Today’s Agenda

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• Todays Agenda
• (1) Journal Questions What did you have for
  breakfast today? Was it healthy? Explain your
  response.
• (2) Lecture Digestion, Absorption, Excretion.
  (Ending on slide 56)
• (3) Film The Diet (Body Story)
• (4) Homework Read Chapter 49.

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Digestion Nutrition

• 1. What is a calorie?
• A calorie is defined as a unit of energy
  supplied by food.

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Digestion Nutrition

• 2. What is normal daily caloric intake?
• a. Teenage Girls, Active Women, Most Men
  2,000 Calories
• per day
• b. Teenage Boys, Active Men 2,400 Calories
  per day

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Digestion Nutrition
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Obesity Definition

• A. Obesity is defined by a Body Mass Index (BMI)
  of greater than 30 with a body fat percentage
  of
• (1) Greater than 28 for males.
• (2) Greater than 36 for females.

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(No Transcript)
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Whos Big? (NIH Study 2010)

• A. Prevalence of overweight and obesity in the
  United States 2010
• (1) Adults (20 years of age and up)
• a. 32.9 of U.S Adults are
• obese.
• (2) Children (Ages 2 19)
• a. 31.9 are overweight and
• obese.

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The Children of 2010

• A. From 2006 - 2010, millions of teenagers and
  young adults joined the ranks of clinically
  obese.
• B. There is an increased incidence in type II
  diabetes in teens.
• C. Even our pets are overweight, 25 of dogs and
  cats are heavier than they should be.

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Fat Animals in the Wild
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The Children of 2010

• D. Twenty years ago, 5 of American kids were
  overweight.
• E. Today 20 are overweight and another 15 are
  headed that way.
• F. In 1969, 80 of kids played sports everyday
  today only 20 play sports everyday.
• G. By age 17, a child has spent 38 more time in
  front of the television or computer than in
  school.
• H. 80 of a teenagers calories come from
  sodas.

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Fruit Juices vs. Soft Drinks

• A. Look at sugar content
• (1) Which has the most grams of total sugar?

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Whos Big? (CDC 2010)

• B. Obese children and adolescents are more likely
  to become obese as adults.
• (1) One study found that approximately 80 of
  the children who were overweight at ages 10 15
  years of age were obese adults at age 25.

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Who exercises?

• A. The proportion of youth (18 years of age) who
  report engaging in no physical activity is high,
  and the proportion increases with age.

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Why is this happening?

• A. We eat too much high-calorie food and we do
  not burn it off with enough exercise.
• B. 3,500 calories 1 pound of fat It is very
  easy to gain 1 pound of fat in a week.

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Fat Cells

• A. The amount of fat cells you are born with
  will probably be the same number when you die.
• (Only the size of the cell increases or
  decreases depending on weight gain and weight
  loss)
• B. There are 3 times in life when you can
  increase the number of fat cells your body has
• (1) The Toddler Years
• (2) Puberty
• (3) Third Trimester of Pregnancy

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First Law of Thermodynamics

• A. Calories In Calories Out
• B. If the calories you take in are greater than
  the calories you expend (exercise) you will get
  fat.
• C. Excess calories are stored as fat.
• D. Average daily caloric intake varies
• 2,000 2,500 calories per day.

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Role Models???
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What did Sushi A say to Sushi B?
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Was up B? (Wasabi)
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Digestion, Absorption Excretion

• By Rick Woodward

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Digestion Starts in the Mouth

• I. The Mouth
• 1. Secretion of saliva upon the sight or smell
  of food.
• A. Lubricates each morsel with mucus to make
  passage easier.
• -Saliva contains amylase, mucus, and lysozymes.

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The Mouth

• B. Contains amylase, an enzyme that breaks down
  starch (carbohydrate chains).
• -Starch digestion begins in the mouth.

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The Mouth

• C. Lysozymes break into the cell walls of
  bacteria that are on or in your food.

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The Mouth

• D. The body manufactures 1-2 quarts of saliva a
  day.
• E. Saliva is mostly water and it is weakly
  alkaline (basic) with a pH of 7.4

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The Mouth

• 2. Chewing creates smaller particles whose
  increased surface area allows digestive enzymes
  to access more surface area of swallowed food.
• (Mastication)

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The Mouth

• 3. The tongue assesses the amounts and types of
  food found in saliva.
• a. Tastes include
• (1) Sweet
• (2) Salty
• (3) Sour
• (4) Bitter

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The Esophagus

• II. The esophagus is a tube through which your
  food travels to your stomach.
• A. Food is transported with a peristaltic
  (pumping) motion.

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The Esophagus

• B. An opening called the glottis is covered by a
  flap of tissue called the epiglottis.

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The Esophagus

• C. The epiglottis prevents choking by covering
  the trachea (wind pipe/breathing tube) when
  swallowing.

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The Esophagus

• D. The lower esophageal valve prevents backflow
  of the stomachs contents from going back into
  the esophagus.
• (Heartburn/Acid Reflux)

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The Stomach

• III. The stomach secretes mucus, hydrochloric
  acid, pepsin, lipase, and an intrinsic factor
  which is necessary to activate and absorb Vitamin
  B-12.

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The Stomach

• A. Digesting protein using
• 1. Stomach acid juices, like hydrochloric acid
  (HCl) pH 2.
• a. Pepsin, an enzyme, works directly on large
  proteins.
• b. Protein digestion begins in the stomach.

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The Stomach

• B. The average capacity of the stomach is one
  liter.

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The Stomach

• C. Food stays in the stomach for about 2-3 hours.

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The Stomach

• D. Fatty meals or solid foods take longer to
  digest than liquids and low-fat meals.
• -Lipase, an enzyme, starts the digestion of
  certain fats.

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The Small Intestine

• IV. The Small Intestine (Duodenum) 95 of all
  digestion and nutrient absorption takes place
  here.

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The Small Intestine

• A. Food entering the small intestine from the
  stomach is strongly acidic.
• -Secretions from the pancreas alkalize the food
  coming in from the stomach.
• -Small Intestine has a pH 8.3

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The Small Intestine

• B. Can be up to 10 feet long (referred to as
  small because of its small diameter.)

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The Small Intestine

• C. Food may remain in it from 4-10 hours.
• D. Most nutrient absorption occurs within the
  small intestine.

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The Pancreas

• V. The Pancreas supplies the following enzymes to
  the duodenal are of the small intestine
• (1) Trypsin, an enzyme, for protein digestion.
• (2) Amylase, an enzyme, for starch digestion.
• (3) Lipase, an enzyme, for fat digestion.
• (4) Bicarbonate, for acid neutralization.

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The Liver

• VI. The Liver supplies the duodenum with bile.
• A. Bile envelopes fat droplets in a fluid for
  intestinal absorption.
• B. Bile emulsifies fats.
• C. Up to one liter of bile is stored in the gall
  bladder.

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The Large Intestine

• VII. The large intestine can be up to six feet
  long.
• A. Can hold food for as long as three days.

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The Large Intestine

• B. Colonies of helpful bacteria are permanent
  residents.
• (1) They aid in the digestion of plant matter.
• (2) Bacteria produce vitamins B12, Riboflavin,
  Thiamine, and Vitamin K.

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The Large Intestine

• C. Water is removed from food in the large
  intestine. (water absorption)
• (1) Some diseases that affect the large
  intestine can cause diarrhea.
• (2) Waste matter is packaged for removal.
• a. About ½ of waste is dead bacteria.

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Overview of Digestive System

• A. Something happens to your food through each
  part of the digestive tract.
• B. Nutrients become available and transported
  throughout your body via the circulatory system
  (blood).

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Excretory System

• A. Your excretory system works in a similar way
  to the equipment that purifies water.
• B. Your excretory organs are
• (1) Kidneys
• (2) Lungs
• (3) Skin
• C. The organs help your body get rid of waste
  products.

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Excretory System

• D. The amount of water in blood is important to
  maintain
• (1) Normal Blood Pressure (120/80)
• (2) Movement of Gases
• (3) Excretion of Solid Waste.

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Excretory System

• E. Filters out nitrogen wastes and helps maintain
  osmotic balance.

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Excretory System

• F. The main excretory organs are two kidneys
  fist size, bean-shaped structures that lie near
  the dorsal abdominal wall.

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Excretory System

• G. Kidneys filter blood that has collected waste
  products from cells.
• -If waste products build up, they act as poisons
  to the body cells.
• (1) Each kidney is made up of about 1 million
  nephrons, the tiny filtering units of the kidney.

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Excretory System

• H. Each nephron is made up of a cup-shaped
  Bowmans capsule, which narrows into a long,
  coiled tubule.
• (1) In the center of each Bowmans capsule is a
  mass of capillaries called the glomerulus.
• (2) A glomerulus forms from a small artery that
  branches from one of the two renal arteries.

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Excretory System

• I. The Filtering Process
• 1. Blood entering the kidney contains needed
  materials being transported to body cells, plus
  urea and excess salts.

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The Filtering Process

• 2. The blood acquires urea when it passes through
  the liver, which converts ammonia to urea.
• a. Urea is less toxic than ammonia.
• b. It conserves water because it requires less
  water for excretion.

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The Filtering Process

• 3. The continuous flow of blood into the kidneys
  forces the liquid out of the cup portion of
  Bowmans capsule and into the tubule.
• a. In the tubule is where the actual filtering
  process takes place.
• b. 99 of the water passing through the kidneys
  is reabsorbed.
• c. What remains in the collecting duct of the
  nephron is urea, salts, and a small amount of
  water.
• -This is called urine.

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The Filtering Process

• 4. Urine passes from the collecting duct to the
  ureter, which conveys urine to a muscular storage
  sac, called the urinary bladder.

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The Filtering Process

• 5. When the bladder becomes filled, a muscular
  valve relaxes, and urine is excreted and
  discharged through the urethra.

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With the remainder of class time

• 1. Answer the vocabulary activity in your
  packet.
• 2. Color in sections of the digestive system in
  your packet.
• 3. Label the organs of the digestive system on
  page 1 of your packet