Transcript Digestive System

Digestive System
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SAP4
Students will analyze the physical, chemical,
and biological properties of process systems as
these relate to transportation, absorption and
excretion, including the cardiovascular,
respiratory, digestive, excretory and immune
systems.
• a. Describe the chemical and physical
mechanisms of digestion, elimination,
transportation, and absorption within the body
to change food and derive energy.
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Essential Question
How can I describe the physical, chemical, and
biological properties of process systems as
they relate to transportation, absorption and
excretion, including the cardiovascular,
respiratory, digestive, excretory and immune
systems?
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Digestive System
• Organs are separated into two main groups:
– Alimentary canal—digest and absorb food
• Also known as the gastrointestinal tract
– Accessory digestive organs—assist alimentary
canal
• Teeth, tongue, and digestive glands
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6 Basic Functions:
• Ingestion
– Taking in food and liquid by mouth
• Secretion
– Oozing out of water, acid, enzymes, etc.
• Mixing/Propulsion
– Contractions and relaxations of muscles
• Digesting
– Breaking down food into smaller pieces
• Absorption
– Taking in needed nutrients, water, etc.
• Defecation
– Removal of feces (indigestible parts)
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Alimentary Canal
• Alimentary Canal
– -coiled, hollow tube
– -opened at both ends:
mouth and anus
– -ORGANS:
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Mouth
Pharynx
Esophagus
Stomach
Small Intestine
Large Intestine
Anal Canal
Anus
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Mouth/ Oral Cavity
• Tongue
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Needed to talk
Anchored to hyoid bone
Held to floor or mouth by the frenulum
When you chew, the tongue pushes up against the roof
of the mouth to form a BOLUS
• Teeth
– Type of teeth
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Incisors-front teeth (bite)
Canines/cuspids (tear)
Bicuspids/premolars
Molars
Chewing or
grinding
– Sets
• First teeth: baby teeth/milk teeth = deciduous
• Second set = permanent
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Mouth cont.
• Palate (Roof of mouth)
– Hard palate: works with tongue to form bolus
– Soft palate: slides back to stop food from being
pushed into the nasal cavity
• Salivary glands
– Secrete saliva into the mouth
– Sets:
• Parotid: Largest; front and below ear
• Sublingual: Under tongue
• Submandibular: Under lower jaw
– Saliva is made up of water, mucus and amylase (digests sugar and
carbohydrates)
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Passage to Stomach
• Pharynx-throat
– Passageway for food from mouth to
esophagus
• Esophagus
– Muscular tube that connects pharynx and
stomach
– Food directed here by epiglottis
– Peristalsis move food to stomach
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Peristalsis
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Concept Check
Match up the terms correctly:
Secretion
rids body of feces
Esophagus
the oozing of stuff
Mouth
tube leads to stomach
Defecation
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produces a bolus
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Stomach
• C shaped organ
• Hidden by liver and muscular sheet called diaphragm
• Physical change:
– Stomach walls contract to “mash up” the food and get it covered
with digestive enzymes
• Chemical change:
– Gastric juices
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HCl
Pepsin
Gastrin
Others
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Protein digestion starts here
Lined with mucosa to prevent it from digesting itself
Small amt. of absorption occurs here
Leaves stomach through the pyloric sphincter in small
amts.
• Food
is now called chyme SAP4a
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Small Intestine
• Major digestive organ
• 16 feet in length
• 3 parts:
– Duodenum, Jejunum, and Ileum
• Most chemical digestion and absorption occur
here
• Accessory organs add digestive juices to
duodenum
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Accessory Organs to Small Intestine
• Accessory organs come into
play to assist the small
intestine:
– Liver-produces bile for large
fats
– Gallbladder-stores bile for
liver
– Pancreas-produces enzymes
• Pancreatic amylase: sugars and
carbs
• Trypsin: proteins
• Lipase: small fats
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Small Intestines cont.
• Makes digestive enzymes
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Peptidase: proteins
Intestinal lipase: fats
Maltase: maltose
Sucrase: sucrose
Lactase: lactose
• Lined with microvilli to increase absorption
• Waste is removed from the ileum to the cecum
through the ileocecal valve
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Small Intestines
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Large Intestine
• Extends from the ileocecal valve to the anus
• Dries out indigestible food
– Water absorbed, resides excreted as feces
– Too little water removed = diarrhea
– Too much water removed = constipation
• Full of bacteria to digest in small intestines; remnants
and old bacteria eliminated in feces
• Secretes large amounts of mucous to lubricate
• Rectum stores feces for removal
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Large Intestine
Food passage through large intestines:
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Cecum
Appendix
Ascending colon
Transverse colon
Descending colon
Sigmoid colon
Rectum
Anus
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Final Result is Excretion…
• Anal Cavity
– Anus: opening to
the outside
• Controlled by the
internal and
external sphincters
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Concept Check
• How does food pass through the
digestive tract? Describe the motion.
• Describe the breakdown of food in the
stomach.
• When does most breakdown of food
occur?
• What is the main thing that occurs in
the large intestine?
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Nutrition
• Nutrients are absorbed in the small intestines
– Passes through the wall of intestines into
bloodstream via microvilli
• Major Nutrients
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Carbohydrates
Lipids
Proteins
Vitamins
Minerals
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Nutrients cont.
• Carbohydrates
– Monosaccharides: simple sugars
– Disaccharides  polysaccharides: will all be
broken down into monosaccharides to be used
• Polysaccharide cellulose are not digested by humans
– Makes up bulk of feces
– Uses: fast energy
– Sources: sweets, potatoes, bread, pasta, cereal
– Tests: sugars-Benedicts solution; starchesIodine
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Nutrients cont.
• Lipids
– Includes fats, oils, and cholesterol
(triglycerides)
– Uses: slow, stored energy = contains more
chemical energy than any other nutrient;
cholesterol strengthens cell membranes
– Sources: butter, mayo, chips, fried foods,
cooking oils
– Tests: brown paper towel and Sudan stain
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Nutrients cont.
• Proteins
– Made up of amino acids that get disassembled
and reassembled in you
– Uses: makes up muscle mass, acts as enzymes,
antibodies, regulates cell cycle, growth and
repair, and channels in cell membranes
– Sources: meat, beans, nuts, eggs
– Tests: Nitric acid
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Nutrients cont.
• Vitamins
– Organic nutrients
Uses: Many function as coenzymes: they act with
an enzyme to accomplish a catalysis
• Sources: broccoli, cabbage, and brussels
sprouts
– acquired through a balanced diet
• A, E, and C have anticancer effects
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Nutrients cont.
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Minerals
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Uses: strengthens structures (bones, teeth), bind to organic
compounds
– Sources: vegetables, legumes, milk, and some
meats
• Seven important elements needed:
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-Ca-Calcium
-P-Phosphorus
-K-Potassium
-S-Sulfur
-Na-Sodium
-Cl-Chlorine
-Mg-Magnesium
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Metabolism
• ALL the chemical reactions of the body
• It can be thought of as a balancing act
occurring in the body because of two processes
occurring simultaneously:
– Anabolism—combining simple substances into
more complex substances
– Catabolism—breaking down complex substances
into more simple ones
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Disorders
• Diarrhea: waste product is pushed through
large intestines too fast; too much water in
feces
• Constipation: waste stays in large intestines
too long and too much water is pulled out
• Gallstones: the cholesterol in the bile is
crystalizes and forms pellets or stones;
painful when they clog the tube leading to
the small intestine.
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Gallstones
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Disorders cont.
• Jaundice: bile accumulation in the tissues and causes
skin and whites of eyes to turn yellowish
• Peritonitis: inflammation of peritoneum by infectious
microbes (surgery or accidental)
• Ulcers: a sore in the lining of the digestive tract
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Stomach: peptic or gastric
Esophagus: esophageal
Duodenum: duodenal
Caused by H. pylori bacteria
Made worse by stress, acid, certain foods and alcohol
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Disorders cont.
• Heartburn: acid reflux; if the sphincter at the
end of the esophagus is weak; gastric juices
back up into the esophagus
• Vomiting: reverse peristalsis; contents comes
up through the esophagus and pharynx
• Lactose intolerance: you don’t have enough
lactase in your small intestines so you can’t
break down lactose in dairy products
• Appendicitis: inflammation of the appendix
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Hepatitis
• Inflammation of the liver caused by viruses, drugs,
and chemicals (alcohol)
• A: Spread by fecal contaminated food, clothing,
toys, eating utensils, or fecal-oral contact. Liver
damage not permanent
• B: Spread by sexual contact & contaminated
syringes & transfusion equipment. Can also be
spread through tears and saliva. Causes chronic
liver inflammation and a vaccine is available
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Hepatitis cont.
• C: Spread by blood transfusions & can
cause cirrhosis (hardening of liver) and liver
cancer
• D: Must be infected with B to get. Results
in severe liver damage & has high fatality
rate
• E: Spreads like A. Responsible for a high
death rate in pregnant women
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Disorders cont.
• Pancreatic Cancer
– Affects males over 50
– Usually few to no symptoms until in
advanced stage
– 4th most common cause of death
– Linked to fatty food, high alcohol
consumption, genetics, smoking &
chronic pancreatitis
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http://www.lesbursteindds.com/Periodontal%20Diseases%20and%20Therapies/default.html
http://www.fluorideandfluorosis.com/diagnosis/diagnosis.html
http://www.checkdent.com/dental-blog/periodontitis-or-parodontosis.html?lang=en
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