the digestive system
DESCRIPTION
The Digestive System. Or…What happens to that “Big Mac” once you take a bite!. What makes up a “Big Mac”?. The six basic groups of nutrients are: Water Carbohydrates Fats Proteins Minerals Vitamins. Water. Water is the most basic nutrient You die first without it - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/1.jpg)
The Digestive System
Or…What happens to that “Big Mac” once you take a bite!
![Page 2: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/2.jpg)
What makes up a “Big Mac”?
• The six basic groups of nutrients are:1. Water2. Carbohydrates3. Fats4. Proteins5. Minerals6. Vitamins
![Page 3: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/3.jpg)
Water
• Water is the most basic nutrient• You die first without it• If you lose 10% of your body water you are in
danger of dying –dehydration.• Water makes up 70% or more of your body
(depending on your age).• You are dehydrated before you actually
experience thirst.
![Page 4: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/4.jpg)
Carbohydrates
• Made of carbon, hydrogen, and oxygen in the proportion of [CH2O]n.
• Nutritional carbs are of plant origin.• Function: provide energy.1. Simple sugars
-Monosaccharides (glucose, fructose, galactose, and mannose) C6H12O6 (isomers)
![Page 5: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/5.jpg)
-Dissaccharides (2 monosaccharides combined by dehydration synthesis)
Sucrose (glucose + fructose)Lactose (glucose + galactose)Maltose (glucose + glucose)
2. Complex Carbohydrates (polysaccharides)-Starches (amylose, amylopectin, glycogen)-Cellulose -mammals have no cellulase –not digestible = FIBER
![Page 6: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/6.jpg)
Isomers: same empirical formula, different structural formula
![Page 7: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/7.jpg)
![Page 8: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/8.jpg)
Something to think about!!!
![Page 9: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/9.jpg)
Lipids (Fats)• Made of carbon, hydrogen, and oxygen.• Functions: stored energy, cell membranes,
insulation and padding, steroid hormones• Calorically dense. 2.54 calories / gram more
that carbs or protein• Triglycerides (LDL and HDL), Cholesterol• Basic component is fatty acids– Saturated –each carbon fully hydrated– Unsaturated –some double bonds
![Page 10: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/10.jpg)
![Page 11: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/11.jpg)
![Page 12: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/12.jpg)
Generalized triglyceride structure
![Page 13: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/13.jpg)
Cholesterol
![Page 14: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/14.jpg)
Triglycerides
• Cylomicrons– Form of fat absorption from the intestines– More about it later
• HDL: High density lipoproteins– Good Cholesterol– Increased by cardiovascular exercise
• LDL: Low density lipoproteins – Bad Cholesterol
![Page 15: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/15.jpg)
Essential Fatty Acids
• Essential: required in the diet for health, not made in adequate amounts by the body to sustain health.• Linoleic acid• Linolenic acid• Aracadonic acid
![Page 16: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/16.jpg)
![Page 17: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/17.jpg)
Proteins• Structure: chains of amino acids coded for on
DNA -C, H, O, N, and sometimes S.• Functions: structural, enzymatic, antibodies,
regulatory (some hormones), energy• Essential Amino Acids: PVT MATT HILL• Non-essential –made by the body.• Complete proteins –have the right combination of
essential amino acids• Incomplete proteins have an imbalance of
essential amino acids –at least one limiting aa.
![Page 18: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/18.jpg)
Meat, milk, eggs, soy.Which is the best protein?
• What is protein quality?• How is protein evaluated?• What about vegetarians?• What is the difference between ouevo-
lacto and vegan?• What is a complementary protein?
![Page 19: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/19.jpg)
![Page 20: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/20.jpg)
![Page 21: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/21.jpg)
Vitamins• Fat Soluble: ADEK1. Vitamin A -retinoic acid –eyesight (night
vision), epithelial tissue health2. Vitamin D –calcitrol –calcium absorption and
bone health. Deficiency disease =Rickets3. Vitamin E –α-tocopherol –antioxidant in fat
soluble tissues.4. Vitamin K – part of the clotting cascade.
Made by gut bacteria.
![Page 22: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/22.jpg)
Water Soluble Vitamins• B vitamins:• B1 =thiamine TPP• B2 =riboflavin FAD -carries hydrogens• B3 =niacin NAD -carries hydrogens• B5 =Pantothenic acid• B6 =Pyridoxine transfers amino acids• B9 = Folic acid• B12 =carboxycobalamine -only one stored!
Animal products only
![Page 23: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/23.jpg)
Vitamin C
• Ascobic acid• Water soluble• Deficiency disease is scurvy• Only required by primates (including humans),
guinea pigs, and fruit bats.• Important in the conversion of proline to
hydroxyproline to make collegen• Important in immune response. Increase turnover
in disease.• Anti-oxidant
![Page 24: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/24.jpg)
Minerals
• Macro-minerals: required in percentage amounts in the diet
–structural: calcium, phosphorus, magnesium
-electrolytes: sodium, potassium, chlorineMicro-minerals: trace elements –ppm (1mg/kg)
-iron, copper, fluoride, iodine, selenium, manganese
![Page 25: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/25.jpg)
Back to the “Big Mac”
• What is in a “Big Mac”• Dissect your burger into its
nutrients?• Explain the caloric effect of fat in the
burger or any food?
• Now what happens!!!
![Page 26: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/26.jpg)
![Page 27: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/27.jpg)
What is digestion?
• Digestion is the sum of the mechanical and chemical processes that convert food elements into small enough particle to be absorbed into the body.
• There are 2 basic aspects of digestion:
• Chemical Processes –enzymatic• Physical process –mechanical like chewing and
mixing
![Page 28: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/28.jpg)
Mouth: ProcessesMechanical digestion:Prehension: food gathering –lips, hands, etc.• Mastication: chewing, breaks food into smaller
pieces (greater surface area) to facilitate enzyme breakdown.• Ensalivation: coats food particles with saliva to
facilitate swallowing -lubrication Chemical digestion • Salivary amylase: breaks down starch (amylose) into
dextrins (6 carbon sugars).
![Page 29: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/29.jpg)
Teeth
• Dental Formula– Set up like a fraction = ½ of the mouth– Numerator = the top of the jaw– Denominator = bottom jaw– Numbers are given in the following order– Incisors/canines/premolars/ molars– Human permanent teeth =– 2123/2123 X 2
![Page 30: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/30.jpg)
Permanent teeth
![Page 31: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/31.jpg)
![Page 32: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/32.jpg)
Do all animals have the same teeth?
![Page 33: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/33.jpg)
Swallowing
• Food is swallowed• Moves through the pharynx• Past the epiglottis
What is the purpose?
– Enters esophagus– Moves by peristalic movement (wave-like
movement)
![Page 34: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/34.jpg)
Stomach: gastric phase
![Page 35: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/35.jpg)
Gastric Activities
• Mixing movements• Gastric secretions: pH=2-3– Pepsinogen– HCl– mucous
• Hormone release: (gastrin and intrinsic factor)• Absorption
alcohol and water
![Page 36: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/36.jpg)
Secretions
• Chief cells -secrete pepsinogen• Parietal cells –secrete HCl• HCl converts pepsinogen to pepsin
![Page 37: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/37.jpg)
Functions of the Stomach
• 1. Break down of proteins into peptides• 2. Absorption of water –especially if
dehydration exists.• 3. Absorption of alcohol• 4. Absorption of acidic drugs (due to pH)• 5. Secretion of “rennin” in babies causes milk
proteins to form “curds” for digestion.
![Page 38: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/38.jpg)
Intestinal Digestion
![Page 39: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/39.jpg)
Small Intestine• Parts: No distinct bounderies.• Duodenum
-first 25 cm (10 inches)-primary area of digestion and absorption
• Jejunum– Continued digestion and absorption
• Ileummostly water
• Ileocecal junction: where SI joins the cecum and LI
![Page 40: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/40.jpg)
Intestinal lining
![Page 41: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/41.jpg)
Intestinal “juices”
ACTION ORIGIN• Sodium bicarbonate -neuralizes pH pancreas• Mucous – -protection
Brunner’s glands goblet cells.
• Chyme has a pH of____7_________.
![Page 42: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/42.jpg)
Enzymes (all enzymes are proteins –coded for on DNA)
• ENZYME ACTION ORIGIN• Peptidase 1 breaks down proteins• Dissaccharidases convert dissacharides SI
to monosaccharides • Lipase breaks down triglicerices SI & P• Enterokinase breaks down proteins SI• Amylase Breaks down amylose SI & P • Chyme passes through the ileocecalvalve into the Large
Intestine
![Page 43: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/43.jpg)
LARGE INTESTINE
• Cecum -in some animals (rabbits and horses) is very large and provides a fermentation vat.
• Vermiform appendix – function is a lymph node• Ascending colon• Transverse colon• Descending colon• Sigmoid colon• Rectum• Anus has 2 sphincters.
![Page 44: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/44.jpg)
Lots of distance –little function
• The digestive function of the large intestine is absorption.
• Only mucous is secreted• Absorption of water.• Intestinal bacteria make: vitamin K, some
amino acids.
![Page 45: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/45.jpg)
LI problems
• Diverticula: balloon like projections that form in the large intestine due to strain and weakness of the intestinal wall.• Diverticulitis= inflammation of the
diverticula–painful
![Page 46: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/46.jpg)
![Page 47: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/47.jpg)
![Page 48: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/48.jpg)
Digestion of Fat:
• Bile emulsifies fat: O (droplets) + Bile o o o o o o • Emulsify means: the mixture of immiscible liquids
(like oil and water).• Lipase attaches to the glycerol of the triglyceride and
breaks off the fatty acids 1 and 3. Glycerol is absorbed into the bloodFatty acids pass through mucosal cells are combined with protein as cylomicrons the lymph system.
![Page 49: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/49.jpg)
Chylomicron
–transport of fat coated with protein from intestines in lymphatics to thoracic duct. -Dumped into the vena cava. -Can go directly to muscle and adipose tissue or to the liver to be reprocessed. • LDL and HDL made by liver and
transport of fat in blood. HDL –happy cholesterol.
![Page 50: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/50.jpg)
LIVER
• Largest gland in the body.• Many important functions:• Carbohydrate metabolism• -maintains blood glucose level• -converts excess glucose to glycogen for
storage.• -gluconeogenesis- breaks down glycogen to
glucose when blood sugar is low.
![Page 51: The Digestive System](https://reader035.vdocuments.site/reader035/viewer/2022062520/568163c8550346895dd4fe84/html5/thumbnails/51.jpg)
Lipid Metabolism
• -oxidation of fat• -converts cylomicrons to VLDL, LDL, and HDLs.• -bile formation and release.• Protein Metabolism• -deamination of amino acids• -formation of urea• Storage• -glycogen• -vitamins A, D, and B12• -iron