Chapter 14: Did you get it?

Why is it important to include cellulose in a healthy diet even though we cannot digest it?

It provides fiber, which is important for moving feces along the colon and defecation.

Are oils saturated lipids or unsaturated lipids?

Oils are unsaturated lipids

What is the proper order of the following stages of food processing?

Ingestion, Digestion, Absorption, and Defecation

How does vasodilation of skin blood vessels affect body temperature on a hot day?

It decreases body temperature

Which of the following would you expect to yield a relatively high BMR: old age, large surface are relatively to body volume, female sex, deficient thyroxine production?

Large surface areas relative to volume.

In which organ of the alimentary canal does protein digestion begin?

Protein digestion begins in the stomach

What happens to the ammonia released when amino acids are "burned" for energy?

.The liver combines ammonia with carbon dioxide to form urea. Urea is then eliminated from the body in urine.

What is the major source of carbohydrates in our diet?

From plants; fruits, vegetables, and grains.

What is the normal number of permanent teeth?

32 permanent teeth.

What dietary changes must be made to prevent brain damage in children with PKU?

A diet low in phenylalanine

What does it mean when we say that food " we down the wrong tube"?

Food went down the air passageway (trachea) instead of the digestive passage (esophagus).

The stomach epithelium secretes several substances, including alkaline mucus and intrinsic factor. What is the function of each of these two secretions?

Alkaline mucus protect the stomach wall from being digested, and Intrinsic factors is needed for intestinal absorption of vitamin B-12.

What are the building blocks (and digestion products) of proteins?

Amino acids

Why is it necessary for the stomach contents to be so acidic?

Pepsin, the main enzyme of the stomach, needs acidic conditions to work.

How does cystic fibrosis affect digestion?

Because it clogs the pancreatic ducts so that pancreatic enzymes cannot reach the small intestine, cystic fibrosis impairs food digestion, and fat digestion is virtually stopped, resulting in fatty stools and an inability to absorb fat-soluble vitamins.

What is the digestive role of bile? What organ secretes bile?

Bile, secreted by the liver, acts as a detergent to mechanically break up large fat masses into smaller ones for enzymatic digestion.

What is the role of CCK in digestion?

CCK causes the pancreas to secretes enzymes-rich fluid and stimulates the gallbladder to contract and the duodenal papilla to open.

What are the major end products of the krebs cycle?

Carbon dioxide and reduced coenzymes.

What name is given to the process in which glucose is combined with oxygen to yield CO-2 , H2O, and ATP?

Cellular respiration

Other than for ATP production, list two uses of fats in the body?

Fats are used in synthesis of myelin sheaths and of cellular membranes, and as body insulation.

If you had your choice, would you prefer to have high blood levels of HDLs or LDLs? Explain why?

HDLs because they are headed back to the liver for breakdown and elimination from the body.

What us gluconeogenesis?

Making glucose from noncarbohydrate molecules, e.g., fats and proteins.

How do mechanical breakdown and digestion differ from each other?

Mechanical breakdown breaks food down physically by squeezing and pummeling it, Digestion uses enzymes to break the chemical bonds of the food molecules and release the units.

What is the most significant role that vitamins play in the body?

Most are coenzymes that work with enzymes to bring about metabolic reactions.

What is the sequential order (mouth to anus) of the digestive organs making up the alimentary canal?

Mouth, pharynx, esophagus, small, small intestine, large intestine, and anus.

Mary has a dry mouth; very little saliva is being secreted. Digestion of which type of food will be affected (decreased) by this situation?

Starch. Saliva contains salivary amylase,.

How does segmentation differ from peristalsis in terms of moving substances along the GI tract?

The main goal of segmentation is to mix the food thoroughly, though some propulsion occurs. Peristalsis is a propulsive activity.

Only one organ produces enzymes capable of digesting all groups of food. Which organ is this?

The pancreas.

Which muscular sphincter regulates the flow of chyme into the small intestine?

The pyloric sphincter

What happens during the buccal stage of swallowing

This is the voluntary stage in which the chewed food is pushed into the pharynx by the tongue.

What are two means of either maintaining or increasing body temperature?

Vasoconstriction of blood vessels serving the skin and shivering.

What are villi, and why are they important?

Villi are small extensions of the mucosa. They increase the surface area of the small intestines.

What are the two main functions of the large intestine?

Water absorption and absorption of some vitamin made by resident bacteria.

What are the major products of the electron transport chain?

Water and ATP

What occurs when your total caloric intake exceeds your TMR?

You gain weight (fat)

What are brush border enzymes?

enzymes located on the mircovilli of intestinal absorptive cells.