anatomy and physiology of sensory system ppt

Eventually, patterns of ganglion cells signals are integrated within the brain (in the occipital cortex) to generate the perception of complex images. Sensory neurons can have either (a) free nerve endings or (b) encapsulated endings. Receptor cell types can be classified on the basis of their structure. Sensory (olfactory) neurons are present at the top of the nasal cavity, extending their axons into the cranium. These two modalities use thermoreceptors and nociceptors to transduce temperature and pain stimuli, respectively. Temperature receptors are stimulated when local temperatures differ from body temperature. 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. Toward the edges of the retina, several photoreceptors converge on RGCs (through the bipolar cells) up to a ratio of 50 to 1. The specific response depends on which molecule is binding to the receptor. Yes or no? The G protein changes the membrane potential of the photoreceptor cell, which then releases less neurotransmitter into the outer synaptic layer of the retina. Balance & Movement (The Vestibular System): C: Romberg Testing Involves Maintaining Balance: source@https://libguides.daltonstate.edu/PrinciplesofBiology/labmanual, Visible light (Electromagnetic Radiation), Multilayered nervous sheet within the eye with muscles and lenses for focusing, Flexible hair cells that release signal molecules based on waves in fluid started by the motion of the, A layer of neurons at the top of the nasal cavity, Clusters of epithelial cells that release signals to neurons if specific chemicals are present (e.g. Free Nerve Endings Direct stimulation of sensory neurons the sensory neuron is also the receptor dendrites of sensory neurons 1. In the video, there is a brief image of a person sticking out their tongue, which has been covered with a colored dye. The middle layer of the eye is the vascular tunic, which is mostly composed of the choroid, ciliary body, and iris. Specifically, photons cause some of the double-bonded carbons within the chain to switch from a cis to a trans conformation. Opsin pigments are actually transmembrane proteins that contain a cofactor known as retinal. Muscles in the iris alter pupil size to vary light entering the eye. Different types of stimuli are sensed by different types of receptor cells. Another way that receptors can be classified is based on their location relative to the stimuli. Use a microscope to explore the cellular aspect of a taste bud. Using a tuning fork, have a subject sit with their eyes closed. Like sweet and bitter, it is based on the activation of G proteincoupled receptors by a specific molecule. The middle ear is connected to the pharynx through the Eustachian tube, which helps equilibrate air pressure across the tympanic membrane. Sensation is the activation of sensory receptor cells at the level of the stimulus. Rhodopsin, the photopigment in rods, is most sensitive to light at a wavelength of 498 nm. See Full PDF Download PDF Related Papers THE SKELETON BONES AND JOINTS The facial nerve connects to taste buds in the anterior third of the tongue. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. The scala tympani ends at the round window, which is covered by a membrane that contains the fluid within the scala. The cochlea encodes auditory stimuli for frequencies between 20 and 20,000 Hz, which is the range of sound that human ears can detect. 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. INTRODUCTION TO ANATOMY AND PHYSIOLOGY.ppt - Academia.edu Note the accuracy at each position of their pointing, and determine the most and least accurate positions for localization. Generally, spinal nerves contain afferent axons from sensory receptors in the periphery, such as from the skin, mixed with efferent axons travelling to the muscles or other effector organs. Learning Objectives. 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. The pain and temperature receptors in the dermis of the skin are examples of neurons that have free nerve endings. Non-tasters can taste food, but they are not as sensitive to certain tastes, such as bitterness. Receptors can be classified structurally on the basis of cell type and their position in relation to stimuli they sense. A single unit of light is called a photon, which is described in physics as a packet of energy with properties of both a particle and a wave. The neural signals generated in the vestibular ganglion are transmitted through the vestibulocochlear nerve to the brain stem and cerebellum. The glossopharyngeal nerve connects to taste buds in the posterior two thirds of the tongue. Practicing careful dissecting is an important skill. Visible light only occupies a small portion of the electromagnetic spectrum. At the fovea, the retina lacks the supporting cells and blood vessels, and only contains photoreceptors. Describing sensory function with the term sensation or perception is a deliberate distinction. Prefrontal Constraints In Volleyball Each component of the motor control system is extremely dependent on the sensory The Somatosensory System Sensory Systems | ScienceDirect A branch may also turn into the posterior (dorsal) column of the white matter to connect with the brain. The stimulus causes the sensory cell to produce an action potential that is relayed into the central nervous system (CNS), where it is integrated with other sensory informationor sometimes higher cognitive functionsto become a conscious perception of that stimulus. Sour flavors are, essentially, the perception of acids in our food. Possible Specimens & Models for examination: (sheep or cow) eyeballs for dissection, microscope slides of the retina, and models of eyes. consent of Rice University. (PPT) Lecture on Sensory System | Jana Makedonska - Academia.edu The central integration may then lead to a motor response. The essential component is neurons, the major functional cells in nervous tissue. 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). Sensory, Motor, & Integrative System - Chapter 16 Anatomy - Cram.com Stretch receptors monitor the stretching of tendons, muscles, and the components of joints. 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. 190 no. In order to get to the first layer, the sclera, you may have to clear away some fat and connective tissue. Receptors, Sensation, and Perception Sensory receptors Specialized cells or multicellular structures that collect information from the environment Stimulate neurons to send impulses along sensory fibers to the brain Sensation A feeling that occurs when brain becomes aware of sensory impulse Perception A person's view of the The organs of Corti contain hair cells, which are named for the hair-like stereocilia extending from the cells apical surfaces (Figure 14.8). Professional fighters often experience anosmia because of repeated trauma to face and head. Concentration 1: ______________ Concentration 2: ______________ Concentration 3: ______________ Concentration 4: ______________ Concentration 5: ______________. Some structures are quite tough including the lens and sclera (in Latin, sclera means tough!). Capsaicin molecules bind to a transmembrane ion channel in nociceptors that is sensitive to temperatures above 37C. There is more variability among individuals than accounted for by the original 1942 map (not shown, intentionally). Terms in this set (50) Five basic senses. Therefore, this RGC does not have to integrate inputs from multiple photoreceptors, which reduces the accuracy of visual transduction. The pigments in human eyes are specialized in perceiving three different primary colors: red, green, and blue. Odorants can be detected by some sensitive individuals at concentrations below the micromolar range. Wavelengths of electromagnetic radiation longer than 720 nm fall into the infrared range, whereas wavelengths shorter than 380 nm fall into the ultraviolet range. _______________, Are your eyes exactly the same? The images in your peripheral vision are focused by the peripheral retina, and have vague, blurry edges and words that are not as clearly identified. Overlaying the ciliary body, and visible in the anterior eye, is the iristhe colored part of the eye. The shape change of retinal in the photoreceptors initiates visual transduction in the retina. 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. This region is referred to as the olfactory epithelium and contains bipolar sensory neurons. Two types of somatosensory signals that are transduced by free nerve endings are pain and temperature. The optic disk, the sight where ganglion cell axons exit the eye, does not contain photoreceptors. One network of neurons in the retina sends signals to one ganglion cell. As the spinal nerve nears the spinal cord, it splits into dorsal and ventral roots. (Micrograph provided by the Regents of University of Michigan Medical School 2012). Comparing the peak sensitivity and absorbance spectra of the four photopigments suggests that they are most sensitive to particular wavelengths. However, this increased sodium intake can increase blood volume and blood pressure, increasing the risk of cardiovascular diseases in the elderly. 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. Humans have five special senses: olfaction (smell), gustation (taste), equilibrium (balance and body position), vision, and hearing. 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. In this lab, we will explore the anatomy & physiology used for interpreting the environment both within and outside our bodies. This spasm is a reflex that is initiated by stretch receptors to avoid muscle tearing. In addition, each photoreceptor cell of the fovea is connected to a single RGC. As stated above, a given region of the basilar membrane will only move if the incoming sound is at a specific frequency. This process is called photoisomerization. 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). An individual sensory modality represents the sensation of a specific type of stimulus. All other colors fall between red and blue at various points along the wavelength scale. Bitter taste is similar to sweet in that food molecules bind to G proteincoupled receptors. Once any sensory cell transduces a stimulus into a nerve impulse, that impulse has to travel along axons to reach the CNS.

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