Chapter 3 Nutrition (Test 1)

hormones

a chemical messenger that is produced in one location in the body, released into the blood, and then travels to other locations, where it elicits responses.

saliva

secreted from salivary glands after the sight, smell, or presence of food. Contains lubricants, enzymes, and other substances

Identify the process that is regarded as absorption:

glucose moves into the cells of the small intestine and then into the blood stream

What is the most common cause of peptic ulcers?

infection w/ H. pylori

constipation

infrequent or difficult defecation

Organs involved in elimination of waste:

kidneys & associated structures

What are the 3 structural features of the small intestine that increases surface area?

large circular folds in the wall of the small intestine, villi, microvilli

What organ produces bile?

liver

ileocecal sphincter

located between the large and small intestine

lower esophageal sphincter

located where esophagus meets stomach

pyloric sphincter

located where stomach meets small intestine

Which two sphincters must be closed to keep food in the stomach?

lower esophageal & pyloric

Organs involved in digestion:

mouth, esophagus, stomach, intestines, pancreas, liver, gallbladder

The substance in the digestive system that lubricated, moistens, and protects the surface of the lumen is:

mucus

The diffusion of water across a membrane is called ______.

osmosis

What is the enzyme in saliva?

pepsin (dissolves proteins)

Identify the enzymes responsible for digestion of the macronutrients

pepsinogen activated into pepsin - digestive enzyme for protein; brush border secretes enzymes for carbs & proteins

Food moves through the esophagus by means of:

peristalsis

The rhythmic contractions that propel food through the GI tract are called _______.

peristalsis

An individual who eats food contaminated with bacteria may be protected form the ill effects of the bacteria because of the presence of:

phagocytes & lymphocytes

enzymes

protein molecules that accelerate the rate of specific chemical reactions without itself being changed

Active transport

requires energy to move nutrients from high to low concentration

Wastes are eliminated form the body by which systems?

respiratory, urinary, integumentary

diverticula

sacs or pouches that protrude from the wall of the large intestine

Heartburn results when the acidic contents of the stomach regurgitate into the esophagus creating a burning sensation, unlike the stomach, the cells lining the esophagus do not:

secrete mucus

What are the 4 main ways that nutrients are absorbed?

simple diffusion, osmosis, facilitated diffusion, active transport

What factors determine how fast food moves through the GI tract?

size of the meal, nutrition composition of the meal, whether the meal is composed of liquids or solids

Most digestion and absorption occur in the ____________.

small intestine

What is most likely to inhibit stomach secretions and stomach motility?

the entry of food into the small intestine

digestion

the process by which food is broken down into components small enough to be absorbed by the body

absorption

the process of taking substances from the gastrointestinal tract into the interior of the body

What causes constipation?

too little fiber or water, lack of exercise

The small intestine is the primary site of absorption for _____ and most nutrients.

water

Describe the causes of food allergies:

when the immune system reacts to non-harmful antigens called allergens

osmosis

when water moves in the direction that balances the concentration of dissolved particles

GERD

(gastrointestinal reflux disease) - chronic reflux of gastric acid in esophagus. May lead to esophageal bleeding, ulcers, cancer of esophagus if left untreated

Explain how the structure of the lim of the small intestine aids in the function of the small intestine.

It has many folds that aid in and speed up the rate of absorption

Describe the role of the cardiovascular system and lymphatic system in distributing nutrients and oxygen to the cells in the body and in the elimination of waste.

Cardiovascular- transports blood, which carries oxygen, nutrients & wastes Lymphatic- lipid-soluble nutrients empty into circulatory system

chemical digestion

Enzymes break down macromolecules into smaller molecules that can be absorbed

(T/F): All absorbed nutrients go directly to the liver

False

(T/F): Bile is important in the digestion and absorption of proteins.

False

(T/F): Each microvilli contains a capillary and a lacteal

False

(T/F): Enzymes signal the pancreas and gallbladder to secrete digestive substances into the small intestine.

False

(T/F): If the gallbladder is removed, bile is no longer produced by the body.

False

(T/F): In cellular respiration, glucose, fatty acids & amino acids are converted into carbon monoxide, water & energy.

False

(T/F): Osmosis of water results in water flowing in one direction only, from the lumen of the small intestine into the cell

False

(T/F): The secretion of digestive juices does not begin until food enters the mouth.

False

facilitated diffusion

Helping things across the membrane from an area of High Concentration to Low Concentration, with the use of a protein, without energy

simple diffusion

Process by which substances move from an area of higher concentration to an area of lower concentration. This process requires energy ALWAYS.

All of the following are true of microvilli:

They help increase the surface area available for absorption, They contain digestive enzymes, They are referred to as the brush border

(T/F): A food allergy occurs when the body's immune system reacts inappropriately to a protein found in a food.

True

(T/F): Foods like peanuts, tree nuts, milk, soy, and shellfish may contain proteins that act as foreign antigens leading to an immune reaction in the gastrointestinal tracts of some individuals.

True

(T/F): Microvilli increase the SA of the small intestine.

True

(T/F): Once nutrients are in the body, they are used either for energy or to make structural and regulatory molecules needed for growth and maintenance.

True

(T/F): The lymph vessels aid in the absorption and transport of fat-soluble vitamins and cholesterol.

True

epiglottis

a piece of elastic connective tissue that covers the opening to the lungs during swallowing

probiotics

a product that contains live bacteria, which when consumed temporarily lives in the colon and confers heath benefits on the host

prebiotics

a substance that pass undigested into the colon and stimulates the growth/activity of certain types of bacteria

mucus

a viscous fluid secreted by glands in the digestive tract and other parts of the body. It lubricates moistens, and protects cells from harsh environments

Discuss methods of absorption of nutrients from the small intestine.

absorption occurs in the villi and microvilli of the small intestine; bile helps in the absorption of fat

Examples of nutrients that require active transport to be absorbed from the lumen of the small intestine are:

amino acids and glucose

diarrhea

an intestinal disorder characterized by frequent/watery stools

peptic ulcer

an open sore in the lining of the stomach, esophagus, or upper small intestine. Commonly caused by the bacterium helicobacter pylori (h. pylori)

Describe celiac disease

auto-immune condition due to allergic reaction to protein in wheat, rye, barley which form: GLUTEN Causes the lumen of the small intestine to flatten (reduces SA ->malabsorption) Symptoms: bloating, abdominal cramps, weight loss, anemia

What causes diarrhea?

bacterial or viral infections, medications, chronic diseases

Discuss the role of microflora in maintaining health, including their function in metabolism of nutrients

beneficial bacteria, breaks down fiber, synthesizes some vitamins

People with celiac disease should avoid what?

breads, grains, wheat

The function of pancreatic proteases is to:

break down proteins in the small intestine

The enzyme salivary amylase begins chemical digestion of:

carbohydrates

The carrier molecule provides a ______ for the nutrient to cross the cell membrane.

channel

mechanical digestion

chewing food

What is a way that the endocrine system interacts with the digestive system?

endocrine system secretes hormones that regulate how much we eat

Which type o chemical speeds up the rate of reaction, without itself being altered or degraded?

enzymes

The _______ prevents food from entering the passageway to the lungs during swallowing.

epiglottis

What organ stores bile, used for the digestion of fat.

gallbaldder