Chapter 38 Digestive & Excretory System

Question of the day  What is the first part of food digestion?  Makes contact with your mouth - chewing!  What is the first part of food digestion?  Makes contact with your mouth - chewing!

38-1 Food & Nutrition  Calories  Nutrients - substances that provide energy for your body  Kinds of Nutrients  Water  Carbohydrates - Sugar  Fats - fatty acids  Proteins - amino acids  Vitamins - organics  Minerals - inorganics  Calories  Nutrients - substances that provide energy for your body  Kinds of Nutrients  Water  Carbohydrates - Sugar  Fats - fatty acids  Proteins - amino acids  Vitamins - organics  Minerals - inorganics

Vitamins  Vitamins are the ignition of a body  Organic molecules work with enzymes to regulate body  Important Vitamins:  A - retinol (green vegetables) for sight & skin cells  B12 - cyanocobalamin (meat, eggs, dairy) for red blood cells  C - ascorbic acid (citrus, broccoli) for immune system  D - calciferol (fish oil, eggs) for bone growth  Vitamins are the ignition of a body  Organic molecules work with enzymes to regulate body  Important Vitamins:  A - retinol (green vegetables) for sight & skin cells  B12 - cyanocobalamin (meat, eggs, dairy) for red blood cells  C - ascorbic acid (citrus, broccoli) for immune system  D - calciferol (fish oil, eggs) for bone growth

Minerals  Inorganic nutrients body needs in small amounts  Body does not digest minerals, loses them  Important minerals  Calcium - dairy (bones)  Potassium - bananas (nerves, acidity)  Sodium - salt (body water balance)  Iron - meats, grains (hemoglobin & ETC)  Zinc - meats, seafood (digestion enzymes)  Inorganic nutrients body needs in small amounts  Body does not digest minerals, loses them  Important minerals  Calcium - dairy (bones)  Potassium - bananas (nerves, acidity)  Sodium - salt (body water balance)  Iron - meats, grains (hemoglobin & ETC)  Zinc - meats, seafood (digestion enzymes)

The Need to Balance a Diet  Important to have each food group in right proportions  5 necessary groups:  Dairy  Proteins  Veggies  Fruits  Grains  1 unnecessary group:  Fats, Oils, & Sweets  Important to have each food group in right proportions  5 necessary groups:  Dairy  Proteins  Veggies  Fruits  Grains  1 unnecessary group:  Fats, Oils, & Sweets

Question of the day  What is the technical term for chewing your food?  Mastication  Refers to your muscles in the jaw called masseters  What is the technical term for chewing your food?  Mastication  Refers to your muscles in the jaw called masseters

38-2 Process of Digestion  Digestion - converts foods into simpler molecules for use  Starts in the mouth with teeth - chewing  Salivary glands kick in - secrete enzymes to digest  Enzymes are called Amylase break down sugar  Turns food into ball  Called BOLUS  Digestion - converts foods into simpler molecules for use  Starts in the mouth with teeth - chewing  Salivary glands kick in - secrete enzymes to digest  Enzymes are called Amylase break down sugar  Turns food into ball  Called BOLUS

Next Part of Digestion  Once food is swallowed:  Moves to PHARYNX (top part of throat)  Does NOT go into Larynx  That’s your windpipe to lungs  Epiglottis prevents food & water going to lungs  Moves to ESOPHAGUS  By PERISTALSIS - rythmic contractions pushing food to stomach  Once food is swallowed:  Moves to PHARYNX (top part of throat)  Does NOT go into Larynx  That’s your windpipe to lungs  Epiglottis prevents food & water going to lungs  Moves to ESOPHAGUS  By PERISTALSIS - rythmic contractions pushing food to stomach

To the Stomach!  How does food enter?  By a Sphincter (Gateway)  Stomach begins digestion 2 ways  Chemically  Mechanically  How does food enter?  By a Sphincter (Gateway)  Stomach begins digestion 2 ways  Chemically  Mechanically

Digestion (Cont.)  Chemical -  Hydrochloric Acid  Mucus - protects stomach lining  Pepsin - break proteins  Mechanical -  Stomach muscles contract & churn  Mix fluids & foods like washing machine  Creates Chyme  Chemical -  Hydrochloric Acid  Mucus - protects stomach lining  Pepsin - break proteins  Mechanical -  Stomach muscles contract & churn  Mix fluids & foods like washing machine  Creates Chyme

Moving to Small Intestine  Leaves stomach via Pyloric Sphincter  Into Small Intestine  Gets help from pancreas & liver  Removes fats, proteins, carbs thru wall  Wall is made of VILLI  Small fingers that absorb all nutrients  Leaves stomach via Pyloric Sphincter  Into Small Intestine  Gets help from pancreas & liver  Removes fats, proteins, carbs thru wall  Wall is made of VILLI  Small fingers that absorb all nutrients

Large Intestine  Food is still Chyme  Gets to Large Intestine  Main goal is to remove remaining nutrients & water  Then moves to colon as waste  Excreted thru rectum & anal sphincter  Called Stool (crap)  Food is still Chyme  Gets to Large Intestine  Main goal is to remove remaining nutrients & water  Then moves to colon as waste  Excreted thru rectum & anal sphincter  Called Stool (crap)

38-3 Excretory System  Kidney - filters blood  Starts in renal artery  Goes to Nephron (1000s in a kidney)  There water, nutrients go back to body  Wastes get filtered, sent to ureter, bladder  What is waste called?  Urine  Kidney - filters blood  Starts in renal artery  Goes to Nephron (1000s in a kidney)  There water, nutrients go back to body  Wastes get filtered, sent to ureter, bladder  What is waste called?  Urine

Cool Nephron  Inside Nephron are three important parts:  Glomerulus - where artery (blood) comes in  Bowman’s Capsule - protects glomerulus  Loop of Henle - tube that collects water, sends back to body  Animals that are efficient w/ water have very long loops of Henle  Examples?  Camels  Other desert animals  Sea Birds  Inside Nephron are three important parts:  Glomerulus - where artery (blood) comes in  Bowman’s Capsule - protects glomerulus  Loop of Henle - tube that collects water, sends back to body  Animals that are efficient w/ water have very long loops of Henle  Examples?  Camels  Other desert animals  Sea Birds

Kidney Problems & Diseases  Two main problems that effect Kidneys:  Renal Failure (Dialysis) - kidneys shut down and unless something filters blood - you die  Diabetes - high blood sugar makes kidneys work very hard  Body can’t absorb sugar in blood  Two main problems that effect Kidneys:  Renal Failure (Dialysis) - kidneys shut down and unless something filters blood - you die  Diabetes - high blood sugar makes kidneys work very hard  Body can’t absorb sugar in blood