Physiology of Swallowing
John C Watkinson, Raymond W Clarke, Terry M Jones, Vinidh Paleri, Nicholas White, Tim Woolford in Head & Neck Surgery Plastic Surgery, 2018
Taste buds are the receptors for taste and are located on the surface of the tongue, soft palate and epiglottis. Each taste bud contains approximately 50–100 cells and has a life span of 10–14 days, and they are under constant regeneration.61 They mature into one of three types of taste cell: type I detects salt; type II sweet, bitter and umami; and type III sour.62 Saliva facilitates the movement of taste molecules to the taste bud and its composition is important for taste perception. Taste-related impulses are transmitted via the facial, glossopharyngeal and vagus nerves to the olfactory area of the cortex. The biomechanical swallowing response can alter with different taste flavours. For example, a sour bolus (e.g. lemon juice) may increase oral tongue pressures and tongue-to-palate contact times, although some dispute this.63, 64 Furthermore, a sour bolus seems to have a longer transit and clearance duration in the distal oesophagus.65, 66
ENTRIES A–Z
Philip Winn in Dictionary of Biological Psychology, 2003
The dendrites of sensory neurons contact taste buds so that information can be sent to the CNS for processing. The action of molecules at receptor sites on the taste buds stimulates activity in these sensory neurons. Several nerves carry information away from the tongue to the CNS: the CHORDA TYMPANI (part of the FACIAL NERVE) carries information from the front of the tongue; the lingual branch of the GLOSSOPHARYNGEAL NERVE carries information from the back; and the VAGUS NERVE carries taste information from the palate and epiglottis. These nerves converge on the NUCLEUS OF THE SOLITARY TRACT from where information is relayed to the THALAMUS (especially the ventral posteromedial nucleus) directly and via the PARABRACHIAL NUCLEI. The thalamus, which is the major relay station for cortical input, sends axons to the primary GUSTATORY CORTEX located in the frontal insular and opercular cortices. This is the principal taste pathway, but fibres conducting gustatory information also reach the AMYGDALA and LATERAL HYPOTHALAMUS. Given that the amygdala is concerned with the ascription of motivational significance to stimuli (that is, deciding whether or not a stimulus is pleasant or aversive) and the lateral hypothalamus performs complex computations involving gustatory and visceral sensations, the representation of gustatory information in these places is not surprising. Perhaps the most curious aspect of the taste pathway however is that taste is not represented bilaterally in the cortex, unlike the other senses.
Infant Nutrition
Praveen S. Goday, Cassandra L. S. Walia in Pediatric Nutrition for Dietitians, 2022
With each new food introduction, the infant should be observed for signs and symptoms of allergic reaction such as a rash, increased work of breathing, emesis, or diarrhea. A wide variety of foods from all food groups should be introduced, and repeatedly offered every few days, weeks, and months – even if it is refused at the first offering. Refusal of unfamiliar foods is a normal part of development. Infant taste buds are partial to sweet and slightly salty tasting foods. Savory (umami), bitter, and sour flavors are important to provide in various different foods to develop a full palate. A majority of caregivers will describe their child as a “picky eater” and this may cause great concern and conflict in families. There is no consensus or definition of what exactly a “picky” eater is, and it is important to encourage repeated exposures to a variety of foods. It does not matter which food is an infant’s first, as long as it is a safe consistency for the infant to swallow.
Amoxicillin chewable tablets intended for pediatric use: formulation development, stability evaluation and taste assessment
Published in Pharmaceutical Development and Technology, 2021
Maria S. Synaridou, Paraskevi Kyriaki Monou, Constantinos K. Zacharis, Dimitrios G. Fatouros, Irene Panderi, Catherine K. Markopoulou
Taste, smell and texture are important factors for any medicine administered orally while, their dissolution rate and the ability to keep drug at the site of absorption are important for peroral administration. Taste sensations arise from stimulation of specialized cells grouped in small clusters called taste buds which exist on the front of the tongue, in folds on the side and in circular grooves on the back of the tongue surface. Undesirable flavor is one of the primary factors determining patients’ non-compliance. Children represent a special group of the population exhibiting difficulties in swallowing medication in tablet form (Gala and Chauhan 2014). Nowadays, the new perception of pharmaceutical technology is that the flavor of an orally administered formulation should be sufficiently pleasant, especially when it is intended for pediatric use. Thus, regulatory authorities, such as the European Formulation Initiative (EuPFI), have recognized the importance of masking the unpleasant flavor of the active pharmaceutical ingredient (API), whereas the European Medicines Agency (EMEA) (EC 2008; EMEA 2006) acknowledge that medicinal products should be made available in age-related formulations (Davies and Tuleu 2008). Pediatric patients with long-term illness requiring continuing medication may be persuaded and trained to take solid dosage forms from a relatively early age of 4–5 years.
Anatomical structure, and expression of CCL4 and CCL13-like during the development of maxillary barbel in Paramisgurnus dabryanus
Published in Organogenesis, 2019
Kianann Tan, Ruijing Geng, Zhiqiang Wang, Han Liu, Weimin Wang
For the longitudinal section, a thick layer of epithelium is the outer-most layer and is full of goblet cells and taste buds. Many taste buds can be found at the tip of a maxillary barbel. The second layer after the epithelium is a dermis layer, with blood vessels, connective tissue and collagen fiber (Fig. 3). The third inner layer is a nerve bundle layer; the nerve bundles are covered with a layer of collagen fiber. Near the center of the barbels, two crucial layers, muscle fibers, and loose connective tissue can be observed. The core of the maxillary barbel is an elastic linear rod structure, and this part is made up of cartilage and referred to as ‘cartilage rod’. Maxillary barbels are fully covered in epidermis, with the epithelium of stratified squamous cells.
The influence of radiation dose on taste impairment in a prospective observational study cohort of oropharyngeal cancer patients
Published in Acta Oncologica, 2022
Sonja Stieb, Grete M. Engeseth, Abdallah S. R. Mohamed, Renjie He, Ismael Perez-Martinez, Stockton Rock, Tanaya S. Deshpande, Adam S. Garden, David I. Rosenthal, Steven J. Frank, G. Brandon Gunn, C. David Fuller
In preclinical studies, radiotherapy has been shown to affect the taste progenitor cells within the taste buds [6]. However, previous clinical studies investigating the association between dose and taste impairment, correlated taste with the prescribed dose to the tumor [7], the dose to the whole tongue [8] or to the entire oral cavity [9–11], instead of using a taste specific organ at risk (OAR) structure. Recently, our group presented a contouring guideline for delineation of the taste bud bearing tongue mucosa [12] as basis for a more advanced dosimetric analysis of taste. The aim of this study was to investigate the impact of radiation dose to this taste specific OAR structure on taste impairment 5 years post-RT in a prospective observational study cohort of exclusively OPC patients treated with intensity-modulated radiotherapy (IMRT).
Related Knowledge Centers
- Cheek
- Sweetness
- Taste
- Taste Receptor
- Esophagus
- Soft Palate
- Tongue
- Epiglottis
- Lingual Papillae
- Tongue Map