CH 11.8 Digestive System
Constipation occurs when too little/too much water is absorbed by the large intestine
Too much
__________ __________ is when saliva mixed with food forms a small round lubricated mass that is easier to transport through the digestive system
Food bolus
The capillaries of a small intestine villus absorbs what nutrients?
Glucose and amino acids
Crypts are __________ in the walls of the __________ __________
Invaginations, small intestine
Bile isn't/is an enzyme
Isn't
The liver metabolizes proteins by: 1.Synthesizing __________ __________ from absorbed __________ __________ 2. Synthesizing __________-__________ __________ __________ 3. Converting __________ to __________ for excretion
1. Plasma proteins, amino acids 2. Non-essential amino acids 3. Ammonia, urea
Cholecystokinin (CCK): 1. Slows down/speeds up gastric __________ to give the small intestine more time to digest and absorb what entered 2. Stimulates the __________ to release its __________ __________ into the duodenum 3. Stimulates the __________ to release __________ into the duodenum
1. Slows down, emptying (transferring stomach contents to small intestine) 2. Pancreas, digestive enzymes 3. Gallbladder, bile
The optimal pH for pepsin is about __________
2 (this is the same pH as the gastric juice)
2/3 of glycogen is stored where? 1/3 of glycogen is stored where?
2/3 stored in liver, 1/3 stored in skeletal muscle
__________ of glycogen is stored in the liver and __________ of glycogen is stored in skeletal muscle
2/3, 1/3
The main function of the ileum is __________
Absorption
The main function of the jejunum is __________
Absorption
Water is absorbed completely at the __________ of the large intestine
Colon
__________ __________ is caused by stomach acid moving backwards into the esophagus through the cardiac sphincter
Acid reflux
Parietal cells secrete gastric juice which is extremely acidic/basic because it has a high concentration of __________. It has a pH of __________
Acidic, HCl, 2
Chyme is an acidic/basic, __________-digested food mixture
Acidic, semi
__________ is a major plasma protein made almost exclusively by the liver
Albumin
The __________ is a small finger-like projection of the cecum
Appendix
The symbiotic bacteria that live in the large intestine make vitamin __________ and __________
B, K **Think of it as Burger King. Burger King = poopy food = large intestine
Stomach acid is beneficial because it kills __________, __________ proteins, and creates a favorable environment for __________ to function
Bacteria, denatures, pepsin
Symbiotic bacteria that live in the large intestine metabolize __________ __________ and ferment __________
Bile acids, fiber
Jaundice is typically caused by obstruction of the __________ __________, __________ disease, or excessive __________ breakdown
Bile duct, liver, RBC
Bilirubin is secreted into __________. Bilirubin is a __________ that gives bile its yellowish-brown color
Bile, pigment
Jaundice is caused by high levels of __________ in the blood
Bilirubin
Kupffer cells in the liver breaks down hemoglobin into __________
Bilirubin
__________ is a pigment that gives bile its yellowish brown color
Bilirubin
Glucose and amino acids are absorbed by __________ of a small intestine
Blood capillaries
The vessels found within a villus are __________ __________ and a __________
Blood capillaries, lacteal
__________ __________ __________ are another plasma protein made by the liver
Blood clotting factors
The 3 important roles of the liver are __________ maintenance, __________ metabolism, and __________ metabolism
Blood, glucose, protein
Food enters the human digestive tract through the mouth. What types of extracellular digestion occurs in the mouth?
Both mechanical and chemical digestion
__________ is a yellowish skin appearance due to high levels of bilirubin in the blood
Jaundice
Absorption of nutrients doesn't occur until it gets to the __________ and __________
Jejunum, ileum
__________ __________ are the phagocytic cells in the liver that are responsible for destroying old or useless RBCs and bacteria
Kupffer cells
The __________ __________ controls the opening between the esophagus and stomach
Cardiac sphincter
The __________ is a pouch that connects the small intestine and the large intestine
Cecum
The appendix is a small finger-like projection of the __________
Cecum
The parts of the large intestine from closest to the small intestine to the furthest are: __________, __________, __________, __________, and __________
Cecum, appendix, colon, rectum, anus
The general path of digested food through the large intestine is: __________ -> __________ -> __________ -> __________
Cecum, colon, rectum, anus
Lamina propria is the __________ __________ that lines the __________
Connective tissue, stomach
__________ occurs when too much water is absorbed by the large intestine
Constipation
The bacteria that live in large intestine have a __________ (__________) relationship because they receive __________ and produce __________
Mutualistic, symbiotic, nutrients, vitamins **Nutrients benefit bacteria, we benefit from vitamins they produce
Chemical digestion is the __________ breakdown of food. It uses __________, __________ __________, and __________ to breakdown food
Chemical, chemicals, pH changes, enzymes
Salivary amylase is an enzyme that begins __________ digestion of carbohydrates in the __________. It converts __________ to __________
Chemical, mouth, starch, maltose **Maltose is a glucose+glucose disaccharide
Examples of mechanical digestion in humans is __________ food and the churning or mixing of food in the __________
Chewing, stomach
__________ cells secrete gastric lipase
Chief
__________ cells secrete pepsinogen
Chief
As the small intestine detects proteins and fats coming in, cells in the lining of the duodenum releases a hormone called __________ (__________) that signals for __________ __________ to help with digestion
Cholecystokinin, CCK, accessory organs
Mechanical digestion in the stomach is the __________ of the stomach by muscles to mix and break down food
Churning
__________ is an acidic, semi-digested food mixture
Chyme
__________ leaves the stomach through the pyloric sphincter to enter the small intestine
Chyme
The zymogen form of chymotrypsin is __________
Chymotrypsinogen
After the cecum, digested food passes through the __________
Colon
__________ are like reverse villi. Instead of projections, they're invaginations in the wall of the small intestine
Crypts
Chemical digestion in the stomach occurs when the acidic pH __________ proteins and activates certain protein __________ such as __________ which digests fats
Denatures, enzymes, lipases
__________ occurs when too little water is absorbed by the large intestine
Diarrhea
The __________ blocks the opening to the larynx (respiratory system) so food doesn't enter the airway
Epiglottis
90% of digestion and nutrient absorption occurs in the __________ __________
Small intestine **The small intestine is ~6m long. It can fit inside an average 1.7m adult because it folds
It's essential for protein-digesting enzymes to be inactive zymogens (inactive precursors to enzymes) while they're inside the cell that produces them because if they were made and secreted active it would __________ the cell that produces it because cells have many __________
Digest, proteins
The main function of the duodenum is __________
Digestion **Think D for Duodenum...Digestion
When a food bolus enters the stomach, the stomach __________ (__________) which signals __________ __________ of the stomach to release __________
Distend (stretch), G cells, gastrin
Absorption of nutrients doesn't/does occur in the duodenum
Doesn't
Absorption of nutrients doesn't/does occur in the stomach
Doesn't
What are the 3 sections of the small intestine from closest to the stomach to the furthest?
Duodenum, jejunum, ileum **Mnemonic: DJ named Iglesias
Pancreatic lipase digests __________ fats and breaks it down into __________ and __________ __________
Emulsified, monoglycerides, fatty acids **Fats become emulsified in the small intestine thanks to bile
The gallbladder secretes bile into the small intestine to __________ the __________
Emulsify, fats **Breaking down fats into smaller fat droplets that are easier to digest
__________ are absorptive cells that make up villi and are lined with microvilli
Enterocytes
When food enters the duodenum, glands in the duodenum release __________ which is an enzyme that activates __________ into __________, which in turn activates __________ to __________
Enteropeptidase, trypsinogen, trypsin, chymotrypsinogen, chymotrypsin **-ogen = zymogen (inactive precursor to enzyme)
Crypts contain cells that secrete __________ and cells that produces __________ cells
Enzymes, epithelial
The __________ guides food from the pharynx and into the stomach
Esophagus
The cardiac sphincter controls the opening between the __________ and __________
Esophagus, stomach
Glycogenesis occurs when what is converted into what?
Excess glucose converted into glycogen
Humans mainly use intracellular/extracellular digestion
Extracellular
True or False. Starch breaks down into glucose in the mouth
False. It breaks down into maltose, a disaccharide of glucose
The lacteal of a small intestine villus absorbs what nutrients?
Fatty acid and glycerol
Parietal cells and chief cells are found within the __________ __________ of the stomach
Gastric glands
The stomach lining is filled with __________ __________ that leads to __________ __________. The stomach lining is also made of __________ __________ (connective tissue) and __________
Gastric pits, gastric glands, lamina propria, muscles
__________ stimulates the parietal cells of the gastric gland to release gastric juice into the stomach, and stimulates chief cells of the gastric gland to secrete gastric lipase and pepsinogen
Gastrin (hormone)
__________ is when the liver converts glycerol and amino acids into glucose
Gluconeogenesis **To make new glucose
Gluconeogenesis occurs when what is converted into what?
Glycerol and amino acids converted into glucose
Glycogenolysis occurs when what is broken down into what?
Glycogen broken down into glucose monomers
__________ occurs when excess glucose is converted into glycogen
Glycogenesis **Glyco = glycogen, genesis = to make.. To make glycogen
The 3 mechanisms the liver uses to maintain blood glucose levels are __________, __________, and __________
Glycogenesis, glycogenolysis, gluconeogenesis
__________ occurs when glycogen is broken down into glucose monomers
Glycogenolysis **Lysis = to break down. Glycogenolysis = to break down glycogen
__________ __________ secrete mucus to protect the small intestinal epithelial lining
Goblet cells
The small intestine protects itself from the highly acidic chyme by using __________ __________ and __________
Goblet cells, neutralization
The pancreas secretes __________, __________ __________, __________ __________, __________, and __________
HCO3- (bicarbonate ions), pancreatic amylase, pancreatic lipase, trypsin, chymotrypsin
Ammonia (unharmful/harmful) is converted to __________ (unharmful/harmful) at the __________ for excretion during oxidative deamination
Harmful, urea, unharmful, liver
Kupffer cells in the liver breaks down __________ into bilirubin
Hemoglobin
The __________ __________ __________ connects the small intestine to the liver, allowing for a fast diffusion of absorbed substances
Hepatic portal system
Emulsification is a type of chemical/mechanical digestion
Mechanical
Zymogen is the inactive/active __________ of an __________
Inactive, precursor, enzyme
Fatty acids and glycerol are absorbed by __________ of a small intestine
Lacteal
The epiglottis blocks the opening to the __________ so food doesn't enter it
Larynx
Blood clotting factors are plasma proteins made by the __________
Liver
Gluconeogenesis predominantly occurs at where?
Liver
The __________ is the only organ that can release glucose to other tissues
Liver
What in our body can do glycogenesis?
Liver and skeletal muscle
The __________ produces bile using __________ and sends it to the __________ for storage and concentration
Liver, cholesterol, gallbladder
The 2 types of extracellular digestion used by humans are __________ and __________ digestion
Mechanical, chemical
__________ are the tiny projections on top of each villus
Microvilli
Lacteal is a __________ __________
Lymphatic capillary
The 2 openings of the human digestive tract are __________ and __________
Mouth, anus
When we have acid reflux, we have a burning sensation in our chest area because the esophagus isn't protected by __________ __________
Mucous cells
__________ __________ secrete mucus to lubricate and protect the stomach lining from the acidic environment of the stomach
Mucous cells
Goblet cells secrete __________ to protect the epithelial lining of the __________ __________
Mucus, small intestine
Mucous cells secrete __________ to lubricate and protect the __________ lining from the acidic environment
Mucus, stomach
Sphincter is a ring of __________ that constricts and relaxes to control __________
Muscles, openings
The liver destroys what 2 things?
Old/useless RBCs and bacteria
Extracellular digestion is digestion that happens within/outside cells
Outside
The liver is responsible for __________ __________ of amino acids, which releases ammonia
Oxidative deamination
__________ __________ is secreted by the pancreas to break down starch into maltose
Pancreatic amylase
__________ __________ is secreted by the pancreas to digest emulsified fats and break it down into monoglycerides and fatty acids
Pancreatic lipase
__________ cells secrete gastric juice
Parietal
What 2 cells are found in the gastric glands of the stomach?
Parietal cells and chief cells
Gastrin (hormone) stimulates __________ __________ of the __________ __________ to release __________ __________ into the stomach, and stimulates __________ __________ of the __________ __________ to secrete __________ __________ and __________
Parietal cells, gastric gland, gastric juice, chief cells, gastric gland, gastric lipase, pepsinogen
Which is the inactive or active forms? Pepsin and pepsinogen.
Pepsinogen = inactive (zymogen) Pepsin = active
__________ __________ are open sores on the stomach epithelium by acid corrosion due to inadequate mucus protection
Peptic ulcers
__________ is a rhythmic wave-like contraction that moves food boluses
Peristalsis
Kupffer cells are __________ cells in the __________ that are responsible for destroying __________ and __________
Phagocytic, liver, RBCs (old/useless), bacteria
The __________ is where the respiratory and digestive systems merge, and it separates into the larynx and esophagus
Pharynx
The esophagus guides food from the __________ into the __________
Pharynx, stomach
Mechanical digestion is the __________ breakdown of food
Physical
Albumin is a major __________ __________ made almost exclusively by the __________
Plasma protein, liver
The esophagus is made of __________ (isn't/is striated) muscle in its upper 1/3 and __________ (isn't/is striated) muscle in its lower 1/3. What muscle is the middle 1/3 made of?
Skeletal, is, smooth, isn't. Middle 1/3 is made of a mix of skeletal and smooth muscle
The cecum is a pouch that connects the __________ __________ and the __________ __________
Small intestine, large intestine
Chymotrypsin digests __________ into __________ __________
Proteins, amino acids
Trypsin digests __________ into __________ __________
Proteins, amino acids
__________ __________ controls the opening between the stomach and small intestine
Pyloric sphincter **Cardiac sphincter controls food entering the stomach, pyloric sphincter controls food exiting the stomach
Feces are stored in the __________ of the large intestine
Rectum **Rectum comes after the colon
The pharynx is where the __________ and __________ systems merge, and it separates into the __________ and __________
Respiratory, digestive, larynx, esophagus
The hepatic portal system connects the __________ __________ to the __________
Small intestine, liver
__________ (__________ __________) is the chemical digestion that occurs in the mouth
Saliva (salivary amylase)
Food bolus is formed when __________ mixes with __________ to form a small, round lubricated mass that's easier to transport through the digestive system
Saliva, food
The __________ __________ absorbs about 95% of the water we ingest
Small intestine **Small intestine does the MOST water absorption. Large intestine just finishes the job
__________ __________ is an enzyme that begins digestion of carbohydrates in the mouth by converting starch to maltose
Salivary amylase
Process of neutralization in the small intestine: 1. The small intestine produces __________ in response to chyme entering the small intestine from the stomach 2. Secretin stimulates the __________ to secrete __________ into the __________ via the __________ __________ 3. Bicarbonate (HCO3-) is acidic/basic which neutralizes the acidic chyme
Secretin (hormone), pancreas, HCO3-, duodenum, pancreatic duct, basic
__________ is a ring of muscles that constricts and relaxes to control openings
Sphincter
Most of RBC destruction is done in the __________
Spleen
Pancreatic amylase breaks down __________ into __________
Starch, maltose
Acid reflux is caused by __________ __________ moving backwards into the __________ through the __________ __________
Stomach acid, esophagus, cardiac sphincter
Peptic ulcers are open sores on the __________ epithelium caused by __________ __________ due to inadequate __________ protection
Stomach, acid corrosion, mucus
Chyme leaves the __________ through the __________ __________ to enter the __________ __________
Stomach, pyloric sphincter, small intestine
Pyloric sphincter controls the opening between the __________ and __________ __________
Stomach, small intestine
The liver __________, __________, and __________ blood coming from the digestive system
Stores, filters, detoxifies
Microvilli further expands the __________ __________ to help in nutrient __________
Surface area, absorption
Villi increase the __________ __________ and efficiency of __________ in the small intestine (particularly, the jejunum and ileum)
Surface area, absorption
Diarrhea occurs when too little/too much water is absorbed by the large intestine
Too little
Chief cells secrete gastric lipase which is an enzyme that breaks down __________ into __________ __________ and __________
Triglycerides (fats), fatty acids, monoglycerides
The zymogen form of trypsin is __________
Trypsinogen
Chief cells also secrete pepsinogen which is a __________. When pepsinogen enters the acidic gastric juice, it will be activated into __________ which is a __________ that cleaves __________ bonds. It converts __________ into __________ __________
Zymogen, pepsin, protease, peptide, proteins, amino acids
The esophagus is made of only smooth muscle, only skeletal muscle, and both smooth and skeletal muscle in which parts of it?
Upper 1/3 = skeletal Middle 1/3 = both Lower 1/3 = smooth
The appendix is a __________ structure that can cause __________ when it becomes inflamed
Vestigial, appendicitis **Vestigial means it has no use
__________ are the finger-like projections on the walls of the small intestine
Villi
Enterocytes are absorptive cells that make up __________ and are lined with __________
Villi, microvilli
__________ is absorbed completely at the colon of the large intestine
Water
The cecum is an important structure for __________ and __________ __________
Water, mineral absorption
The 3 main functions of the large intestine are: 1. __________ absorption 2. __________ absorption 3. __________ production and absorption
Water, mineral, vitamin **Mineral absorption is when some salts are absorbed together with the water (NaCl)
Intracellular digestion is digestion that happens within/outside cells
Within **ex: Amoeba grabs a chunk of food and digests it inside its cells
__________ is the inactive precursor of an enzyme
Zymogen