Chapter 9

What is the function of the large intestine?

Absorb water and salt

The large surface area of the small intestine is important for what process?

Absorption of nutrients

Why is the pH of the small intestinal contents normally slightly basic?

Because pancreatic juice contains sodium bicarbonate

What is the lumen defined as?

Central space

After their absorption form the gut lumen, monoglycerides and fatty acids are rejoined in the villi epithelial cells, forming lipid droplets called:

Chylomicrons

What is the function of the pancreas?

Contains digestive enzymes, sends them to the small intestine, produces insulin and secretes it into blood

What is the function of the stomach?

Control movement of food into small intestine, digestion of proteins, storage of food

During chemical digestion, what protein molecules hydrolyze food macromolecules?

Digestive enzymes

A duct brings bile from the gallbladder directly into the...

Duodenum

What is the function of bile?

Emulsifies fats

What is the structure that prevents swallowed food from entering the lungs?

Epiglottis

Heartburn is caused by the irritation of what tract?

Esophagus

What is the component of the food passageway that leads away from the pharynx?

Esophagus

What are symptoms of lactose intolerance?

Excessive gas, bloating, abdominal cramps

Gastric juice is produced by...

Gastric glands

When some of the stomach contents infiltrate the esophagus, it is commonly known as the condition called...

Heartburn

What is the ultimate purpose of digestion?

Hydrolyze food

Organic macromolecules are too big to cross the plasma membrane of cells, so they need to be what?

Hydrolyzed

Alcohol can be absorbed by the stomach because...

It is fat soluble

What enzymes are involved in the digestion of carbohydrates?

Lactase and amylase

In the small intestine, each villus contains blood capillaries and a small lymphatic capillary called what?

Lacteals

What are the digestive enzymes produced by the pancreas?

Lipase, amylase, and nuclease

From innermost to outermost, what are the layers of the GI tract wall?

Lumen, mucosa, submucosa, muscularis, serosa

What is the function of amylase?

Made by salivary glands or pancreas; digests starch

What is the function of lipase?

Made in the pancreas; digests lipids

What is the function of pepsin?

Made in the stomach; digests proteins

What structures increase the surface area of the small intestine?

Microvilli

What is the function of the small intestine?

Mixes chyme with digestive enzymes, absorbs nutrients, secretes hormones into blood

Where does chemical digestion begin?

Mouth

In the small and large intestine, peristalsis most directly results in what?

Movement of digestive tract contents

What are components of gastric juices?

Pepsin, mucus, hydrochloric acid

Digestive enzymes produced by the small intestine:

Peptidases, maltase, lactase

What is the process of contents of the digestive system being moved along by rhythmic contractions and relaxations of smooth muscle?

Peristalsis

The esophagus and trachea both connect to what?

Pharynx

The mouth and nasal passages lead to a hollow space at the back of the throat called the...

Pharynx.

What is the function of the liver?

Processes and stores nutrients, produces bile, important to metabolism

What is saliva?

Solution containing mucus, water, and salivary amylase, bicarbonate, and lysozyme secreted in the mouth

Which three parts of the human digestive tract contain mucus layers that produce digestive enzymes?

Stomach, mouth, small intestine

What is the function of the gallbladder?

Stores bile from the liver, sends it to the small intestine

What is the relationship between the epiglottis and glottis during swallowing?

The epiglottis covers the glottis

What is the serosa?

The thin, double-layered membrane that is the outermost layer

In diverticulitis, what happens to the abnormal pouches in the wall of the GI tract?

They become infected or inflamed

What are the enzymes involved in the digestion of proteins?

Trypsin, pepsin, and peptidase

What is the muscularis?

Two layers of smooth muscle

Diverticulosis

abnormal outpouchings in the intestinal wall of the colon

Hydrolyze

break down (a compound) by chemical reaction with water.

Chylomicrons

fat droplets covered in protein that diffuse into capillaries in small intestine

What are the steps of digestion?

ingestion, digestion, movement, absorption, elimination

What is the mucosa?

inner lining of digestive tract, glands release enzymes

What is the submucosa?

loose connective tissue that contains nerves, blood, and lymphatic vessels