tongue for bsc students 2024 there are .pptx

The tongue is a muscular organ located in the oral cavity that plays a crucial role in speech, taste, swallowing, and food manipulation. Its anatomy is complex, involving muscles, nerves, blood vessels, and specialized structures that contribute to its various functions. Here’s a detailed overview of the tongue's anatomy:

1. Structure and Parts

Root: The posterior part that attaches to the hyoid bone and the floor of the mouth.

Body: The main part that extends forward, making up the majority of the tongue.

Apex (Tip): The free, highly mobile part of the tongue, located at the front.

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1. tongue

2. Intro.. Muscular organ It covered with moist,pink tissue called mucosa Papillae give the tongue its rough texture. Vital for chewing,swallowing food as well as for speech.

3. Cont.. The sense of taste, or gustation , is closely linked to the sense of smell and, like smell, also involves stimulation of chemoreceptors by dissolved chemicals. Taste buds contain chemoreceptors (sensory receptors) that are found in the papillae of the tongue and widely distributed in the epithelia of the tongue .

4. Cont.. They consist of small sensory nerve endings of the glossopharyngeal, facial and vagus nerves (cranial nerves VII, IX and X). Some of the cells have hair-like cilia on their free border, projecting towards tiny pores in the epithelium . The sensory receptors are highly sensitive and stimulated by very small amounts of chemicals that enter the pores dissolved in saliva .

5. Cont.. Nerve impulses are generated and conducted along the glossopharyngeal, facial and vagus nerves before synapsing in the medulla and thalamus. Their final destination is the taste area in the parietal lobe of the cerebral cortex where taste is perceived .

6. Physiology of taste Four fundamental sensations of taste have been described – sweet, sour, bitter and salt; however, others have also been suggested, including metallic and umami (a Japanese ‘savoury’ taste). However, perception varies widely and many ‘tastes’ cannot be easily classified. It is thought that all taste buds are stimulated by all ‘tastes’.

7. Cont.. Taste is impaired when the mouth is dry, because substances can only be ‘tasted’ when in solution. The sense of taste is closely linked to the sense of smell. For example when one has a cold, it is common for food to taste bland and unappealing. In addition, taste triggers salivation and the secretion of gastric juice (see Ch. 12). The sense of taste also has a protective function, e.g. when foul-tasting food is eaten, reflex gagging or vomiting may be induced .