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El sentido del gusto (fisiologia:sentidos especiales) Papilas gustativas ,sabor umami y más.
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El sentido del gusto (fisiologia:sentidos especiales) Papilas gustativas ,sabor umami y más.

Understanding the Sense of Taste

Overview of Taste and Its Mechanisms

  • The sense of taste, like smell, is a chemical sense but is simpler as it distinguishes only five primary tastes: sour, sweet, salty, bitter, and umami.
  • Umami was introduced by the Japanese and is described as savory or delicious; it is believed to originate from receptors stimulated by monosodium glutamate (MSG).

Interaction Between Taste and Smell

  • Other flavors such as chocolate or coffee arise from combinations of the five main tastes along with olfactory stimuli.
  • The olfactory sense is significantly more sensitive than taste; thus, many food flavors are perceived through smell rather than taste alone. This explains why colds can diminish our ability to taste food.

Anatomy of Taste Receptors

  • Taste receptors are located in structures called taste buds; an average adult has about 10,000 taste buds primarily on the tongue but also in other areas like the soft palate and throat.
  • As people age, the number of taste buds decreases; each bud consists of three types of epithelial cells: supporting cells, gustatory receptor cells, and basal cells. Supporting cells surround approximately 50 gustatory receptor cells per bud.

Functionality of Gustatory Cells

  • Gustatory receptor cells have microvilli that extend through a pore to interact with tastants dissolved in saliva. Basal cells act as stem cells for renewing supporting and receptor cells every ten days on average.
  • These receptor cells synapse with first-order neurons forming part of the gustatory pathway; their axons connect with various taste buds across different regions on the tongue's surface known as papillae.

Types of Papillae and Their Functions

  • There are three main types of papillae:
  • Circumvallate: Located at the back base of the tongue with 100 to 300 taste buds each.
  • Fungiform: Mushroom-shaped papillae distributed across the tongue's surface containing about five taste buds each.
  • Foliate: Found in grooves on the sides but often degenerate during early childhood.

Additionally, there are filiform papillae which do not contain taste buds but serve tactile functions.

Physiology Behind Taste Perception

  • Substances that stimulate gustatory receptors are termed tastants; upon dissolving in saliva they contact gustatory hairs leading to potential changes within these receptor cells that trigger neurotransmitter release causing nerve impulses in first-order neurons.
  • Different tastes activate distinct pathways:
  • Salty flavor involves sodium ions causing depolarization.
  • Sour flavor results from hydrogen ions affecting neurotransmitter release.

Understanding Taste Receptors and Neural Pathways

Mechanism of Taste Perception

  • The process of taste involves a second messenger pathway, culminating in the release of neurotransmitters. Despite all flavors leading to this common endpoint, the formation of different tastes is attributed to varying neuronal patterns.
  • Different groups of first-order taste neurons are activated for distinct flavors, which generates unique taste perceptions. The thresholds for these flavors vary significantly.

Flavor Thresholds and Their Implications

  • The threshold for bitter taste is notably low due to its association with toxic substances, serving as a protective mechanism. In contrast, the thresholds for sour, salty, and sweet tastes are higher.

Neural Pathways Involved in Taste

  • Three cranial nerves are responsible for transmitting signals from taste buds: the facial nerve (innervating the anterior two-thirds of the tongue), glossopharyngeal nerve (posterior third), and vagus nerve (taste buds in the throat).
  • These cranial nerves carry impulses from taste receptors to the brainstem's medulla oblongata.

Processing Taste Signals in the Brain

  • From the medulla oblongata, signals are relayed to both the limbic system and hypothalamus, as well as to the thalamus. Subsequently, information is sent to the parietal lobe where primary gustatory processing occurs.
Video description

Si te gusta este contenido, ¡apóyanos en nuestras demás redes! MIS REDES: https://www.facebook.com/MedsToons https://www.instagram.com/medstoons_mipo El gusto, como el olfato, es un sentido químico. Es, sin embargo, mucho más simple que el olfato ya que solamente se distinguen 5 gustos primarios: agrio, dulce, amargo, salado y umami. El sabor umami, recientemente introducido por científicos japoneses, se describe como “delicioso” o “sabroso”. Se cree que proviene de receptores gustativos que son estimulados por el glutamato monosódico (MSG), una sustancia naturalmente presente en muchas comidas y que se añade a otras como un potenciador del sabor.