Nutrition and Digestion

Nutrition and Digestion Nutrition: - The process of how your body obtains raw materials. -Ingestion: the act of eating or drinking.

Nutrition and Digestion Digestive System: - the process of breaking food down into molecules small enough for the body to absorb. -Digestion occurs in 2 ways: 1. MECHANICAL 2. CHEMICAL

mostly by making various digestive fluids. TRUE DIGESTIVE STRUCTURE: A digestive organ that food actually comes into contact with and is directly involved in digestion. ACCESSORY DIGESTIVE STRUCTURE: No food actually passes through these organs, BUT they HELP the true digestive organs do their job, mostly by making various digestive fluids. MECHANICAL DIGESTION: PHYSICAL tearing, shredding, crushing, etc…of food into smaller pieces to help with chemical digestion! CHEMICAL DIGESTION: Breaking the chemical bonds in the food molecules so they can be used by our bodies.

A slender tube lined with 2 layers of muscle. Structure Function MOUTH CONTAINS: * Teeth * Salivary Glands * Tongue 1) The tongue has taste buds that sense sweet, salty, bitter and sour and it helps move food around so that it can be chewed and swallowed. 2) The salivary Glands produce saliva which is made of 90% water and 10% enzymes. 3) The saliva ENZYMES (called AMYLASE) partially digest STARCH and turn it into Glucose. A slender tube lined with 2 layers of muscle. To prevent choking when swallowing there is a flap of tissue called the epiglottis that covers over the trachea which leads to the lungs. ESOPHAGUS It uses muscle contractions called peristalsis to push the food down to the stomach.

A slender tube lined with 2 layers of muscle. Structure Function MOUTH CONTAINS: * Teeth * Salivary Glands * Tongue 1) The tongue has taste buds that sense sweet, salty, bitter and sour and it helps move food around so that it can be chewed and swallowed. 2) The salivary Glands produce saliva which is made of 90% water and 10% enzymes. VIDEO 3) The saliva ENZYMES (called AMYLASE) partially digest STARCH and turn it into Glucose. A slender tube lined with 2 layers of muscle. To prevent choking when swallowing there is a flap of tissue called the epiglottis that covers over the trachea which leads to the lungs. ESOPHAGUS It uses muscle contractions called peristalsis to push the food down to the stomach.

Function Structure STOMACH Is the size of a large grapefruit, lined with 3 layers of muscle and contains: STOMACH Enzymes continue to chemically digest the food molecules with the help of hydrochloric acid. 1) ACID Place where caffeine, aspirin and some water is directly absorbed into the bloodstream. 2) ENZYMES 3) MUCOUS which protects the lining of the stomach. One of the body’s first lines of defense against disease and infection.

Structure Function 20-30 feet in length and lined with tiny projections called VILLI Completes the digestion process. SMALL INTESTINE The VILLI absorb all the digested food molecules and send them to the bloodstream Wall of SI Digested food molecules Mesentery keeps the SI from kinking. villi Bloodstream Delivered to all parts of the body. Blood Vessels

Structure Function LIVER & GALL BLADDER The liver makes a VERY watery bile which it sends to the GB. The GB is filled with a green fluid called bile. The GB removes the extra WATER from the bile The GB is tucked under the fleshy lobes of the liver. This makes the bile able to NEUTRALIZE the acidic material entering the SI from the stomach.

Function Structure Looks like a cluster of grapes covered in cottage cheese—yum. Produces the ENZYMES that chemically digest the food in the SI. PANCREAS Also produces insulin which is used to help the body regulate the amount of sugar in the bloodstream. Removes the WATER from the left over digested material that enters it from the SI and forms a solid waste. LARGE INTESTINE Between 5-10 feet in length and is the home to millions of little bacteria. Bacteria live in the LI and digest the food our ENZYMES cannot (various vegetables like corn, lettuce, fibrous material, etc). As a by-product of this, the bacteria create various vitamins that get absorbed and used by the body.

Function Structure STOMACH Is the size of a large grapefruit, lined with 3 layers of muscle and contains: STOMACH Place where caffeine, aspirin and some water is directly absorbed into the bloodstream. 1) ACID One of the body’s first lines of defense against disease and infection. 2) ENZYMES 3) MUCOUS which protects the lining of the stomach. The enzymes (called PEPSIN) partially digest PROTEIN into smaller molecules called amino acids.

Structure Function 20-30 feet in length and lined with tiny projections called VILLI Completes the digestion process. SMALL INTESTINE The VILLI absorb all the digested food molecules and send them to the bloodstream Wall of SI Digested food molecules Mesentery keeps the SI from kinking. villi Bloodstream Blood Vessels The enzymes in the SI (called TRYPSIN) completely digest STARCH, PROTEIN and FAT!!

Very Acidic (Battery Acid) Function Structure Enzymes chemically digest food by BREAKING chemical bonds in large food molecules like STARCH, PROTEIN & FAT ENZYMES Helper Molecules that are secreted into the digestive system This leaves behind smaller molecules the body can absorb & easily use. Enzymes require a SPECIFIC temperature and pH at which to work. pH is a measure of how acidic something is. 1 7 14 Very Acidic (Battery Acid) Neutral (water) Basic (Bleach)

Digestive System Diagram the digestive system (use model on back of notes). Include all parts Color code each part of system. Use page 638 in Biology book for help.