Human tongue - class-IX

• The taste receptors are located around the small structures known as papillae found on the upper surface of the tongue, soft palate, upper oesophagus, the cheek, and epiglottis.
• The cranial nerves innervate these sites and carry taste information to the brain.
• Hence Cranial nerves carry taste information from Tongue, Palate and Epiglottis.
• So, the correct answer is 'All the above'.

• The sense of taste is stimulated when nutrients or other chemical compounds activate specialized receptor cells within the oral cavity.
•  Taste helps us decide what to eat and influences how efficiently we digest these foods. 
• They would have used their sense of taste to identify nutritious food items. Hence,  the function of taste receptors is to Enhance the diet.

• Tongue consist of taste buds. Each taste bud contains 50 to 100 taste receptor cells.  
• The sensation of taste includes five established basic flavours: sweetness, sourness, saltiness, bitterness, and umami. Hence, Flavours can be detected with the combination of the 5 taste perceptions (salty, sour, bitter, sweet and umami).
So, the correct answer is 'Flavours'.

• A taste receptor is a type of receptor which facilitates the sensation of taste. These receptors are of four types.
•  When food or other substances enter the mouth, molecules interact with saliva and are bound to taste receptors in the oral cavity and other locations. Hence, Taste receptors help in the sensation of taste.

There are small elevated cells in the tongue which are called as the taste buds. There are the receptor or the neurosensory cells in these taste buds. There are about 5-15 neurosensory cells in each taste bud. There are cilia-like structures on one end and there are nerve fibres which extend from the other end to the brain. There are taste buds for the detection of different type of taste like sweet, sour, bitter, etc.

Salivation in response to the sight or smell of food is a conditioned reflex mediated by the nervous system, specifically the autonomic nervous system.

The eight muscles of the human tongue are classified as either intrinsic or extrinsic. The four intrinsic muscles act to change the shape of the tongue and are not attached to any bone. The four extrinsic muscles act to change the position of the tongue and are anchored to bone. Therefore, the correct answer is option B.

Gustatory receptors are the specialized sensory receptors located in the taste buds on the tongue that detect chemical stimuli associated with taste.

Taste buds are the taste receptors that are present on the surface of tongue in small projections called as papillae. Saliva of mouth dissolves the food and turns it into liquid or small solid molecules suspended in liquid. The liquid food enters the small pores of taste buds and stimulates the taste receptors to release chemicals and generate a nerve impulse. Since only liquid food can enter the small openings or pores of taste buds, taste buds can detect the substances present in the liquid state. 

In human beings tongue helps in the ingestion, chewing and swallowing of the food. The anterior part of tongue perceives sweet taste, posterior part bitter, lateral sides sour, and the sides just behind the tip of the tongue perceive salty taste. Thus option D is the correct answer.

Gustatory receptors are also called taste receptors. Taste receptors recognize five basic tastes such as salty, sour, sweet, bitter and umami. Salty and sour tastes are detected with the help of ion channels in the tongue. Sweet, bitter, and umami tastes are detected with the help of G protein-coupled taste receptors. 

• The tongue functions as a digestive organ by facilitating the movement of food during mastication and help in swallowing.
•  Other important functions include speech and taste. Our teeth help our tongue to grind food as the tongue mixes the food around your mouth.
•  A dry tongue can't taste a thing, so saliva helps the tongue by keeping it wet. Saliva moistens food and helps to break it down, which makes it easier for the tongue to push the food back to swallow it. 
• Hence, The function of the tongue is to help in the act of swallowing and Help in mixing saliva with the food.
•  So, the correct answer is 'Both A and B'.

Taste buds are located within the papillae, which are the small projections found on the upper surface of the tongue.

Papillae give the tongue its rough texture. The surface of the papillae is covered by thousands of taste buds.
Taste buds have the taste sensors or the taste receptors inside them.
Each taste bud has a cavity with a pore called as the taste pore.
Inside each cavity is taste receptor cells or gustatory receptor cells, bathed in saliva.
Each receptor cell has a free hair-like cilium also called as the taste hair which projects into the outer taste pore.
Additionally, each receptor cell has a nerve fibre called as the gustatory nerve extending from its base to the taste centre of the brain.

Humans possess fungiform, circumvallate, and foliate papillae. Since all these are found in humans, the statement that none of the above are missing is technically true, or the question is flawed.

The rough texture of the tongue surface is caused by papillae, which are small nipple-like projections on the tongue epithelium. These include fungiform, filiform, circumvallate, and foliate papillae, with filiform papillae being the most numerous and responsible for the tongue's rough surface texture.

A- Papillae contain taste buds. Taste receptors are situated around the papillae. Tastebuds are a combination of basal, structural and taste receptor cells. 

Gustatory receptors are specialized epithelial cells located within the taste buds that transduce chemical signals into neural impulses.

The gustatory system is a sensory system responsible for the perception of taste.

The human tongue is covered with a moist, pink tissue called as the mucosa or the mucous membrane. On this membrane are present tiny bumps, called as papillae.

On the tongue, papillae are situated anteriorly to the sulcus terminalis. There are three types of papillae on the tongue: filiform papillae, circumvallate papillae and fungiform papillae. The filiform papillae are the smallest and most abundant. They help in holding the food. Circumvallate papillae are large papillae arranged in a "V" shape. Fungiform papillae are mushroom shaped. Taste buds are found on circumvallate and fungiform. 

Umami is the fifth taste which detects the flavour of savoury. This taste receptor was found mostly in the Japanese. Many food preparations in Japan has a savoury flavour. These people are known to make a combination of food which has savoury flavour. So, it is considered that the taste buds for umami flavour are mainly found in the people of Japan. This taste is detected with the help of glutamate specific taste receptors because there is more amount of glutamate in the savoury food.

Taste is perceived when chemicals are dissolved in saliva. Sugar crystals on the tongue dissolve quickly in saliva, allowing for rapid perception of sweetness.

• Terminal sulcus of the tongue is a V-shaped groove, with a posteriorly oriented apex, on the surface of the tongue, marking the separation between the anterior (oral or horizontal) and the posterior (pharyngeal or vertical) parts of the tongue. Hence, Terminal sulcus separates the two parts of the tongue.

The chemicals or the substances which can stimulate the taste receptor cells are known as tastants. The upper surface contains papillae. There are several taste receptors on the papillae. When the tastants gets dissolved in the saliva, the taste can be detected by the taste receptors.

The taste buds are comprised of two main type of cells, receptor cell and the supporting cell. The receptor cells are neurosensory. They have one free end and the other nerve ending travelling to the taste area of the brain. The supporting cells are the columnar cells. These cells are present between the receptor cells. These cells are about 40 in number. 

• Lingual papillae (singular papilla) are the small, nipple-like structures on the upper surface of the tongue that give it its characteristic rough texture.
•  The four types of papillae on the human tongue have different structures and are accordingly classified as circumvallate (or vallate), fungiform, filiform, and foliate. All except the filiform papillae are associated with taste buds. Hence, Papillae states the location of taste buds on the tongue.

Bitterness is the most sensitive of the tastes and perceived as unpleasant, sharp, or disagreeable. The transduction of bitter tastes involves several mechanisms: 

• Fungiform papillae contain taste buds (especially for bitter taste), temperature receptors and have a good blood supply. They are scattered over the top and sides of the tongue, mainly towards the tip.
• Cranial nerves are the nerves which arise from the brain and spinal cord. The facial nerve is the 7th cranial nerve it arises from the pons of the brain stem.
• The fungiform papillae are innervated by the VII cranial nerve. Hence through 7th cranial nerve fungiform papillae send sensory signals of taste to the brain stem.
• So, the correct answer is 'VII'.

The taste receptor cells send information detected by clusters of various receptors and ion channels to the gustatory areas of the brain via the seventh, ninth and tenth cranial nerves. The X nerve or vagus nerve carries information from the back of the oral cavity and the epiglottis.

• Ionotropic glutamate receptors are ligand-gated ion channels that are activated by the neurotransmitter glutamate.
• Umami describes foods with an inherent savoriness(delicious, tasty). It has been described as brothy or meaty. You can taste umami in foods like Parmesan cheese, seaweed, miso, and mushrooms, which contain a high level of the amino acid, glutamate.
  
• As the umami food contains a high level of amino acid glutamate its mediated by ionotropic glutamate receptor. The receptor detects glutamate in the food and sends signals to the brain.
• So, the correct answer is 'Umami'.

• The taste receptors are located around the small structures known as papillae found on the upper surface of the tongue, soft palate, upper esophagus, the cheek, and epiglottis.
• Taste receptors detect the taste by G protein-coupled mechanism.
  
• G protein-coupled receptors constitute a large protein family of receptors that detect molecules outside the cell and activate internal signal transduction pathways and, ultimately, cellular responses. Coupling with G proteins.
  
• So, the correct answer is 'G protein-coupled receptor.

The facial nerve (cranial nerve VII) controls taste sensation from the anterior two-thirds of the tongue. This region includes the tip, edges, and most of the tongue surface where sweet, salty, and sour tastes are primarily detected. The chorda tympani branch of the facial nerve carries these taste signals.

• A single U-shaped bone which is present at the base of the buccal cavity is called as Hyoid. Hyoid bone occurs in the skull.
  
• The hyoid bone is also called and lingual or tongue bone. The term hyoid apparatus refers to the bones of the tongue.
  
• The primary function of the hyoid bone is to serve as an anchoring structure for the tongue. Hence surface for attachment of tongue is Hyoid apparatus.
• So, the correct answer is 'Hyoid apparatus'.

Myxoedema occurs due to deficiency of thyroxine is adults. It is characterised by low BMR, low body temperature, reduced heart rate, pulse rate, cardiac output Face and hands become swollen.

The vagus nerve (cranial nerve X) is involved in parasympathetic control of the heart, lungs, and digestive tract. Tongue movements are controlled by the hypoglossal nerve (cranial nerve XII), not the vagus nerve.

The hypoglossal nerve (cranial nerve XII) is responsible for controlling the muscles of the tongue.

According to the traditional tongue map, the posterior (back) portion of the tongue is most sensitive to bitter taste.

Saltish taste is typically perceived by the receptors located on the antero-lateral (front-side) edges of the tongue.

The tongue has specific regions for taste sensitivity, though the traditional map is a simplification. The tip of the tongue is generally considered most sensitive to sweet tastes.

Sour taste receptors are primarily located along the lateral edges of the tongue. This allows for the detection of acidic substances during chewing.

Bitter taste receptors are concentrated at the posterior part (back) of the tongue. This is thought to be an evolutionary mechanism to trigger a gag reflex for potentially toxic substances.

The tongue of a person is exposed to a high salty taste then the tongue fails to taste a less salty thing just after exposure. This happens because the taste receptors on the surface of the tongue get adapted to the salty taste.

In tongue, small structures called papillae are present. They are mainly of four types- filiform papillae, fungiform papillae, foliate papillae, circumvallate papillae. Most of them are associated with taste buds. The filiform papillae are the smallest amongst the four and are most numerous. They are scattered throughout the dorsal surface of the tongue and not just at the center of the tongue.

The function of the tongue is to help in the act of swallowing and help in mixing saliva with the food. It is a muscular organ in the mouth. It is vital for chewing and swallowing food, as well as for speech. It consists of eight interwoven, striated muscles that can move in any direction, making it quite flexible. So, the correct answer is option C.

Ageusia refers to the lost ability of tongue to taste, particularly the inability to detect sweetness, sourness, bitterness, saltiness, and umami (meaning "pleasant/savory taste"). It is sometimes confused with anosmia a loss of the sense of smell.