Chapter 22 - Digestive System Flashcards
Take in food, breaks it down into nutrient molecules, absorbs these molecules into the bloodstream, and then rids the body of the indigestible remains.
The digestive system
Two groups of the digestive system:
- Alimentary Canal
2. The accessory organs
The continuous muscular tube that winds through the body from the mouth to the anus
The Alimentary Canal; The Gastrointestinal (GI) Tract
Breaks down food into smaller fragments
Digests
Assimilates digested fragments through it’s lining into the blood
Absorbs
Organs of the Alimentary Canal
Esophagus
Stomach
Small Intestine
Large Intestine
The large intestine leads to the terminal opening or the _____.
Anus
Food in the alimentary canal is technically _____ the body.
Outside
Organs of the Accessory Digestive Organs
Teeth Tongue Gallbladder Salivary Glands Liver Pancreas
We can view the digestive tract as a ______ ______ in which food becomes less complex at each step of processing and its nutrients become available to the body.
Disassembly line
We can view the digestive tract as a ______ ______ in which food becomes less complex at each step of processing and its nutrients become available to the body.
Disassembly line
Six essential activities:
Ingestion Propulsion Mechanical breakdown Digestion Absorption Defecation
Taking food into the digestive tract (eating)
Ingestion
Moves food through the alimentary canal, includes swallowing, which is initiated voluntarily, and peristalsis, an involuntary process.
Propulsion
The major means of propulsion, involves alternate waves of contraction and relaxation of muscles in the organ walls.
Main effect is to squeeze food along the tract, but some mixing occurs as well.
Peristalsis
Page 762 (Figure 22.2)
Increases the surface area of ingested food and physically preparing it for digestion by enzymes.
Chewing, mixing food with saliva by the tongue, churning food in the stomach and segmentation.
Mechanical breakdown
Rhythmic local constrictions of the small intestine.
Mixes food with digestive juices and makes absorption more efficient by repeatedly moving different parts of the food mass over the intestinal wall.
Segmentation
Involves a series of steps in which enzymes secreted into the lumen (cavity) of the alimentary canal break down complex food molecules to their chemical building blocks.
Catabolic process.
Digestion
The passage of digested end products (plus vitamins, minerals, and water) from the lumen of the GI tract through mucosal cells by active or passive transport into the blood or lymph.
Absorption
Eliminates indigestible substances from the body via the anus in the form of feces.
Defecation
The most extensive serous membrane in the abdominopelvic cavity.
Peritoneum
Covers the the external surfaces of most of the digestive organs
Visceral Peritoneum
Lines the body wall
Parietal Peritoneum
Between the two peritoneum is the slit like potential space containing a slippery fluid secreted by the serous membranes.
Peritoneal cavity