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