University:
Bradley University
Course:
BIO 466 | Human Anatomy
Academic year:

2022
Views:

447

Pages:

30
Author:

segolhandworked

SENSORY SYSTEM > Sensory System A sensory system is a part of the nervous system responsible for processing sensory information. A sensory system consists of sensory receptors, neural pathways, and parts of the brain involved in sensory perception. Commonly recognized sensory systems are those for vision, hearing, somatic sensation (touch), taste and olfaction (smell). In short, senses are transducers from the physical world to the realm of the mind. Olfactory (Smell) The nose has two primary functions. The first is olfaction the sense of smell. However, the second function is of primary interest to this discussion-filtration, heating and humidification of the inhaled air. To accomplish the second task, the nasal cavity contains a convoluted set of passageways called the turbinates on the lateral wall of each nasal cavity. The nose performs other various functions such as: Respiration. Air conditioning of the inspired air, Filtration of the inspired air. Olfaction or sense of smell. Resonating the spoken voice. Draining the para nasal sinuses and the nasolacrimal duct ANATOMY OF THE NOSE The nose consists of the following: External nose-triangular-shaped projection in the center of the face. Nostrils-The two openings into the nasal passages. Nasal passages-passages that are lined with mucous membranes and tiny hairs (cilia) that help to filter the air and move nasal and sinus mucous to the back of the throat. Nasal passages are separated by the nasal septum. Septum-made up of cartilage and bone and covered by mucous membranes. The cartilage also gives support to the lower part of the nose and divides the nasal passages into right and left sides. Sinuses-four-paired, air-filled cavilles. OLFACTORY RECEPTORS AND THE SENSE OF SMELL Chemoreceptors are those that respond to chemicals in solution for taste and olfaction. The olfactory receptors are believed to be sensitive to a much wider range of chemicals. Thousands of olfactory receptors occupy a postage stamp-sized area in the roof of each nasal cavity. These are the receptors for the sense of smell. Air entering the nasal cavities must make a hairpin turn to enter the respiratory passageway below which 1 . causes more air to flow superiorly across the olfactory receptors, thus, intensifying the sense of smell. Olfactory receptor cells are special neurons that are equipped with olfactory hairs. Olfactory hairs are long cilia that protrude from the nasal epithelium and are continually bathed by a layer of mucus secreted by underlying glands. When the receptors are stimulated by chemicals that are dissolved in the mucus, they transmit impulses along the olfactory filaments, which collectively make up the olfactory nerve (cranial nerve I) to the olfactory complex of the brain. It is in the brain that the interpretation of the odor occurs. The olfactory pathways are closely tied into the limbic system, the emotional-visceral part of the brain. Hence, olfactory impressions are long lasting and are very much part of our memories and emotions. The olfactory receptors are extremely sensitive. Only a few molecules are required to activate them. Olfactory neurons tend to adapt rather quickly when they are exposed to unchanging stimulus of odor. This is the main reason why a woman stops smelling her own perfume but quickly picks up the scent of another person's perfume. How Taste Works The Tongue Tongue Clocumralte Papila Taste Bud Dustatory Basal Cet Ripita Pungos Papia Supporting Cell Qustatory Receptor Cell Fibers of Cranial Nerve Connective Tisaun Gustatory (taste) TASTE BUDS AND SENSE OF TASTE The tongue is a versatile organ with specialized functions like taste and speech. Beneath a cover of taste buds, the tongue is almost entirely made up of muscle. The muscles of the tongue are essential for its bodily movement and intrinsic manipulations, required for actions like speech, articulation, deglutition or swallowing, whistling, licking, kissing and even cleaning teeth. Taste is the brain's interpretation of chemicals that trigger receptors on the tongue, which are housed in the taste buds. The basic chemical components, are found in foods, toxins, and other ingested matter. Unappealing tastes are usually associated with toxins, as this is a defense mechanism preventing consumption. The chemicals bind their particular receptors and initiate signaling that travels through the nerves to the brain, where they are interpreted. Taste Buds The taste buds are specific receptors for the sense of taste which are widely distributed in the oral cavity. Of the 10,000 taste buds that humans have, most are located in the tongue. Few are found on the soft light as it passes through the eye. The lens is divided into two segments namely: Anterior (aqueous) segment-located anterior to the lens and contains a clear wayetry fluid called aquecus humor. The aqueous humor helps to nourish the cornea and the lens. It is continually produced by the ciliary body. 2. Posterior (vitreous) segment-located posterior to the lens and is filled with a gel-like substance called the vitreous humor or the vitreous body. The vitreous is a thick, transparent substance that fills the center of the eye. It is composed mainly of water and comprises about 2/3 of the eye's volume, giving it form and shape. The viscous properties of the vitreous allow the eye to return to its normal shape if compressed. The vitreous humor helps maintain the shape of the eye Terms of the Sensory System Perception- the process of using the senses to acquire information about the surrounding environment or situation Sensation- physical feeling: a physical feeling caused by having one or more of the sense organs stimulated Sensory deficit- a defect in the function of one or more of the senses. Sensory deprivation-The reduction or absence of usual external stimuli or perceptual opportunities, commonly resulting in psychological distress and sometimes in unpleasant hallucinations. Sensory overload- a condition in which an individual receives an excessive or intolerable amount of sensory stimuli, as in a busy hospital or clinic or an intensive care unit. The effects of sensory overload are similar to those of sensory deprivation, including confusion and hallucination. Affect- An observed emotional expression or response. In some situations, anxiety would be considered an inappropriate affect. Astigmatism- Astigmatism is the result of an inability of the cornea to properly focus an image onto the retina. The result is a blurred image. Awareness- the ability to receive and differentiate sensory stimuli. Cerumen- The brownish yellow, waxy secretion of the ceruminous glands of the external auditory meatus; earwax Chalazion- a smali, nonmalignant, localized swelling of the eyelid resulting from obstruction and retained secretions of the meibomian glands Cognition-The mental faculty of knowing, which includes perceiving, recognizing, conceiving, judging. reasoning, and imagining Conductive hearing loss- A type of medically treatable hearing loss in which the inner ear is usually normal, but there are specific problems in the middle or outer ears that prevent sound from getting to the inner ear in a normal way. Conjunctivitis-Conjuctivitis is an inflammation or redness of the lining of the white part of the eye and the underside of the eyelid (conjunctiva) that can be caused by infection, allergic reaction, or physical agents like infrared or ultraviolet light. Consciousness- A sense of one's personal or collective identity, especially the complex of attitudes, beliefs, and sensitivities held by or considered characteristic of an Individual or a group Disorientation- the loss of proper bearings, or a state of mental confusion as to time, place, or identity. Hallucination- False or distorted perception of objects or events with a compelling sense of their reality, usually resulting from a mental disorder or drug. Hyperopia- Hyperopia (farsightedness) is the condition of the eye where incoming rays of light reach the retina before they converge into a focused image. Illusion- A false visual perception of an object that others perceive correctly. A common example is the number of sightings of "UFOs" that turn out to be airplanes or weather balloons. Judegement- the ability to make logical, rational decisions and decide whether a given action is right or wrong Keratitis- Keralitis is an inflammation of the cornea, the transparent membrane that covers the colored part of the eye (iris) and pupil of the eye. Myopia- Myopia is the medical term for nearsightedness. People with myopia see objects more clearly when they are close to the eye, while distant objects appear blurred or fuzzy. Reading and close-up work may be clear, but distance vision is blurry. Nystagmus- Rhythmic, oscillating motions of the eyes are called nystagmus. The to-and-fro motion is generally involuntary. Vertical nystagmus occurs much less frequently than horizontal nystagmus and is often, but not necessarily, a sign of serious brain damage. Nystagmus can be a normal physiological response or a result of a pathologic problem Orientation-awareness of one's environment with reference to time, place, and people. Presbycusis- progressive, bilaterally symmetrical sensorineural hearing loss occurring with age

Sensory System Part I

Related Documents

Recommended Documents

Description

Related Documents

Free up your schedule!

Take 5 seconds to unlock