Which conducts food from the throat to the stomach

The anterior region of the palate serves as a wall or septum between the oral and nasal cavities as well as a rigid shelf against which the tongue can push food. It is created by the maxillary and palatine bones of the skull and, given its bony structure, is known as the hard palate. This part of the palate, known as the soft palate , is composed mainly of skeletal muscle. You can therefore manipulate, subconsciously, the soft palate—for instance, to yawn, swallow, or sing see Figure A fleshy bead of tissue called the uvula drops down from the center of the posterior edge of the soft palate.

Although some have suggested that the uvula is a vestigial organ, it serves an important purpose. When you swallow, the soft palate and uvula move upward, helping to keep foods and liquid from entering the nasal cavity.

Unfortunately, it can also contribute to the sound produced by snoring. Two muscular folds extend downward from the soft palate, on either side of the uvula. Toward the front, the palatoglossal arch lies next to the base of the tongue; behind it, the palatopharyngeal arch forms the superior and lateral margins of the fauces. Between these two arches are the palatine tonsils, clusters of lymphoid tissue that protect the pharynx. The lingual tonsils are located at the base of the tongue.

Perhaps you have heard it said that the tongue is the strongest muscle in the body. Those who stake this claim cite its strength proportionate to its size.

Although it is difficult to quantify the relative strength of different muscles, it remains indisputable that the tongue is a workhorse, facilitating ingestion, mechanical digestion, chemical digestion lingual lipase , sensation of taste, texture, and temperature of food , swallowing, and vocalization.

The tongue is attached to the mandible, the styloid processes of the temporal bones, and the hyoid bone. The tongue is positioned over the floor of the oral cavity. A medial septum extends the entire length of the tongue, dividing it into symmetrical halves. Beneath its mucous membrane covering, each half of the tongue is composed of the same number and type of intrinsic and extrinsic skeletal muscles. The intrinsic muscles those within the tongue are the longitudinalis inferior, longitudinalis superior, transversus linguae, and verticalis linguae muscles.

These allow you to change the size and shape of your tongue, as well as to stick it out, if you wish. Having such a flexible tongue facilitates both swallowing and speech. As you learned in your study of the muscular system, the extrinsic muscles of the tongue are the mylohyoid, hyoglossus, styloglossus, and genioglossus muscles.

These muscles originate outside the tongue and insert into connective tissues within the tongue. The mylohyoid is responsible for raising the tongue, the hyoglossus pulls it down and back, the styloglossus pulls it up and back, and the genioglossus pulls it forward. Working in concert, these muscles perform three important digestive functions in the mouth: 1 position food for optimal chewing, 2 gather food into a bolus rounded mass , and 3 position food so it can be swallowed.

The top and sides of the tongue are studded with papillae, extensions of lamina propria of the mucosa, which are covered in stratified squamous epithelium Figure Fungiform papillae , which are mushroom shaped, cover a large area of the tongue; they tend to be larger toward the rear of the tongue and smaller on the tip and sides. Circumvallate papillae are much fewer in number, only 8 to 12, and lie in a row along the posterior portion of the tongue anterior to the lingual tonsil.

In contrast, filiform papillae are long and thin. Fungiform and circumvallate papillae contain taste buds, and filiform papillae have touch receptors that help the tongue move food around in the mouth.

Lingual glands in the lamina propria of the tongue secrete mucus and a watery serous fluid that contains the enzyme lingual lipase , which plays a minor role in breaking down triglycerides but does not begin working until it is activated in the stomach. A fold of mucous membrane on the underside of the tongue, the lingual frenulum , tethers the tongue to the floor of the mouth. Severe ankyloglossia can impair speech and must be corrected with surgery.

Many small salivary glands are housed within the mucous membranes of the mouth and tongue. These minor exocrine glands are constantly secreting saliva, either directly into the oral cavity or indirectly through ducts, even while you sleep. In fact, an average of 1 to 1.

Usually just enough saliva is present to moisten the mouth and teeth. Secretion increases when you eat, because saliva is essential to moisten food and initiate the chemical breakdown of carbohydrates.

Small amounts of saliva are also secreted by the labial glands in the lips. In addition, the buccal glands in the cheeks, palatal glands in the palate, and lingual glands in the tongue help ensure that all areas of the mouth are supplied with adequate saliva. Outside the oral mucosa are three pairs of major salivary glands, which secrete the majority of saliva into ducts that open into the mouth:. Saliva is essentially The remaining 4. Perhaps the most important ingredient in salvia from the perspective of digestion is the enzyme salivary amylase , which initiates the breakdown of carbohydrates.

Food does not spend enough time in the mouth to allow all the carbohydrates to break down, but salivary amylase continues acting until it is inactivated by stomach acids. Bicarbonate and phosphate ions function as chemical buffers, maintaining saliva at a pH between 6.

Salivary mucus helps lubricate food, facilitating movement in the mouth, bolus formation, and swallowing. Saliva contains immunoglobulin A, which prevents microbes from penetrating the epithelium, and lysozyme, which makes saliva antimicrobial. Each of the major salivary glands secretes a unique formulation of saliva according to its cellular makeup. For example, the parotid glands secrete a watery solution that contains salivary amylase. The submandibular glands have cells similar to those of the parotid glands, as well as mucus-secreting cells.

Bile is stored in the gallbladder until it is needed. The pancreas makes enzymes that help digest proteins, fats, and carbs. It also makes a substance that neutralizes stomach acid. These enzymes and bile travel through special pathways called ducts into the small intestine, where they help to break down food. The liver also helps process nutrients in the bloodstream.

From the small intestine, undigested food and some water travels to the large intestine through a muscular ring or valve that prevents food from returning to the small intestine. By the time food reaches the large intestine, the work of absorbing nutrients is nearly finished. The large intestine's main job is to remove water from the undigested matter and form solid waste poop to be excreted. Reviewed by: Larissa Hirsch, MD. Larger text size Large text size Regular text size.

What Is the Digestive System? Almost all animals have a tube-type digestive system in which food: enters the mouth passes through a long tube exits the body as feces poop through the anus Along the way, food is broken down into tiny molecules so that the body can absorb nutrients it needs: Protein must be broken down into amino acids.

Starches break down into simple sugars. Anatomical stands five parts of the stomach: cardia, the relationship I pass the esophagus into the stomach, fundus, extended, most proximal part, the corpus or body of the stomach, antrum and pylorus, which is a transitional zone between the stomach and duodenum.

Its shape is reminiscent of the stomach letter J or vertically laid the hook and may vary longer vertical part cardia, fundus and corpus and horizontal antrum and pylorus that each smaller part of town right corner. Clearly distinguish the front and back walls of the stomach and large and small curves. Stomach wall is constructed of four layers of the mucosa, submucosa, muscularis and serosa.

The stomach is located in the upper abdomen below the left dome of the diaphragm. Clouds covered the left costal margin and partly in the upper central part of the abdomen, called epigastrium. Vascularization of the stomach is extremely rich and persistent. In parallel with vascular network mainly covers richly branched lymphatic network. Duodenum in a frame surrounding the head of the pancreas. Welding is a process that implies fragmentation and breakdown of food to enough small parts that our body can later use to build and maintain cells and provides energy for the body.

Digestion begins in the mouth and ends in the small intestine where the fully processed products ingested food are absorbed into the bloodstream. Digestion involves chewing food, the passage of food through the digestive tract, and its chemical decomposition of large molecules in sitnnije.

Food and liquid through the digestive tract run special undulating movements called peristalsis. Start welding means the act of swallowing. The first phase of the act of swallowing is consciously controlled movement, but the further course of food intake takes place through a series of reflex mechanisms.

The first phase of the act of swallowing is an oral phase. After entering the bites, the food is chewed and mixed with saliva. After that, the bolus of food is of her tongue moves into the pharynx oropharynx and hypopharynx when performing the pharyngeal stage of swallowing. This is where conscious control of food and fluid intake, and further control the swallowing reflex is being implemented.

Pharyngeal stage of swallowing takes about 1. After swallowing pharyngeal phase begins esophageal phase. All statements describe the esophagus. Cardiac region: the area closest to the small intestine B.

Fundus: the most superior portion of the stomach C. Pyloric opening: opening from the stomach into the small intestine D. Body: the largest portion of the stomach. It breaks large food particles into smaller ones.

It involves the breaking of covalent chemical bonds in organic molecules by digestive enzymes. It begins in the stomach, where some small, lipid-soluble molecules, such as alcohol and aspirin , can diffuse through the stomach epithelium into the circulation.

It requires carrier molecules and includes facilitated diffusion, cotransport, and active transport. All the statements describe mechanical digestion. Mucous neck cells B.