Digestive System Flashcards
What is the purpose of the digestive system?
Break down large macromolecules into smaller molecules so they can be absorbed into blood stream and delivered to cells
Carbohydrates break down into
Monosaccharides
Lipids break down into
-fatty acids and
-mono-glycerides
Proteins break down into
Amino acids
Monosaccharides have
-needs enzyme or no
-Glucose, Fructose, Galactose
-No need for digestive enzymes. Already in size that can be absorbed and moved into the blood stream.
Disaccharides: need enzymes to breakdown
*Maltose = Glucose—Glucose (Maltase)- beer sugar
•Sucrose = Glucose–Fructose (Sucrase)-table sugar
•Lactose = Glucose–Galactose (Lactase)-milk sugar
Polysaccharides: need enzymes to breakdown
•Starch (Amylose) = Glucose—Glucose–Glucose………..
•Amylase
What are the major macromolecules in food
*carbohydrates
-monosaccharide
-disaccharides
-polysaccharides
-proteins
-lipids
-nucleic acids
The Digestive Tract
-also called
-what is it?
-extends from?
-passes through —
-also called -gastrointestinal (GI) tract or alimentary canal
-A muscular tube made of smooth muscle
-Extends from oral cavity to anus
-Passes through pharynx, esophagus, stomach, and small and large intestines
Functions ofThe Digestive Tract
*ingestion
*Mechanical Digestion
*Chemical Digestion
*Secretion
*Absorption
*defecation/elimination
Ingestion
When materials enter digestive tract by the mouth
Mechanical Digestion
•Crushing and shearing/mastication/muscle contractions
•Materials are easier to move along digestive tract
Chemical Digestion
•The chemical breakdown of food into small organic molecules for absorption by digestive epithelium
Secretion
The release of water, acids, enzymes, buffers, and salts
•By epithelium of digestive tract
•By glandular accessory organs
Absorption
•Movement of organic molecules, electrolytes, vitamins, and water across digestive epithelium
•Into interstitial fluid of digestive tract
•And then into the blood stream
Excretion
• Removal of waste products from body fluids
•Substances that were not completely digested
•Process called defecation removes feces
Propulsion and Mixing
•Propulsion is movement of food in down the G I tract—-uses parasitic contractions to help get food down
•Mixing is movement of food back and forth.
What are the major parts of the alimentary canal?
mouth, pharynx, esophagus, stomach, small and large intestines, rectum and anus.
Mesenteries
-Are double sheets of peritoneal membrane
-•Suspend portions of digestive tract within peritoneal cavity by sheets of serous membrane
•Connects parietal peritoneum with visceral peritoneum
•Provides an access route to and from the digestive tract
•For passage of blood vessels, nerves, and lymphatic vessels
•Stabilize positions of attached organs
•Prevent intestines from becoming entangled
The Dorsal Mesentery
Enlarges to form an enormous pouch, called
the greater omentum
Lesser Omentum
Stabilizes position of stomach
•Access route for blood vessels and other structures entering or leaving liver
Peritoneal Fluid is produced by
-provides what
-separates what?
-allows what?
-how much produced/absorbed daily?
-Is produced by serous membrane lining
-Provides essential lubrication
-Separates parietal and visceral surfaces
-Allows sliding without friction or irritation
About 7 liters produced and absorbed daily, but very little in peritoneal cavity at one time
Adipose Tissue in Greater Omentum
•Conforms to shapes of surrounding organs
•Pads and protects surfaces of abdomen
•Provides insulation to reduce heat loss
•Stores lipid energy reserves
Modifications of Digestive Tract
Folding increases surface area for absorption
•Longitudinal folds, disappear as digestive tract fills
•Permanent transverse folds (plicae circulares)
Four major layers of the digestive tract
1.Mucosa
2.Submucosa
3.Muscularis externa
4.Serosa
Mucosa is
Inner lining of digestive tract
Identify the folds of the mucous membrane within the lining of the stomach that allow for stretching of the stomach
Rugae
Identify the small dead-ended tube attached to the cecum
Appendix
The superior portion of the esophagus consists of ____ muscle and the inferior portion consists of____ muscle.
Skeletal, smooth
The valve that allows intestinal contents to move from the ileum to the large intestine is called the_____ valve
ileocecal valve
Bile salts are necessary to
Emulsify lipids
What are the functions of the digestive system
-defecation
-absorption
-ingestion
-mastication
-digestion
The emulsification of lipid’s primarily through the action of___ ____.
Bile salts
Primary function of the stomach is
Store and mix chyme
Majority of digestion occurs within the
Duodenum
Identify the structures that secrete lipases
-lingual glands
- pancreas
functions of mucus secretion in the large intestine
-protects intestinal lining
-lubricates colon wall
Order of food through digestive system starting with ingestion
1-mouth
2-pharynx (throat)
3- esophagus
4- stomach
5-small intestine
6- large intestine
7-rectum
Structure within mediastinum, posterior to the trachea is
Esophagus
The openings in the mucous membrane of the stomach that contain gastric glands are called ___ ____.
Gastric pits
Mechanical breakdown
Includes mastication and mixing of food
Digestion
Enzymatic action that breaks larger organic molecules down into smaller components.
Identify the secretions of small intestine
1-secretin
2-peptidases
3-disaccharides
4- cholecystokinin (CCK)
5- mucus
What substance stimulate gallbladder to release bile
Cholecystokinin
Process by which bile salts transform large lipid droplets into much smaller lipid droplets is called ?
Emulsification
Why is emulsification of lipids important
Emulsification increases surface area for digestive enzymes
Identify components of bile
1-cholesterol
2-bile salts
3-bilirubin
Structures that secrete amylase
1- salivary glands
2- pancreas
Place steps in production of hydrochloric acid in correct order
1-CO2 diffuses into parietal cells
2-CO2 combines with H2O to form H2CO3
3-H2CO3 dissociates into HCO3- and H+
4- HCO3- is exchanged for CL- within bloodstream
5- diffusion of Cl- into duct of gastric gland
6- H+ is pumped to the duct of gastric gland
During stomach filling the rugae
Flatten and allow stomach to increase in volume
Majority of nutrient absorption occurs in large intestine true or false
False
Cardiac sphincter is
Constrictor between the esophagus and the stomach
Pyloric sphincter
Constrictor between stomach and small intestine
Fundus is
Rounded superior portion of stomach
Pyloric part is
Lower part of stomach leading to small intestine
Name outer most superficial layer of organs in digestive system
-serosa and adventitia
Identify structures where lipid digestion occurs
Stomach, mouth, small intestine
Enzyme of small intestine that activates trypsinogen is___
Enterokinase
Match digestive enzymes with structure that secretes the enzyme :
1: Pepsin-
2-Peptidase
3- Amylase
1: stomach
2:small intestine
3: salivary glands
Identify structures that secrete enzymes that aid in the digestion of PROTEINS
-small intestine, stomach and pancreas
The semi- fluid material within the stomach that is a mixture of ingested food and gastric secretions ____
Chyme
Disaccharides and proteases are enzymes secreted by the ____.
Small intestine
Lipase does
Breaks down triglycerides into fatty acids and monoglycerides
Pepsin does
Digests proteins into small polypeptide chains
Disaccharides do
Break down disaccharide into monosaccharides
Peptidases do
Breaks down small polypeptide chains into amino acids
Identify layer of mucosa from inside out
Mucosa epithelium— lamina propria——muscularis mucosa
Pancreatic amylase
Starch digestion
Pancreatic lipase
Fat digestion
Trypsin
Digests proteins
Ribonuclease
Digests RNA
The process that moves a bolus from the oral cavity into the esophagus is called swallowing or_____.
Deglutition
Bicarbonate ion
Raise the pH of small intestine
Proteolytic enzymes are
Chemical digestion of proteins
Amylase is
Chemical digestion of polysaccharides
Lipases
Chemical digestion of fats
The ______ moves food with the mouth, holds food in place during mastication, aids in swallowing and detects taste sensations
Tongue
The pancreatic islets produce_____ and the acini of the pancreas produce ____.
Hormones and digestive enzymes
Mucosa
Consists of epithelial lining
-a layer of connective tissue referred to as lamina propria and a thin layer of muscle
Muscularis
Throughout most of digestive tract, this layer consists of two layers of smooth muscle
Serosa
Consists of a thin layer of connective tissue and simple squamous
Submucosa
Consists of a THICK layer connective tissue containing nerves, blood vessels lymphatic and glands
Structures that secrete enzymes that aid in chemical digestion of CARBOHYDRATES
Salivary glands, pancreas, small intestine
Intrinsic factors is secreted by the organ called the
Stomach
Identify nutrients that will be absorbed into the capillaries of small intestine
Amino acids and monosaccharides
Match digestive enzyme with structure that secrets the enzyme
1: Trypsin
2:disaccharides
3: bile salts
1:pancreas
2: small intestine
3: liver
Enzymes do what
Break down of large food molecules into smaller food molecule La to promote absorption
Mucus does what
Lubricates food and protects lining of digestive tract
Teniae coli are bands of longitudinal muscle of the ___ that form haustra
Colon
Digestive organ that primarily functions as a storage and mixing chamber
Stomach
Substance that aid in digestion of PROTEINS
Peptidases, trypsin, carboxypeptidases, pepsin
Secretions of the stomach
- Gastrin
-intrinsic factor
-mucus
-hydrochloric acid
-pepsinogen
Function of gallbladder
Storage of bile and
Concentration of bile
Hydrochloric acid does what
Destroys ingested bacteria and activates pepsin
Gastrin does
Stimulates gastric secretions
Intrinsic factor
AIDS in absorption of vitamin B12
Pepsinogen
Active form aids in breaking down proteins into smaller peptide chains
Mucus protect what’s
Protects lining of stomach
Identify the ducts that bile passes through beginning with the gallbladder and ending with the small intestine
1:cystic duct
2: common bile duct
3:hepatopancreatic ampulla
4: duodenum
Place parts of colon in order from beginning to end
1-ascending colon
2-transverse colon
3-descending colon
4- sigmoid colon
Submucosal plexus controls ___ and the myenteric plexus controls——
Glandular secretions——
Movement of the digestive tract
The pancreatic islets is the _____ part of the pancreas’s and acini is the ___ part of the pancreas’s
Endocrine———- exocrine
Identify functions of hydrochloride acid in stomach
-destroys ingested bacteria
-inactivates salivary amylase
-activates pepsin
Process by which water is absorbed into small intestine is
Osmosis
Lipase is
Breaks down triglycerides into fatty acids and monoglycerides
Vitamin B12 absorption occurs when____ ____ is present in the small intestine
Intrinsic factor
Hydrochloric acid activates what
Activates pepsin
Enterokinase activates what
Activates trypsin
Bike salts do what
Emulsifies lipids
Hydrochloric acid (secretion) —-what organ produces it
Stomach
Trypsinogen—- what organ produces it
Pancreas
Peptidases—- what organ produces it
Small intestine
Majority of nutrients absorption occurs in
-duodenum and jejunum
What is bile ?
A substance produced by hepatocytes
In digestive system creates amount of digestion and absorption occurs in the
SMALL intestine
