TASTE Flashcards
(34 cards)
Describe how taste is sensed in the human body.
Taste is sensed through chemoreceptors located in taste buds, primarily on the tongue, which detect gustatory signals.
Explain the role of taste buds in taste perception.
Taste buds are sensory organs that house gustatory epithelial cells and are responsible for detecting taste sensations.
Identify the locations of the different types of papillae on the tongue.
Fungiform papillae are scattered across the tongue, foliate papillae are located on the side walls, and vallate papillae form a ‘V’ shape at the back of the tongue.
How do gustatory signals reach the brain?
Gustatory signals are transmitted to the brain via sensory dendrites that coil around gustatory epithelial cells, sending taste signals when activated.
Define the five basic taste sensations.
The five basic taste sensations are sweet, sour, salty, bitter, and umami.
Explain the protective role of taste preferences.
Taste preferences, such as disliking sourness and bitterness, serve a protective function by warning us against spoiled or poisonous substances.
Describe the process of taste receptor activation.
Taste receptor activation occurs when a food chemical (tastant) binds to gustatory epithelial cells, causing depolarization and the release of neurotransmitters.
How does the salty taste cause depolarization in gustatory cells?
The salty taste is due to sodium ions (Na+) influx, which directly causes depolarization of the gustatory epithelial cell membrane.
What is the significance of adaptation in taste perception?
All taste receptors adapt within 3–5 seconds, with complete adaptation in 1–5 minutes, allowing for a dynamic response to continuous stimuli.
Explain the requirements for a chemical to be tasted.
To be tasted, a chemical must be dissolved in saliva, diffuse into the taste pore, and contact the gustatory hairs.
Describe the role of basal epithelial cells in taste buds.
Basal epithelial cells are dynamic stem cells in taste buds that divide every 7–10 days, contributing to the renewal of taste receptor cells.
Identify which taste receptors are most sensitive.
Bitter receptors are the most sensitive among the different gustatory cells.
How does the sour taste activate gustatory cells?
The sour taste is activated by hydrogen ions (H+) that act intracellularly by opening ion channels in gustatory cells.
Explain the concept of gustatory transduction.
Gustatory transduction refers to the process by which binding of tastants to gustatory epithelial cells leads to depolarization and the generation of action potentials.
Describe the role of saliva in taste perception.
Saliva acts as a solvent that facilitates the clearance of taste particles, enhancing the ability to perceive different flavors.
Explain how taste is related to smell.
Taste is significantly influenced by smell, with approximately 80% of taste perception being attributed to olfactory input. When the nose is blocked, foods often taste bland.
Define the types of receptors involved in taste.
Taste involves unique receptors for sweet, bitter, and umami flavors, all of which are coupled to the G protein gustducin.
How do temperature and texture affect taste perception?
Temperature and texture can enhance or detract from taste, influencing the overall flavor experience.
What is the role of pain receptors in taste perception?
Spicy foods can excite pain receptors in the mouth, which some individuals may experience as pleasurable, such as the sensation from hot chili peppers.
Identify the cranial nerves involved in taste transmission.
The facial nerve (VII) carries taste impulses from the anterior two-thirds of the tongue, the glossopharyngeal nerve (IX) from the posterior one-third and pharynx, and the vagus nerve (X) from the epiglottis and lower pharynx.
Explain the pathway of taste impulses from the tongue to the brain.
Taste impulses travel from the tongue through cranial nerves to the solitary nucleus of the medulla, then to the thalamus, and finally to the gustatory cortex in the insula.
Describe the involvement of the hypothalamus and limbic system in taste perception.
The hypothalamus and limbic system are involved in taste perception, influencing appetite, satiety, and emotional responses to flavors.
What reflexes are triggered by taste?
Taste can trigger reflexes involved in digestion, such as increased secretion of saliva and gastric juices, as well as protective reactions like gagging and reflexive vomiting.
Define the components of the gustatory system.
The gustatory system includes sensory input from taste buds (gustatory), mechanoreceptors in the oral cavity (touch), nerve endings in the oral cavity (temperature), and olfactory input from the olfactory epithelium.
