1. Digestive System part II Chemistry and Cells

2. Atoms Three major parts. Protons: Positive Charge. Inside Nucleus
Neutrons: Neutral Charge. Inside Nucleus:
Electrons: Negative Charge. Outside Nucleus
2 electrons in first shell
8 electrons in the second shell
Eight is Great! Will not React with other atoms.
If the outer shell is not full it will react.

3. Periodic
Table
Bonding
Combining Chemicals
Compound: When two or more different elements combine.
Hydrogen Bond: H2O - H2O
When hydrogen bonds with another atom or molecule. Bonds are like Velcro. Make and break easily.
Covalent bond: CO2
When atoms on the same side of the chart (same size) bond. Share electrons.
Both Hydrogen and Covalent bonds form molecules, ionic bonds do not.
Ionic/
Covalent
Bonds

4. Combining Chemicals continued
Ionic Bonds: When atoms on different sides of the chart (different size) bond. Steal electrons. Create Ions. Make teeth and bones.
Ion: Charged particle either negative or positive. NaCl = table salt
Electrolytes: Ionic compounds that break into cations and anions when dissolved. (Salt)
Free Radical: Electrically charged ion with an unpaired electron in its outer shell.

5. Antioxidants, What are they?
Substances that inactivate oxygen derived free-radicals
Slows damage from free-radicals
Examples: Selenium, Zinc Beta-carotene, Vitamins C & E
Free Radicals
Acai Berry

6. Ph Scale Measured on grams of Hydrogen (H+)
pH of 0= 1g of H+, pH of 1= .1g of H+
Acid: form hydronium ions (H+)
pH of less than 7 ( 1 to 6.9)
Base: form hydroxide ions (OH-)
pH of more than 7 (7.1 to 14)
Acid + Base: salt & water, the solution is neutral with a pH of 7.
NaOH + HCL = H2O + NaCl with a pH of 7

7. What is a Buffer?
Chemical substances that neutralizes small amounts of an acid or base added to a solution.
Why are these important to your body?
 three main buffers in the body:
bicarbonate buffer system: in the blood and stomach to neutralize acids
protein buffer system: inter and extra cellular buffering used with hemoglobin and blood
phosphate buffer system: used in the urinary system to remove H+ ions and make urine acidic
he bicarbonate buffer system is also responsible for regulating the acid base balance in the stomach and neutralizing the acidity of stomach content as it reaches the small intestine. Although the bicarbonate system is smaller in capacity when compared with other buffer systems, it is the most useful in relation to eliminating most of the acid wastes over a long period of time. The reason for this is its ability to continuously eliminate CO2 and H+ from the tissues and blood, eliminate H+ and CO2 in the lungs as well as eliminate H+ in the kidneys.
A highly acidic urine pH occurs in:
Acidosis
Uncontrolled diabetes
Diarrhea
Starvation and dehydration
Respiratory diseases in which carbon dioxide retention occurs and acidosis develops
A highly alkaline urine occurs in:
Urinary tract obstruction
Pyloric obstruction
Salicylate intoxication
Renal tubular acidosis
Chronic renal failure
Respiratory diseases that involve hyperventilation (blowing off carbon dioxide and the development of alkalosis)
In people who are not vegetarians, the pH of urine tends to be acidic. A diet rich in citrus fruits, legumes, and vegetables raises the pH and produces urine that is more alkaline. Most of the bacteria responsible for urinary tract infections make the urine more alkaline because the bacteria split urea into ammonia and other alkaline waste products. The urine pH varies in different types of acidosis and alkalosis. Control of pH is important in the management of several diseases, including bacteriuria, renal calculi, and drug therapy.

8. Metabolism: All chemical reactions necessary to maintain life
Catabolism – chemical reactions that break down complex organic compounds into simple ones, energy is released and captured to make ATP
Anabolism –synthetic (not produced naturally) process where larger molecules are built from smaller ones

9. The Digestive System and Body Metabolism
Overview Of
Digestion
Chapter 19
The Digestive System and Body Metabolism
Takes in food, breaks it down into nutrient molecules and absorbs them into the bloodstream, then rids the body of indigestible remains

10. The cartoon
Pill Cam

11. Metabolism & What We Eat
Carbohydrates (glucose) - broken down to make ATP, stored as glycogen. 1g= 4KCal
Lipids- build cell membranes, myelin sheaths, insulate, ATP. 1g= 9 KCal
Proteins - structural materials hoarded by body cells, ATP. 1g= 4KCal
What is a calorie? Energy value measured in kilocalories (Kcal) : amount of energy needed to raise the temp. of 1 kg of H2O 1 deg C.
Starch is the major energy source in the diet and is broken down into glucose in the body that can be stored in the liver and in the muscles as glycogen. Glycogen can then be used to maintain blood sugar at a constant level for optimal energy supply.
the energy needed to raise the temperature of 1 kilogram of water through 1 °C, equal to one thousand small calories and often used to measure the energy value of foods.
noun: large calorie; plural noun: large calories

12. Anatomy of Digestive System
Alimentary canal –
or GI Tract - continuous hollow tube: mouth, pharynx, esophagus, stomach, small and large intestine
Accessory digestive organs - assist: teeth, tongue,salivary glands, liver, gallbladder and pancreas

13. Mouth (Oral Cavity) Food enters Mucus membrane-lined cavity
lips, cheeks, hard palate soft palate
uvula - fingerlike projection of soft palate

14. Mouth
Tongue – muscle covered with mucous membrane, attached to hyoid bone and styloid processes of skull
papillae upper surface and sides of tongue which contains your taste buds
Frenulum - secures tongue and limits its posterior movements
Taste

15. Salivary Glands - 3 pair Parotid glands - anterior to ears
mumps is inflammation of parotid glands
Submandibular and sublingual glands - empty secretions into mouth through ducts
Mumps (epidemic parotitis) is a viral disease of the human species, caused by the mumps virus. Before the development of vaccination and the introduction of a vaccine, it was a common childhood disease worldwide. It is still a significant threat to health in developing countries, and outbreaks still occur sporadically in developed countries.[1]
Painful swelling of the salivary glands – classically the parotid gland – is the most typical presentation.[2] Painful testicular swelling (orchitis) and rash may also occur. The symptoms are generally not severe in children. In teenage males and men, complications such as infertility or subfertility are more common, although still rare in absolute terms.[3][4][5] The disease is generally self-limiting, running its course before receding, with no specific treatment apart from controlling the symptoms with pain medication.
Fever and headache are prodromal symptoms of mumps, together with malaise and anorexia. Other symptoms of mumps can include dry mouth, sore face and/or ears and occasionally in more serious cases, loss of voice. In addition, up to 20% of persons infected with the mumps virus do not show symptoms, so it is possible to be infected and spread the virus without knowing it.[6]
Males past puberty who develop mumps have a 15–20 percent risk of orchitis,[7] painful inflammation of the testicles.[8]

16. Polls
Everywhere
Saliva
Product of salivary glands, mixture of mucus and serous fluids (99.5% water)
Creates a Bolus: mucus bound mass of food
Enzymes of saliva:
Amylase : for starch digestion
Lysozyme: kills bacteria

17. Teeth Masticate (chew)
Deciduous (baby or milk) teeth - first set (20); formed from 6 months to 2 years
Permanent teeth - cause baby teeth to fall out b/t 6 and 12
32 permanent teeth
3rd molars (wisdom teeth) form b/t 17 and 25; sometimes absent or impacted in jawbone and must be surgically removed
 Primary (baby) teeth start to form between the sixth and eighth week of prenatal development, and permanent teeth begin to form in the twentieth week.[1] If teeth do not start to develop at or near these times, they will not develop at all, resulting in hypodontia oranodontia.
Enamel: Hardest substance of the body! (Calcium phosphate and calcium carbonate)
Dentin: Calcified connective tissue.
Cavities

18. Teeth by shape/function: omnivores
Incisors - chisel-shaped, cutting
Canines - fanglike, tearing/piercing
Premolars (bicuspids)
Molars - broad crowns w/ rounded tips, grinding

19. Organic Compounds: contain C-H bonds
Carbohydrates
Carbohydrate: fast energy
made of Carbon, Hydrogen, and Oxygen. 1:2:1 proportion. Sacchar = sugar
Monosaccharides:C6H12O6, glucose,fructose (plants)
Disaccharides: 2 sacchar’s: Sucrose: table sugar, Lactose: milk
Polysaccharides: Many sacchar’s: starch: Grains, Legumes (beans)

20. Carbohydrate Metabolism
Carbs - preferred fuel to produce ATP from glucose (blood sugar)

21. Carbohydrate Metabolism - Homeostasis of blood glucose
Hyperglycemia - high levels; excess stored as glycogen and converted to fats
Hypoglycemia - low levels; liver breaks down stored glycogen and releases glucose to blood

22. Pharynx
Nasopharynx (respiratory)
oropharynx (potesterior to oral cavity)
laryngopharynx (continuous w/ esophagus)
Peristalsis: Alternating contraction of muscles propel food into esophagus
Peristalsis

23. Esophagus Conducts food from pharynx through diaphragm to stomach
25 cm long

24. Walls of Alimentary Canal
Mucosa - innermost layer; moist membrane
Submucosa - blood vessels, nerve endings, lymph
Muscularis externa - inner circular, outer longitudinal smooth muscle
Serosa - outermost layer

25. Food entering the stomach
Peristalsis
C-shaped, left side, nearly hidden by liver and diaphragm
cardioesophageal sphincter - food enters from esophagus
Pyloric sphincter - goes to small intestine
25 cm long
when full, holds 4 L of food
empty - collapses into folds (rugae)
3rd oblique layer in muscularis externa to move, churn, mix, and pummel food
chemically breakdown proteins
Food entering the stomach

26. Stomach: Physiology
Mucosa has gastric pits which lead into gastric glands that secrete gastric juice
chief cells - produce protein-digesting enzymes (pepsionogen)
parietal cells - produce HCl
Chyme is produced
contractions squirt 3 ml of chyme into small intestine
takes 4 hrs for stomach to empty
How stomach acid is
Made!

27. Organic Compounds: All organic compounds contain Carbon.
Protein: the working molecule
50 or more Amino Acids make a protein
Food: Beans, meat, nuts
Types of Proteins
Muscle
Enzymes: Control chemical reactions and can be re-used like a key in a lock
Hair
When used for food: amine groups are removed as ammonia which is toxic so it combines w/ CO2 to form urea
Protein

28. General Metabolic Function
Albumin - most abundant protein; holds fluids in bloodstream
insufficient albumin causes fluid to go from blood to tissues (edema)
Synthesize amino acids and detoxify ammonia

29. Small Intestine Major digestive organ
Muscular tube extending from pyloric sphincter to ileocecal valve
average length: 2 m (6 feet)

32. Small Intestine - 3 structures that increase absorption
Microvilli - tiny projections that give fuzzy look (brush border)
Villi - fingerlike projections that give velvety appearance
Circular folds - deep folds of both mucosa and submucosa

34. Small Intestine - 3 subdivisions DJI
Duodenum - curves around head of pancreas
Jejunum - extends from duodenum to ileum
ileum - terminal part that joins large intestine at ileocecal valve

35. Small Intestine: Food Breakdown and Absorption
Takes 3-6 hours
By end, digestion is complete and most absorption has occurred
Microvilli have brush border enzymes to break down sugars and complete protein digestion
Pancreatic enzymes from pancreatic duct and bile from bile duct enter duodenum

36. Food Breakdown and Absorption
Pancreatic juice digests starch, proteins, fats, and nucleic acids; contains bicarbonate to neutralize chyme
When chyme enters, it stimulates hormones secretin and cholecystokinin to release bile

37. Food Breakdown and Absorption
Bile is necessary for absorption of fats and fat-soluble vitamins K,D,A
At end, all that remains is water, indigestible food and bacteria which enters large intestine
Food propulsion - peristalsis

39. Organic Compounds: C-H bonds
Lipids: long term energy, very few oxygen atoms
Cholesterol: LDL & HDL
(HDL is heart healthy)
Saturated fats: Lard, and butter.
Unsaturated fats: C is double bonded to itself. Oil. Currently considered healthier.
“Good” fats—monounsaturated and polyunsaturated fats—lower disease risk. Foods high in good fats include vegetable oils (such as olive, canola, sunflower, soy, and corn), nuts, seeds, and fish.
“Bad” fats—saturated and, especially, trans fats—increase disease risk. Foods high in bad fats include red meat, butter, cheese, and ice cream, as well as processed foods made with trans fat from partially hydrogenated oil.
The key to a healthy diet is to choose foods that have more good fats than bad fats—vegetable oils instead of butter, salmon instead of steak—and that don’t contain any trans fat.
What is trans fat?
Some meat and dairy products contain small amounts of naturally occurring trans fat. But most trans fat is formed through an industrial process that adds hydrogen to vegetable oil, which causes the oil to become solid at room temperature.
This partially hydrogenated oil is less likely to spoil, so foods made with it have a longer shelf life. Some restaurants use partially hydrogenated vegetable oil in their deep fryers, because it doesn't have to be changed as often as do other oils.
Trans fats
Lipids

40. Lipids
Neutral fats: saturated in animal products, unsaturated in seeds, nuts, vegetable oils
Cholesterol - egg yolk, meats, and milk
Phospholipids: the plasma membrane
PS What organelle in the cell makes lipids?
Answer: Smooth ER

41. Lipid Metabolism
Liver - make ATP, synthesize lipoproteins, clotting protein and cholesterol for membranes or steroid hormones
Form myelin sheaths and fatty cushions around organs
Liver makes Bile ships it to the Gallbladder. Bile emulsifies fats. The bilirubin in bile turns feces brown.

42. Lipid Metabolism
To be used for ATP synthesis, it must be broken down into acetic acid; when not enough glucose, acetone accumulates in blood making it acidic (acidosis/ketosis)
no carb diets, diabetes, and starvation
People smell of keytones when they get diabetes, why?

43. Central Role of Liver
Manufactures bile, detoxifies drugs and alcohol, degrades hormones, makes substances vital to body, metabolism
This process uses many enzymes: Speed up chemical reactions and reduce activation energy.
Most enzymes are Proteins some are RNA
We have more liver tissue than needed, so if damaged, it regenerates rapidly and easily

44. General Metabolic Functions
Liver maintains blood glucose levels
After high carb meal, glucose is removed from blood and converted to glycogen (glycogenesis) and stored in liver

45. General Metabolic Functions
As body cells remove glucose from blood, liver breaks down stored glycogen (glycogenolysis)
gluconeogenesis - make glucose from fat and protein

46. Organic Compounds: All organic compounds contain Carbon.
Nucleic Acids: pg. 37 DNA and RNA
Made of nucleotides: Sugar, Phosphate, and X
ATP: energy cells run on.
DNA

47. What is a calorie?
Energy value measured in kilocalories (kcal) or Calories (C

48. Vitamins: the last of the Organics
Organic nutrients, small amounts
No one food contains all required vitamins, need balanced diet
Most function as coenzymes: act w/ enzymes for task

49. Vitamins: the last of the Organics
Organic nutrients, small amounts
No one food contains all required vitamins, need balanced diet
Most function as coenzymes: act w/ enzymes for task

50. Minerals
Requires adequate supplies of 7: Ca, P, K, S, Na, Cl, and Mg; trace amounts of others
Fats/sugars have none, cereals and grains poor sources
In veggies, legumes, milk, meats

51. Basal Metabolic Rate
Carbs & proteins yield 4 kcal/g, fats yield 9 kcal/g
Basal metabolic rate (BMR) - amount of heat produced by body per unit time at rest; energy supply for breathing, heartbeat, and kidney function

52. Basal Metabolic Rate
Avg. adult has BMR of kcal/hr; influenced by surface area, gender, age, and thyroxin production (more thyroxin produced by thyroid gland, higher O2 consumption and ATP use and metabolic rate)

53. Basal Metabolic Rate
Hyperthyroidism - excessive rate, lose weight despite increased hunger and food intake, bones and muscles weaken
Hypothyroidism - slow rate, obesity, diminished thought process

54. Total Metabolic Rate
When active, more glucose must be oxidized to provide more energy for activities
Total Metabolic Rate (TMR) - total amount of kcal body must consume to fuel all activities

55. Total Metabolic Rate When total calories = TMR, weight is constant
If eat more, excess calories appear as fat deposits
If active w/o enough food, break down fat reserves and even tissues to satisfy TMR

56. Large Intestine Larger in diameter, shorter in length (1.5 m)
Extends from ileocecal valve to anus
Dries out indigestible food by absorbing water, eliminates residue as feces

57. Large Intestine Subdivisions
Cecum - saclike, first part
Appendix - wormlike structure hanging from cecum; ideal bacteria location - appendicitis
Colon - ascending, transverse, descending, and sigmoid
Rectum
Anal canal - ends in anus which opens to exterior; has external voluntary sphincter and internal involuntary sphincter

58. Large Intestine
Lots of goblet cells to produce mucus to act as lubricant to ease passage of feces

59. Large Intestine: Food Breakdown and Absorption
Residue is there hours
Bacteria metabolize nutrients and release gases (methane, hydrogen sulfide)
500 ml of gas produced each day

60. Gallbladder
Small, thin-walled green sac in the inferior surface of liver
When digestion is not occurring, bile is stored and concentrated by removal of water
bile stored too long, it crystallizes forming gallstones
Yellow-green, watery solution of bile salts, bile pigments (bilirubin), cholesterol, phospholipids, and electrolytes
bile salts emulsify fats to provide more surface area

61. Digestive System
Review

62. Disease: Jaundice Bile pigments enter bloodstream
Can result from hepatitis (inflammation of liver from viral infection of contaminated water or blood transfusion) or cirrhosis (severe damage from drinking excess alcoholic beverages)

63. Nutrition and Metabolism
Most foods used as metabolic fuels (transformed into ATP); some nutrients build cellular molecules
Energy value measured in kilocalories (kcal) or Calories (C)

64. Nutrition
Nutrient - substance in food used to promote normal growth, maintenance and repair
Carbohydrates, lipids, proteins - bulk of food; vitamins, and minerals in minute amounts

65. . Water - 60% of volume of food
Most foods are combination of nutrients from 5 food groups (grains, fruits, vegetables, meats, and milk products)

66. Obesity Rates
in the US.

68. Dietary Sources of Major Nutrients - Carbohydrates
From plants except lactose and glycogen in meats
sugar - fruit, sugar cane, milk
starch - grains, legumes, root vegetables
cellulose - most vegetables

69. Food Breakdown and Absorption
Absorption limited to vitamins, some ions, and most of remaining water
Feces - solid product delivered to rectum; undigested food residue, mucus, bacteria, and some water

70. Large Intestine: Propulsion and Defecation
Peristalsis and mass movements (long, slow-moving, powerful contractile waves that move over colon 3-4 times daily to push contents toward rectum)
occur after eating; fiber increases strength of contraction

71. Propulsion and Defecation
When feces in rectum, defecation reflex causes rectum to contract and anal sphincters to relax
Diarrhea - food rushes through before water is absorbed, can result in dehydration and electrolyte imbalance

72. Propulsion and Defecation
Constipation - food residue remains too long and too much water is absorbed; due to lack of fiber, poor bowel habits, or laxative abuse
Poll
Everywhere
Poll
Everywhere
A constipated body
Poll
Everywhere

73. Other Accessory Digestive Organs – Pancreas
Soft, pink, triangular gland extending from spleen to duodenum
produces enzymes that break down food and neutralize acidic chyme from stomach, produces hormones insulin, glucagon

74. Liver Liver - largest gland in body; under diaphragm on right 4 lobes
produces bile which leaves liver through common hepatic duct

75. Developmental Aspects
5th week - alimentary canal forms
cleft palate/lip - child unable to suck properly
tracheoesophageal fistula - connection b/t esophagus and trachea - causes drool, cyanosis during feedings

76. Development Aspect
Cystic fibrosis - blockage of pancreatic ducts so that fats and fat-soluble vitamins are not digested or absorbed
PKU - inability of tissue cells to use phenylalanine (amino acid) causes brain damage

77. Developmental Aspects
Newborn: rooting & sucking reflex
Appetite decreases in elementary age and increases in adolescence
Gastroenteritis - inflammation of GI tract due to contaminated food
Appendicitis - common in teens

78. Developmental Aspects
Middle age - metabolic rate decreases 5-8% every 10 yrs
ulcers & gallbladder problems
Old age - activity of GI tract declines, taste and smell decrease
cancer of stomach and colon