Hun 3- Chapter 3: Digestion, Absorption, and Transport

what else can affect a food's flavor

-aroma -appearance -texture -temperature

the chyme travels down the small intestine through its 3 segments: name them

-duodenum -jejunum -ileum *almost 10 feet of tubing coiled within the abdomen

what occurs in the lower portion of the stomach

-juices are added to the bolus and it grinds it to a semiliquid massed called chyme

what 3 types of muscles does the stomach have?

-longitudinal muscles -circular muscles - additional third layer ; diagonal muscles that also alternately contract and relax

what is the role of segmentation

-mix the chyme and promote close contact with the digestive juices and the absorbing cells of the intestinal walls before letting the contents move slowly along

Sphincter contractions are responsible for

-periodically opening and closing -controlling the pace of the movement of the GI tract contents

What does saliva contain and and what nutrient does it digest first

-saliva contains water, salts, mucus, and enzymes that initiate the digestion of carbohydrates

what are the 5 basic

-sweet -sour -bitter -salty -umami

describe how food would go down the esophagus

-the food would now be considered a bolus -During swallowing, the upper esophageal sphincter opens. -The bolus then slides down the esophagus , which passes through a hole in the diaphragm to the stomach -The lower esophagus sphincter at the entrance to the stomach closes behind the bolus so that is proceeds forward and doesn't slip into the esophagus (challenge 3)

Each cell in the body needs a continuous supply of many specific nutrients to maintain itself and carry out its work. Describe how this process works

-the nutrients comes from food we eat -food must be broken down mechanically and chemically -then the body's cells can use the nutrients

The breakdown of food intro nutrients requires secretions from five different organs: what are they?

-the salivary glands -stomach -the pancreas -the liver ( via the gallbladder) -and the small intestine

what is the gastric juice made up of

-water -enzymes -hydrochloric acid (which primarily acts as a protein digestion )

in the process of digestion, the body overcomes many challenges without any conscious effort. what are they? 1st: Multiple tasks of the mouth

1. Human beings breathe, eat, and drink through their mouths. Air must go to the lungs; food and liquid must go to the stomach. The throat must be arranged so that swallowing and breathing don't interfere with each other

`review of sphincter contraction

1. at the top of the esophagus, the upper esophageal sphincter opens in response to swallowing 2. At the bottom of the esophagus, the lower esophageal sphincter (sometimes called the cardiac sphincter because of its proximity to the heart) prevents reflux of the stomach contents. 3. At the bottom of the stomach, the pyloric sphincter, which stays closed most of the time, holds the chyme in the stomach long enough for it to be thoroughly mixed with gastric juice and liquefied. -The pyloric sphincter also prevents the intestinal contents from backing up into the stomach 4. At the end of the small intestine, the ileocecal valve performs a similar function, allowing the contents of the small intestine to empty into the large intestine 5.Finally, the tightness of the rectal muscle acts as a kind of safety device; together with the two sphincters of the anus, it prevents continuous elimination

What is the umami taste?

A savory flavor commonly associated with monosodium glutamate

what is a blind sac about the size of my little finger and houses bacteria and lymph

Appendix

At the beginning of the small intestine, the chyme bypasses the opening from what / also place of lubrication

At the beginning of the small intestine, the chyme bypasses the opening from the common bile duct (challenge 4 : lubrication )

the acidity (pH) of the gastric juice is

Below 2

in the process of digestion, the body overcomes many challenges without any conscious effort. what are they? 2nd: Passage through the diaphragm

Below the lungs lies the diaphragm, a dome of muscle that separates the upper half of the major body cavity from the lower half. The body needs a passageway that will allow food from the mouth to pass through the diaphragm to reach the stomach below

Conducts bile from the gallbladder to the small intestine

Bile duct

the digestive system is finely coordinated and fully integrated with which one of the other systems: A) Circulatory systems B) Nervous system C) Hormonal systems D) All of the above

D) all of the above

Separates the abdomen from the thoracic cavity. what structure is this?

Diaphragm

Allow passage from mouth to esophagus and from esophagus to stomach; prevent backflow from stomach to esophagus and from esophagus to mouth. what is this structure

Esophageal sphincters

in the process of digestion, the body overcomes many challenges without any conscious effort. what are they? 5th: Digestive enzyme functions

For digestive enzymes to work, foods must be broken down into small particles and suspended in enough liquid to that every particle is accessible. Once digestion is complete and nutrients have been absorbed from the GI tract into the body, the remaining waste must be excreted. Excreting all the water along with the solid residue, however, would be both wasteful and messy. some must be withdrawn , leaving a solid waste product that is easy to pass

Allows passage from small to large intestine; prevents backflow from large intestine. what is the structure?

Ileocecal valve (sphincter)

in the process of digestion, the body overcomes many challenges without any conscious effort. what are they? 7th: Excretion of waste

Once waste matter has reached the end of the GI tract, it must be excreted, but it would be inconvenient and embarrassing if this function occurred continuously. Evacuation needs to occur periodically

when a mouthful of food is swallowed , it passes through what structure?

Pharynx

what is the function of the rectum?

Stores waste prior to elimination

in the process of digestion, the body overcomes many challenges without any conscious effort. what are they? 3rd: Steady movement

The contents of the digestive tract should be kept moving forward, slowly but steadily, at pace that permits all reactions to reach completion

in the process of digestion, the body overcomes many challenges without any conscious effort. what are they? 6th: Protection

The digestive enzymes are designed to digest carbohydrate, fat, and protein. The cells of the GI tract are also made of carbohydrate, fat, and protein. The cells must be protected against the power

in the process of digestion, the body overcomes many challenges without any conscious effort. what are they? 4th: Lubrication of food

To move through the system, the food must be lubricated with fluids. Too much would form a liquid that would flow too rapidly; too little would form a paste too dry and compact to move at all. The amount of fluids must be regulated to keep the intestinal contents at the right consistency to move along smoothly

the hydrochloric acid is so strong that is would destroy the cells of the stomach as well; however, what is used to protect the stomach from damage from the acid

To protect themselves from gastric juice, the cells of the stomach wall (in fact, of the entire gastrointestinal lining) secrete mucus

when stimulated, the taste buds detect one or a combination of the five basic taste sensation. True or False

True

what is the function of the trachea

allows air to pass from the mouth to the lungs

what do all these by organs provide that allows for the breakdown of food intro nutrients

an abundance of water and variety of enzymes

does the waves of contraction normally ripple along the GI tract at varying rates or the same rate?

at varying rates and intensities depending on the part of the GI tract and on whether food is present

what is a mouthful of food called when it has been chewed and swallowed

bolus

when the ring relax and the long muscles tighten, the tube

bulges

what is the function of the epiglottis

bypass the entrance to the lungs; closes off the airway so that coking doesn't occur when swallowing; thus resolving the first challenge

a compound that facilitates chemical reactions without itself being changed in the process.

catalyst

what is peristalsis

circular/ring muscles and longitudinal muscles surrounding the GI tract working together continuously to push intestinal contents along

the large intestine is also known as

colon

The Muscular Action of Digestion such as chewing, addition of saliva, the action of the tongue transform food into a coarse mash that can be swallowed all occur without

concerted effort on your part

when the rings tighten and longitudinal muscles relax, the tube is

constricted

proteins found in digestive juices that act on food substances, causing them to break down into simpler compounds are known as

digestive enzymes

the function of the pharynx

directs food from mouth to esophagus

an is a protein that facilitates a chemical reaction- making a molecule, breaking a molecule apart, changing the arrangement of a molecule, or exchanging parts of molecules

enzyme

the word ending -ase denotes an

enzyme

The gastrointestinal (GI) tract is a flexible muscular tube that extends from the what to what?

extends from the mouth, through the esophagus, stomach, small intestine, large intestine, and rectum to the anus

When is the only time the tongue can taste

fluids must be involved so that the tongue can test it; only particles that are involved in solution can react with taste buds

Stores bile until needed; what structure is this

gallbladder

what does the gastric gland secrete

gastric juice

The enzymes involved in digestion facilitate a chemical reaction known as

hydrolysis - the addition of water (hydro) to break (lysis) a molecule into smaller pieces

having traveled the length of the small intestine, in the large intestine the remaining contents arrive at another sphincter called

ileocecal valve

what is located at the beginning of the large intestine (colon) in the lower right side of the abdomen and receives the arrival of the chyme after it leavings the small intestine

ileocecal valve

Where does the process of digestion begins ?

in the mouth

where is the gastric gland located

in the stomach

what are the role of salivary gland in digestion

it allows for the food the be swallowed with ease by secreting saliva

what is the function of the tongue

it provide taste sensation and moves food around the mouth facilitating chewing and swallowing

little by little, the stomach transfers the food to its

lower portion

what is the inner space within the GI tract that is continuous from one end to the other

lumen

what is a thick, slippery, white substance that coats the cells, protecting them from the acid, enzymes, and disease causing bacteria that might otherwise harm

mucus

does ALL material that pass through the GI tract get digested and absorbed

no many material don't get digested or absorbed

when does a nutrient or substance enter the body proper?

only when a nutrient/substance finally penetrates the GI tract's wall does it enter the body proper

what is the pyloric sphincter responsible for?

opens into the small intestine and then closes behind the chyme

Manufactures enzymes to digest all energy-yielding nutrients and releases bicarbonate to neutralize acid chyme that enters the small intestine. what structure is this?

pancreas

Conducts pancreatic juice from the pancreas to the small intestine. what structure is this?

pancreatic duct

what is the function of the esophagus

passes food from the mouth to the stomach

The entire GI tract is ringed with

peristalsis

what structure is known to be a short tube that is shared by both the digestive system and the respiratory system

pharynx

then, bit by bit, the stomach release the chyme through the

pyloric sphincter

Allows passage from stomach to small intestine; prevents backflow from small intestine. what structure does this?

pyloric structure

what is the protective role that saliva plays

saliva protects the teeth and the lining of the mouth, esophagus, and stomach from substances that might cause damage

what is it called when circular muscles of the intestines rhythmically contract and squeeze their content

segmentation

what type of muscle does the esophagus have at each end

sphincter muscle

Role of salivary gland

squirt just enough saliva to moisten each mouthful of food so that pass easily doen the esophagus

3 factors that interferes with normal GI tract contractions

stress, medicines, and medical conditions

negative of hydrochloric acid

the acid is so strong that it causes the sensation of heartburn if it happens to reflux into the esophagus

if the content does take that opening to the colon, where will it end up?

the appendix

What is digestion?

the body's ingenious way of breaking down foods intro nutrients in preparation for absorption

as the intestinal content pass to the rectum, what is the function of the colon

the colon withdraws water, leaving semisolid waste (challenge 5)

the common bile duct drips fluids into the small intestine from which two organs outside the GI tract?

the gallbladder and the pancrease

enzymes are often identified by

the organ they come from and the compound they work on. Gastric lipase, for example, is a stomach enzyme that acts on lipids, whereas pancreatic lipase comes from the pancreas (and also works on lipids).

how does waste ultimately release?

the rectal muscles relax and the two sphincter of the anus opens to allow passage of the waste

the content normally avoids going through the opening that leads to the colon and instead travel through the large intestine; when this happens, the content goes to what struture

the rectum

Churns, mixes, and grinds food to a liquid mass; adds acid, enzymes, and fluid. what structure does this?

the stomach

out of all of the GI tract organs, which has the thickest walls and strongest muscles

the stomach

positive of hydrochloric acid

the strong acidity of the stomach prevents bacterial growth and kills most bacteria that enters the body with food

how does the waste get hold back until it's time to defecate

the strong muscles of the rectum and anal canal

the 3 sets of muscles in the stomach work to force what? what ultimately happens?

timing the release of chyme/ force the chyme downward; however, what ultimately happens is the chyme does go down at first; the pyloric sphincter remain tightly closed until the stomach wall releases a gastric juice to liquefied the chyme and allow to flow through little by little . at this point, the chyme no longer represents food

what is the function of the mouth

to chew and mixes food with with saliva

True/False the human body surrounds the GI tract

true

in the process of digestion, the body overcomes many challenges without any conscious effort. what are they?

try to list them by yourself

as a catalyst, the enzyme itself remains

unchanged

Two sphincter muscles control movement

upper esophageal sphincter and lower esophageal sphincter

The stomach retain the bolus for a while in its

upper portion

does the content pass through ANOTHER opening after entering the colon

yes