to structures within the limbic system and hypothalamus, where smells become associated with long-term memory and emotional responses. Capsaicin molecules bind to a transmembrane ion channel in nociceptors that is sensitive to temperatures above 37C. You will work in groups of two or three to dissect an eye. Toward the edges of the retina, several photoreceptors converge on RGCs (through the bipolar cells) up to a ratio of 50 to 1. These modalities include pressure, vibration, light touch, tickle, itch, temperature, pain, proprioception, and kinesthesia. Some stimuli are ions and macromolecules that affect transmembrane receptor proteins when these chemicals diffuse across the cell membrane. Have the subject stand with their back to the whiteboard. These cells release neurotransmitters onto a bipolar cell, which then synapses with the optic nerve neurons. Except where otherwise noted, textbooks on this site The middle layer of the eye is the vascular tunic, which is mostly composed of the choroid, ciliary body, and iris. Possible Specimens & Models for examination: (sheep or cow) eyeballs for dissection, microscope slides of the retina, and models of eyes. Perception of the network of interconnected neuron signals is eventually perceived in the occipital cortex. ________. However, this increased sodium intake can increase blood volume and blood pressure, increasing the risk of cardiovascular diseases in the elderly. Specific wavelengths of sound cause specific regions of the basilar membrane to vibrate, much like the keys of a piano produce sound at different frequencies. 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. The sensory system is a network of sensory nerves and tissues that enable the body to receive information about its surroundings. 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. However, at the exact center of the retina is a small area known as the fovea. Learning Objectives. You are responsible for identifying these major anatomical structures of the eye: sclera (tough, outer layer), choroid (dark, middle layer), pigmented epithelium, fovea, vitreous humor, aqueous humor, iris, lens, ciliary body, cornea, conjunctiva, optic nerve, blind spot (or optic disc), retina (thin, and pale inner layer). After placing the strip on your tongue do you taste anything? The hair cell is a mechanoreceptor with an array of stereocilia emerging from its apical surface. For example, the general sense of touch, which is known as somatosensation, can be separated into light pressure, deep pressure, vibration, itch, pain, temperature, or hair movement. Watch this video to learn more about how the structures of the ear convert sound waves into a neural signal by moving the hairs, or stereocilia, of the cochlear duct. Professional fighters often experience anosmia because of repeated trauma to face and head. 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. Increasing hydrogen ion concentrations in the saliva (lowering saliva pH) triggers progressively stronger graded potentials in the gustatory cells. A third classification of receptors is by how the receptor transduces stimuli into membrane potential changes. The surface of the tongue, along with the rest of the oral cavity, is lined by a stratified squamous epithelium. Within the realm of physiology, senses can be classified as either general or specific. The board should be marked at approximately shoulder height with centimeter units covering ~1 meter. Note that the photoreceptors in the retina (rods and cones) are located behind the axons, RGCs, bipolar cells, and retinal blood vessels. Choroid body muscles surround the lens. There are several ways to slice through an eye. As vibrations of the ossicles travel through the oval window, the fluid of the scala vestibuli and scala tympani moves in a wave-like motion. For example, when the superior rectus contracts, the eye rotates to look up. Neurotransmitters from the gustatory cells can activate sensory neurons in the facial, glossopharyngeal, and vagus cranial nerves. Young, James A. Bulbous corpuscles are also present in joint capsules, where they measure stretch in the components of the skeletal system within the joint. The human sensory system is highly evolved and processes thousands of incoming messages simultaneously. When the stereocilia bend toward the shortest member of their array, the tension on the tethers slackens and the ion channels close. The stereocilia extend up from the hair cells to the overlying tectorial membrane, which is attached medially to the organ of Corti. Stressed or damaged tissues release chemicals that activate receptor proteins in the nociceptors. 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 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. The eye can focus light images on the retina using the cornea and the lens. Sensory epithelial cells release neurotransmitter signal molecules to sensory neurons of cranial nerves. Also, what is referred to simply as touch can be further subdivided into pressure, vibration, stretch, and hair-follicle position, on the basis of the type of mechanoreceptors that perceive these touch sensations. These nerve endings detect the movement of hair at the surface of the skin, such as when an insect may be walking along the skin. These cells are located within the vestibule of the inner ear. The conjunctiva extends over the white areas of the eye (the sclera), connecting the eyelids to the eyeball. Strike the fork so it makes a sound and move it to front, back, side, and top of the head at a constant distance, holding it to allow the subject to point out the location. Why or why not? This is how Dr. Reed is able to visualize and count papillae on the surface of the tongue. The central integration may then lead to a motor response. The scala vestibuli extends from the oval window, travelling above the cochlear duct, which is the central cavity of the cochlea that contains the sound-transducing neurons. In skeletal muscle tissue, these stretch receptors are called muscle spindles. Cone outer segments are short, tapered shapes with folds of membrane in place of the discs in the rods. Comparing the peak sensitivity and absorbance spectra of the four photopigments suggests that they are most sensitive to particular wavelengths. The glossopharyngeal nerve connects to taste buds in the posterior two thirds of the tongue. mucous membrane that lines the anterior surface of the eye and the posterior surface of the eyelid. PPT - Anatomy and physiology of pain PowerPoint Presentation, free This spasm is a reflex that is initiated by stretch receptors to avoid muscle tearing. On top of the otolithic membrane is a layer of calcium carbonate crystals, called otoliths. List the positions for localization from most to least accurate: Describe any differences in relation to the sensory input required to maintain balance. Retinal is a hydrocarbon molecule related to vitamin A. The relative activation of the three different cones is calculated by the brain, which perceives the color as blue. Sensory neurons can have either (a) free nerve endings or (b) encapsulated endings. Inner ear Cochlea, which contains the hair cells (receptors) within the Organ of Corti. The frequency of the fluid waves match the frequencies of the sound waves (Figure 14.6).