It is filled with a watery fluid called the aqueous humor. Hearing involves the signal transduction of mechanical waves into neural signals in the cochlea, within the inner ear. 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). INTRODUCTION TO ANATOMY AND PHYSIOLOGY.ppt - Academia.edu 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. Using the model of the ear find the following structures: ear canal, tympanum (tympanic membrane), ossicles (malleus, incus, stapes in order moving inward into the ear), cochlea, semicircular canals. If you have missed laboratory or class; complete the makeup work below. There are four types of papillae, based on their appearance (Figure 14.3): circumvallate, foliate, filiform, and fungiform. This will help to underscore the relationships between the different components. 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. Overlaying the ciliary body, and visible in the anterior eye, is the iristhe colored part of the eye. Use the standard eye chart (Snellen chart) at the appropriate distances (usually 20 feet) to measure your acuity. These ganglia are located within the spiral-shaped cochlea of the inner ear. However, at the exact center of the retina is a small area known as the fovea. Plate #: _______________ Image that you see: _____________. The sweet taste is the sensitivity of gustatory cells to the presence of glucose dissolved in the saliva. A photon interacting with the molecule causes the flexible double-bonded carbons to change to the trans- conformation, forming all-trans-retinal, which has a straight hydrocarbon chain (Figure 14.17). General senses often contribute to the sense of touch, as described above, or to proprioception (body movement) and kinesthesia (body movement), or to a visceral sense, which is most important to autonomic functions. This book uses the The molecule that activates this receptor is the amino acid L-glutamate. There, amacrine cells additionally contribute to retinal processing before an action potential is produced by the RGC. At the end of the auditory canal is the tympanic membrane, or ear drum, which vibrates after it is struck by sound waves. From there, the axons split to travel to several brain regions. Signal transduction is the process of a receptor detecting specific forms of matter or energy, and activating chemical and electrical changes in neurons. BIOL 1108: Principles of Biology II Lab Manual (Burran and DesRochers), { "Lab_01:_Cystic_Fibrosis_and_Evolutionary_Changes" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Lab_02:_Natural_Selection" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Lab_03:_Ecology_Game" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Lab_04:_Nervous_System" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Lab_05:_Sensory_Systems" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Lab_06:_Circulatory_Systems" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Lab_07:_Respiratory_Systems" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Lab_08-11:_Fetal_Pig_Dissection" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Lab_12:_Endocrine_System" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Lab_13:_Reproduction" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, { BCCC_MASTER_Biology_PLC : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", Biology_II_Laboratory_Manual : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", Biology_I_Laboratory_Manual : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Biology_Labs_(under_construction)" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "BIOL_1107:_Principles_of_Biology_I_Lab_Manual_(Burran_and_DesRochers)" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "BIOL_1108:_Principles_of_Biology_II_Lab_Manual_(Burran_and_DesRochers)" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", General_Biology_Labs : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Unfolding_the_Mystery_of_Life_-_Biology_Lab_Manual_for_Non-Science_Majors_(Genovesi_Blinderman_and_Natale)" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, [ "article:topic", "showtoc:no", "license:ccbysa", "authorname:burrananddesrochers", "program:galileo", "licenseversion:40", "source@https://libguides.daltonstate.edu/PrinciplesofBiology/labmanual" ], https://bio.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fbio.libretexts.org%2FLearning_Objects%2FLaboratory_Experiments%2FGeneral_Biology_Labs%2FBIOL_1108%253A_Principles_of_Biology_II_Lab_Manual_(Burran_and_DesRochers)%2FLab_05%253A_Sensory_Systems, \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}}}\) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\). [Anatomy and physiology of the peripheral nerve] - PubMed Bulbous corpuscles are also known as Ruffini corpuscles, or type II cutaneous mechanoreceptors. Comparing the peak sensitivity and absorbance spectra of the four photopigments suggests that they are most sensitive to particular wavelengths. When a large group of photopigments is bleached, the retina will send information as if opposing visual information is being perceived. A general sense is one that is distributed throughout the body and has receptor cells within the structures of other organs. The orbit is surrounded by cranial bones of the skull. 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. The stereocilia extend up from the hair cells to the overlying tectorial membrane, which is attached medially to the organ of Corti. Ask anyone what the senses are, and they are likely to list the five major sensestaste, smell, touch, hearing, and sight. It is the bipolar cell in the retina that connects a photoreceptor to a retinal ganglion cell (RGC) in the inner synaptic layer. The energy of a photon is represented by its wavelength, with each wavelength of visible light corresponding to a particular color. Some bitter molecules depolarize gustatory cells, whereas others hyperpolarize gustatory cells. Want to cite, share, or modify this book? 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. The facial nerve connects to taste buds in the anterior third of the tongue. _______________ Right eye? Taste buds are arranged along the tongue epithelium. Humans consistently recognize certain odorants (e.g. Publication types Review Olfactory neurons will undergo adaptation and decrease signals to the brain with constant exposure to a stimulus. 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 first two tastes (salty and sour) are triggered by the cations Na+ and H+. Bulbous corpuscles are also present in joint capsules, where they measure stretch in the components of the skeletal system within the joint. The general sense that is usually referred to as touch includes chemical sensation in the form of nociception, or pain. Some cranial nerves contain only sensory axons, such as the olfactory, optic, and vestibulocochlear nerves. The general senses of somatosensation for the face travel through the trigeminal system. Taste involves stimulation of receptor proteins on gustatory cells within taste buds. They preferentially absorb light at different wavelengths, shown in the figure below. The cochlea encodes auditory stimuli for frequencies between 20 and 20,000 Hz, which is the range of sound that human ears can detect. In many sensory organs, additional cells and tissues will contribute to the process of signal transduction. The canal enters the skull through the external auditory meatus of the temporal bone. Connections between the body and the CNS occur through the spinal cord. Merkel cells are located in the stratum basale of the epidermis. The wavelength of visible light determines its color. In addition, two separate clusters of hair cells the saccule and utricle are oriented to detect vertical and horizontal movements. Now, she studies the genetic differences between people and their sensitivities to taste stimuli. 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. You can locate the blind spot by moving the image below toward your head. Write your acuity here: ____________________. 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). Receptor is a term used for the part of a sensory organ that detects the signal. After placing the strip on your tongue do you taste anything? Can you explain any differences? The anterior and posterior vertical canals are oriented at approximately 45 degrees relative to the sagittal plane (Figure 14.12). The affinity for each of these molecules varies, and some will taste sweeter than glucose because they bind to the G proteincoupled receptor differently. Wavelengths of electromagnetic radiation longer than 720 nm fall into the infrared range, whereas wavelengths shorter than 380 nm fall into the ultraviolet range. Therefore, visual acuity, or the sharpness of vision, is greatest at the fovea. Other stimuli include the electromagnetic radiation from visible light. The basilar membrane is the thin membrane that extends from the central core of the cochlea to the edge. Each of the hair cell clusters has a small collection of dense connective tissue attached to the hair cell membrane extensions (stereocilia) to add mass to the system. The scala tympani ends at the round window, which is covered by a membrane that contains the fluid within the scala. All of our muscles and organs depen. Protein fibers tether adjacent hairs together within each array, such that the array will bend in response to movements of the basilar membrane. Anatomy and Physiology Anatomy is the branch of science that deals with the structure (morphology) of body partsforms and organization. The malleus is attached to the tympanic membrane and articulates with the incus. When it contracts, it laterally rotates the eye, in opposition to the superior oblique. Sensory neurons can have either (a) free nerve endings or (b) encapsulated endings. Each olfactory sensory neuron has dendrites that extend from the apical surface of the epithelium into the mucus lining the cavity. In this lab, we will explore the anatomy & physiology used for interpreting the environment both within and outside our bodies. The center of the retina has a small indentation known as the fovea. Vision is the special sense of sight that is based on the transduction of light stimuli received through the eyes. 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. The middle ear consists of a space spanned by three small bones called the ossicles. This distinction reveals how sensory deficits can result from damage in brain regions, even though the sensory organ is intact. 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. Prefrontal Constraints In Volleyball Each component of the motor control system is extremely dependent on the sensory The Somatosensory System Until the retinal molecule is changed back to the 11-cis-retinal shape, the opsin cannot respond to light energy, which is called bleaching. The lateral rectus, which causes abduction of the eye, is innervated by the abducens nerve. The stereocilia are an array of microvilli-like structures arranged from tallest to shortest. Comparisons on the chart will refer to this standard measure. The frequency of the fluid waves match the frequencies of the sound waves (Figure 14.6). These cells are located within the vestibule of the inner ear. a. 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. Individuals can map their tongues for taste buds, once sensitivity thresholds have been determined. When a photon hits retinal, the long hydrocarbon chain of the molecule is biochemically altered. These receptors are G proteincoupled, and will produce a graded membrane potential in the olfactory neurons. The neural signals generated in the vestibular ganglion are transmitted through the vestibulocochlear nerve to the brain stem and cerebellum. 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. Such low frequency vibrations are sensed by mechanoreceptors called Merkel cells, also known as type I cutaneous mechanoreceptors. Blunt force trauma to the face, such as that common in many car accidents, can lead to the loss of the olfactory nerve, and subsequently, loss of the sense of smell. Other somatosensory receptors are found in the joints and muscles. Other monosaccharides such as fructose, or artificial sweeteners such as aspartame (NutraSweet), saccharine, or sucralose (Splenda) also activate the sweet receptors. The Na+ concentration becomes high outside the gustatory cells, creating a strong concentration gradient that drives the diffusion of the ion into the cells. The extraocular muscles are innervated by three cranial nerves. The three ossicles are the malleus, incus, and stapes, which are Latin names that roughly translate to hammer, anvil, and stirrup. Explain your answer. Loss of the sense of smell can result in food tasting bland. Physiology of Sensory system. For example, in the retina, axons from RGCs in the fovea are located at the center of the optic nerve, where they are surrounded by axons from the more peripheral RGCs. For example, when the superior rectus contracts, the eye rotates to look up. They provide information about the position or movement of different parts of the body as well as the length and extent of contraction along with muscle tension. The transparent cornea covers the anterior tip of the eye and allows light to enter the eye. Stimuli in the environment activate specialized receptor cells in the peripheral nervous system. The group of axons called the olfactory tract connect to the olfactory bulb on the ventral surface of the frontal lobe. Anatomy Terms to Know: Extra-ocular muscles, sclera, choroid, pigmented epithelium, fovea, vitreous humor, aqueous humor, iris, lens, ciliary body, cornea, conjunctiva, optic nerve, blind spot (or optic disc), retina [retinal neurons - ganglion cells, amacrine cells, bipolar cells, horizontal cells, photoreceptors (rods, cones)], and occipital (visual) cortex of the brain. The dynamics of capsaicin binding with this transmembrane ion channel is unusual in that the molecule remains bound for a long time. The external ear contains the auricle, ear canal, and tympanic membrane. Also located in the dermis of the skin are lamellated corpuscles, neurons with encapsulated nerve endings that respond to pressure and touch. Anatomy and physiology of pain. Receptors are the cells or structures that detect sensations. Like taste, the sense of smell, or olfaction, is also responsive to chemical stimuli. Sensory Receptors - CliffsNotes Light striking photoreceptor neurons activate networks of retinal neurons. Which ear structures are responsible for the amplification and transfer of sound from the external ear to the inner ear? Light passes through the eyeball via the cornea, pupil, and lens. 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. On top of the otolithic membrane is a layer of calcium carbonate crystals, called otoliths. This intimate connection between the olfactory system and the cerebral cortex is one reason why smell can be a potent trigger of memories and emotion. sucrose), Bitter (various, common test is Ca2+), sour (H+), and umami (glutamate). The other tastes result from food molecules binding to a G proteincoupled receptor. Concentration 1: ______________ Concentration 2: ______________ Concentration 3: ______________ Concentration 4: ______________ Concentration 5: ______________. A significant amount of light is absorbed by these structures before the light reaches the photoreceptor cells. Note the accuracy at each position of their pointing, and determine the most and least accurate positions for localization. LM 412. Legal. These two modalities use thermoreceptors and nociceptors to transduce temperature and pain stimuli, respectively. 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. In many sensory organs, additional cells and tissues will contribute to the process of signal transduction. The outermost layer is the fibrous tunic, which includes the white sclera and clear cornea. Middle ear - contains 3 ossicles, anchored between tympanum & oval window. Common disorders of vision and hearing are also considered, including glaucoma, cataract, age-related hearing impairment and conductive hearing impairment. The chemical senses are taste and smell. Neurons responding to physical force, temperature, and specific chemicals to warn of (potential) damage. The posterior cavity is the space behind the lens that extends to the posterior side of the interior eyeball, where the retina is located. 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. Photoreceptors in the eyes, such as rod cells, are examples of (c) specialized receptor cells. The membrane covering the round window will bulge out or pucker in with the movement of the fluid within the scala tympani. Umami is a Japanese word that means delicious taste, and is often translated to mean savory. A third classification of receptors is by how the receptor transduces stimuli into membrane potential changes. Why or why not? The complexity of the pressure waves is determined by the changes in amplitude and frequency of the sound waves entering the ear. This video gives an abbreviated overview of the visual system by concentrating on the pathway from the eyes to the occipital lobe. Likewise, some bitter molecules increase G protein activation within the gustatory cells, whereas other bitter molecules decrease G protein activation. When the pressure waves from the scala move the basilar membrane, the tectorial membrane slides across the stereocilia. This article describes the anatomy and physiology of the sensory systems, examining structures associated with vision and hearing, equilibrium and sensation. The organs of Corti contain hair cells, which are named for the hair-like stereocilia extending from the cells apical surfaces (Figure 14.8). Deep pressure and vibration is transduced by lamellated (Pacinian) corpuscles, which are receptors with encapsulated endings found deep in the dermis, or subcutaneous tissue. Because these axons pass through the retina, there are no photoreceptors at the very back of the eye, where the optic nerve begins. Receptor can refer to specific protein molecules which first interact with the matter or energy, the cell(s) that contains those proteins, or an assembly of cells in the larger organ. Tears are produced by the lacrimal gland, located just inside the orbit, superior and lateral to the eyeball. For example, a bright blue light that has a wavelength of approximately 450 nm would activate the red cones minimally, the green cones marginally, and the blue cones predominantly. Mechanical, chemical, or thermal stimuli beyond a set threshold will elicit painful sensations. The amplified vibration is picked up by the oval window causing pressure waves in the fluid of the scala vestibuli and scala tympani. Movements generate electrical signals in hair cells, which signal sensory neurons with released chemical neurotransmitters. The stapes is then attached to the inner ear, where the sound waves will be transduced into a neural signal. 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. Eyelid. If you drag your finger across a textured surface, the skin of your finger will vibrate. She recognized that her sense of taste was unique compared with other people she knew. As airborne molecules are inhaled through the nose, they pass over the olfactory epithelial region and dissolve into the mucus. The semicircular canals contain several ampullae, with some oriented horizontally and others oriented vertically. This molecule is referred to as 11-cis-retinal. Resources Notes: Chapter 2: Tissues | Presentation Slides Olfactory signals are the only sensory system to send signals directly to the limbic system, which is integral to memory and emotional functions. The visual stimulus in the middle of the field of view falls on the fovea and is in the sharpest focus. Other species and artificial technologies can detect other parts of this energy spectrum. The anterior cavity is the space between the cornea and lens, including the iris and ciliary body. The auricle, ear canal, and tympanic membrane are often referred to as the external ear. The choroid is posterior to the ciliary body, a muscular structure that is attached to the lens by suspensory ligaments, or zonule fibers. These odorant molecules bind to proteins that keep them dissolved in the mucus and help transport them to the olfactory dendrites. Relate damage in the spinal cord to sensory or motor deficits. The entry of Na+ into these cells results in the depolarization of the cell membrane and the generation of a receptor potential. Two types of somatosensory signals that are transduced by free nerve endings are pain and temperature. As the spinal nerve nears the spinal cord, it splits into dorsal and ventral roots. The difference in inertia between the hair cell stereocilia and the otolithic membrane in which they are embedded leads to a shearing force that causes the stereocilia to bend in the direction of that linear acceleration. For example, a molecule in food can serve as a ligand for taste receptors. An exteroceptor is a receptor that is located near a stimulus in the external environment, such as the somatosensory receptors that are located in the skin.