Module 20: Digestive System Flashcards
What is another name for the digestive tract?
Alimentary canal
Four layers of tissue make up the walls of the digestive tract. Describe the mucosa
Innermost layer – consist of three layers, an inner layer of epithelium, a layer of loose connective tissue, and a thin layer of smooth muscle
What is the function of the muscularis?
regularly contracts and relaxes to propel food through the digestive tract
What is mechanical digestion?
Involves physically breaking down food into smaller pieces, beginning with chewing in the mouth and continuing with contractions and churning in the stomach and small intestine
What is chemical digestion?
Uses digestive enzymes produced in the salivary gland’s, stomach, pancreas, and small intestines to break down food particles into nutrients (such as glucose, amino acids, and fatty acids) that cells can use
What is the peritoneum?
Large membrane in the abdominal cavity that connects and supports internal organs
What are mesenteries?
Layers of visceral peritoneum which suspend the digestive organs within the abdominal cavity while anchoring them loosely to the abdominal wall
What do the mesenteries contain and supply?
Blood vessels, nerves, lymphatic vessels, and lymph nodes That supply the digestive tract
What is the greater omentum and its function?
Portion of the mesentery- extends from the greater curvature of the stomach and hangs down over the small intestines.
Function - Prevents friction and helps localize infection
What is the lingual frenulum?
A fold of mucous membrane that anchors the tongue to the floor of the mouth
What is the difference between the hard palate and soft palate?
Hard palate - Separates the mouth from the nasal cavity
Soft palate - consists of mostly skeletal muscle, forms an arch between the mouth and nasopharynx
What does saliva consist of?
Mostly water, but also containing mucus, an enzyme that kills bacteria, antibacterial compounds, electrolytes, and two digestive enzymes - amylase and lipase
What is the function of amylase in the saliva?
Breaks down starch
What is the function of lipase in saliva?
Begins the digestion of fat
What saliva gland becomes swollen with the mumps?
Parotid gland
What connects the pharynx to the stomach?
Esophagus
The muscularis layer of the stomach has an extra layer of oblique muscle. What does this allow the stomach to do?
contract and churn vigourously as it processes food
What happens to the rugae of the stomach when we eat?
the rugae flatten and the stomach expands
What is the role of mucous cells in the gastric pit?
secrete mucus, which protects the stomach lining and keeps the stomach from digesting itself
What is the role of the parietal cells in the gastric pit?
Secrete hydrochloric acid and intrinsic factor. Hydrochloric acid helps kill microbes in swallowed food
What is the role of chief cells in the gastric pit?
secrete digestive enzymes, such as pepsinogen
What is the role of Enteroendocrine cells in the gastric pit?
Secrete the hormone ghrelin (which stimulates the hypothalamus to increase appetite) and gastrin (which influences digestive function)
What is chyme?
Semi-fluid mixture of small food particles and gastric juice
What are the primary functions of the liver?
Storing and releasing glucose, processing vitamins and minerals, filtering toxins, and recycling old blood cells