How long does food typically process in the stomach?
Click to see answer
About 4 hours.
Click to see question
How long does food typically process in the stomach?
About 4 hours.
What is the role of pancreatic nucleases?
They digest nucleic acids.
What is the main function of the gallbladder?
To store and concentrate bile between meals.
What do chylomicrons contain?
Triglycerides (TG), cholesterol, and phospholipids.
What connects the Cavum Oris to the pharynx?
The posterior side of the mouth.
What are the two main categories of organs in the digestive system?
Gastrointestinal tract (alimentary canal) and accessory digestive organs.
What type of muscle is the esophagus composed of?
Muscular tube.
What is the composition of permanent teeth?
M3M2M1 PM2PM1 C I2I1 I1I2 C PM1PM2 M1M2M3 (sup) and M3M2M1 PM2PM1 C I2I1 I1I2 C PM1PM2 M1M2M3 (inf).
What triggers the release of bile from the gallbladder?
The influence of CCK (cholecystokinin).
What is notable about the vena cava's relationship with the liver?
The vena cava does not enter the liver.
How does peristalsis differ from segmentation?
Peristalsis moves food along the digestive tract, while segmentation mixes food in place.
What is the function of pancreatic amylase?
It splits glycogen into disaccharides.
Why is the gastrointestinal tract considered part of the outside of the body?
Because the mouth and anus both open to the outer environment.
What is the role of bacteria in the large intestine?
To help in the fermentation of undigested materials.
What does the parasympathetic defecation reflex do to the internal and external sphincters?
It opens the internal sphincter and closes the external sphincter.
Which hormone is responsible for the release of bile from the gallbladder?
Cholecystokinin (CCK).
What do microvilli form on the intestinal surface?
A 'brush border'.
What structures bound the Cavum Oris?
Lips, cheeks, palate, and tongue.
What is the state of the lumen of the esophagus when not in use?
Typically collapsed.
What are the accessory organs of the digestive system?
Teeth, tongue, salivary glands, liver, gallbladder, and pancreas.
What does the round ligament belong to?
The falciform ligament.
What is the composition of deciduous teeth?
20 teeth: M2M1 C I2I1 I1I2 C M1M2 (sup) and M2M1 C I2I1 I1I2 C M1M2 (inf).
What type of glands are salivary glands?
Compound tubular glands.
What role does secretin play in bile release?
It causes the bile ducts and pancreatic ducts to secrete bile rich in bicarbonate (HCO3-).
What are plicae circulares?
Permanent circular folds of mucosa that increase surface area for absorption.
How does the large intestine contribute to the digestive system?
By forming and storing feces.
What is the length of the large intestine in adults?
Approximately 1.5 meters (5 feet).
How are fat-soluble vitamins absorbed in the small intestine?
They dissolve in dietary fats (vitamins A, D, E, K).
What role does the duodenum play in digestion?
It is where most chemical digestion occurs, aided by bile and pancreatic juices.
What is the role of digestive enzymes?
They are specific and function at an optimum temperature and pH.
What is mechanical digestion?
The physical change of food particles from large to small to increase surface area for chemical digestion.
What is the round ligament of the liver a remnant of?
The fetal umbilical vein.
What is the process of fat absorption in the small intestine?
Several steps leading to absorption into lymph and then into blood.
What is the Cavum Oris commonly known as?
The oral cavity.
What are the main components of saliva?
Water, mucus, proteins, a buffer, and enzymes.
Name three hormones secreted by enteroendocrine cells.
Enterokinase, gastrin, and secretin.
What is the primary purpose of saliva?
To moisten, begin digestion of starch, neutralize acids, stimulate growth of beneficial bacteria, and dissolve food chemicals for taste.
What effect does CCK have on stomach emptying?
It reduces the emptying of the stomach.
What sensory structures are found on the tongue?
Taste buds.
What is the pharynx?
The cavity behind the mouth that food passes into after leaving the mouth.
What is the role of bile salts?
Emulsification of fats, increasing surface area for digestive enzymes.
How long is the average small intestine in adults?
About 6 meters (20 feet).
What is the significance of the number 43?
It is often associated with various cultural, scientific, or mathematical contexts.
What stimulates the gallbladder (GB) to release bile?
Fatty chyme entering the duodenum.
What do intestinal glands secrete to aid in digestion?
An abundant watery fluid that helps absorb products of digestion.
What is the primary function of the large intestine?
To absorb water and electrolytes from indigestible food matter.
What is the typical length of the esophagus?
20 to 25 cm.
What is another name for the digestive tract?
Alimentary canal.
What are some examples of accessory digestive organs?
Teeth, tongue, salivary glands, pancreas, and liver.
What happens to the hepatopancreatic sphincter when CCK is released?
It relaxes the hepatopancreatic sphincter.
What is the primary function of the small intestine?
To absorb nutrients from digested food.
What are the two parts of the pharynx that food moves through?
Oropharynx and laryngopharynx.
How does CCK contribute to nutrient delivery?
It matches nutrient delivery to digestive and absorptive capability.
What type of muscle controls swallowing?
Skeletal muscle.
What attaches the tongue to the floor of the mouth?
The lingual frenulum.
Where is vitamin K absorbed?
In the large intestine, along with other lipids.
How does the digestive system contribute to homeostasis?
It works with other systems of the body to maintain homeostasis.
What are the main regions of the stomach?
Cardiac region, fundus, body, pyloric antrum, pyloric canal.
What is the primary movement in the stomach responsible for mixing food?
The movement that mixes food with gastric secretions and empties the stomach.
What is produced when food mixes with gastric secretions?
Chyme.
What is the role of the pyloricae glands?
They produce hormones.
What is one of the primary actions of Cholecystokinin (CCK) on digestion?
Contraction of the gallbladder.
What are the three general categories of liver functions?
Metabolic regulation, hematological regulation, and synthesis and secretion of bile.
What is the main function of plicae, villi, and microvilli?
To increase the surface area for absorption.
Which glands are classified as salivary glands?
Parotid, submandibular, and sublingual glands.
How does saliva help with tasting food?
By dissolving food chemicals to stimulate the chemoreceptors of the mouth.
How does bile aid in the absorption of nutrients?
It helps absorb fatty acids, cholesterol, and fat-soluble vitamins.
What is the primary function of the stomach?
To liquefy food, mix it with stomach acid, and turn it into chyme.
What happens to the remaining 20% of bile?
It is excreted in feces, disposing of excess cholesterol.
What is the hardest substance in the body found in teeth?
Enamel.
What is the main muscle involved in pushing food into the esophagus?
The constrictor muscle.
What type of wave moves through the large intestine?
Peristaltic wave from the transverse colon through the rest of the large intestine.
What is peristalsis?
A wave-like muscle contraction that moves food through the digestive tract.
What do the gastricae glands produce?
Pepsin and stomach acid (HCl/Chloride Acid).
What is the primary function of the esophagus?
To move food through peristalsis.
What are the main functions of the small intestine?
Chemical digestion and absorption of nutrients (90%) from chyme.
What does the large intestine primarily process?
Indigestible food matter.
What percentage of nutrient absorption occurs in the small intestine?
90%.
What types of nutrients are absorbed in the small intestine?
Monosaccharides, amino acids, electrolytes, water, and vitamins.
What lines the inside of the mouth?
Mucous membranes and epithelial cells.
What does the submucosa of the duodenum contain?
Mucus-secreting glands known as Brunner’s glands.
What is the function of Brunner’s glands?
To protect the small intestine by secreting mucus.
What enzyme begins protein digestion in the stomach?
Pepsin.
What substances can be absorbed through the stomach?
Water, electrolytes, and some drugs.
What stimulates mass movements in the large intestine?
Distension of the stomach and duodenum, usually following meals.
What is chemical digestion?
The chemical change of food particles where bonds are broken to convert large molecules into smaller ones for better absorption.
What accelerates segmentation and peristalsis in the small intestine?
Nervous stimulation.
What is the function of the cardiacae glands in the stomach?
They produce mucus.
What is the primary function of the digestive tract?
To serve as a tube extending from the mouth to the anus, facilitating the passage of food.
What type of cells are found in intestinal glands?
Enteroendocrine cells.
What is the primary composition of the tongue?
Skeletal muscle.
What is involved in metabolic regulation by the liver?
Interconversion of carbohydrates, lipids, amino acids, removal of wastes, vitamin and mineral metabolism, drug inactivation, and storage of fats, glycogen, iron, and vitamins A, B12, D, E, and K.
How much does the surface area for absorption increase in the small intestine?
From about 3.6 ft² to about 2200 ft².
What types of nutrients does CCK help absorb and digest?
Proteins, carbohydrates, and lipids.
What is bilirubin converted into in the large intestine?
Uro- and stercobilinogen.
What role does intestinal flora play in the large intestine?
It houses ~800 species of bacteria and absorbs vitamins liberated by bacterial action (K, B5, and Biotin).
What is propulsion in the digestive process?
Moving food through the GI tract, aided by peristalsis.
What is the role of the lower esophageal sphincter?
To prevent the backflow of stomach contents into the esophagus.
What triggers a 'peristaltic rush'?
Overdistended or irritated wall of the small intestine.
What does the pulp cavity contain?
Blood vessels and nerves.
How much food can the stomach hold at one time?
Up to 4 liters.
What type of cells are numerous in the large intestine?
Goblet cells, which produce mucus.
What are the primary components absorbed during fat absorption in the small intestine?
Fatty acids and glycerol.
How many permanent teeth do humans have?
32 teeth.
How long is the digestive tract?
About 30 feet.
What do pancreatic lipases break down?
Triglycerides.
What is the role of the tongue during chewing?
It repositions food and shapes it into a bolus.
What is the primary digestive function of the large intestine?
It has little or no digestive function.
What are the main components of bile?
Water, bile salts, bile pigments, electrolytes.
What are the two sets of teeth that humans develop?
Deciduous (20 milk teeth) and permanent teeth (32 teeth).
What processes are involved in the absorption of electrolytes and water in the small intestine?
Diffusion, osmosis, and active transport.
What holds teeth in place within the alveoli?
The periodontal ligament.
What type of tissue lines the esophagus?
Stratified squamous epithelium.
What are the two main functions of the large intestine regarding waste?
It forms and stores feces and carries out defecation.
What is the appearance of bile?
A yellowish-green liquid.
What is the gastrocolic reflex?
A reflex that stimulates mass movements in the large intestine after eating.
What supplies each tooth with blood and nerves?
The pulp.
What does enterokinase convert?
It converts trypsinogen to trypsin.
What triggers the urge to defecate?
Distension of the rectum.
What happens to the internal anal sphincter in response to distension?
It relaxes.
What is segmentation?
A process that involves the contraction of circular muscles in the digestive tract to mix and break down food.
What structure in the small intestine increases the surface area for absorption?
Microvilli.
Which organs are included in the gastrointestinal tract?
Mouth, esophagus, stomach, and intestines.
How does CCK affect pancreatic enzymes?
It stimulates the secretion of pancreatic enzymes.
How do plicae circulares differ from rugae of the stomach?
Plicae circulares do not flatten out with distention, unlike rugae.
What are the hematological functions of the liver?
Phagocytosis and antigen presentation, synthesis of plasma proteins, removal of circulating hormones, removal of worn-out RBCs (by Kupffer cells), and removal or storage of toxins.
What role does the liver play in digestion?
Synthesis and secretion of bile.
What happens to food in the digestive system?
Food is ingested, digested into small molecules, absorbed, and indigestible materials are eliminated.
What are the three main parts of the small intestine?
Duodenum, jejunum, and ileum.
What gas is produced by the large intestine?
Intestinal gas (flatus).
What is the significance of the ileocecal valve?
It regulates the flow of material from the small intestine to the large intestine.
What happens at the junction of the esophagus and stomach during digestion?
Food passes through the lower esophageal sphincter into the stomach.
What substances are involved in chemical digestion?
Enzymes, hydrochloric acid, and other digestive juices.
What is the size of the lumen in the large intestine?
The lumen of the large intestine is larger than that of the small intestine.
Does the large intestine produce digestive enzymes?
No, the large intestine does not produce enzymes; digestion occurs from previously introduced enzymes or bacteria.
What is required for defecation to occur?
Voluntary relaxation of the external sphincter.
What are the main components of gastric secretions?
Mucus, gastric acid, trypsin, lipase, amylase, and protease.
What is the role of the small intestine in digestion?
It acts as a 'mixing bowl' for acid neutralization and is where the bulk of chemical digestion and nutrient absorption occurs.
Where are digestive enzymes embedded in the small intestine?
In the membrane of microvilli.
What is another term for intestinal cells?
Enterocytes.
What is the pH level of pancreatic juice?
8 (alkaline).
What are the main components found in the Cavum Oris?
Teeth, tongue, and salivary glands.
What are the sphincters at both ends of the stomach?
The cardiac sphincter superiorly and the pyloric sphincter inferiorly.
How does the tongue contribute to speech?
It helps to shape sounds.
How are water-soluble vitamins absorbed in the small intestine?
Through diffusion, except for vitamin B12, which requires active transport.
What are bile pigments derived from?
Breakdown of red blood cells (RBCs), specifically bilirubin and biliverdin.
What actions are involved in mechanical digestion?
Chewing, churning of food in the stomach, and mixing food with digestive juices.
What enzyme breaks down peptides into amino acids in the small intestine?
Peptidase.
What is the function of intestinal lipase?
It breaks down fats into fatty acids and glycerol.
What are the roles of gastrin and somatostatin?
They are hormones that stimulate/inhibit acid secretion by the stomach.
What structures are absent in the large intestine that are present in the small intestine?
Villi are absent in the large intestine.
What is the state of the internal anal sphincter under normal conditions?
It is usually contracted.
Where are plicae circulares especially prominent?
In the lower duodenum and upper jejunum.
What is the purpose of bicarbonate ions in pancreatic juice?
To make pancreatic juice alkaline and neutralize acid coming from the stomach.
What does the term 'bowel' refer to?
It consists of the small and large intestines.
How does food enter the esophagus from the pharynx?
By contractions of the pharyngeal constrictor muscles.
What is the first food processing activity in digestion?
Ingestion - bringing food into the mouth (eating).
What are the three layers that compose a tooth?
Enamel, dentin, and pulp cavity.
What is haustral churning?
Mixing movements in the large intestine that occur every 30 minutes.
What layers compose the pharynx?
Mucosal, fibrous, and muscle layers.
What can result from a 'peristaltic rush'?
Diarrhea.
What is absorption in the digestive process?
The transport of digested food molecules from the GI tract into the blood and lymphatic vessels.
What are the three layers of smooth muscle in the stomach?
Longitudinal layer, circular layer, and oblique layer.
What type of epithelium is found in the anal canal?
Keratinized stratified squamous epithelium.
What does the prefix 'Procto-' refer to?
Anus or rectum.
What vitamin is specifically absorbed in the small intestine?
Vitamin B12.
How are monosaccharides and amino acids absorbed in the small intestine?
Through facilitated diffusion and active transport.
What does the large intestine secrete and why?
It secretes mucus for lubrication, binding, protection, and pH balance.
What are the accessory organs of digestion?
Teeth, tongue, saliva glands, pancreas, liver, and gallbladder.
What are the products of digestion?
Small molecules such as amino acids, fatty acids, and glucose.
What are the three divisions of the pharynx?
Pars nasalis, pars oralis, and pars larynx.
What additional structures are present on the tongue?
Lingual tonsils.
What does proper nutrition provide to the body?
Energy, nutrients, vitamins, and minerals.
What is the duodenocolic reflex?
A reflex that also stimulates mass movements in the large intestine.
What substances does the large intestine absorb?
Water, bile salts, and electrolytes.
What is the primary function of accessory organs in the digestive system?
To assist in the digestion of food.
What are the sockets in the gums where teeth are found called?
Alveoli.
What percentage of bile is recycled in the body?
80%.
How do the movements of the large intestine compare to those of the small intestine?
They are slower and less frequent.
What structures increase the surface area for absorption in the small intestine?
Villi and microvilli.
What is segmentation in the small intestine?
Ringlike contractions that aid in mixing and slowing peristalsis.
What is dentin compared to in terms of hardness?
It is harder than bone.
Where is bile continually secreted from?
Hepatocytes.
What are the folds inside the stomach called?
Rugae.
How do the walls of the large intestine compare to those of the small intestine?
The walls of the large intestine are much thinner than those of the small intestine.
What is the gastroileal reflex?
It causes relaxation of the ileocecal sphincter.
What must happen to the external anal sphincter to retain feces?
It must be tensed reflexively.
What is the structure at the junction of the esophagus and stomach?
The lower esophageal sphincter (LES).
What is the primary function of the esophagus?
To transport food from the mouth to the stomach.
What is peristalsis in the small intestine?
Pushing movements that help move contents through the intestine.
What is the lowest part of the posterior pharynx called?
Laryngeal pharynx.
What is the shape of the stomach?
Generally J-shaped.
Can movements in local segments of the small intestine occur without nervous stimulation?
Yes, they can occur without stimulation by the parasympathetic nervous system.
What triggers 'long distance' movements in the small intestine?
Stomach filling.
What does secretin stimulate?
It stimulates the pancreas to release bicarbonate ions and the gallbladder to release bicarbonate-rich bile.
What are the three sections of a tooth?
Crown, neck, and root.
Which enzymes break down disaccharides into monosaccharides?
Sucrase, maltase, and lactase.
What is defecation?
The elimination of feces (indigestible substances/digestive waste).
What is the primary function of the rectum?
Temporary storage of fecal material.
What do the rectal valves do?
Help in the retention of feces.
What is the gastroenteric reflex?
It increases motility and secretion along the length of the small intestine.
What is the function of cholecystokinin (CCK)?
It inhibits gastric glands, stimulates the pancreas to release enzymes, stimulates the gallbladder to release bile, and relaxes the hepatopancreatic sphincter.
What is the primary function of the digestive system?
To break down food and absorb nutrients.
What is the human digestive system?
An extended tube with specialized parts between the mouth and the anus.
Who is the author of 'Digestive System and Nutrition'?
Gofarana Wilar, S.Si., M.Si., Ph.D.
What role does nutrition play in the digestive system?
Nutrition provides the necessary substances for energy, growth, and maintenance of body functions.
