digestion Flashcards
What is the structure of the digestive system?
The digestive system is complete; it includes a mouth, gut, and anus.
How do buccal muscles function in the digestive process?
Buccal muscles and anterior esophageal muscles contract to open the mouth and suck in food.
What role does hydrostatic pressure play in the digestive system?
Hydrostatic pressure in the pseudocoel closes the mouth and esophageal lumen.
How does food move through the esophagus?
Food passes down the esophagus via muscle contractions until it reaches the intestine.
What is the function of the posterior bulb?
The posterior bulb acts as a one-way valve.
How does hydrostatic pressure assist in food movement?
Hydrostatic pressure pushes food posteriorly; newly ingested food and locomotor activity help.
What is the structure of the intestine?
The intestine is constructed of a single layer of intestinal cells.
What is the role of depressor ani muscles?
Depressor ani (anal dilator muscles) contract to open the anus.
How does hydrostatic pressure affect defecation?
Hydrostatic pressure causes defecation when the anus is opened.
What types of food do nematodes consume?
Food of nematodes includes blood, tissue cells, fluid, and intestinal contents.
