GROUP 5 Chemical Senses: Olfaction & Gustation (PDF)

GROUP 5 Chemical Senses: Olfaction & Gustation ____________________________________________________________ PART 1: THE NOSE NOSE - The nose is a prominent facial feature with a complex structure. It plays a vital role in breathing, smell, and speech. - The nose has two cavities, separate...

GROUP 5 Chemical Senses: Olfaction & Gustation ____________________________________________________________ PART 1: THE NOSE NOSE - The nose is a prominent facial feature with a complex structure. It plays a vital role in breathing, smell, and speech. - The nose has two cavities, separated from one another by a wall of Cartilage called the Septum. The external openings are known as nares or nostrils. STRUCTURE/PARTS OF THE NOSE & ITS FUNCTIONS 1. Nostrils - The nostrils are the two external openings on the nose. They are responsible for taking in air for breathing. Function: - AIR FILTRATION: nostrils contain tiny hairs called cilia that filter out dust and other particles from the air we inhale. - MOISTENING AIR: the mucous membranes lining the nostrils humidify the incoming air, preventing irritation of the lungs. - WARMING AIR: nostrils help warm the air before it reaches the lungs, protecting the delicate tissues from cold air. 2. Nasal Cavity - The nasal cavity is a hollow space located inside the nose. It is lined with a moist, pink mucous membrane. Function: - AIR FLOW: the nasal cavity is divided into two sections by the nasal septum. This allows for smooth and efficient airflow. a) Inhalation b) exhalation - SMELL RECEPTION: the olfactory receptors are located in the upper part of the nasal cavity. They detect odor molecules in the air. a) Sweet b) Sour c) Salty d) bitter  - MUCUS PRODUCTION: the nasal cavity produces mucus to trap foreign particles, dut, and allergen. 3. Nasal Septum - The nasal septum is a thin wall of cartilage and bone that divides the nasal cavity into two separate chambers. a. STRUCTURE: the nasal septum is composed of cartilage and bone, providing structural support to the nose. b. FUNCTION: the septum plays a crucial role in maintaining the shape of the nose and ensuring proper airflow. c. DEVIATED SEPTUM: the deviated septum is a condition where the septum is off center, potentially affecting breathing and causing congestion. 4. Turbinates - Turbinates are bony, shelf-like structures located on the slides of the nasal cavity. They help to warm, moisten, and filter the air we breathe. THREE PARTS OF TURBINATE a. SUPERIOR TURBINATE: it is responsible for the sense of smell and plays a crucial role in the olfactory system. b. MIDDLE TURBINATE: it is responsible for warming and moistening the air, protecting the lungs from dryness and temperature extremes. c. INFERIOR TURBINATE: it helps to filter out dust and other particles from the air, preventing them from entering the lungs. 5. Paranasal Sinuses - Paranasal sinuses are air-filled cavities located around the nasal cavity in the bones of the skull. They contribute to sound resonance and reduce the weight of the skull. Function: a. VOICE RESONANCE: the sinuses contribute to sound resonance, influencing the tone and clarity of our voice. b. REDUCED SKULL WEIGHT: the sinuses reduce the weight of the skull, making it lighter and easier to carry. c. PROTECTION & SUPPORT: the sinuses provide protection to delicate structures in the head and support the facial bones. 6. Olfactory System - The olfactory system is responsible for our sense of smell. It begins with the olfactory receptors located in the nasal cavity. Function: a. OLFACTORY RECEPTORS: these receptors detect odor molecules and send signals to the olfactory bulb b. OLFACTORY BULB: the olfactory bulb processes these signals and transmit them to the brain. c. BRAIN: the brain interprets the signals as specific smells, allowing us to identify and experience a wide range of aromas. The nose is a vital organ with a complex structure and important functions, contributing to breathing, smell, and speech. STRUCTURE FUNCTIONS Nostrils Air intake and filtration Nasal Cavity Air passage, smell reception, mucus production Nasal Septum Structural support, airflow regulations Turbinates Air warming, moistening, and filtering Paranasal Sinuses Sound resonance, skill weight reduction Olfactory System Sense of smell MOST COMMON COMPLICATIONS AND DISEASES OF THE NOSE DISEASE OVERVIEW SYMPTOMS COMPLICATIONS 1. Allergic Allergic rhinitis is These include If left Rhinitis a common frequent untreated, condition where sneezing, allergic rhinitis the body's itchy nose, can lead to immune system runny or stuffy chronic overreacts to nose, and sinusitis (due allergens like watery eyes. to blocked pollen, dust Some people sinuses), ear mites, or pet may also infections experience (especially in dander. This coughing or a children), and causes sore throat poor sleep inflammation of due to quality, which  the nasal postnasal can impact mucosa. drip. daily functioning and overall well-being. 2. Sinusitis Sinusitis occurs These include when the sinuses facial pain or Acute sinusitis become inflamed, pressure, can become often due to nasal chronic, infection, congestion, lasting for allergies, or thick nasal more than 12 structural issues discharge weeks, and within the nose. (which may can lead to be green or more severe The sinuses are yellow), issues like air-filled spaces reduced orbital within the bones sense of cellulitis (an around the nose, infection of smell, and and their proper headaches. the eye drainage is socket), which crucial for nasal can threaten health. vision, or meningitis (an infection of the membranes surrounding the brain and spinal cord), which is life-threatenin g. 3. Nasal Nasal polyps are Small polyps Untreated Polyps soft, painless, might not polyps can non-cancerous cause lead to growths that symptoms, chronic develop on the but larger breathing lining of the nasal ones can lead difficulties, passages or to nasal and severe sinuses due to obstruction, cases may chronic difficulty require breathing surgical inflammation, through the removal. Even often associated nose, loss of after surgery, with conditions smell, polyps can like asthma, frequent sinus recur. allergies, or infections, chronic sinus and a feeling  infections. of pressure in the face or forehead. 4. Deviated The nasal septum These include A deviated Septum is the wall that difficulty septum can separates the left breathing lead to and right nostrils. through one chronic A deviated or both sinusitis, septum occurs nostrils, frequent when this wall is frequent nosebleeds, significantly nosebleeds, and may off-center, which facial pain, worsen and noisy snoring or can restrict breathing sleep apnea, airflow and lead during sleep potentially to various (which can affecting symptoms. contribute to sleep quality conditions like and overall sleep apnea). health. 5. Epistaxis Nosebleeds are Causes Frequent or (Noseble common and can include severe eds) occur when the trauma (like nosebleeds small blood picking the can indicate vessels in the nose or underlying nasal lining injury), dry air, health rupture. They can allergies, problems be classified as infections, such as anterior (from the blood-thinning hypertension medications, or blood front part of the or underlying clotting nose, more health disorders. common and less conditions like Recurrent severe) or high blood nosebleeds posterior (from pressure. can also lead deeper in the to anemia if nose, less significant common but blood loss potentially more occurs over serious). time. 6. Nasal Nasal fractures These include A broken Fractures are breaks or pain, swelling, nose can cracks in the bruising cause bones of the around the breathing nose, often nose and difficulties, resulting from eyes, difficulty permanent trauma like sports breathing deformity if injuries, car through the not properly  accidents, or nose, and treated, and physical assaults. possible can also lead deformity to chronic (crooked or sinusitis due misshapen to disrupted nose). nasal airflow. In severe cases, surgery may be required to correct the damage. 7. Olfactory Olfactory Difficulty A reduced Dysfuncti dysfunction refers detecting sense of smell on to the impaired smells, can ability to smell, altered taste significantly which can be (since smell is impact quality partial (hyposmia) closely linked of life, leading or complete to taste), and to a lack of (anosmia). This in severe enjoyment in can result from cases, food, an complete loss increased risk aging, nasal of the ability of dangers obstructions, viral to smell. like gas leaks infections, head or spoiled trauma, or food going neurological undetected, conditions. and possible psychological effects such as depression or anxiety. WAYS OF CARING THE NOSE 1. Keep It Clean - Cleaning your nose helps remove dirt and bacteria. - Use a saline nasal spray or rinse. Tilt your head slightly, spray into one nostril, and let it drain out. Repeat for the other side. 2. Moisturize - Dry air can make your nose dry and cracked. - Apply a little moisturizer or petroleum jelly around your nostrils. Do this when your nose feels dry.  3. Blow Your Nose Properly - Blowing your nose helps clear mucus but can irritate it if done too hard. - Gently press one nostril closed, and blow softly through the other. Switch sides and repeat. 4. Stay Hydrated - Drinking water keeps the mucus in your nose thin, making it easier to clear. - Aim to drink at least 8 glasses of water a day. Herbal teas or clear soups also count. 5. Avoid Irritants - Things like smoke, strong smells, or dust can irritate your nose. - Try to stay away from areas with smoke or strong odors. If you're around dust, wear a mask. 6. Manage Allergies - Allergies can make your nose runny or stuffy. - Talk to a doctor about allergy medications if you have symptoms like sneezing or congestion. COMMON RESEARCH FINDING OF THE NOSE UCLA Health Article: A Study Linking the Nose Temperature and the Immune System Feb. 17 2023 By Ask the Doctor Research reveals that the reason people catch more colds in winter, compared to summer, may be due to how cold weather affects the immune response in the nasal passages. While it has been thought that spending more time indoors during winter contributes to increased virus transmission, new studies suggest that cold air weakens the nasal immune defenses. A study from Massachusetts Eye and Ear Hospital found that lower nasal temperatures reduce the number and effectiveness of extracellular vesicles (EVs), microscopic structures that help kill viruses and bacteria. Even a drop of 9°F in nasal tissue temperature can decrease the availability of EVs by 40%, making it harder for the body to fight off respiratory viruses. This weakened defense is thought to contribute to the rise in respiratory infections during winter, such as flu, RSV, and COVID-19. While we can't control the weather, flu vaccines and masks can help protect against these infections by reducing exposure and maintaining nasal warmth. PART 2: THE TONGUE ____________________________________________________________ STRUCTURE OF THE TONGUE AND ITS FUNCTIONS Human Tongue The tongue is a muscular organ in the mouth covered with a moist, pink tissue called the mucosa. It is involved in licking, tasting, breathing, swallowing, and speaking. The papillae present on the tongue gives it a rough texture. It is covered by a number of taste buds. There are several nerves in the tongue that help in transmitting taste signals to the brain, and thus helps in taste sensation. This gustatory organ or the sense organs for taste are made of small ovoid bodies called the taste buds. About 10,000 taste buds are present in adults, and this number is more in children. In old people, many taste buds degenerate and the taste sensitivity also decreases. Here, let us learn more about the structure of the Human Tongue with a well-labeled diagram. THE THREE DISTINCT PARTS OF THE TONGUE TIP: The most mobile section of the tongue BODY: The main portion of the tongue that is rough on the surface and smooth on the underside, covered with papillae. BASE: The back of the tongue that extends down to the hyoid bone, contains papillae and aggregates of lymph tissue. Your tongue is mostly made of muscles. It’s anchored inside of your mouth by webs of strong tissue and it’s covered by mucosa (a moist, pink lining that covers certain organs and body cavities). Your tongue is also covered with different types of papillae (bumps) and taste buds. FOUR TYPES OF PAPILLAE 1. Filiform - Located on the front two-thirds of your tongue, filiform papillae are thread-like in appearance. Unlike other types of papillae, filiform papillae don’t contain taste buds. 2. Fungiform - These papillae get their name from their mushroom-like shape. Located mostly on the sides and tip of your tongue, fungiform papillae consist of approximately 1,600 taste buds. 3. Circumvallate - The small bumps on the back of your tongue are the circumvallate papillae. They appear larger than the other types of papillae, and they contain approximately 250 taste buds.  4. Foliate - Located on each side of the back portion of your tongue, the foliate papillae look like rough folds of tissue. Each person has about 20 foliate papillae, which contain several hundred taste buds. TASTE BUDS - Taste buds are tiny sensory organs that allow you to experience taste. They’re located inside the tiny bumps covering your tongue called papillae. Taste buds let you know what you’re eating and drinking and whether it tastes “good” or “bad.” This information makes eating pleasurable, which helps keep your body nourished. Your taste buds also alert you when something isn’t safe to consume, like spoiled milk or rotten meat. FRENUM - A frenum (or frenulum) is a thin, ropelike piece of tissue that connects two bodily structures. You have frenums in various areas of your body, like your genitals, digestive tract and brain. You also have them in your mouth — and you might notice them whenever you brush your teeth or smile in front of a mirror. MOST COMMON COMPLICATIONS AND DISEASE OF THE TONGUE - The tongue, a vital organ, is prone to various complications and diseases that can affect its function and overall health. Understanding these conditions is crucial for timely diagnosis and treatment. TONGUE ANATOMY & FUNCTIONS The tongue is composed of muscles, nerves, and blood vessels. It plays crucial roles in speech, swallowing, taste perception, and oral hygiene. a) MUSCLES: the tongues’ complex muscles structure enables its intricate movements for speech and chewing. b) NERVES: nerves transmit taste sensations from taste buds to the brain and control tongue movements. c) BLOOD VESSELS: blood vessels provide oxygen and nutrients, and remove waste products. MOST COMMON COMPLICATIONS AND DISEASE OF THE TONGUE 1. Tongue Inflammation (Glossitis) Ir is an inflammation of the tongue, causing swelling, redness, and pain. ➔ CAUSES: Common causes include vitamin deficiencies, infections, allergies, and certain medications.  ➔ SYMPTOMS: Symptoms can include burning, soreness, difficulty swallowing, and a change in taste ➔ TREATMENT: Treatment depends on the underlying cause and involves addressing deficiencies, treating inflections, or avoiding triggers. 2. Tongue Ulcers and Sores Tongue ulcers are painful sores that can appear on the tongue’s surface or sides. ➔ TYPES: Types include canker sores (aphthous ulcers) and herpetic ulcers. ➔ SYMPTOMS: Symptoms include pain, burning, and sensitivity to hot and spicy foods. ➔ TREATMENT: Treatment often involves over-the-counter remedies for pain relief and healing. 3. Tongue Cancer It is a serious condition that affects the tongue’s tissues ➔ CAUSES: Risk factors include smoking, excessive alcohol consumption, and exposure to certain viruses. ➔ SYMPTOMS: Symptoms may include lumps, sores, white or red patches, and difficulty swallowing. ➔ TREATMENT: Treatment options include surgery, radiation therapy, and chemotherapy. 4. Geographic Tongue It is a harmless condition characterized by a map-like pattern on the tongue’s surface. ➔ APPEARANCE: The tongue exhibits patches of smooth, red areas surrounded by white borders. ➔ CAUSES: The exact cause is unknown but may be related to genetics or immune system dysfunction. ➔ TREATMENT: No specific treatment is needed, and the condition often revolves on its own. 5. Hairy Tongue Hairy tongue is a condition where the tongue’s papillae (tiny projections) become elongated, creating a hairy appearance. ➔ CAUSES: It’s often caused by poor oral hygiene, smoking, or certain medications. ➔ SYMPTOMS: The tongue may feel coated, have a foul taste and appear white, yellow, or brown ➔ TREATMENT: Treatment involves improving oral hygiene and addressing any underlying causes. 6. Fissured Tongue Fissured tongue, also known as scrotal tongue, is a condition where deep grooves or fissures appear on the tongue’s surface.  ➔ CAUSES: The exact cause is unknown, but genetics may play a role. ➔ SYMPTOMS: The tongue may appear dry, cracked, and prone to food debris accumulation. ➔ TREATMENT: No specific treatment is needed, but good oral hygiene is important. 7. Tongue Injuries and Trauma Tongue injuries can result from biting, burns, or accidents. ➔ CUTS & LACERATIONS: These injuries may require stitches or other medical interventions. ➔ BURNS: Tongue burns can be caused by hot foods or liquids, and they may need special care to heal. PREVENTING AND MANAGING TONGUE CONDITIONS Maintaining good oral hygiene practices can help prevent and manage many tonge conditions. 1. Oral Hygiene - brush twice daily, floss regularly, and gently scrape your tongue 2. Diet - eat a balanced diet rich in fruits, vegetables, & whole grains. 3. Hydration - stay well-hydrated by drinking plenty of water throughout the day. 4. Avoid Irritants - avoid smoking, excessive alcohol consumption, and spicy foods. WAYS OF CARING THE TONGUE WAYS DESCRIPTION HOW TO 1. Maintain Good Oral Brush your tongue Gently brush the Hygiene daily using a tongue with a toothbrush or a soft-bristled tongue scraper. This toothbrush or use a helps remove tongue scraper to bacteria, food clean from back to particles, and dead front. Avoid excessive cells that can cause brushing, which can bad breath and irritate the tongue. contribute to oral health issues. 2. Stay Hydrated Drinking plenty of Aim to drink at least 8 water helps keep the cups (about 2 liters) of mouth hydrated and water per day. Avoid supports saliva excessive production, which is consumption of essential for sugary or acidic neutralizing acids and drinks, which can washing away food contribute to oral particles. problems. 3. Avoid Smoking and Tobacco use can If you smoke or use Tobacco Products cause a range of oral tobacco products, health issues, seek support to quit. including tongue Various resources and discoloration, bad programs are breath, and an available to help with increased risk of oral cessation. cancer. 4. Eat a Balanced Diet Consuming a variety Include fruits, of nutrients helps vegetables, lean maintain the health of proteins, and whole the tongue and oral grains in your diet. tissues. Vitamins and Foods rich in vitamins minerals are B12 and iron are particularly important important for tongue for maintaining a health. healthy tongue. 5. Monitor and Manage Pay attention to any Regularly check your Oral Health Issues changes in the tongue for changes appearance of your and consult a dentist tongue, such as or healthcare provider unusual discoloration, if you notice persistent swelling, or sores. symptoms. These can indicate underlying health issues. 6. Use Antimicrobial An antimicrobial Use mouthwash as Mouthwash mouthwash can help directed, typically reduce bacteria in the once or twice daily, mouth and on the and follow up with tongue, which can brushing and flossing. contribute to better oral health. 7. Regular Dental Regular visits to the Schedule dental Check-Ups (if dentist help ensure check-ups every six possible) that any issues with months or as your tongue and recommended by your overall oral health are dentist. addressed promptly. COMMON RESEARCH FINDING OF THE TONGUE New York Times - Science Article: The Textbooks Were Wrong About How Your Tongue Works May 29, 2024 By Joanne Silberner The long-standing belief that different areas of the tongue are responsible for specific tastes—sweet, salty, sour, and bitter—is a myth, debunked by decades of research. While textbooks often show a "taste map," new evidence reveals that all parts of the tongue can detect multiple flavors, although some areas may be more sensitive. This misconception originated from a misunderstood 1901 study by David Hanig, which actually measured the varying sensitivity of taste across different parts of the tongue rather than segregating tastes by region. Taste is a far more complex process than previously thought. Receptors on the tongue signal the brain when they detect certain chemicals, but these receptors are not limited to the mouth. They're also found in the gut, liver, lungs, and other organs. These receptors help the body sense nutrients or harmful substances, triggering responses like digestion. For example, when sugar is detected in the gut, the brain is alerted to release insulin and prepare the body for digestion, ensuring that food is processed efficiently. Dr. Paul Breslin, a researcher at Monell Chemical Senses Center, compares the body’s preparation for digestion to an airport getting ready for a landing. The body coordinates multiple systems—salivation, stomach preparation, and insulin release—once taste signals are detected, ensuring the digestive process runs smoothly. In addition, taste can change over time. Dr. Diego Bohórquez of Duke University explored how gut-brain communication influences food preferences. Inspired by a case where a friend’s taste preferences shifted after bariatric surgery, Bohórquez theorized that the gut’s altered receptors were sending new signals to the brain, changing the perception of certain foods. Overall, taste perception involves a complex network between the tongue, brain, and various organs, far beyond the outdated idea of the "taste map." This system helps the body not only enjoy food but also metabolize it efficiently. BONUS TOPIC ____________________________________________________________ HOW THE FUNCTIONS OF THE NOSE AND TONGUE RELATE TO EYES The sense of sight perceives things that a normal being can visualize or see. Studies have shown that the color and appearance of an object can influence how we perceive its odor. For example, a neutral odor may be perceived as more pleasant when paired with a positive visual cue, such as a picture of fresh flowers. The appearance of food, including its color, shape, and presentation, can influence our expectations and experiences of its taste. Taste and smell work together to create the perception of flavor. While the tongue is responsible for basic tastes, the nose detects volatile compounds released from food, which significantly contributes to our overall taste experience. The eyes provide visual information that complements these other senses The eyes play a significant role in our perception of smell and taste, even though they are not directly involved in those senses.While the eyes are responsible for vision, they also play a crucial role in how we perceive food and our environment. Visual cues can influence our expectations and experiences of taste. This interplay between sight, smell, and taste illustrates how the senses work together to create a comprehensive experience of our environment COMMON RESEARCH FINDING OF THE RELATION OF NOSE AND TONGUE The taste buds of the tongue identify taste, and the nerves in the nose identify smell. Both sensations are communicated to the brain, which integrates the information so that flavors can be recognized and appreciated. Some tastes—such as salty, bitter, sweet, and sour—can be recognized without the sense of smell. However, more complex flavors (such as raspberry) require both taste and smell sensations to be recognized. We know that some things affect taste, and having a cold is the most familiar example. Researchers have found that when volunteers wore nose plugs, their sense of taste was less accurate and less intense than when they tasted the food without the nose plugs. The sensation of flavor is actually a combination of taste and smell. This happens because as you chew, you force air through your nasal passage. These food odors or odorants are detected by receptor proteins on hair-like cilia at the tips of the sensory cells in your nose, which in turn send neural messages to the brain – these two messages are what we would perceive as a flavor or taste.