Chapter 25- Digestive System Flashcards
6 different activities that the digestive system carries out:
- Ingestion
- Secretion
- Propulsion/Motility
- Mechanical & Chemical Digestion
- Absorption
- Elimination
Ingestion
Intake of food
Secretion
enzymes (pH)
Motility
The food that is being digested will be ____ from one part of the tract to the next. Most of this movement occurs because of involuntary muscle contractions along the length of the ___________ ______ This muscle contraction is termed ______
The food that is being digested will be MOVED from one part of the tract to the next. Most of this movement occurs because of involuntary muscle contractions along the length of the GASTROINTESTINAL TRACT. This muscle contraction is termed PERISTALSIS.
Mechanical Digestion
The physical breakdown of particles into smaller pieces
Chemical Digestion
The molecular breakdown of molecules into smaller ones.
Usually involves enzymes
Enzyme:
a substance that increases the rate of chemical reactions without changing themselves. Each enzyme will have its own ______ that it can work on, and will work best at _____ _____ and _____ ___
a substance that increases the rate of chemical reactions without changing themselves. Each enzyme will have its own SUBSTRATE that it can work on, and will work best at OPTIMAL TEMP and OPTIMAL pH.
Absorption
passage of digested food into the blood and lymphatics
Elimination
waste
Elimination: removal of undigested substances from the G.I. tract termed_______ This would include some water, foods that cannot be digested, foods that were digested but not absorbed, cells of the GI tract that were sloughed off, bacteria. The eliminated material is termed _____ or _____
removal of undigested substances from the G.I. tract termed DEFECATION. This would include some water, foods that cannot be digested, foods that were digested but not absorbed, cells of the GI tract that were sloughed off, bacteria. The eliminated material is termed FECES or STOOL.
2 main groups that the organs of digestive system can be divided into
The G.I. tract (alimentary tract) and the accessory structures
The G.I. tract (alimentary tract): these are the organs that the food ____ _____ ____
List the pathway
The G.I. tract (alimentary tract): these are the organs that the food actually passes through:
mouth–> pharynx–> esophagus–> stomach–> small intestine–> large intestine
Accessory structures:
aid in ______, but the food ___ ___ __ ____ ___
Exs:
aid in digestion, but the food does not go through them
Exs: teeth, tongue, salivary glands, liver, gall bladder, and pancreas.
Organs are surrounded by visceral peritoneum which is continuous with the parietal peritoneum. The connection between visceral and parietal is called the _________. Some organs are located retroperitoneal (including pancreas, duodenum, and part of the large intestines).
Organs are surrounded by visceral peritoneum which is continuous with the parietal peritoneum. The connection between visceral and parietal is called the MESENTERY. Some organs are located retroperitoneal (including pancreas, duodenum, and part of the large intestines).
Mouth- distance and time
Distance: a few inches
Time: a few seconds
The mouth is the opening to the digestive tract from ___ to _____
from lips to pharynx
Two compartments of the mouth
Vestibule and Oral cavity
Vestibule
area of mouth between the cheeks and the gums outside teeth
Oral cavity
lined by hard and soft palate superior, uvula posterior, teeth anterior
inside teeth
2 sets of teeth
The deciduous (20 teeth), followed by permanent (32 teeth)
The deciduous teeth enter thru gingiva beginning at _________ and is usually complete by age _______. The permanent teeth then begin entering at ________ and are complete by age _____________.
The deciduous teeth enter thru gingiva beginning at 6 months and is usually complete by age 2 yrs.. The permanent teeth then begin entering at 6 yrs and are complete by age 12
Accessory structures of the mouth
Teeth
Tongue
Salivary glands
4 different types of teeth, amount, and purpose
Incisors (8), bite/cut
Canines (4), tear
Premolars (8) and Molars (12), grind
Tongue - structure composed mostly of skeletal muscle. It is attached to the bottom of the mouth by the ______ _____. Functions:
Tongue - structure composed mostly of skeletal muscle. It is attached to the bottom of the mouth by the LINGUAL FRENULUM. Functions:
1. chewing / swallowing
2. taste
3. speech
Salivary glands: There are 3 major pairs of salivary glands which produce serous (watery) or mucus secretions. 1.Parotid Glands:_____of salivary glands, found anterior to the ears producing serous secretion. Secretions enter over the upper 2nd molar.
2. Submandibular glands: found under ____ producing primarily a _____secretion. Secretions enter adjacent to the lingual frenulum.
3. Sublingual glands: found under_____ producing more _____ ___. Numerous openings compared to the parotid and submandibular glands.
Salivary glands: There are 3 major pairs of salivary glands which produce serous (watery) or mucus secretions. 1.Parotid Glands: Largest of salivary glands, found anterior to the ears producing serous secretion. Secretions enter over the upper 2nd molar.
2. Submandibular glands: found under mandible producing primarily a serous secretion. Secretions enter adjacent to the lingual frenulum.
3. Sublingual glands: found under tongue producing more mucus secretion. Numerous openings compared to the parotid and submandibular glands.
Functions of the salivary glands: these 3 sets of exocrine glands will secrete ____ into the mouth. Secretion is under the control of the nervous system (parasympathetic primarily) releasing 1-1.5L a day.
Functions of the salivary glands: these 3 sets of exocrine glands will secrete SALIVA into the mouth. Secretion is under the control of the nervous system (parasympathetic primarily) releasing 1-1.5L a day.
Functions of the salivary glands:
- Taste
- Lubrication
- Antibacterial
- Digestion
Contents of saliva
- Water
- Lysozymes
- Mucin
- Enzymes
1.Mechanical Digestion: The _____ will move the food around the mouth, allowing it to mix with the saliva. Chewing , termed _______, due to the teeth will break up the food, increasing the surface area and therefore allowing for more digestive enzymes to come into contact with more of the food and also decreasing the size of the food so that it can be swallowed safely. Chewing is important because chemical digestion occurs on the surface of cells- vital to increase surface area.
1.Mechanical Digestion: The TONGUE will move the food around the mouth, allowing it to mix with the saliva. Chewing , termed MASTICATION, due to the teeth will break up the food, increasing the surface area and therefore allowing for more digestive enzymes to come into contact with more of the food and also decreasing the size of the food so that it can be swallowed safely. Chewing is important because chemical digestion occurs on the surface of cells- vital to increase surface area.
The result of the actions of the teeth and tongue is the formation of a soft rounded ball of food called a ____.
The result of the actions of the teeth and tongue is the formation of a soft rounded ball of food called a BOLUS. The bolus, with the help of the tongue, will be passed from the mouth into the pharynx.
What enzyme comes from saliva?
Salivary Amylase
Chemical Digestion: The mouth is the site for the beginning of the digestion of
________ by the enzyme, _______ _____. This enzyme is specialized to digest ___saccharides into ___saccharides. Only the monosaccharide form of the carbohydrate can actually enter the cell, so these disaccharides will need to be further digested in another part of the digestive system. Only 3-5% (____ ___) of the total CHO digestion occurs in the mouth.
Chemical Digestion: The mouth is the site for the beginning of the digestion of
CARBOHYDRATES by the enzyme, SALIVARY AMYLASE. This enzyme is specialized to digest polysaccharides into disaccharides. Only the monosaccharide form of the carbohydrate can actually enter the cell, so these disaccharides will need to be further digested in another part of the digestive system. Only 3-5% (very little) of the total CHO digestion occurs in the mouth.
The salivary amylase is produced primarily by which glands? (hint: serous secretion)
Parotid and Submandibular
Lingual lipase
Works at a pH of 5 and digests lipids
Summary (for mouth):
Ingestion-
Motility-
Mechanical Digestion-
Chemical Digestion-
Absorption-
Elimination-
Ingestion- yes! (mouth is only area for this)
Motility- mastication
Mechanical Digestion- mastication
Chemical Digestion- salivary amylase
Absorption- no
Elimination- no
Mastication is ____ and is important because..
Mastication is voluntary and is important because it increases the surface area, allowing enzymes to work better
Salivary amylase is made in the ____, but can function in other areas
mouth
The pharynx is from the ____ to the _____ and is the location of the ____
- from the uvula to the epiglottis
- location of the tonsils
Pharynx:
When the bolus is formed, ______ (swallowing) occurs pushing the bolus into the _____ and with the help of _______, the bolus continues into the esophagus. The _______ covers the larynx and prevents food/water from entering as the bolus passes
When the bolus is formed, DEGLUTITION (swallowing) occurs pushing the bolus into the PHARYNX and with the help of PERISTALSIS, the bolus continues into the esophagus. The EPIGLOTTIS covers the larynx and prevents food/water from entering as the bolus passes
The pharynx consists of 3 areas:
oro-
naso-
laryngo-
Summary (for pharynx):
Ingestion-
Motility-
Mechanical Digestion-
Chemical Digestion-
Absorption-
Elimination-
Ingestion- no
Motility- deglutination
Mechanical Digestion- deglutination
Chemical Digestion- continuation of salivary amylase (functions, but not produced)
Absorption- no
Elimination- no
____ in the pharynx (______) is the last time where things are voluntary
Motility in the pharynx (deglutination)
The esophagus is from the ____ to the ____
epiglottis to the stomach
The esophagus is located in the ______ of the thorax and contains the 4 tunicas common to the alimentary canal. However, it’s unique due to
The esophagus is located in the mediastinum of the thorax and contains the 4 tunicas common to the alimentary canal. However, it’s unique due to the tunica muscularis, which is made up of involuntary skeletal muscle
Esophagus:
As the bolus moves from the pharynx into the esophagus, it will pass through a _____ called the _____ _____ _____
As the bolus moves from the pharynx into the esophagus, it will pass through a SPHINCTER called the UPPER ESOPHAGEAL SPHINCTER
Sphincter: circular muscle that can constrict an opening regulating movement of digestive contents through the G.I. tract. Typically these are composed of ___________ and is _______
Sphincter: circular muscle that can constrict an opening regulating movement of digestive contents through the G.I. tract. Typically these are composed of smooth muscle and is involuntary
The esophagus will go through the ______, the large muscle that separates the thoracic cavity from the abdominal cavity, at an opening called the ________ _____. Sometimes this opening causes a weakness in the diaphragm and the portions of abdominal organs (like the lower esophagus and upper stomach) can protrude into the thoracic cavity, causing pain and discomfort. This pathology is called a _____ ____. The esophagus eventually narrows and the bolus will go through the LOWER ESOPHAGEAL SPHINCTER (_____ _____) into the stomach.
The esophagus will go through the DIAPHRAGM, the large muscle that separates the thoracic cavity from the abdominal cavity, at an opening called the ESOPHAGEAL HIATUS. Sometimes this opening causes a weakness in the diaphragm and the portions of abdominal organs (like the lower esophagus and upper stomach) can protrude into the thoracic cavity, causing pain and discomfort. This pathology is called a HIATAL HERNIA. The esophagus eventually narrows and the bolus will go through the LOWER ESOPHAGEAL SPHINCTER (CARDIAC SPHINCTER) into the stomach.
Peristalsis
Involuntary wave-like contractions of smooth muscle. In the G.I. tract, these contractions push digesting food forward.
Distance and time for esophagus
Distance: 8-10 inches
Time: few seconds
Summary (for esophagus):
Ingestion-
Motility-
Mechanical Digestion-
Chemical Digestion-
Absorption-
Elimination-
Ingestion- no
Motility- peristalsis
Mechanical Digestion- peristalsis
Chemical Digestion- salivary amylase (still functions)
Absorption- no
Elimination- no
Stomach:
- a ______ organ 6-10 inches in length located in the ____ _____ ____
- attached to other organs and body wall via an _____
Stomach:
- a J-shaped organ 6-10 inches in length located in the upper left quadrant
- attached to other organs and body wall via an OMENTUM.
The stomach has the 4 tunicas common to alimentary canal although the tunica muscularis is unique in that it
has 3 layers instead of the typical two: circular, longitudinal, and oblique
4 areas to the stomach
- _____ _____-surrounds ____ ____
- fundus-rounded portion
- body- large central portion
- _____- most inferior portion, right around the ____ _____
- cardiac region -surrounds cardiac sphincter
- fundus-rounded portion
- body- large central portion
- pylorus- most inferior portion, right around the PYLORIC SPHINCTER
The walls are not smooth but are arranged in large folds when the stomach is empty= ____ When empty the stomach is the size of a clenched fist holding approx. 50ml but can hold up to 4L when full.
Ex: Joey Chestnut
Rugae contain _____ _____and lead to gastric glands.
The walls are not smooth but are arranged in large folds when the stomach is empty= Rugae When empty the stomach is the size of a clenched fist holding approx. 50ml but can hold up to 4L when full.
Ex: Joey Chestnut
Rugae contain gastric pits and lead to gastric glands.
Distance and time for the stomach
Distance: 6 inches
Time: 2-6 hours
MECHANICAL DIGESTION (stomach): When the food enters the stomach, _____ ____ will push the bolus around, causing it to be mixed with the digestive enzymes of this organ. The bolus becomes more liquified and is called ____. Continue to have peristaltic waves which propels the food particles forward.
MECHANICAL DIGESTION: When the food enters the stomach, MIXING WAVES will push the bolus around, causing it to be mixed with the digestive enzymes of this organ. The bolus becomes more liquified and is called CHYME. Continue to have peristaltic waves which propels the food particles forward.
CHEMICAL DIGESTION (stomach): Unlike the mouth and other parts of the digestive system in which the pH is maintained around 6-8, the stomach pH is around __.. Total amount of secretions roughly__-___ L although influenced by the amount and type of food ingested.
This acidic pH is due to the secretion of HCL(hydrochloric acid) by the _____ ____ found in the stomach wall. This HCL will maintain an optimal pH for the enzymes of the stomach to work. It also offers some protection to the person by killing microbes that enter the body through the food that they ingest. Has a minor effect directly on digestion of food. Inactivates salivary amylase due to pH change.
CHEMICAL DIGESTION: Unlike the mouth and other parts of the digestive system in which the pH is maintained around 6-8, the stomach pH is around 2. Total amount of secretions roughly 2-3 L although influenced by the amount and type of food ingested.
This acidic pH is due to the secretion of HCL(hydrochloric acid) by the PARIETAL CELLS found in the stomach wall. This HCL will maintain an optimal pH for the enzymes of the stomach to work. It also offers some protection to the person by killing microbes that enter the body through the food that they ingest. Has a minor effect directly on the digestion of food. Inactivates salivary amylase due to pH change.
PEPSIN - an enzyme that is secreted into the stomach lumen by ____ ____
It is responsible for beginning the digestion of ______. Pepsin is secreted in inactive form = _______, and will be converted to pepsin in the presence of HCL.
PEPSIN - an enzyme that is secreted into the stomach lumen by CHIEF CELLS.
It is responsible for beginning the digestion of proteins. Pepsin is secreted in inactive form = PEPSINOGEN, and will be converted to pepsin in the presence of HCL.
MUCUS: alkaline substance that is produced by ____ ____ in stomach lining is also important in digestion. It moistens bolus and offers protection to lining of stomach.
MUCUS: alkaline substance that is produced by mucous cells in stomach lining is also important in digestion. It moistens bolus and offers protection to lining of stomach.
Gastrin and Histamine are
hormones produced by enteroendocrine cells
INTRINSIC FACTOR: a glycoprotein that is also secreted by ____ ___ that allows for the intestinal absorption of vit. B12, needed for the production of RBCs ( due to synthesis of DNA).
INTRINSIC FACTOR: a glycoprotein that is also secreted by parietal cells that allows for the intestinal absorption of vit. B12, needed for the production of RBCs ( due to synthesis of DNA).
The biggest problem for people who have their stomach removed is the lack of intrinsic factor, which may lead to _____, a decrease of red blood cells in the blood. This problem is solved by taking vit B12 exogenously.
The biggest problem for people who have their stomach removed is the lack of intrinsic factor, which may lead to ANEMIA, a decrease of red blood cells in the blood. This problem is solved by taking vit B12 exogenously.
3 phases to stomach digestion
- Cephalic phase
- Gastric phase
- Intestinal phase
Cephalic phase
smell, taste, and thought of food
Cephalic phase: neurological signal that tells ________ ___ to release ___ quantities of ______ and _____. There’s also a small release of ____ and ______
neurological signal that tells enteroendocrine cells to release small quantities of Histamine and Gastrin. There’s also a small release of HCl and Pepsinogen
Gastric phase:
- _____ enters the stomach
- _______ are stretched
- Enteroendocrine cells release ___ quantities of _____ and _____, as well as a ___ release of _____ and _____
- Bolus enters the stomach
- Mechanoreceptors are stretched
- Enteroendocrine cells release large quantities of Histamine and Gastrin, as well as a large release of HCl and Pepsinogen
Intestinal phase
- ____ the ____
- ______ the ______ _______
- _____ exiting the ____ ____
- stops the stomach
- starts the small intestines
- chyme exiting the pyloric sphincter
Comes in the stomach:
Leaves the stomach:
Comes in the stomach: bolus
Leaves the stomach: chyme
The ______provides the ____ ____ for beginning absorption even though the wall is impermeable to most material.
The stomach provides the first area for beginning absorption even though the wall is impermeable to most material (most absorption occurs in the small intestine).
What gets absorbed in the stomach?
water, electrolytes, some drugs (aspirin), alcohol
During the intestinal phase, what gets released?
Secretin, Cholecystokinin (CCK), Gastric Inhibitory Polypeptide
Chyme leaves the stomach, goes through the ____ ______ and into the ______, the first part of the ____ ____
Chyme leaves the stomach, goes through the pyloric sphincter and into the duodenum, the first part of the small intestine.
Summary for stomach:
Ingestion-
Motility-
Mechanical Digestion-
Chemical Digestion-
Absorption-
Elimination-
Ingestion- no
Motility- Peristalsis
Mechanical Digestion- Peristalsis and Mixing waves
Chemical Digestion- Pepsin (digests proteins) and Gastric lipase (optional)
Absorption- Yes, limited
Elimination- no
What does the majority of mechanical digestion
stomach
What does the majority of absorption and chemical digestion
small intestine
As the chyme leaves the stomach, it will pass into the duodenum and come in contact with material from the ______,______,_______ , the _______ organs. It will also be digested by material from the small intestine itself.
as the chyme leaves the stomach, it will pass into the duodenum and come in contact with material from the pancreas, gall bladder and liver, the accessory organs. It will also be digested by material from the small intestine itself.
ACCESSORY ORGANS OF THE SMALL INTESTINE = pancreas, gall bladder, liver
PANCREAS: (both exocrine and endocrine organ)
1. ________, located posterior to the greater curvature of the stomach and connected by 2 ducts to the duodenum.
2. _____ cells make up the ______ glands within the organ. These cells will secrete ______ _____ that contains a number of ______ ______. This pancreatic juice will be secreted into one of the 2 major ducts that will lead into the duodenum, the ______ duct and the smaller accessory duct.
PANCREAS: (both exocrine and endocrine organ)
1. Retroperitoneal, located posterior to the greater curvature of the stomach and connected by 2 ducts to the duodenum.
2. Acini cells make up the exocrine glands within the organ. These cells will secrete pancreatic juice that contains a number of digestive enzymes. This pancreatic juice will be secreted into one of the 2 major ducts that will lead into the duodenum, the pancreatic duct and the smaller accessory duct.
Endocrine (pancreas):
Exocrine:
Endocrine (pancreas): glucose homeostasis
Exocrine: digestive enzymes
Pancreatic Juice:
a. clear, colorless, 1-1.5L, composed of water, electrolytes (HCO3-),and ______
b. pH = 7.2 - 8.2 therefore will _______________
Pancreatic Juice:
a. clear, colorless, 1-1.5L, composed of water, electrolytes (HCO3-),and enzymes
b. pH = 7.2 - 8.2 therefore will stop the action of pepsin
Pancreas _____ digestive enzymes, but it doesn’t actually _____ until it’s released into the duodenum
Pancreas makes digestive enzymes, but it doesn’t actually function until it’s released into the duodenum
Pancreatic juice contains enzymes that are very important in digestion:
______ _____ :continues digestion of __________ that was started in the mouth (converts ___->___)
pancreatic amylase :continues digestion of carbohydrates that was started in the mouth (converts poly->di)
Pancreatic juice contains enzymes that are very important in digestion:
Trypsin, chymotrypsin and carboxypeptidase: all of these enzymes will be secreted in inactive forms and will continue Protein digestion started in stomach. Activated by: ________________
Enterokinase
Pancreatic lipase
digests lipids
Nucleases
digest nucleic acids (DNA/RNA)
The pancreas makes what enzymes? What do they work on?
Trypsin, chymotrypsin and carboxypeptidase- works on proteins
Enterokinase is made by the _____ ______ and converts trypsinogen into trypsin, chymotrypsinogen into chymotrypsin, and procarboxypeptidase into carboxypeptidase
small intestines
Endocrine functions of the pancreas: secretes the hormones _____ and _____- both important to maintaining the level of glucose in the blood. These hormones are produced in small structures of the pancreas called ______ ___ ____, which are composed of 2 types of cells, alpha and beta cells.
Endocrine functions of the pancreas: secretes the hormones glucagon and insulin- both important to maintaining the level of glucose in the blood. These hormones are produced in small structures of the pancreas called ISLETS OF LANGERHANS, which are composed of 2 types of cells, alpha and beta cells.
Alpha cells
produce glucagon when blood glucose levels decrease
Beta cells
produce insulin when blood glucose levels increase
Inability of the body to produce insulin, to produce active insulin, or failure of receptors to work properly. The result is that the blood glucose levels rise and none reach the cells.
Diabetes Mellitus
Glycogenolysis
Alpha cells (breakdown of glucose)
Glycogenesis
Beta cells (Bonding of glucose molecules)
LIVER:
The liver is one of the largest organs in the body and is located in right upper quadrant. In the human, it has 4 lobes: right, left, caudate and quadrate lobes. The liver is held in place by the ________ ____ which attaches to the inferior portion of the diaphragm and anterior abdominal wall.
The liver is one of the largest organs in the body and is located in right upper quadrant. In the human, it has 4 lobes: right, left, caudate and quadrate lobes. The liver is held in place by the FALCIFORM LIGAMENT, which attaches to the inferior portion of the diaphragm and anterior abdominal wall.
Internal Anatomy of Liver:
The liver has many modified blood vessels inside of it = _____. The flow of the blood will decrease in rate as it moves through the sinusoids. These sinusoids are lined with _____ _____. These are phagocytic cells that will engulf and destroy old red blood cells old white blood cells, bacteria, viruses and other toxic materials.
Internal Anatomy of Liver:
The liver has many modified blood vessels inside of it = SINUSOIDS The flow of the blood will decrease in rate as it moves through the sinusoids. These sinusoids are lined with KUPFFER CELLS. These are phagocytic cells that will engulf and destroy old red blood cells old white blood cells, bacteria, viruses and other toxic materials.
Components of the portal triad
Hepatic artery, Hepatic portal vein, Hepatic duct
Portal triad carries ______ blood and central vein carries _____
Portal triad carries oxygenated blood and central vein carries deoxygenated blood
Sinusoid carries… &
a mixture of both oxy. and deoxy. blood & kupffer cells
Kupffer cells
removes old RBCs
In the portal triad, blood flows..
towards the central vein
In the bile canaliculus, bile goes ___ from the ____ _____, towards the ___ ___, and out a ____ ____. Keep in mind that blood and bile ___ ___
In the bile canaliculus, bile goes away from the central vein, towards the portal triad, out a hepatic duct. Keep in mind that blood and bile never mix
Carbohydrate Metabolism
Stores glycogen
T/F- Carbohydrate Metabolism involves the digestion of carbs
False
Protein Metabolism
Nitrogen breakdown- converts ammonia (NH3) into urea, which is excreted by kidneys
Lipid Metabolism
Synthesizes/makes cholesterol
Production of bile:
- Produced by the liver and stored in gallbladder
- Breaks down lipids
3 other functions of the liver:
1. ______: the removal of some _____/_____ from the blood. These potentially toxic materials will be molecularly rearranged into non-toxic substances. ( alcohol, drugs, ammonia)
2. _____: vitamins, minerals (____)
3. ______- _____,_____,____
- Detoxification: the removal of some drugs and alcohol from the blood. These potentially toxic materials will be molecularly rearranged into non-toxic substances. ( alcohol, drugs, ammonia)
- Storage: vitamins, minerals (iron)
- Synthesis- albumin, heparin, clotting factors
Jaundice: yellowing of the skin and sclera of the eyes. Indicates problem with liver (or red blood cells) and is due to ______
the build up of bilirubin
2 causes for jaundice
Cirrhosis and Hepatitis
Cirrhosis: This is a condition that occurs due to the wide spread _______of ____ cells by viral infections, drugs, and alcohol. The normal liver cells die and are replaced by connective tissue. The liver is capable of regeneration but occurs slowly over 6-12 months.
This is a condition that occurs due to the wide spread destruction of liver cells by viral infections, drugs, and alcohol. The normal liver cells die and are replaced by connective tissue. The liver is capable of regeneration but occurs slowly over 6-12 months.
Hepatitis:
Inflammation of the liver
In the US, Hep. A (_______ HEPATITIS) accounts for approximately 30% of hepatitis cases. It can be transmitted by sewage-contaminated foods, raw shellfish, tainted water, and by the feces-mouth route – which explains why it is important that restaurant employees wash their hands after using the bathroom. Vaccine available.
Hep B(______HEPATITIS) is transmitted by ____ ____, account for 50% of the cases in the US and is considered to be more serious. Vaccine available.
Hep. C (20% of cases) has emerged as the most important liver disease in the US because it produces ____ ____ _____ It seems to be transmitted through ___ ___. Healthcare workers have a higher risk than most.
In the US, Hep. A (INFECTIOUS HEPATITIS) accounts for approximately 30% of hepatitis cases. It can be transmitted by sewage-contaminated foods, raw shellfish, tainted water, and by the feces-mouth route – which explains why it is important that restaurant employees wash their hands after using the bathroom. Vaccine available.
Hep B(SERUM HEPATITIS) is transmitted by body fluids, account for 50% of the cases in the US and is considered to be more serious. Vaccine available.
Hep. C (20% of cases) has emerged as the most important liver disease in the US because it produces chronic liver infections. It seems to be transmitted through body fluids. Healthcare workers have a higher risk than most.
Rank the commonality of the types of hepatitis
Hepatitis B- most common
Hepatitis A- in the middle
Hepatitis C- least common
Gall bladder
stores and concentrates bile
Sometimes the bile becomes so concentrated that it crystallizes (especially due to cholesterol precipitation) and blocks the ducts of the gallbladder =
gallstones
Stimulus for emptying of the gall bladder (contraction/relaxation of the sphincter)
Cholecystokinin (CCK)
List the anatomical relationships of accessory organs and duodenum
Right and left hepatic duct -> common hepatic duct -> cystic duct -> common bile duct -> pancreatic duct -> hepatopancreatic ampulla -> sphincter of Oddi -> major duodenal papilla
What opens, allowing contents to enter the duodenum?
Sphincter of Oddi
There are 3 sections to the small intestine:
- Duodenum 2. Jejunum 3. Ileum
The duodenum, jejunum, and ileum all look very similar but the ____ is unique due to the ____ _____
Ileum is unique due to peyers patch
Distance/time for small intestine
Distance: 20 ft
Time: 3-4 hrs
90% of all absorption occurs in the small intestine. The anatomy of this organ is well-suited for absorption due to its ____ surface area. The ______ _____ are large folds found in the walls of the small intestine similar to stomach rugae.
90% of all absorption occurs in the small intestine. The anatomy of this organ is well suited for absorption due to its large surface area. The CIRCULAR FOLDS are large folds found in the walls of the small intestine similar to stomach rugae.
The microscopic anatomy of the small intestine also adds to the surface area of the small intestine, and therefore aids in absorption. The surface is lined with ____, which are finger-like projections that extend into the lumen, allowing for an increase in surface area. Also, on the surface of the epithelial cells that line the s.i. lumen, there are more projections of cytoplasm called ______. Again, this results in an increase in surface area. These microvilli appear like small brushes under an electron microscope, and are referred to as a _____ _____
The microscopic anatomy of the small intestine also adds to the surface area of the small intestine, and therefore aids in absorption. The surface is lined with VILLI, which are finger-like projections that extend into the lumen, allowing for an increase in surface area. Also, on the surface of the epithelial cells that line the s.i. lumen, there are more projections of cytoplasm called MICROVILLI. Again, this results in an increase in surface area. These microvilli appear like small brushes under an electron microscope, and are referred to as a BRUSH BORDER.
Small Intestine:
Carbs, proteins, nucleic acids, lipids, H2O
Where do they go?
Carbs, proteins, nucleic acids = HPV (goes to blood)
H2O= goes to both HPV (blood) and lacteals
Lipids = only goes to lacteals
Digestion in small intestine
a. MECHANICAL DIGESTION: ________ - _____ ______ of the small intestine. These contractions will mix the chyme with the digestive juice. _____ is also important in propelling chyme distally.
Digestion in small intestine
a. MECHANICAL DIGESTION: segmentation - localized contractions of the small intestine. These contractions will mix the chyme with the digestive juice. Peristalsis is also important in propelling chyme distally.
Small intestine- Chemical Digestion:
List the brush border enzymes
Disaccharides, Peptidases, Nucleases
Disaccharides, Peptidases, and Nucleases are made by the
small intestine
Disaccharidases: These are responsible for finishing the digestion of ______. Maltase, Lactase and Sucrase are the major enzymes. They break down ________ to ______. In _______ ______, the individual fails to produce lactase, the enzyme that breaks down lactose, a dissaccharide found in milk products. Undigested lactose leads to fluid retention, pain , gas, diarrhea and cramping
Disaccharidases: These are responsible for finishing the digestion of carbohydrates. Maltase, Lactase and Sucrase are the major enzymes. They break down disaccharides to monosaccharides. In LACTOSE INTOLERANCE, the individual fails to produce lactase, the enzyme that breaks down lactose, a dissaccharide found in milk products. Undigested lactose leads to fluid retention, pain , gas, diarrhea and cramping
Peptidases: Another group of enzymes of the small intestine that..
finish the digestion of proteins
Absorption of organic molecules in the small intestine:
1. Carbohydrates are absorbed as ______. They enter the free end of the epithelial cells, pass through the cytoplasm, move out of the basal side and pass into a blood capillary. They will finally enter the ______ ___ _____, go to the liver and then to the rest of the body.
2. Proteins are absorbed as ____ ______. Proteins follow the same route as carbohydrates.
3. Nucleic acids are absorbed as ______ and follow the same path as proteins and carbohydrates
4. Lipids(triglycerides) are absorbed as ____ ____ and _____ molecules, and their route into the blood is different from carbohydrates and proteins.
Absorption of organic molecules in the small intestine:
1. Carbohydrates are absorbed as monosaccharides. They enter the free end of the epithelial cells, pass through the cytoplasm, move out of the basal side and pass into a blood capillary. They will finally enter the HEPATIC PORTAL VEIN, go to the liver and then to the rest of the body.
2. Proteins are absorbed as amino acids. Proteins follow the same route as carbohydrates.
3. Nucleic acids are absorbed as nucleotides and follow the same path as proteins and carbohydrates
4. Lipids(triglycerides) are absorbed as fatty acids and glycerol molecules, and their route into the blood is different from carbohydrates and proteins.
Lipids(triglycerides) are absorbed as fatty acids and glycerol molecules, and their route into the blood is _____ from carbohydrates and proteins. Fatty acids diffuse from the lumen of the small intestine into the free end of the epithelial cells, go through the basal side and finally pass into a _____ of the villus.
Lipids(triglycerides) are absorbed as fatty acids and glycerol molecules, and their route into the blood is different from carbohydrates and proteins. Fatty acids diffuse from the lumen of the small intestine into the free end of the epithelial cells, go through the basal side and finally pass into a LACTEAL of the villus.
LACTEAL: a vessel of the lymphatic system that absorbs ___. This fat then becomes part of the ____and will finally be passed into the bloodstream. ____ ___ go through the hepatic portal vein.
LACTEAL: a vessel of the lymphatic system that absorbs fat. This fat then becomes part of the LYMPH and will finally be passed into the bloodstream. Does NOT go through the hepatic portal vein.
Most _____ ____ occurs in the small intestine. After passing thorough the small intestine, the chyme is ready to go through the _____ ____/_____ and into the large intestine.
Most water reabsorption occurs in the small intestine After passing thorough the small intestine, the chyme is ready to go through the ILEOCECAL VALVE/SPHINCTER and into the large intestine.
Summary for the small intestine-
Ingestion-
Motility-
Mechanical Digestion-
Chemical Digestion-
Absorption-
Elimination-
Ingestion- no
Motility- Peristalsis
Mechanical Digestion- Peristalsis, segmentation
Chemical Digestion- Disaccharides, Nucleases, Peptidases
Absorption- HPV, lacteal
Elimination- no
Elimination-
1st place absorption begins
stomach
1st place organic molecules are absorbed
small intestine
What structure is responsible for controlling the movement of air and food?
Epiglottis
Pepsinogen is activated by..
HCL
Proper anatomical term for swallowing
Deglutition
T/F: The majority of mechanical digestion and absorption occurs in the stomach
False- not absorption
Acini cells produce all of the following except:
Bile
Trypsinogen
Amylase
Nuclease
Bile
Bile is made by the
hepatocytes
The reason it’s called the “small” and “large” intestine is due to the
diameter
Distance/time of large intestine
Distance: 5-6 ft
Time: 12-18 hrs
Externally, the large intestine will have a series of pouches, referred to as ______which gives it a segmented appearance. The sections/ 4 regions of the large intestine are the..
Externally, the large intestine will have a series of pouches, referred to as HAUSTRA which gives it a segmented appearance. The sections/ 4 regions of the large intestine are the cecum, the colon, the rectum, and the anal canal.
Cecum: This is a blind pouch, right after the ileocecal valve. It is about 2.5 inches long and the VERMIFORM ______ is attached to it.
Appendix
There are 4 subdivisions of the colon – the ASCENDING COLON, the TRANSVERSE COLON, the DESCENDING COLON and the SIGMOID COLON. Note the _____ and ______ ____. There are also bands of longitudinal muscle fibers called ______ _____- the longitudinal layer of the tunica muscularis is ____ ____. Also get formation of _____- individual pouches.
There are 4 subdivisions of the colon – the ASCENDING COLON, the TRANSVERSE COLON, the DESCENDING COLON and the SIGMOID COLON. Note the HEPATIC and SPLENIC FLEXURES. There are also bands of longitudinal muscle fibers called TENIAE COLI- the longitudinal layer of the tunica muscularis is not complete. Also get formation of HAUSTRA- individual pouches.
The tunica muscularis is unique in the ___ of the large intestine due to the
colon, teniae coli
Rectum: This is a straight muscular tube. The tunica muscularis is
complete
Anal Canal: This is the terminal 1 inch of the digestive tract. The tunica muscularis is also complete here. There is an ______ ______ muscle that is smooth muscle (involuntary) and an ____ _____ that is ___ ______ (_____). The external sphincter takes time to develop and children should not be expected to have control over having a bowel movement before 1 year of age (usually later in boys).
Anal Canal: This is the terminal 1 inch of the digestive tract. The tunica muscularis is also complete here. There is an internal sphincter muscle that is smooth muscle (involuntary) and an external sphincter that is skeletal muscle (voluntary). The external sphincter takes time to develop and children should not be expected to have control over having a bowel movement before 1 year of age (usually later in boys).
Sometimes the veins in the anal canal become enlarged and inflamed and can burst =_____ This is seen in pregnancy and people with chronic constipation.
hemorrhoids
The external sphincter controls
elimination
Mechanical digestion: (large intestine)
1._____ _____: The haustra remain relaxed as the chyme fills them up. When distended, the walls will contract and squeeze the chyme into the next haustrum.
2_______: continues to occur in the large intestine, but it is at a slower pace.
Strong peristaltic contractions occurring over a large portion of the colon leads to _____ ______. An example is the _____ ____: forceful contractions that begins in the middle of the transverse colon and pushes chyme into the rectum. Food in the stomach initiates this action. Usually 3-4 mass movements a day, strongest after a meal.
Mechanical digestion:
1.Haustral Churning: The haustra remain relaxed as the chyme fills them up. When distended, the walls will contract and squeeze the chyme into the next haustrum.
2.Peristalsis: continues to occur in the large intestine, but it is at a slower pace.
Strong peristaltic contractions occurring over a large portion of the colon leads to MASS MOVEMENTS. An example is the gastrocolic reflex: forceful contractions that begins in the middle of the transverse colon and pushes chyme into the rectum. Food in the stomach initiates this action. Usually 3-4 mass movements a day, strongest after a meal.
Chemical digestion in the large intestine:
The chemical digestion that takes place here is due to the activity of bacteria, which live in the large intestine. There are ___ _____ ____ in the large intestine, but there is a tremendous amount of mucus that is secreted from _______________________.
Chemical digestion in the large intestine:
The chemical digestion that takes place here is due to the activity of bacteria, which live in the large intestine. There are no digestive enzymes in the large intestine, but there is a tremendous amount of mucus that is secreted from goblet cells
Chemical digestion in the large intestine:
The existence of these E.coli in the large intestine is a _____ ______ - both organisms benefit. E.coli get ___ from the G.I. tract. The person gets the_____ of ______ from the bacteria. Vit K is important in ____ _____.
Chemical digestion in the large intestine:
The existence of these E.coli in the large intestine is a symbiotic relationship - both organisms benefit. E.coli get fed from the G.I. tract. The person gets the production of vitamin K from the bacteria. Vit K is important in blood clotting
Absorption in large intestine- primarily ___.
_____ consists of some water, mucus, bile pigments, epithelial cells from GI tract, bacteria, undigested food (roughage).
Peristalsis moves fecal material into the rectum, where there is distention of the walls and therefore stimulation of the stretch receptors. The impulse is set up, travels to the brain, and the person becomes conscious of these urge and have control over the voluntary muscles in the anal canal, resulting in _____
Absorption in large intestine- primarily water.
FECES consists of some water, mucus, bile pigments, epithelial cells from GI tract, bacteria, undigested food (roughage).
Peristalsis moves fecal material into the rectum, where there is distention of the walls and therefore stimulation of the stretch receptors. The impulse is set up, travels to the brain, and the person becomes conscious of these urge and have control over the voluntary muscles in the anal canal, resulting in DEFECATION.
What consists of feces?
Water
Mucus
Bile
Cells
Bacteria
Fiber
Summary for large intestine:
Ingestion-
Motility-
Mechanical Digestion-
Chemical Digestion-
Absorption-
Elimination-
Ingestion- No
Motility- Peristalsis, Haustral, Mass moving
Mechanical Digestion- Peristalsis, Haustral, Mass moving
Chemical Digestion- E. coli
Absorption- H2O, vitamins (carbs and protein)
Elimination- Yes, fecal material
If a person coughs and transmits a microbe through a ventilation system it’s ____. However, if they coughed within 3 ft of you, it’s _____
