What role does water play in saliva?
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It dissolves food and helps produce taste to initiate digestion.
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What role does water play in saliva?
It dissolves food and helps produce taste to initiate digestion.
Where are the submandibular glands found?
In the floor of the mouth, below the lower jaw.
What is the structure of the digestive system?
A tubular system that extends from the mouth to the anus.
How do chloride ions in saliva contribute to digestion?
They activate salivary amylase, which starts the breakdown of starch.
What role does immunoglobulin A (IgA) play in saliva?
It prevents microbes from entering or attaching to epithelial cells.
What are some locations of minor salivary glands?
In the cheeks, palates, tongue, and lips.
What is defecation?
The process of eliminating wastes, indigestible substances, and digested materials that were not absorbed through the anus.
What is the visible portion of a tooth above the gums called?
Crown.
What do lymphatic vessels provide in the digestive system?
Protection.
What types of muscle make up the upper and lower esophageal sphincters?
The upper esophageal sphincter consists of skeletal muscle, while the lower esophageal sphincter consists of smooth muscle.
What is the main composition of saliva?
99.5% water and 0.5% solutes.
What is the purpose of the muscularis mucosae?
Increases the surface area of the stomach and small intestine to enhance digestion and absorption.
What is the location of the sublingual glands?
Beneath the tongue and superior to the submandibular glands.
What is the serosa?
A protective and connective tissue that forms the outer layer of the gastrointestinal tract.
What is the process of ingestion?
Taking foods and liquids into the mouth.
What is motility in the context of the digestive system?
The capability of the GI tract to mix and move material along its length through alternating contractions and relaxations of smooth muscle.
What are the two types of muscles in the tongue?
Extrinsic muscles and intrinsic muscles.
What do lingual glands secrete?
Mucus and fluid containing the enzyme lingual lipase.
What do root canals contain?
Blood vessels, nerves, and lymphatic vessels.
What is the role of saliva in digestion?
It dissolves small food molecules and contains enzymes.
What is peristalsis?
A progression of coordinated contractions and relaxations of the muscularis that pushes the bolus toward the stomach.
What is the inner lining of the GI tract called?
Mucosa.
How many pairs of major salivary glands are there?
Three pairs.
What is the function of mucus in saliva?
It lubricates and moistens food for easy swallowing.
What is the composition and function of the tongue?
The tongue is composed of skeletal muscle covered with mucous membrane; it helps taste, swallow food, and speak.
What is the hard palate made up of?
Palatine and maxillae bones covered with mucous membrane.
What is the length of the esophagus?
25 cm long.
Why is intrinsic factor important?
It is needed for the absorption of vitamin B12.
What hormone do G cells secrete?
Gastrin.
What protects the stomach epithelial cells from gastric juices?
A 1-3 mm thick layer of alkaline mucus.
What role does carbonic anhydrase play in parietal cells?
It produces carbonic acid from CO2 and H2O, which dissociates into H+ and HCO3-.
What is pancreatic juice composed of?
Water, salts, sodium bicarbonate, and several enzymes.
How is the liver anatomically divided?
Into two lobes: the right lobe (larger) and the left lobe (smaller), separated by the falciform ligament.
What is the primary function of the gall bladder?
To store and concentrate bile.
What is the role of bile salts in digestion?
They aid in emulsification and absorption of lipids.
What do chemoreceptors in the stomach monitor?
The pH of the stomach chyme.
What are the four layers of the GI tract wall?
Mucosa, submucosa, muscularis, and serosa.
What is eliminated from the body by the digestive system?
Wastes.
What does the submucosa contain that is important for nutrient absorption?
Many blood and lymphatic vessels.
Where do the ducts of the submandibular glands open?
Into the oral cavity lateral to the lingual frenulum.
What role do accessory digestive organs play?
They assist in digestion but do not come into direct contact with food; they produce secretions that aid in chemical breakdown.
What are papillae on the tongue?
Structures that cover the upper and lateral surfaces of the tongue, many of which contain taste buds.
What is the function of nerves in the digestive system?
They provide sensation.
What regulates the movement of food from the pharynx into the esophagus?
The upper esophageal sphincter (UES).
What is the tail of the pancreas?
The last tapering portion of the pancreas.
What hormone decreases blood sugar levels?
Insulin.
What is the function of pancreatic amylase?
It is a starch-digesting enzyme.
What are the main components of bile?
Water, bile salts, cholesterol, lecithin, bile pigments, and several ions.
What is the function of the small intestine?
It plays a major role in digestion and absorption of nutrients.
What are circular folds in the small intestine?
Folds of mucosa and submucosa that increase surface area and facilitate the movement of chime.
What does the submucosa of the duodenum secrete?
Alkaline mucus that helps neutralize gastric acid in the chyme.
How are dietary lipids absorbed?
By simple diffusion.
Which vitamins are absorbed by simple diffusion?
Water-soluble vitamins B and C.
What is the terminal portion of the rectum called?
Anal canal.
What role does the epithelium play in the GI tract?
Protection, secretion, and absorption.
What type of tissue binds the mucosa to the muscularis in the submucosa?
Areolar connective tissue.
What is the function of lysozyme in saliva?
It destroys harmful bacteria.
What is the peritoneum?
The largest serous membrane in the body.
How does mechanical digestion occur?
Through the cutting and grinding of food by teeth and the mixing by smooth muscles in the stomach and small intestine.
What is the role of blood vessels in the digestive system?
They bring nourishment.
What is the mass of chewed food called?
Bolus.
What facilitates the act of swallowing?
The secretion of saliva and mucus.
In what environment is lingual lipase activated?
In the acidic environment of the stomach.
What is the function of the nasopharynx?
It helps in respiration.
What do exocrine cells in the pancreas secrete?
Pancreatic juice, a mixture of fluid and digestive enzymes.
What does pancreatic polypeptide control?
Somatostatin secretion.
What are the three anatomical parts of the pancreas?
Head, Body, and Tail.
Which enzymes in pancreatic juice are responsible for protein digestion?
Trypsin, Chymotrypsin, Carboxypeptidase, and Elastase.
How does the gall bladder concentrate bile?
By the absorption of water and ions.
How does the liver maintain normal blood glucose levels?
By breaking down glycogen to glucose and converting lactic acid and amino acids into glucose.
What is the role of the liver in vitamin D synthesis?
The liver, along with skin and kidneys, participates in synthesizing the active form of vitamin D.
Where does the small intestine begin?
At the pyloric sphincter of the stomach.
What do Goblet cells secrete?
Mucus.
What are villi and their function?
Fingerlike projections of mucosa that vastly increase surface area for absorption and digestion.
What are the three layers of the mucosa?
Epithelium, lamina propria, and muscularis mucosae.
What are the organs involved in the breakdown of food collectively called?
The digestive system.
What types of muscles are found in the muscularis layer of the gastrointestinal tract?
Both skeletal muscles and smooth muscles.
What are the two types of digestion?
Mechanical digestion and chemical digestion.
What covers the alveolar processes in the mouth?
Gingivae (gums).
What covers the dentin of the root?
Cementum.
What substances do chief cells secrete?
Pepsinogen and gastric lipase.
What does salivary amylase convert starch into?
Monosaccharides and disaccharides.
What connects the esophagus to the duodenum?
The stomach.
What are the four main regions of the stomach?
Cardia, fundus, body, and pylorus.
What are rugae in the stomach?
Large folds in the mucosa that can be seen with the unaided eye when the stomach is empty.
What type of tissue makes up the submucosa?
Areolar connective tissue.
What are the small clusters of glandular epithelial cells in the pancreas called?
Acini.
What stimulates HCl secretion in parietal cells?
Gastrin, Acetylcholine, and Histamine.
Where is the head of the pancreas located?
Near the curve of the duodenum.
What are the three portions of the gallbladder?
Fundus (inferior broad portion), body (middle portion), and neck (upper taper portion).
What is the pH range of bile?
7.6 – 8.6.
What are the three major parts of the small intestine?
Duodenum, jejunum, and ileum.
What surrounds the small intestine?
The serosa (or visceral peritoneum).
What is saliva's role in the mouth?
To keep mucous membranes moist, cleanse the mouth and teeth, lubricate, dissolve, and begin the chemical breakdown of food.
What is the pH range of saliva, and why is it important?
6.35 - 6.85; phosphate and bicarbonate ions buffer acidic food.
What is the myenteric plexus?
A bundle of neurons present in the muscularis layer.
What forms the lateral walls of the mouth?
Cheeks.
What is absorption in the digestive system?
The entrance of ingested and secreted fluids, ions, and products of digestion into the epithelial cells lining the GI tract.
What substance forms the majority of the tooth?
Dentin.
What does enamel primarily consist of?
Calcium phosphate and calcium carbonate.
What is the function of teeth in the digestive system?
To cut, tear, and pulverize solid food into smaller particles for easier swallowing and digestion.
What is the opening at the base of each root canal called?
Apical foramen.
What is the primary function of the esophagus?
To secrete mucus and transport food into the stomach.
What is the soupy liquid formed in the stomach called?
Chyme.
How is pepsin kept from digesting the proteins in stomach cells?
It is secreted in an inactive form called pepsinogen.
What is the function of the pancreatic duct?
It carries pancreatic juices into the duodenum and combines with the common bile duct to form the hepatopancreatic ampulla.
What hormone increases blood sugar levels?
Glucagon.
What is the anatomical position of the pancreas?
It is a retroperitoneal gland located posterior to the greater curvature of the stomach.
What is the location of the liver in the body?
Inferior to the diaphragm.
What is the pathway of bile from hepatocytes to the common bile duct?
Bile canaliculi → bile ductules → left/right hepatic ducts → common hepatic duct → cystic duct → common bile duct.
What happens to excess glucose when blood sugar levels rise?
It is converted into glycogen and triglycerides for storage.
What is the function of absorptive cells in the small intestine?
They digest and absorb nutrients.
What is the function of the lamina propria?
Contains blood and lymphatic vessels that transfer absorbed nutrients and contains immune system cells.
What is the submucosal plexus?
An extensive network of neurons that is part of the enteric nervous system (ENS).
What are the two divisions of the peritoneum?
Parietal peritoneum and visceral peritoneum.
What are the three parts of a tooth?
Crown, root, and neck.
What is the role of intrinsic muscles of the tongue?
They alter the shape and size of the tongue for speech and swallowing.
Where does the esophagus start and end?
Starts from the inferior end of the laryngopharynx and ends at the superior portion of the stomach.
What type of glands are found in the mucosa of the stomach?
Gastric glands.
What is deglutition?
The act of swallowing.
Does the esophagus produce digestive enzymes?
No, it does not produce digestive enzymes.
What process involves the periodic pushing of chyme into the small intestine?
Gastric emptying.
What enzyme splits short-chain triglycerides in fat molecules?
Gastric lipase.
What is the hepatopancreatic ampulla?
It is formed by the combination of the pancreatic duct and the common bile duct, opening into the duodenum.
What is the basic structural unit of the liver?
Lobule.
What triggers the ejection of bile from the gall bladder?
Contraction of smooth muscles.
What is the function of hepatocytes in lipid metabolism?
They store triglycerides, break down fatty acids for ATP, synthesize lipoproteins, and produce bile salts from cholesterol.
What types of cells are found in the mucosa of the small intestine?
Absorptive cells, Goblet cells, Paneth cells, and Endocrine cells.
How are carbohydrates absorbed in the small intestine?
As monosaccharides.
What types of nucleotide-digesting enzymes are present in brush border enzymes?
Nucleosidases and phosphatases.
What is attached to the cecum?
The appendix or vermiform appendix.
What are the four basic layers of the large intestine?
Mucosa, Submucosa, Muscularis, and Serosa.
What are some solutes found in saliva?
Chloride ions, sodium, potassium, bicarbonate, and phosphate ions.
What is the function of the parotid duct?
To secrete saliva into the oral cavity opposite the second maxillary molar tooth.
What is the process of saliva secretion called?
Salivation.
What is secretion in the digestive system?
The release of about 7 liters of water, acid, buffers, and enzymes into the GI tract to aid digestion.
What is the lingual frenulum?
A fold of mucous membrane that controls the posterior movement of the tongue.
What is the main function of the esophagus?
To transfer the bolus from the mouth to the stomach.
What do mucous neck cells secrete?
Mucus.
What enzyme breaks down starch in the mouth?
Salivary amylase.
What shape does the stomach resemble?
A 'J' shape.
What happens to the semisolid bolus in the stomach?
It is converted into liquid.
Where are G cells primarily located?
In the mucous of the pyloric antrum.
What enzyme begins the enzymatic digestion of proteins in the stomach?
Pepsin.
What percentage of acini in the pancreas are exocrine cells?
99%.
How do proton pumps function in parietal cells?
They actively transport H+ into the lumen and bring K+ back into the cell.
Where is the body of the pancreas situated?
It is left and superior to the head.
What role does sodium bicarbonate play in pancreatic juice?
It makes pancreatic juice slightly alkaline (pH 7.1 - 8.2) and stops the action of pepsin from the stomach.
What enzymes in pancreatic juice digest nucleic acids?
Ribonuclease and deoxyribonuclease.
What do hepatocytes secrete?
Bile.
What is the daily secretion amount of bile by hepatocytes?
About 1 liter.
What type of cells in the liver are responsible for phagocytosis?
Stellate reticuloendothelial (Kupffer) cells.
What is bilirubin and how is it processed by the liver?
Bilirubin is derived from aged red blood cells and is absorbed by the liver to be secreted into bile, where it is metabolized in the small intestine.
What hormones do endocrine cells in the small intestine secrete?
Secretin, cholecystokinin (CCK), and glucose-dependent insulinotropic peptide (GIP).
What is the role of brush border enzymes?
They have digestive functions and are located on the brush border formed by microvilli.
What type of transport is used for the absorption of glucose and galactose?
Secondary active transport.
What are the two types of movements that result in mechanical digestion in the small intestine?
Segmentation and Migrating Motility Complex (MMC).
What are the four major regions of the large intestine?
Cecum, colon, rectum, and anal canal.
What is the role of maltase in carbohydrate digestion?
It splits maltose and maltriose into 2-3 units of glucose.
What is the primary function of salivary glands?
To release saliva into the oral cavity.
Where are the parotid glands located?
Near the ears.
What is the function of skeletal muscles in the muscularis layer?
They help in voluntary swallowing and defecation.
What is the gastrointestinal tract?
A continuous tube extending from the mouth to the anus, including organs like the mouth, pharynx, esophagus, stomach, small intestine, and large intestine.
What is the mouth also known as?
Oral cavity or Buccal cavity.
What is the function of the uvula?
It prevents the entrance of swallowed food and liquid into the nasal cavity.
What is the space enclosed by dentin called?
Pulp cavity.
What initiates mechanical digestion in the mouth?
Chewing or mastication by teeth.
What is the role of lingual lipase?
It breaks down triglycerides into diglycerides and fatty acids.
What are the three parts of the pharynx?
Nasopharynx, oropharynx, and laryngopharynx.
What is the role of the pyloric sphincter?
It regulates communication between the stomach and the duodenum.
What are the gentle peristaltic waves in the stomach called?
Mixing waves.
What is the outermost layer of the stomach called?
Serosa.
What are the dimensions of the pancreas?
It is 12-15 cm long and 2-3 cm thick.
What is the primary storage function of the liver?
The liver stores glycogen, certain vitamins (A, B12, D, E, and K), and minerals (iron and copper).
Where does the ileum end?
At the ileocecal junction of the large intestine.
What are the two layers of smooth muscle in the muscularis of the small intestine?
Outer longitudinal and inner circular muscles.
What do bile salts form to help absorb long-chain fatty acids and monoglycerides?
Micelles.
Where does the large intestine extend from and to?
From the ileum to the anus.
What enzymes are involved in the digestion of carbohydrates in the small intestine?
Pancreatic amylase and brush border enzymes.
What are the two nucleases found in pancreatic juice?
Ribonuclease (digests RNA) and deoxyribonuclease (digests DNA).
What is absent in the large intestine that is present in the small intestine?
Villi and circular folds.
What is mass peristalsis in the large intestine?
A strong peristaltic wave that drives colonic contents into the rectum.
What happens when the pH of the stomach chyme falls below 2?
Gastrin secretion stops.
What causes flatulence in the large intestine?
Excessive production of gases by bacteria.
What percentage of water absorption occurs in the small intestine?
90%.
What is vomiting (emesis)?
The forcible expulsion of contents from the upper GI tract through the mouth.
What is the primary mode of transmission for Hepatitis B?
Sexual contact and contaminated syringes.
What are the two main parts of the digestive system?
The gastrointestinal (GI) tract and the accessory digestive organs.
What is the function of extrinsic muscles of the tongue?
They move the tongue from side to side and in and out to maneuver food for chewing and swallowing.
What is the hardest substance in the body that covers the crown of the tooth?
Enamel.
What are the four basic layers of the stomach wall?
Mucosa, submucosa, muscularis, and serosa.
Where are teeth located?
In the alveolar processes of the mandible and maxillae.
What are the three stages of swallowing?
What are the main functions of the stomach?
Mixing chamber, holding reservoir for food, and initiating digestion.
What do the oropharynx and laryngopharynx assist with?
They help in respiration and swallowing of food.
What do the secretions of mucous, parietal, and chief cells collectively form?
Gastric juice (2 – 3 liters per day).
What strong acid is secreted by parietal cells in the stomach?
Hydrochloric acid (HCl).
What is the size comparison between the pancreatic duct and the accessory duct?
The pancreatic duct is larger in size, while the accessory duct is smaller.
What type of cells act as phagocytes in the liver?
Kupffer cells.
What type of cells make up the gall bladder?
Simple epithelial cells.
What is the length of the duodenum?
It extends up to 25 cm.
What is the pH of the intestinal juice?
7.6.
What is the primary function of the large intestine?
Completion of absorption, production of certain vitamins, formation of feces, and expulsion of feces from the body.
How long does chyme remain in the small intestine?
3 to 5 hours.
How are fat-soluble vitamins A, D, E, and K absorbed?
By simple diffusion through micelle formation.
What are haustra in the large intestine?
Pouches formed by the tonic contraction of circular muscles.
Which vitamins are produced by bacteria in the large intestine?
Vitamin B and K.
What are peptic ulcers?
Ulcers that develop in areas of the GI tract exposed to acidic gastric juice.
What is the function of parietal cells in the stomach?
They produce intrinsic factor and hydrochloric acid.
What is the pharynx?
A funnel-shaped tube covered with mucous and composed of skeletal muscle.
What are the lesser and greater curvatures of the stomach?
The concave medial border is the lesser curvature, and the convex lateral border is the greater curvature.
What are the three layers of smooth muscle in the muscularis?
Oblique muscles, circular muscles, and longitudinal muscles.
What nutrients are absorbed in the stomach?
Water, ions, short-chain fatty acids, certain drugs (like aspirin), and alcohol.
What are the endocrine cells in the pancreas called?
Pancreatic Islets or Islet of Langerhans.
How much pancreatic juice is produced daily?
1200 - 1500 ml.
What is the major triglyceride-digesting enzyme in pancreatic juice?
Pancreatic lipase.
What are the basic layers of the small intestine?
The small intestine is composed of four basic layers.
What enzyme do Paneth cells secrete?
Lysozyme, which has a bactericidal function.
How much intestinal juice is secreted daily?
About 1 - 2 liters.
What are the main electrolytes absorbed in the small intestine?
Na+, Ca2+, bicarbonate, chloride, iodide, nitrate.
What does α-Dextrinase do?
It acts on α-dextrin to produce glucose.
How are lipids digested in the small intestine?
Triglycerides are broken into fatty acids and monoglycerides by pancreatic lipase, and bile salts emulsify long chain fatty acids.
What initiates the intestinal phase of digestion?
Food entering the small intestine.
What does cholecystokinin (CCK) stimulate?
Secretion of pancreatic juice and contraction of the gallbladder.
What causes heartburn in GERD?
Irritation of the esophageal wall by hydrochloric acid (HCl) from stomach contents.
What is jaundice?
A yellowish coloration of the sclerae, skin, and mucous membranes due to a buildup of bilirubin.
What enzyme is activated when food moves into the body of the stomach?
Lingual lipase.
What are the two ducts of the pancreas that open into the duodenum?
Pancreatic duct and accessory duct.
What do parietal cells secrete into the stomach lumen?
H+ and Cl- separately, resulting in the secretion of HCl.
What is the function of somatostatin?
It maintains glucagon and insulin levels in the body.
What specialized cells are found in liver lobules?
Hepatocytes.
How does the liver process amino acids?
By removing the amino group to produce ATP or convert them into carbohydrates or fats, and converting harmful amino groups into urea.
What substances can the liver detoxify?
Alcohol and various drugs such as penicillin and erythromycin.
What are microvilli and where are they found?
Projections from the free membrane of absorptive cells that form a brush border.
What percentage of nutrient absorption occurs in the small intestine?
90%.
What are the protein-digesting enzymes found in brush border enzymes?
Aminopeptidase and dipeptidase.
What controls the movement of material from the small intestine to the large intestine?
Ileocecal sphincter.
How are minerals like iron, potassium, magnesium, and phosphate absorbed in the digestive system?
By active or passive transport.
How is Vitamin B12 absorbed in the digestive system?
It combines with intrinsic factor produced by the stomach and is absorbed in the ileum via active transport.
What factors influence water absorption from the small intestine?
The absorption of electrolytes and nutrients to maintain osmotic balance with the blood.
What hormones are involved in hormonal regulation during the intestinal phase?
Cholecystokinin (CCK) and secretin.
What is gastroesophageal reflux disease (GERD)?
A condition where stomach contents reflux into the esophagus due to inadequate closure of the lower esophageal sphincter.
What is the role of bile salts in the small intestine?
They are used for emulsification and absorption of lipids.
What are nucleotides further digested into by brush-border enzymes?
Pentoses, phosphates, and nitrogenous bases.
What types of enzymes are found in brush border enzymes?
Carbohydrate-digesting enzymes, protein-digesting enzymes, and nucleotide-digesting enzymes.
What is segmentation in the context of the small intestine?
Localized mixing contractions that help in mixing and absorption of chyme without pushing it forward.
What enzymes convert proteins into peptide units?
Trypsin, chymotrypsin, carboxypeptidase, and elastase.
How does water absorption occur in the gastrointestinal tract?
All water absorption occurs via osmosis.
What types of cells are primarily found in the mucosa of the large intestine?
Absorptive and goblet cells.
What gases are released by bacteria during fermentation in the large intestine?
Hydrogen, CO2, and methane gas.
What is the effect of the intestinal phase on gastric emptying?
It slows the exit of chyme from the stomach.
What are the three overlapping phases of digestion?
Cephalic phase, gastric phase, and intestinal phase.
What is the role of Helicobacter pylori in PUD?
It produces urease, which damages the protective mucous layer of the stomach.
What are the three main categories of jaundice?
Prehepatic, hepatic, and extrahepatic jaundice.
What is the process called when digested nutrients pass from the gastrointestinal tract into blood or lymph?
Absorption.
Name the carbohydrate-digesting enzymes secreted by brush border enzymes.
α-dextrinase, maltase, sucrase, and lactase.
What is the cecum?
A small pouch-like organ next to the ileocecal sphincter.
What do goblet cells secrete in the large intestine?
Mucus that lubricates the passage of colonic contents.
What is the role of the muscularis layer in the large intestine?
It consists of circular and longitudinal muscles that aid in movement.
How often does mass peristalsis occur in the large intestine?
3 to 4 times a day.
What stimulates the stretch receptors in the stomach?
Food distending the stomach.
What pigment is produced from the decomposition of bilirubin by bacteria?
Stercobilin, which gives brown color to fecal material.
What happens during the gastric phase of digestion?
Neural and hormonal mechanisms regulate gastric secretion and motility.
What are some stimuli that can trigger vomiting?
Irritation and distension of the stomach, unpleasant sights, general anesthesia, dizziness, and certain drugs.
What lifestyle factors should be avoided to prevent PUD?
Cigarette smoke, alcohol, caffeine, and NSAIDs.
What causes gallstones?
Insufficient bile salts or lecithin or excessive cholesterol in bile.
How does Hepatitis C compare to Hepatitis B?
Clinically similar and can also cause cirrhosis and liver cancer.
What process is responsible for breaking down larger food molecules?
Digestion.
What role does intestinal juice play in digestion?
It mixes with pancreatic juices and provides a liquid medium for absorption from chyme into the small intestine.
How long is the large intestine?
About 1.5 meters.
How is the colon divided?
Into ascending colon, transverse colon, descending colon, and sigmoid colon.
What is the function of absorptive cells in the large intestine?
Water absorption.
What occurs during haustral churning in the colon?
Hustra remain relaxed and distend when filled, then contract to move contents.
What is the role of bacteria in chemical digestion in the large intestine?
Bacteria ferment remaining carbohydrates and convert proteins to amino acids and simpler substances.
What is the composition of feces?
Water, inorganic salts, sloughed-off epithelial cells, bacteria, products of bacterial decomposition, unabsorbed digested materials, and indigestible parts of food.
What are the three distinct causes of Peptic Ulcer Disease (PUD)?
What are the symptoms of Hepatitis A?
Loss of appetite, malaise, nausea, diarrhea, fever, and chills.
What is the role of micelles in lipid absorption?
They carry fatty acids and monoglycerides to absorptive cells and help solubilize other large hydrophobic molecules.
What does the Migrating Motility Complex (MMC) do?
It is a type of peristaltic movement that pushes chyme forward when the volume in the small intestine decreases.
What is the rectum's approximate length?
About 20 cm.
What guards the opening of the anal canal?
Internal sphincter of smooth muscles and external sphincter of skeletal muscles.
What reflex is caused by the distension of the duodenum?
Enterogastric reflex.
What role does secretin play in the digestive system?
Secretin buffers acid in chyme that reaches the duodenum and slows acid production in the stomach.
How is Hepatitis A primarily spread?
Via fecal contamination of objects (fecal-oral route).
What are the potential long-term effects of Hepatitis B?
Cirrhosis and possibly liver cancer.
What is the role of gastrin in gastric secretion?
Stimulates gastric glands to secrete gastric juice.
What does secretin stimulate when acidic chyme enters the duodenum?
Flow of pancreatic juice rich in bicarbonate ions.
What lifestyle factors can worsen GERD symptoms?
Drinking alcohol and smoking.
How does the liver contribute to the detoxification process in the large intestine?
It converts toxic substances like indole and hydrogen sulfide into less toxic substances.
What activates the cephalic phase of digestion?
Smell, sight, thought, or initial taste of food.
How long does chyme remain in the large intestine?
3 to 10 hours.
What is the most common complication of peptic ulcers?
Bleeding, which can lead to anemia.
What is hepatitis?
An inflammation of the liver caused by viruses, drugs, and chemicals.
What additional substances does the digestive system absorb?
Water, vitamins, and minerals.
What is the primary function of the digestive system?
To break down food into forms that can be absorbed and used by body cells.