Download Human Digestive System

Human Digestive System
Study Guide Answer
26. order of the organs of digestion:
• mouth
• esophagus
• esophageal sphincter
• stomach
• pyloric sphincter
• small intestine
• common bile duct/gall bladder/liver
• pancreatic duct/ pancreas
• appendix
• large intestine
• rectum
• anal sphincter
Ingestion
Ingestion is the process of placing food into your
mouth.
Mouth Digestion - Mechanical
• Mechanical (Physical) Digestion – breaking
the food into smaller and smaller pieces
without changing the chemistry of the food.
Only the size
of the pieces
changes!
Study Guide Answer
1. mechanical digestion- the process by which
food particles are physically broken down into
smaller pieces without changing the chemical
composition of the food. This process begins in
the mouth where the teeth masticate food and
continues in the stomach where the three layers
of muscle contract to grind the food up even
further. By making the pieces smaller, the
chemicals of the digestive process are able to
touch more surface area of the food.
Study Guide Answer
32. ingestion and mastication (chewing) –
Ingestion is the process of putting food into your
mouth. When you chew it, it is called
mastication.
Mouth Digestion - Chemical
• Chemical Digestion – amylase and ptyalin are
two salivary enzymes that break starches
down into simpler chemical substances called
sugars.
Study Guide Answer
15. starches and sugars – Starches are molecules made up of long
chains of sugars. When digested, starches are broken down into these
sugars. Starch digestion begins in the mouth, where the salivary
enzymes chemically attack the starches and break them down into
individual sugars. Sugars are chemicals that end in “ose.” Fructose,
lactose, maltose, and glucose are all sugars. A person should consume
only about 40 grams of sugar a day.
16. carbohydrates – Carbohydrates are another name for starches.
Complex carbs is a term given to starches that have not been
processed. Whole grains are an example of complex carbohydrates.
Simple carbohydrates are usually processed whole grains. Wheat is
stripped of its outer bran and then ground and bleached. This becomes
white flour from which many crackers, breads, rolls, pizza crusts, and
cookies can be made. It has to be vitamin fortified since the nutritious
bran has been removed. Carbohydrates are also found in beans or
other starchy vegetables. When digested, the simple sugars are
released and absorbed into the blood stream.
Study Guide Answer
2. chemical digestion – the process by which
food particles are chemically altered so that they
can be more easily used by the body. Many
organs of the body make chemicals of digestion.
The salivary glands, stomach, liver, and pancreas
all make digestive chemicals.
Study Guide Answer
18. glands and secretions – There are many
groupings of specialized cells called glands that
make chemicals that the body needs. Sweat
glands in the skin, salivary glands in the cheek
and under the tongue, and the pituitary gland in
the brain, are all examples of glands.
Saliva and Salivary Enzymes
When you chew (masticate)
you make the pieces smaller
and you mix the food with the
saliva.
Saliva contains special
chemicals called enzymes that
immediately start to chemically
digest starches into sugars.
Study Guide Answer
3. saliva and salivary glands (parotid and
sublingual) – the saliva-producing glands make
saliva (spit). This keeps your mouth moist so
that you can talk and chew food. Saliva makes
food easier to swallow. Saliva contains enzymes
that start the process of chemical digestion on
starches. Both amylase and ptyalin are salivary
enzymes that help chemically break down
starches into sugars.
Study Guide Answer
4. amylase and ptyalin – these two salivary enzymes
chemically change starches (bread, pasta, crackers,
cookies, etc.) into simpler sugars that can be
absorbed by the bloodstream.
5. enzymes – these are special chemicals that act on
specific foods to alter them chemically. Enzymes are
made by the body by specific organs. The pancreas
makes pancreatic juice which contains enzymes to
digest all types of foods.
The Bolus is Swallowed
• As you continue to chew, the
food mass becomes a ballshaped bolus which is
ultimately swallowed.
• The bolus travels down the
esophagus and into the
stomach.
http://resources.schoolscience.co.uk/abpi/dig
estion/images/5d4oesoph.gif
Study Guide Question
17. smooth muscle – This type of muscle is NOT
striated (striped). It is NOT responsible for the
movement of bones or the beating of the heart.
It is found in the walls of the digestive system,
sphincters, sweat glands, eye pupils, etc.
Peristalsis
• Peristalsis is the wavelike contraction of the
smooth muscles lining
the digestive tract.
• This squeezing action
moves along the entire
tract and helps push
the digesting food in
one direction.
http://www.emc.maricopa.edu/faculty/farabe
e/biobk/peristalsis.gif
Study Guide Answer
6. peristalsis - this is a wave-like contraction of
the smooth muscle lining the digestive tract.
Peristalsis begins in the esophagus when you
swallow. It continues into the stomach and then
to the small intestine and large intestine.
Peristalsis helps move food along the digestive
tract so that it can be digested, absorbed, and
ultimately the unused food or waste eliminated.
Pharynx – The Back of the Mouth
• The area in the back
of the mouth is called
the pharynx. It
connects the mouth
and sinus/nose to the
esophagus.
• This area is
sometimes called the
throat.
http://www.singingforsnorers.com/images/dia
gram-of-pharynx.gif
Uvula
http://www.health.com/health/static/hw/med
ia/medical/hw/hwkb17_073.jpg
Study Guide Answer
7. uvula (the "punching bag" organ that hangs
down) – The uvula is the small finger-like
projection that hangs down in the back of the
mouth. It acts as a sensory organ to let you
“sense” when you have swallowed.
Epiglottis
http://www.umm.edu/graphics/images/en/19595.jpg
Study Guide Answer
7. The epiglottis is the tissue flap that covers the
trachea (wind tube that goes to the lungs). It
prevents you from choking on food as you
swallow. If food enters the trachea, it can cause
gagging, choking, or can even block the airway.
Sphincters
• A sphincter is a ring of smooth muscle that
can open and close to regulate the
movement of food through the digestive
system.
• The sphincter between the stomach and
the esophagus is called the esophageal
sphincter.
• The sphincter between the stomach and
the small intestine is called the pyloric
sphincter.
Study Guide Answer
19. sphincter – Sphincters are rings of smooth muscle that can
relax and close or contract and open the hole that lies in the
middle of the sphincter. The pupils of the eye, the esophageal
and pyloric sphincters on either end of the stomach, the anal
sphincter at the end of the digestive system are all examples.
20. esophageal sphincter – This ring of smooth muscle is
located at the entrance to the stomach. It closes to keep the
contents of the stomach in the stomach.
21. pyloric sphincter – This sphincter is located at the end of
the stomach where the small intestine begins. It opens and
closes to regulate the quantity of chyme released into the
small intestine from the stomach.
Esophageal Sphincter
The Entranceway to the Stomach!
Closed Sphincter
Open Sphincter
http://www.becomehealthynow.com/article/b
odydigestive/727
Study Guide Answer
8. esophagus and trachea (which is which?) –
the esophagus is the food tube and it takes food
from the mouth to the stomach. It is lined with
smooth muscle rings that contract to allow for
peristalsis. The trachea is the air tube that takes
air from the nose and mouth to the lungs and
vis-versa. The trachea is semi-rigid and lined
with rings of cartilage.
Stomach Digestion - Mechanical
• Mechanical Digestion
– the stomach has
three layers of
smooth muscle, all
going in different
directions.
• These muscles can
contract and relax,
allowing the stomach
to grind food up into
smaller pieces.
http://www.health-choices-forlife.com/images/stomach_diagram.jpg
Stomach Digestion - Chemical
• The stomach makes hydrochloric
acid that works with a stomach
enzyme called pepsin.
• Together these two chemicals
make up what is called gastric
juice.
• Gastric juice chemically digests
proteins.
Study Guide Answer
29. acid and base pH - neutralizing stomach acid –
The inside of the stomach must remain acidic so
that the gastric juice can work properly to digest
proteins. However, sometimes the stomach acid
levels become too strong and a person gets what is
called “acid indigestion.” To decrease the quantity
of acid in the stomach, an antacid medication can
be taken. These medicines are chemically
formulated to be “basic” which neutralizes the
stomach acid relieving the burning symptoms of
acid indigestion.
Digestion of Proteins
• Proteins are made up of long chains of amino acids.
• When digested, the chain is broken and the individual
amino acids are released.
• The body then reassembles the amino acids to make
new proteins that your body can use.
http://www.agewa
tchers.net/images/
amino_acid_chain.j
pg
A Little More Complicated Than That
• Image of a single amino acid:
http://www.chemistryexplained.com/images/chfa_02_img0371.jpg
Image of Different Types of Proteins
Simplest Type
Most Complex Type
http://www.accessexcellence.org/RC/VL/GG/images/protein.gif
Study Guide Answer
9. hydrochloric acid (HCl) – this strong acid is made by
the cells of the stomach. It works with pepsin (a stomach
enzyme) to begin the chemical digestion of proteins.
10. pepsin – this stomach-made enzyme is specific for
the digestion of proteins. It works in an acid environment
only. Therefore, the hydrochloric acid of the stomach is
necessary for the pepsin to work to digest proteins. When
proteins are chemically digested, they are broken apart
into their amino acids. The body can then absorb the
amino acids and reassemble them to make new proteins
that the body can use.
Study Guide Answer
11. gastric juice – this is the combination of
hydrochloric acid and pepsin made by the
cells that line the stomach. The gastric juice
does not harm the protein in the walls of the
stomach because of the mucus (also made by
stomach cells) that coats the entire inside of
the stomach wall.
Study Guide Answer
14. proteins and amino acids – Proteins are molecules
made up of long chains of amino acids. The order and
types of amino acids in the chain determines what type
of protein will be made. The healthy diet consists of many
different types of proteins. Chemical digestion of protein
begins in the stomach where hydrochloric acid and pepsin
work together. When the digestive system breaks apart a
protein, the individual amino acids can be reassembled to
make a new protein that the body can use. A teenager
needs about 40 – 50 grams of protein a day. Without
protein we cannot make healthy cells, especially muscle
cells.
Study Guide Answer
12. calorie – A calorie is a unit of measure for the
quantity of heat energy it takes to raise one
kilogram of pure water one degree Celsius. Foods
are actually combusted (burned in the presence of
oxygen) in special laboratory devices called
calorimeter to see how much heat energy they
release. This is how a food’s calorie content is
determined. As your body moves and works during
the day, you use up the calorie content of the food
you have eaten. If you consume more calories than
you use up, you gain weight in the form of fat. If
you use up more calories than you consume in the
food you eat, then you loose weight.
Pyloric Sphincter
The pyloric
sphincter (valve)
is located where
the stomach ends
and the small
intestine begins.
http://www.naturalhealthschool.com/img/stomach.gif
Small Intestine Digestion - Chemical
• Helper organs contribute digestive
enzymes into the small intestine to
enhance the chemical digestion of
food.
• The liver makes bile which is stored in
the gall bladder.
• The pancreas makes pancreatic juice.
Helper Organs
The helper organs are the liver, gall bladder, and
pancreas.
Food DOES NOT pass through the helper organs.
http://www.caring4cancer.com/uploadedImages/Website-C4C-20/Liver/The_Basics/Liver2.gif
Ducts Transport Chemicals
Bile Duct - The gall bladder releases bile
into the bile duct. The duct connects to
and releases the bile into the upper part
of the small intestine.
Pancreatic Duct - The pancreatic duct
transports pancreatic juice to the upper
part of the small intestine.
Fats and Oils
13. fats and oils – There are many different types of fats. Oils
are fats that are liquids at room temperature. The chemical
composition of fats makes a difference in how our bodies use
them. Fats are a necessary part of human nutrition and
health. Without fats we could not make cells, hormones, and
our hair and skin would be very dry. Fully saturated or
hydrogenated trans fats are not good for us. Many saturated
fats are found in animal products (meat and dairy). Trans fats
are artificially made by bonding extra hydrogen molecules to
an already existing fat. Unsaturated fats are healthier. Mono
and polyunsaturated oils are good for us. Your total diet
should not consist of more than 41 – 58 grams of total fats of
all kinds in any one day.
Duodenum of the Small Intestine
• The first 29
cm of the
small
intestine is
called the
duodenum.
http://static.howstuffworks.com/gif/adam/ima
ges/en/annular-pancreas-picture.jpg
Duodenum and Ducts
• The bile duct
and the
pancreatic
duct connect
to the
duodenum.
http://www.caring4cancer.com/uploadedImages/Website-C4C-20/Liver/The_Basics/Liver2.gif
Study Guide Answer
27. helper organs – What are they and what do
they do?
• Liver – makes the emulsifying chemical bile which
mechanically digests fats and oils.
• Gall Bladder – small organ attached to the liver
that stores the bile.
• Bile Duct – a tube that attaches the gall bladder
to the duodenum. The bile is transported down
the bile duct and is squirted onto the chime as it
passes. The stimulation of this release of bile is
triggered by the fats and oils in the chime.
Study Guide Answer
22. bile – The green chemical bile is made by the liver and
stored by the gall bladder. It travels to the duodenum by the
bile duct. It is an emulsifier. An emulsifier takes fat and oil and
causes them to break apart mechanically into smaller and
smaller globules (spheres). By emulsifying the fats and oils
eaten in the diet, the body can better absorb them into the
blood stream. Bile is a chemical that actually causes
MECHANICAL digestion of a nutrient. The chemical
composition of the fat or oil is not changed, but the sizes of
the globules are just made smaller and smaller.
23. gall bladder and the bile duct – The gall bladder is the
organ that is attached to the liver that stores bile (made in the
liver). The bile duct is a tube that allows the bile to be
transported from the gall bladder to the duodenum.
Study Guide Answer
24. pancreatic juice and the pancreatic duct – The
pancreas makes a chemical called pancreatic juice. This
liquid chemical is transported to the duodenum by the
pancreatic duct. When food passes by the duct, it is
squirted by the liquid pancreatic juice. Pancreatic juice
chemically digests all different types of foods.
25. pancreas – This helper organ sits behind and below
the stomach. It makes insulin which enters the
bloodstream and allows glucose to be transported into
cells. It also makes pancreatic juice which is a very strong
digestive chemical that is squirted onto food as it passes
the opening of the pancreatic duct in the duodenum.
Inside the Small Intestine
• Villi are finger-like
projections that
increase the
surface area of
the inside of the
small intestine.
http://www.astrographics.com/GalleryPrints/D
isplay/GP2134.jpg
Study Guide Answer
35. purpose and structure of villi and micro-villi
in the small intestine – The villi are finger-like
projections that line the entire inside of the
small intestine. Villi are made of cells. Hundreds
of them (just like your finger is made of cells). If
all the villi were cut open and spread out, the
surface area would be as large as a tennis court.
Micro-Villi
• Every villi is totally coated with micro-villi to
increase absorption even more!
Inside the Small Intestine
http://www.nutters.com/villus.jpg
The Appendix
• The appendix is
located in the area
where the small
intestine meets
the large intestine.
http://www.health-informationfitness.com/images/appendix.gif
What Is the Appendix For?
• It is NOT where
humans used to
digest twigs and
leaves.
• It IS now considered
to be a place where
the “good” bacteria
can be stored for
emergencies.
Click on the image above to learn more.
Large Intestine – The Colon
• The large intestine is
where most of the water
is absorbed back into the
blood stream.
• The large intestine is
where the “good”
bacteria live. These small
organisms work to digest
the cellulose and to
make vitamins.
http://www.pillfreevitamins.com/images/colon.jpg
Inside the Large Intestine
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Rectum
• The rectum holds
feces (poop) until
it is time for it to
be eliminated.
http://0.tqn.com/d/coloncancer/1/0/8/3/Rect
um.300x300.jpg
Study Guide Answer
36. rectum – This part of the digestive tract is
after the large intestine and before the anal
sphincter. Fecal material is stored in the rectum
until you go to the bathroom.
Anal Sphincter
• The anal sphincter
is the last
sphincter of the
digestive system.
• It allows the feces
to be held inside
until they can be
eliminated from
the body.
http://oxfordpelvicfloor.co.uk/Images/AnatomyImage1.jpg
Study Guide Answer
37. anal sphincter – This is the last sphincter of
the digestive system. It is located between the
rectum and the outside of the body. This
sphincter holds in your solid wastes until you
choose to eliminate them.
Study Guide Answer
28. voluntary vs. involuntary muscle movement
– Voluntary muscle movement is controlled by
your motor cortex of the brain. You think about
moving a body part, a signal leaves the brain
and travels to the appropriate skeletal muscles
and the body part moves when the muscles
contract. Involuntary muscle movement usually
involves both smooth muscle and cardiac
muscle. These muscles are moving as needed
without conscious thought.
Study Guide Answer
30. diffusion (passive transport) and H L concentrate gradient
compared to active transport – Diffusion is the movement of
molecules through the semi-permeable cellular membrane into and
out of the cytoplasm of the cell. Diffusion is considered passive
transport since the cell does not need to make special transport
molecules for it to occur. Active transport, on the other hand, involves
the movement of larger and more complicated molecules into and out
of a cell. Therefore the cell has to expend energy to make the special
transport molecules that will open up the cell membrane and/or carry
the large molecules into and out of a cell.
31. absorption/cell membrane/capillary beds – Like a sponge soaking
up water, the wall lining the inside of the small and large intestine are
able to absorb nutrients from the food you have eaten.
Study Guide Answer
33. cellular respiration and ATP production (aerobic and
anaerobic) – The body cells use glucose to make ATP, a
chemical that is used for cellular energy.
• Aerobic = C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy (34-36 ATP + heat)
• Anaerobic = 2ATP"+ C 6H 1206 Enzymes 2CH3CH2OH + 2CO2 + 4ATP
34. mitochondria – This cell organelle is called the
“powerhouse of the cell” because this is the place
where cellular respiration occurs.