Chapter 3

The stomach holds food for

2-4 hours

Sphincters**(know all of them)

A muscular and circular valve in the GI tract that controls the flow of food stuff

Some nutrients such as glucose and amino acids must be absorbed actively through _____.

Active transport

Pepsin *

An enzyme that breaks down proteins

Last sphincter of the body

Anal sphincter

_____ may help indigestion

Antacids and acid controllers

The pancreas also produces ___, which is needed to neutralize chyme

Bicarbonate(very acidic)

Gallbladder stores ___ that is produced in the liver

Bile *

Vomiting

Body's adaptive mechanism Dehydration is a concern. May be self-induced as in eating disorders

Found at the end of the esophagus

Cardiac sphincter

Prevents reflux of stomach content to cause heartburn and ulcers

Cardiac sphincter

"Waste"

Cecum(first part of large intenstine) Ascending colon Transverse colon Descending colon Sigmoid colon

Stimulated by the presence of fat and protein in the duodenum

Cholecystokinin

The ____ passes by the opening of the appendix

Chyme

The stomach adds gastric juices and grinds the bolus to a semi liquid mass called

Chyme *

Saliva

Comes from salivary glands, moistens food

Constipation

Defecation habits are different among people. Many causes are possible. Hemorrhoids may be a problem. Diverticulosis is a condition in which the intestinal walls weaken and bulge. The bulging pockets are called diverticula. Diverticulitis is a worsened condition and requires intervention. Use of laxatives, enemas and mineral oil may not be necessary with lifestyle changes.

By the time food crosses the ____, most nutrients are absorbed

Duodenum

Cholecystokinin originates from the

Duodenum

Chyme

Duodenum Ileum Jejunum

Final stage of digestion

Energy-yielding nutrients are disassembled for absorption. Vitamins, minerals and water can be absorbed. Undigested residues, including some fibers, continue through the digestive tract and form stool. Recycling of usable materials

Some nutrients, such as the water-soluble vitamins, are absorbed by _______.

Facilitated diffusion

T/F The environment in the stomach is poorly acidic due to the hydrochloric acid

False, very acidic

Rectum

Fecal material is stored Stimulates elimination

Choking

Food becomes lodged in the trachea. The larnyx cannot make sounds. The Heimlich maneuver may need to be used.

Diarrhea

Frequent, loose, watery stools Irritable bowel syndrome or colitis is one of the common GI disorders.

Stimulates contraction of gallbladder and flow of bile into the small intestine*

Function of Cholecystokinin

Stimulates the release of enzyme rich pancreatic fluids*

Function of Cholecystokinin

Heartburn and "Acid Indigestion"

Gastroesophageal reflux is the backward flow of stomach contents into the esophagus

The _____ of the stomach wall secrete mucus to protect the walls of the stomach from the high acidity levels that are measured by pH units.

Goblet cells

Strategies of constipation

High-fiber diet Increased fluids Exercise regularly. Respond quickly to the urge to defecate.

Between the small and large intestine

Ileocecal sphincter

Prevents large intestine content (bacteria) back up into the small intestine

Ileocecal sphincter

The Secretions of Digestion

Includes digestive enzymes that act as catalysts in hydrolysis reactions

Millions of bacteria colonize the

Large intesntion

The large intestine

Little digestion occurs

The Stomach is located between the _____ sphincter and _____sphincter

Lower esophageal, pyloric

The Pancreas

Manufactures digestive enzymes

the microscopic hairlike projections on each villi

Microvilli

Food Bolus

Mouth Esophagus Stomach

Accessory Organs

Pancreas Gallbladder Liver

_____is the action pushing the intestinal contents along

Peristalsis**

Between the stomach and small intestine

Pyloric sphincter

Controls the amount of stomach content into the small intestine

Pyloric sphincter

Strategies to avoid diarrhea

Rest Drink fluids Medical help is needed if it persists.

Salivary envymes

Salivary amylase Lingual lipase

Stimulated by the presence of acidic chyme and the presence of peptones in the duodenum

Secretin

Hormones

Secretin Cholecystokinin

Function of the stomach

Secretion of hydrochloric acid and gastric enzymes, mainly pepsin *

Some nutrients, such as water and small lipids, are absorbed by _______.

Simple Diffusion

Nutrients can be absorbed through

Simple diffusion Facilitated diffusion Active transport

Strategies to avoid choking

Small bites Chew thoroughly. Don't talk or laugh with food in the mouth. Don't eat when breathing hard.

Controls the amount of bile into the small intestine

Sphincter of Oddi

Function of secretin *

Stimulates the secretion of bicarbonate from the pancreas

Belching and Gas

Strategies Eat slowly. Chew thoroughly. Relax while eating. Watch bothersome foods.

______ has the strongest muscles in the GI tract

The Stomach

____ transports bile from the gallbladder into the small intestine

The common bile duct

_____is the flexible muscular tube from mouth to anus

The gastrointestinal (GI) tract

Beginning of the digestive system

The mouth

Chyme *

The semiliquid mass of food

The esophagus

Tube that leads the bolus to the stomach. There is a sphincter at the upper and lower (also known as the cardiac sphincter) ends of the esophagus.

the fingerlike projections within the folds of the small intestine that move in a wave-like pattern to trap nutrients

Villi

intrinsic factor

Vital for vitamin B12 absorption Secreted by the stomach

________ are absorbed in the large intestine

Water, sodium and potassium

The Circulatory System

Water-soluble nutrients and small fats enter the bloodstream, are routed to the liver before being transported to the cells

The Muscular Action of Digestion is under ____ control

autonomic

Small mouthful of food that are swallowed are called a

bolus *

Pancreatic lipase *

breaks down lipids

Pancreatic protease *

breaks down proteins

Pancreatic amylase *

breaks down starch

Salivary amylase *

breaks down starch into

Results in the formation of ____

chyme *

Stomach action involves

circular, longitudinal, and diagonal muscles

The epiglottis *

closes to prevent food from entering the pharynx(lungs)

Gastric juice

comes from the gastric glands and includes hydrochloric acid

Segmentation

contractions by circular muscles that contract and squeeze contents to promote mixing with digestive juices Mainly occurs in the intestine

The hepatic portal vein

directs blood from the GI tract to the liver

Secretin originates from the

duodenum

Hiccups are triggered by

eating or drinking too fast.

Function of Fat-soluble nutrients*

enter the lymphatic system*, bypass the liver at first and eventually enter the vascular system.

What does the enormous surface area of the small intestine do?

facilitates nutrient absorption

The small intestine receives digestive juices from the

gallbladder and the pancreas

The pancreas produces

glucagon and insulin

The large intestine (colon) begins at the _____ and ends at the_____.

ileocecal valve, rectum and anus

Pancreatic juice contains

intestinal enzymes (carbohydrase, lipase, protease) and bicarbonate

Bile is produced by the ___, stored in the _____, and acts as an emulsifier to suspend fat

liver, gall bladder

Digestion in the mouth involves

mastication (chewing), the stimulation of taste buds, and swallowing.

Lingual lipase

more effective in breaking down milk fats in infants

Function of sphincter contractions

open and close passageways. This prevents reflux and controls the passage of contents

Mucus layer

prevents autodigestion

Bile

produced by the liver, stored in the gall bladder, and acts as an emulsifier to break down fat

The pyloric sphincter

regulates the flow of partially digested food into the small intestine.

Cholecystokinin *

stimulates release of bile from the gallbladder

The hepatic vein

takes blood from the liver to the heart.

The three segments of the small intestine

the duodenum, the jejunum and the ileum.

Digestion

the process of breaking down foods into nutrients to prepare for absorption

Crypts

the tubular glands that lie between the intestinal villi Digestible secretions

Bacteria produce

vitamins - biotin and vitamin K

Capacity of the stomach

~4 cups