digestive system unit

what is the soft plate made of

Behind the hard palate is the soft palate, made from a movable mucous membrane fold. The soft palate is an arch-shaped structure, separating the mouth from the nasopharynx.

what is the uvula

Hanging from the middle of the soft palate is a cone-shaped flap of tissue called the uvula (YOO-vyuh-luh).This prevents food from entering the nasal cavity when swallowing

what is the function of bile in the liver

Manufactures bile, a yellow to green fluid that is necessary for the digestion of fat. About 800 to 1,000 mL of bile is produced daily. Bile contains bile salts, bile pigments (mainly bilirubin [bill-ih-ROO-bin], which comes from the breakdown of the hemoglobin molecule), cholesterol, phospholipids, and some electrolytes

what are the pancreatic juices

Pancreatic juices include protease (PRO-tee-ace), which breaks down protein to amino acids; amylase (carbohydrase), which breaks down starches to glucose; and lipase (LIP-ace), which breaks down fats to fatty acids and glycerol. The pancreatic juices also contain sodium bicarbonate, which neutralizes the food content of the stomach, which is high in acid.

what are the walls of the esophagus?

The esophageal walls have four layers: the mucosa, submucosa, muscular, and external serous layers. The muscles in the upper third are voluntary and the lower portion is smooth muscle, or involuntary.

what are the walls of the alimentary canal are composed of

1. The innermost lining, called the mucosa, is made of epithelial cells. 2. The submucosa consists of connective tissue with fibers, blood vessels, and nerve endings. 3. The third layer, the muscularis of the mouth, pharynx, and first part of the esophagus, consists of skeletal muscle that allows the voluntary act of swallowing. The rest of the tract consists of smooth muscle, which helps break down food and propel the food through the tract. 4. The fourth, the serosa, is also known as the visceral peritoneum.

what is a dentist

A dentist, also known as a dental surgeon, is a surgeon who specializes in dentistry, the diagnosis, prevention, and treatment of diseases and conditions of the oral cavity. The dentist's supporting team aids in providing oral health services.

what does the paratoid duct carrie

A parotid duct carries its secretions, consisting almost entirely of salivary amylase (ptyalin) (TYE-ah-lin), into the mouth. It opens on the inner surface of the cheeks, opposite the second molar of the upper jaw.

what is an inflammation of the peritoneum membrane called

An inflammation of the lining of this cavity caused by disease-producing organisms is called peritonitis

where is the submandibular gland found and what is it

Below the parotid salivary gland and near the angle of the lower jaw is a submandibular gland (sub-man-DIB-yoo-lar).This gland is about the size of a walnut and its secretions contain both mucin (forms mucus) and salivary amylase. The secretions enter the buccal cavity via the submandibular duct at the anterior base of the tongue.

when do the deciduous teeth come in and leave and what do they include

Deciduous (dih-SIH-joo-us) teeth start to erupt at about 6 months and continue until around 2 years of age. In total, 20 deciduous teeth are cut during the first 2 years. They include four incisors, two canines, and four molars. There are no premolars among the deciduous teeth. Deciduous teeth may last up to the age of 12.

dental assistant

Dental assistants are members of the dental team. They may support a dental operator in providing more efficient dental treatment. Dental assistants are distinguished from other groups of dental auxiliaries by differing training, roles and patient scopes..

what is a dental hygienist

Dental hygienists provide preventative oral care under a dentist's supervision. They clean patients' teeth and examine their mouths for signs of damage, gingivitis, and other diseases. Hygienists teach patients how to maintain good oral health. Their scope of practice—what services they are legally allowed to deliver—differs according to the rules of the state in which they work.

Dental Laboratory Technician

Dental laboratory technicians fill prescriptions from dentists for crowns, bridges, dentures, and other dental prosthetics.

what are the two sets of teeth a human develops

During normal growth and development, the human mouth develops two sets of teeth: the deciduous or milk teeth, which are later replaced by the permanent teeth.

what is the major parts of the tooth

Each tooth may be divided into three major parts: the crown, the neck, and the root

What do enzymes do for digestion?

Enzymes (EN-zimez) promote chemical reactions in living things, although they themselves are unaffected by the chemical reactions.

what stimulates the digestive juices in the pancreas, liver and gallbladder

Enzymes, secretin , and cholecystokinin stimulate the digestive juices

what is the purpose of teeth

Food must be thoroughly chewed, or masticated (MASS-tih-kay-ted), by the teeth. Teeth help break food down into very small morsels, increasing the food's surface area. This activity enables the digestive enzymes to digest the food more efficiently and quickly.

what is gum disease

Gum disease or periodontal disease describes bacterial growth and factors that gradually destroy the tissue surrounding and supporting the teeth. When gum disease is untreated, it can advance to periodontitis, an inflammation around the tooth. At this point the inner layer of gum and bone recede from the teeth and form pockets that can collect debris and become infected. As the disease progresses, the teeth lose their anchor and may become loose and fall out.

what is mumps

If a person has mumps, chewing is painful, because the motion squeezes these tender, inflamed glands

what is inside the tooth

Inside the tooth is the pulp cavity, which contains the nerves and blood supply. Enamel is the hardest substance in the body. Narrow extensions of the pulp cavity (root canals) project into the root. At the base of each root canal is the opening for blood vessels and nerves. The dentin of the root is covered with a substance called cementum, which attaches the root to the periodontal membrane (pehr-ee-oh-DON-tal MEM-brain), anchoring the tooth in place.

what does the intestinal juices secreted by the cells of the small intestine include

Intestinal juices secreted by the cells of the small intestine—including maltase, lactase, and sucrase—change starch into glucose; peptidase changes proteoses and peptone into amino acids; and lipase changes fat into fatty acids and glycerol.

what is the esophagus

It begins at the lower end of the pharynx, behind the trachea. It continues downward through the mediastinum, in front of the vertebral column, and passes through the diaphragm. From there the esophagus enters the upper part, or cardiac portion, of the stomach.

what is the function of the pancreas

It functions as both an exocrine gland and an endocrine gland. Internally, the pancreas consists of groups of clusters of cells. The islets of Langerhans, one group of cells, are part of the endocrine system and produce insulin and glucagon (refer to Chapter 11). The acini cells (ASS-uh-nigh) produce the digestive juices, and the duct cells secrete sodium bicarbonate, which helps neutralize the acidic content of food as it leaves the stomach.

what is the tongue connected too

It is attached to four bones: the hyoid, the mandible, and two temporal bones.

what does liver produce

Liver produces bile, which is necessary to break down or emulsify fat into smaller fat globules to be digested by lipase.

what are taste buds

On the tongue's epithelial surface are projections called papillae. There are nerve endings located in many of these papillae, forming the sense organs of taste, or taste buds. These taste buds respond to bitterness, saltiness, sweetness, sourness, and umami in foods. They are also sensitive to cold, heat, and pressure.

permanent teeth

Permanent teeth begin developing at about the age of 6, pushing out their deciduous predecessors. The last permanent teeth to emerge are the third molars, or wisdom teeth,

what is saliva made of

Saliva is 99.5% water, which provides a medium for dissolving foods. The remainder is chlorides, which activate salivary amylase (SAL-ih-vehr-ee AM-eh-layz), mucin, and the enzyme lysozyme, which destroys bacteria.

what is the saliva secreted into and by who

Saliva is secreted into the oral cavity by three pairs of salivary glands: the parotid, the submandibular, and the sublingual

what is salivary amylase

Salivary amylase begins the breakdown of complex carbohydrates into simple sugars.

what are the multiple functions of the digestive system

Take food into the mouth, where it is mechanically and chemically broken down. Uses peristalsis (pehr-ih-STALL-sis) that is rhythmic muscular contractions and segmented movement when single segments of the intestine alternate between contraction and relaxation to push food through the digestive tract. Use both mechanical (teeth) and chemical mechanisms (digestive enzymes) to break down food into the end products of fat, carbohydrates, and protein. Absorb nutrients into the blood capillaries and lacteals of the small intestines for use in the body. Eliminate the waste products of digestion.

what are bicuspid teeth

The adult mouth has eight premolars, or bicuspids (bye-KUS-pidz): four in the upper jaw and four in the lower. Bicuspids are broad, with two ridges on each crown, and have only two roots. Their design is ideal for grinding food. Figure 18-4 shows the arrangement of the deciduous and permanent teeth.

The combined action of pancreatic juice, bile, and intestinal juice completes the process of

The combined action of pancreatic juice, bile, and intestinal juice completes the process of changing carbohydrates first into starch then into glucose, protein into amino acids, and fats into fatty acids and glycerol (Figure 18-7). The end products of digestion are now ready for absorption

what is the crown, neck and root of the tooth

The crown is the part of the tooth that is visible; the neck is where the tooth enters the gumline; the root is embedded in the alveolar processes of the jaw.

where are the sublingual glands found and what do they secrete

The final pair of salivary glands are the sublingual glands (sub-LING-gwuhl), the smallest of the three. They are found under the sides of the tongue. Their secretion consists mainly of mucus and contains no salivary amylase.

where does the final preparation of food occur

The final preparation of food to be absorbed occurs in the small intestine.

what do the gums do and made of

The gingivae (JIN-jih-vee), or gums, support and protect the teeth. They are made up of fleshy tissue covered with mucous membrane. This membrane surrounds the narrow portions of the teeth (also called cervix or neck), and covers the structures in the upper and lower jaws.

what is the hard palate in the formed of

The hard palate is hard because it is formed from the maxillary and palatine bones, which are covered by mucous membrane.

whats the liver divided into

The liver is divided into two principal lobes: the right lobe and the left lobe. The lobes of the liver are made up of many functional units called lobule

what is the mucosa layer of the stomach

The mucosa layer is the innermost layer. It is a thick layer made up of small gastric glands embedded in connective tissue. When the stomach is not distended with food, the gastric mucosa is thrown into folds called rugae

what is the purpose of the mucosa

The mucosa secretes slimy mucus. In some areas, it also produces digestive juices. This slimy mucus lubricates the alimentary canal, aiding in the passage of food. It also insulates the digestive tract from the effects of powerful enzymes while protecting the delicate epithelial cells from abrasive substances within the food.

what is the muscularis layer of the stomach

The muscularis layer consists of three layers of smooth muscle: the outer longitudinal layer, a middle circular layer, and an inner oblique layer (Figure 18-5A). These muscles help the stomach perform peristalsis, which pushes food into the small intestine.

what is the muscle that is in between esophagus into the stomach

The opening from the esophagus into the stomach is through a circle of muscle called the cardiac sphincter or esophageal sphincter. It is called the cardiac sphincter because of its proximity to the cardiac portion of the stomach.

where is the pancrease found and what shape

The pancreas is a feather-shaped organ located behind the stomach

what are the parotid glands

The parotid glands (pah-RAH-tid) are found on both sides of the face, in front of and below the ears. They are the largest salivary glands, the ones that become inflamed during an attack of mumps.

what are the two specialized layers of peritoneum.

The peritoneum that attaches to the posterior wall of the abdominal cavity is called the mesentery (MEZ-in-tehr-ee). The small intestines are attached to this layer. In the anterior portion of the abdominal cavity, a double fold of peritoneum extends down from the greater curvature of the stomach. This hangs over the abdominal organs like a protective apron. This layer contains large amounts of fat and is called the greater omentum (oh-MEN-tum). The peritoneal structure between the liver and stomach is called the lesser omentum.

what is the portal vein

The portal vein carries the products of digestion from the small intestine to the liver

how is the sensation of taste coupled with the sense of smell

The sensation of taste is coupled with the sense of smell. When we experience an odor, it stimulates the olfactory nerve endings in the upper part of the nasal cavity. We may confuse the odor of a food with its flavor. A bad cold, with nasal congestion, frequently impedes the ability to taste the flavor of foods, because increased mucous secretions cover the olfactory nerve endings.

what is the serosa layer of the stomach

The serosa is the thick outer layer covering the stomach. It is continuous with the peritoneum. The serosa and peritoneum meet at certain points, surrounding the organs around the stomach and holding them in a kind of sling.

what is the shape of the stomach

The shape and position are determined by several factors. These include the amount of food contained within the stomach, the stage of digestion, the position of a person's body, and the pressure exerted on the stomach from the intestines below.

what are the layers of the small intestine

The small intestine has the same four layers as the stomach: the mucosa, submucosa, muscularis, and serosa. The mucosa of the small intestine is in numerous folds called plicae (PLYE-kee) circularis.

what are the small intestines divided into

The small intestine is divided into three sections: the duodenum, the jejunum (jih-JOO-num), and the ileum

why do experts call the stomach and the small intesine ¨A mini brain¨

The stomach and small intestines have more nerve cells than the spinal cord does, causing some experts to call it "a mini-brain."

what are the portions of the stomach

The stomach is divided into three portions: the upper part or fundus, the middle section called the body or greater curvature, and the lower portion called the pylorus.

where is the stomach found

The stomach is found in the upper part of the abdominal cavity, just to the left of and below the diaphragm.

what is the submucosa layer of the stomach

The submucosa layer is made of loose areolar connective tissue.

What does the tongue help with and what is it made of

The tongue and its muscles are attached to the floor of the mouth, helping in both chewing and swallowing. The tongue is made from skeletal muscles that lie in many different planes. Because of this, the tongue can be moved in various directions.

The first segment of the small intestine is the duodenum which

This 12-inch structure curves around the head of the pancreas. A few inches into the duodenum is the hepatopancreatic ampulla, which is the site where the pancreatic duct and the common bile duct of the liver enter. The pancreatic duct empties the digestive juices of the pancreas and the common bile duct empties bile from the liver.

what is the peritoneum membrane

This is a two-layered membrane with the outer, or parietal, side lining the abdominal cavity and the inner, or visceral, side covering the outside of each organ in the abdominal cavity.

what has to happen to all food before it can be used by all the cells?

This means that certain physical and chemical changes must take place to change the insoluble complex food molecules into simpler soluble one

what is the spincter that is on the other side of the stomach

Toward the other end of the stomach lies the pyloric sphincter (pye-LOR-ick) valve, which regulates entrance of food into the duodenum (dew-uh-DEE-num), the first part of the small intestine.

what is lingual frenulum

a band of tissue that attaches the tongue to the floor of the mouth. The frenulum limits the motion of the tongue. A condition known as tongue-tie may occur if there is congenital shortness of the frenulum, which interferes with speech.

Rennin produces

a digestive enzyme, is found in infants and children, but not adults. It prepares milk proteins for digestion by other enzymes.

how is digestion accomplished

accomplished by the action of various digestive juices containing enzymes.

where is the liver located

below the diaphragm, in the upper right quadrant of the abdomen

what is the small intestine help in place by and what it is covered with

by the mesentery. The small intestine lining secretes digestive juices and is covered with villi, which absorb the end products of digestion

how long is the coiled portion of the alimentary canal

can be as long as 20 feet.

what is the muscle ring between the esophagus and stomach

cardiac sphincter

gastric mucosa contains

contains millions of gastric glands that secrete the gastric juices necessary for digestion

what is the inside of the moulth covered with

covered with a mucous membrane

what happenes in enamel wears down

f the enamel wears down on the surface of the tooth, bacteria may enter and caries or cavities will develop.

what is the medterm for gums

gingivae

what are the incisors used for

have sharp edges for biting

how many teeth does an adult have

he adult mouth develops 32 teeth, 16 in each jaw

how is food tasted

it must be in solution. The solution passes through the taste bud openings, stimulating the nerve endings in the taste cells.

what is the alimentary canal and what organs does it contain

known as the digestive tract or gastrointestinal (GI) tract. The alimentary canal consists of the mouth (oral cavity), pharynx (throat), esophagus (gullet), stomach, small intestine, large intestine (colon), and anus (Figure 18-1). It is a continuous tube some 30 feet

what membrane lines the abdominal cavity

lined with a serous membrane called the peritoneum.

what is the med term for chewing

masticated

what are the layers of the stomach

mucosa, submucosa, muscularis, and serosa layers

what does the roof of the moulth consist of

of a hard and a soft palate

what is the name for the moulth

oral or buccal cavity

what are the canines

pointed for tearing

what does digestion mean?

process of changing complex solid foods into simpler soluble forms that can be absorbed by the body cells

Parietal cells produce

produce HCl acid, which converts pepsinogen into pepsin and destroys bacteria and microorganisms that enter the stomach. It is the body's natural sterilizer. also produce the intrinsic factor, an element necessary for the absorption of vitamin ; without it, a condition known as pernicious anemia develops.

wisdom teeth

r wisdom teeth, which may appear anywhere from 17 to 25 years of age

what are the molars

ridges designed for crushing and grinding.

Chief-type cells produce

s produce pepsinogen, which converts to pepsin. The enzyme pepsin breaks down protein into smaller pieces called proteoses and peptone.

Mucous cells produce

secrete alkaline mucus, which helps neutralize the effects of HCl acid and the other digestive juices. Mucous cells in the stomach replace themselves every 3 to 5 days.

Enteroendocrine glands produce

secrete gastrin, which in turn stimulates cells to produce hydrochloric acid (HCl) and pepsinogen.

what is the third section of the small intestine and how long is it

the ileum, which is 10 to 12 feet long.

what is the second section of the small intestine and bow long is it

the jejunum, which is about 8 feet long,

absorbtion in the small inestine is possible because

the lining of the small intestine is not smooth. It is covered with millions of tiny projections called villi (VILL-eye). Each microscopic villus contains a network of blood and lymph capillaries (lacteals) Figure 18-8). The digested portion of the food passes through the villi, into the bloodstream and lacteals, and on to the body cells. The undigestible portion passes on to the large intestine.

what protects the opening of the mouth

the lips

what is the largest organ in the body

the liver

how do the secretions leave the pancreas

through a large duct called the pancreatic duct. The secretions unite with the common bile duct of the liver and enter the duodenum in a common duct called the hepatopancreatic ampulla.

what is the function of the digestive system

to change food into forms that the body can use and to eliminate the waste products.

what happens to food when it just became simpler soluble ones from physical and chemical changes?

transported by the blood to the cells and absorbed through the cell membranes.

what is the pylorospasm condition

when the pyloric sphincter valve fails to relax in infants. In such cases, food remaining in the stomach does not get completely digested and eventually is vomited.