objective 6 pt 1 Flashcards
what are the main functions of the digestive system?
- Take in food
- Break it down into nutrient molecules
- Absorb molecules into the bloodstream
- Rid body of any indigestible remains
continuous muscular tube that runs from the mouth to the anus
absorbs fragments through lining into blood
Alimentary Canal
breaks down into smaller fragments
digests food
what are the organs of the alimentary canal?
mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus
what are the accessory digestive organs?
teeth, tongue, gallbladder, digestive glands (salivary glands, liver, pancreas)
produce secretions that help break down foodstuffs
digestive glands
what are the 6 essential activities that the processing of food involves?
ingestion
propulsion
mechanical breakdown
digestion
absorption
defacation
eating
ingestion
movements of food through the tract
propulsion
major means of propulsion of food that involves alternating waves of contraction and relaxation
peristalsis
processes that physically mix and break foods down into smaller fragments
mechanical breakdown
local constriction of intestine that mixes food with digestive juices; makes absorption more efficient by repeatedly moving different parts of food mass over the intestinal wall
segmentation
catabolic process that involves enzymes that break down food molecules into their chemical building blocks
digestion
passage of digested end products from intestinal mucosa into blood or lymph
absorption
elimination of undigested substances via anus in form if feces
defecation
serous membranes of abdominal cavity that consists of…
peritoneum
what are the 2 parts of peritoneum?
visceral peritoneum
parietal peritoneum
membrane on external surface of most digestive organs
visceral peritoneum
membrane that lines body wall
parietal peritoneum
fluid-filled space between two peritoneum’s
serous fluid lubricates and allows mobile digestive organs to glide easily across one another and along body wall to carry out their activities
peritoneal cavity
double layer of peritoneum; layers are fused back to back
extends from body wall to digestive organs
provides routes for BV, lymphatics, and nerves
holds organs in place and also stores fat
mesentery
what are the 4 basic layers of all digestive organs?
mucosa
submucosa
muscularis externa
serosa
innermost tunic layer that lines lumen
mucosa
what are the functions of the mucosa?
vary depending on region of the GI system
* Secretes mucus, digestive enzymes, and hormones
* Absorbs end products of digestion
* Protects against infectious disease
contains blood and lymphatic vessels, lymphoid follicles, and nerve fibers that supply surrounding GI tract tissues
has abundant amount of elastic tissues that help organs to regain shape after storing large meal
submucosa
muscle layer responsible for segmentation and peristalsis
contains inner circular muscle layer and outer longitudinal layers
muscularis externa
thickens in some areas to form sphincters that act as valves to control food passage from one organ to the next and prevent backflow
circular layer
outermost layer which is made up of the visceral peritoneum
serosa