11 The Digestive System Free Online FlashCards

What is peristalsis?

Peristalsis is a series of muscular contractions that propels and mixes contents through the gastrointestinal tract.

What does salivary amylase begin digesting?

Salivary amylase begins the chemical digestion of starch in the mouth.

What is the role of the lower esophageal sphincter?

The lower esophageal sphincter helps prevent stomach contents from flowing backward into the esophagus.

How do acid and pepsin contribute to stomach digestion?

Stomach acid helps denature proteins, and pepsin begins their digestion.

Which regions make up the small intestine, and what mainly happens there?

The duodenum, jejunum, and ileum make up the small intestine, where most chemical digestion and nutrient absorption occur.

What does pancreatic bicarbonate do?

The pancreas supplies bicarbonate, which helps neutralize stomach acid entering the small intestine.

Name two functions of the large intestine.

The colon absorbs water and electrolytes. Gut microbes ferment some undigested material and produce substances such as vitamin K.

How do mechanical and chemical digestion differ?

Mechanical digestion physically breaks up or mixes food; chemical digestion uses enzymes to split large food molecules into smaller units.

How do villi and microvilli support nutrient absorption?

Folds, villi, and microvilli create a large surface area that supports absorption in the small intestine.

Where do absorbed sugars and amino acids travel first?

Absorbed sugars and amino acids enter intestinal blood vessels and travel through the hepatic portal vein to the liver.

How does insulin respond to rising blood glucose?

When blood glucose rises, the pancreas releases insulin, which promotes glucose uptake and storage in many tissues.

What is chyme?

Chyme is the fluid mixture formed when stomach contents are mixed with acid and enzymes.