23.1 - 23.6 Quiz Flashcards
Main 4 functions of the digestive system
- Take in food
- Break it down into nutrient molecules
- Absorb molecules into the bloodstream
- Rid the body of any indigestible remains
Two groups of the organs of the digestive system
Alimentary canal and Accessory digestive organs
What is involved in the alimentary canal?
GI tract, gut, from mouth to anus.
What is involved in the accessory digestive organs?
Teeth, tongue, gallbladder, digestive glands (salivary, liver, pancreas)
What are the 6 processes of digestion?
- Ingestion
- Propulsion.
- Mechanical breakdown
- Digestion
- Absorption
- Defecation
Define ingestion
Eating
Define propulsion
Movement of food through the alimentary canal (Swallowing and peristalsis)
Define mechanical breakdown
Chewing, mixing food with saliva, churning food in stomach and segmentation
Define digestion
Series of catabolic steps involves enzymes that break down complex food molecules into chemical building blocks
Define absorption
Passage of digested fragments from lumen of GI tract into blood and lymph
Define defecation
Elimination of indigestible substances via anus in form of feces
Define peritoneum
Serous membranes of abdominal cavity that consist of visceral and parietal peritoneum.
Define visceral peritoneum
Membrane on external surface of digestive organs
Define parietal peritoneum
Membranes that line body wall
What is the peritoneal cavity?
Fluid filled space between two peritoneums. Lubricates mobile organs
Define mesentery
Double layer of peritoneum, fused back to back. Body wall to digestive organs. Holds organs in place and stores fat.
Where are intraperitoneal organs located?
Within the peritoneum
Where are retroperitoneal organs located?
Outside or posterior to the peritoneum
All digestive organs have the same four basic layers
- Mucosa
- Submucosa
- Muscularis externa
- Serosa
What is the purpose of mucosa?
Tunic layer that lines lumen. Different layers perform one or all three. Secretes mucus, digestive enzymes and hormones. Absorbs end products of digestion. Protects against infectious disease.
What is the purpose of submucosa?
Consists of areolar connective tissue. Contains blood, lymphatic vessels.
What is the purpose of muscularis externa?
Muscle layer responsible for segmentation and peristalsis. Circular layer thickens in some areas to form sphincters
What is the purpose of serosa?
Outermost layer of visceral peritoneum. Formed from areolar connective covered with mesothelium.
Sphlanchic circulation includes what?
Arteries that branch off aorta to serve digestive organs. Hepatic, splenic, and left gastric arteries. Inferior and superior mesenteric arteries.
Hepatic portal circulation purpose?
Drains nutrient rich blood from digestive organs. Delivers blood to the liver of processing.
