Warm Up

Get a Digestion and Metabolism Fill in from the front counter

• What is Digestion?

• TODAY:– Digestion PPT/ Fill In Notes– Begin Posters

Digestion and Metabolism

Summary and notes

What is digestion?

• Process the body uses to transform food into a form it can use

• 2 types• Chemical

– Food is combined with enzymes and acids (HCL) which cause chemical reactions in the body to help break down nutrients so they can be absorbed

• Mechanical– Happens as food is crushed and churned

What are enzymes?

• Enzymes do the job of converting food into compounds the body can use for energy, metabolism and other functions

Where does digestion take place?

• Gastrointestinal Tract

• AKA the GI tract

• Muscular tube, divided into parts that perform specific functions

• Can be as long as 30 feet!

How many parts?

• Six– Mouth– Esophagus– Stomach– Small intestine– liver– Large intestine

Begins the mechanical digestive process

Chewing: Food is crushed by the teeth into smaller pieces

Begins the chemical digestive process when ptyalin breaks down complex carbs into simple carbs

The physical process of chewing helps move the food to the next step

Moves food to the stomach

12 inches long

Peristalsis: Muscles contract and relax in wave-like patternsThis moves the food along entire GI tract

Emotions can decrease or increase this actionIncrease: aggressive, angryDecrease: sad, depressed, afraid, and nervous

Largest area in the digestive tract

Can hold 2-3 pints of food

Mainly breaks down proteins with the enzymes: Rennin and Pepsin and gastric juices produced by the stomach walls

Churned until it turns into chyme

Satiety: feeling of fullnessProteins stay in the stomach the longestProteins: 5 hoursCarbs: 2 hours

Small Intestine

• Next the food answers the duodenum• Mixed and combines with chemicals: Bile and

Pancreatic juice, Intestinal fluids and enzymes

• Lined with villi: hair like projections that filter and absorb materials from the intestine and help move them to the large intestine– Carbs: changed to glucose– Proteins: changed to amino acids– Fats: changed into fatty acids to provide energy– Vitamins and Minerals remain unchanged

Liver

• Manufactures changes and stores nutrients and chemicals

• Turns glucose into glycogen for storage and sends it into the bloodstream when the body needs it

• Recycles worn out blood cells

Large Intestine

• Water is absorbed and sent to the kidneys

• Fiber absorbs some of the water and helps to soften waste

• Acts as a holding place for waste

• 10% of food eaten ends up as waste

Process where nutrients are burned for heat and energy or used to build new tissue

Body needs energy to carry out three functions:

Basal Metabolism: maintaining heart rate, sleeping

Activity: running, walking, working

Thermic Effect of Food: metabolism, digestion, absorption, storage

Basal Metabolism

• The amount of energy needed for the body at physical, digestive and emotional rest

• Also referred to as BMR or basal metabolic rate

• Many factors affect your BMR

Gender

Environment

BodySurface

BodyTemp.

Supply of Nutrients

Age

BMR

What’s my BMR?

• To calculate your BMR

• Weight in kg X 1 or .9 X 24= BMR

• Males: 1 calorie per Kg of body weight per hour

• Females: 0.9 calories per Kg of body weight per hour

Weight in pounds = weight in Kg

2.2

Calculating BMR

• Weight in kg X BMR factor (1 for M, .9 for F)

• Multiply weight in kg times 24

• Example: 165 lb male

• 165/2.2 = 75 kg

• 75 kg X 1.0 = 75 cal/hr

• 75 X 24 = 1800 calories

• Metabolic rate = 1800 calories per day

Another Example

• 136/2.2= 61.8 kg

• 61.8 X .09 = 55.62 cal/hr

• 55.62 X 24= 1334.8 calories

• Basal Metabolic Rate is 1334.8

Fiber

• Need 20-30 g of fiber per day• Functions:

– Keeps contents of the intestines moving, prevents constipation

– Helps reduce the risk of colon cancer by allowing food to pass quickly through the GI tract

– Stimulates muscles of the digestive tract– Absorbs water and gives the feeling of

fullness, contributes to healthy eating

Top Ten High Fiber Foods

Assignment

• Working with 2-3 people, create a poster of the digestive system

• Draw out the digestive system, Label and color each part

• Describe what each part of the digestive system does

• Due at the end of class on Thursday (: