Digestive System

In Class Notes:

Functions

• The digestive system breaks down food for nutrients and energy.

• The food is taken through the mouth and then is broken down into small molecules that are converted to energy.

Four Stages of Food Processing

• Ingestion-Act of eating or drinking

• Digestion-Process of breaking food down into molecules small enough for the body to absorb.

• Absorption-Cells take up the small molecules.

• Elimination-Undigested material passes out of the body as waste.

Two Types of Digestion

• Mechanical Digestion-Chewing that chops and grinds food into small pieces.

• Chemical Digestion-Breaks the chemical bonds of large molecules that make up food.

Organs of the Digestive System

Mouth: Were digestive system starts

Throat: passageway that connects the mouth and the esophagus

Esophagus: food passes through it to get to the stomach

Stomach: Breaks down food into nutrients

Small Intestine: help absorb the nutrients from the 'food' into the bloodstream

Organs Continued

Large Intestine: absorb the remaining water from indigestible food matter

Rectum: temporary storage facility for feces (waste)

Anus: Feces (non-liquid waste products) are expelled from the body through the anus

Pictures

• Ingestion - teeth, tongue, saliva, esophagus (with the help of peristalsis)

• Digestion - stomach, liver, pancreas, gallbladder

• Absorption - small/large intestines

• Elimination - rectum, anus,

Nutrition: (29.3)• Carbohydrates

– Surgars for energy, used by body often

• Water– Used in cellular respiration for breaking bonds in sugars

• Lipids– Stores more energy than Carbs or proteins. Used by body less often however

• Vitamins– Organic molecules used by body paired with enzymes to carry out functions such as

growth, repairs, ect…– Fat soluble

» Stored by the body– Water soluble

» Cannot be stored by body

• Minerals– Elements that the body requires in inorganic forms

• Used in small amounts, like vitamins

• Proteins/ amino acids– Proteins make structure such as hair, make up muscle fibers, and are used for

nutrient storage – 8 essential amino acids

• Amino acids required for protein production– Body cant store excess amino acids

• Fibers– Indigestible

• used for poop

Diagram:

• Here are all the parts:

Parts you should know:

LITTLE BOOKSCOLIC

WHEN AN INFANT HAS UNCONTROLLABLE CRYING DUE TO STOMACH DISCOMFORTMANY INFANTS GO THROUGH IRT, BUT IT IS ONLY TEMPORARY

HERNIARIPPED TISSUE OFTEN DUE TO HEAVY LIFTINGBULGE OR LUMP IN ABDOMEN AREA

ALCOHOLIC LIVER DISEASEFEVER, FATIGUE, NAUSEA AND LIVER PROBLEMSDUE TO ALCOHOL ABUSE

LACTOSE INTOLERANCEWHEN THE BODY DOESN’T PRODUCE LACTATE(THAT BREAKS DOWN LACTOSE)IT CAUSES NAUSEA, CRAMPS, HEARTBURN, VOMITING AND GENERAL STOMACH DISCOMFORT

ACID REFLUX/ GERDACIDIC STOMACH JUICES FLOW BACK INTO ESOPHAGUSCAUSES IMMFLAMATION IN THE ESOPHAGUS

ROTAVIRUSA VIRUS THAT CAUSES VOMITING, WATERY DIARRHEA, FEVER, DEHYDRATIONPREVENTED BY WASHING YOUR HANDS

• Malnutrition- a diet lacking in one or more essential nutrients

• Undernutrition- deficient in Calories • Obesity- seriously overweight • Anorexia- disorder involving self-starvation • Bulimia- disorder involving bingeing and

purging • Bingeing without purging is not a good

idea, either.

Function: (29.1)

• Function of the digestive system

• 4 stages of food processing (describe each)

• 2 types of digestion– Give examples of each

Vocabulary:

• Bolus- a chewed clump of food that is pushed down the throat

• Peristalsis- a series of muscle contractions when food is pushed down the esophagus

• Constipation-a condition of the bowels in which the feces are dry and hardened and evacuation is difficult and infrequent

• Diarrhea- an intestinal disorder characterized by abnormal frequency and fluidity of fecal evacuations

Vocabulary:

• Nutrition- process of how your body obtains raw materials from food

• Ingestion- the act of eating food or drinking; the first stage of food processing

• Absorption- uptake of small nutrient molecules; third stage of food processing

• Elimination- passage of undigested material from the digestive tract; fourth stage of food processing

Vocabulary:

• Feces- undigested food material and other food products

• Chyme- liquid mixture of food and stomach fluids release from the stomach into the small intestine

• Saliva- liquid secreted into the mouth that contains mucus and digestive enzymes that start chemical digestion

• Villus- fingerlike projections of the inner surface if the small intestine that functions in absorbing materials

Vocabulary: [pictures]