Digestive and Excretory systems SC.6.L.14.5 identify and investigate the general functions of the major systems of the human body and describe ways these system interact with each other to maintain homeostasis.

Essential unit Questions How do the digestive and excretory systems work together to maintain homeostasis? What is the pathway in which food is processed as it moves through the human body

Organs of the Digestive system Mouth Esophagus Stomach Small intestine Large intestine bacteria

The Digestive System What does the digestive system do? How do the parts of the digestive system work together? How does the digestive system interact with other systems?

Functions of the digestive system Ingestion 1 Digestion 2 Absorption 3 elimination 4

Ingestion- why do we taking in food Energy- every function of your body requires energy. Sleeping, walking, thinking, breathing are examples of ways our bodies use energy. Nutrients- substances that provide energy and materials for cell development growth, and repair. We get most of the nutrients we need from food.

Nutrients Proteins- Carbohydrate Fats Vitamins minerals

Proteins- large molecule that: PROTIENS Proteins- large molecule that: Made from amino acids Contain: carbon, hydrogen, oxygen, nitrogen and sometimes sulfur Relay signals between cells Protect against disease Provides support to cells We have 20 different amino that combine in different ways to make many different proteins Cells make most of these amino acids but some must come from food and supplemnets.

Carbohydrates- our bodies major source of energy. Good carbohydrates Bad carbohydrates Fruit Vegetables Whole grain foods Breads Pasta Sugar- candy High fructose corn syrup

Fats- also called lipids Functions Good fats Bad fats -provide energy Helps body absorb vitamins Builds cell membranes Insulates body from cold Should only be 25-35 percent of the Calories you consume Unsaturated fats Nuts Avocados Fish Olive oil Flax seed Saturated fats Increase cholesterol Fats from animal products Butter Lunch meat Dairy Red meat Poultry and skin

Vitamins, Minerals and water Inorganic nutrients ( do not contain carbon) Regulate many chemical reactions. Nutrients needed in small quantity For growth regulating body functions Preventing disease Your body is mostly water Water is necessary in every part of your body for most chemical reactions. Water is lost though sweat, cellular respiration, urination and breathing. If not replaced symptoms of dehydration will begin to show: Thirst, headache, muscle craps dizziness , weakness and reduced urine output.

Digestion Two types of digestion Just like two types of weathering: Mechanical and chemical Two types of digestion Mechanical-physically chewing food begins to break down food into smaller pieces which increases the speed of chemical digestion Chemical- chemical reaction as that break down molecules using enzymes.

Enzymes – proteins that help break down larger molecules into smaller molecules Functions Specialized enzymes Break down large molecules into smaller molecules so they can be more easily taken in by cells. Speed up reactions Cause reaction Made in the digestive system Amylase- breaks down carbohydrates Lipase- breaks down fats Pepsin and papain- break down proteins

Organs of Digestive System Mouth- Esophagus Stomach Small intestine Large intestine Bacteria (considered an organ)

MOUTH Saliva- Chemical digestion starts The very thought of food causes your mouth to begin producing saliva. At least one liter a day Contains amylase (enzyme that breaks down carbohydrates) Contains substances that neutralize acids in foods. Slippery texture allows food to slide down throat more easily. Tongue and teeth- work together to begin the process of mechanical digestion by chewing and moving food around the mouth

ESPHAGUS A muscular tube that connects the mouth to the stomach. Food moved by muscle contractions called peristalsis Like squeezing a tube of tooth paste..

STOMACH Large hollow organ Temporarily stores food- to allow time between meals And adult stomach can hold about 2 liters Aids in chemical digestion- produces enzymes and gastric juice Gastric juices produces stomach acid that Breaks down cell structures of plants and animals. As food combines with gastric juices it creates a thin water liquid called chyme

SMALL INTESTINE Most chemical digestion takes place here Most nutrients are absorbed here Long tube that connects to the stomach About 7 meters longs About 2.5 cm in diameter(hence, small intestine) The folds are covered with finger-like projections called villi Each villi has small capillaries that allow diffusion of nutrients from the intestine to the blood. Pancreas and liver make substances that are delivered to the small intestine to help with digestion.

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LARGE INTESTINE Food that is not digested (waste) by the small intestine move into the large intestine. Larger diameter -about 5 cm- Water that has not been absorbed by the small intestine will be absorbed here by the large intestine. The food that has not be digested by now is waste. As undigested food moves through the large intestine more and more water is removed and the waste becomes more solid. Muscle contractions move the waste through the large intestine into the last section of the large intestine that is called the rectum

elimination Muscles in the rectum and anus continue to contract until the semi solid waste- now called feces (poop) is removed from your body.

BACTERIA While some bacteria is harmful , there are many types of bacteria that are helpful. In our intestines there billions of healthy bacteria that are necessary for our digestion Some good bacteria even produces necessary vitamins

DIGESTIVE SYSTEM AND HOMEOSTASIS Blood absorbs nutrients Muscle contract in the intestines to .move food through the system

You should be able to: Use nutrients in a sentence Explain the difference between chemical and physical digestion Identify which nutrient is a major source of energy for our body Examine why it is important to consume vitamins. Identify which nutrient helps the body absorb vitamins Give examples signs of dehydration List 6 groups of nutrients and state one fact for each Plan a meal that contains food from each of the six food groups Identify which part of the digestive system absorbs most nutrients. Explain how is waste eliminated. Explain the role of bacteria in digestion Explain the role of different enzymes Identify and explain the types of digestion that take place in the mouth.