Digestion Respiration Excretion Chapter 14 Digestion Respiration Excretion

14.1 Digestive System

A. Digestion -Breaking down food into small molecules that can be absorbed by the blood 1. Mechanical- physical process -chew, mix, churn, swallow 2. Chemical- chemical process -reactions, enzymes

B. 4 Stages of Digestion Ingestion Digestion Absorption Elimination

C. Enzymes -proteins that start or speed up chemical reactions -digestion of carbohydrates, proteins, and fats

D. Organs 1. Mouth- tongue, teeth, saliva -change food into a soft mass 2. Esophagus- muscular tube that moves food to stomach using peristalsis (waves of muscular contractions) 3. Stomach- food becomes a thin, watery mixture called chyme -mechanical- peristalsis -chemical- enzymes & hydrochloric acid

4. Small intestine- blood transports nutrients to cells -folds called villi increase the surface area to increase food absorption 5. Large intestine (colon) -absorbs water from undigested chyme -rectum and anus control and release solid waste from the body

E. Accessory Organs -Pancreas- controls blood sugar -Liver- produces bile; breakdown fats -Gall Bladder- digest “rough” material -Salivary Glands – produce saliva *all contain enzymes to help digest food particles

Do we need our gall bladder? Fortunately, the gallbladder is an organ that people can live without. Losing it won't even require a change in diet. Once the gallbladder is removed, bile flows out of the liver through the hepatic ducts into the common bile duct and goes directly into the small intestine, instead of being stored in the gallbladder. However, because the bile isn't stored in the gallbladder, it flows into the small intestine more frequently, causing diarrhea in some people. Also, some studies suggest that removing the gallbladder may cause higher blood cholesterol levels, so occasional cholesterol tests may be necessary.

F. Bacteria -found in the large intestine -feed on undigested material like cellulose -make vitamins you need -Vitamin K: needed for blood clotting -Vitamin B: needed for nervous system -the breakdown of intestinal materials by bacteria is called “flatulence” (“poof”)

14.2 Chart from overhead

14.3 Respiratory System

A. Functions 1. Breathing supplies O2 & releases CO2 2. Cellular Respiration- releases energy 3. Waste products- CO2 and water

B. Organs Nose/Mouth- take in air Pharynx (throat)- passage for food & air Larynx- contains vocal chords Trachea- tube of cartilage lined with cilia & mucus that takes air into lungs Bronchi- short tubes that branch from trachea and lead into lungs

Bronchioles- smallest tubes Alveoli- clusters of air sacs at the end of the bronchioles Capillaries- smallest blood vessels where O2 & CO2 are exchanged Diaphragm- sheet of muscle below lungs

C. Diseases & Disorders 1. Respiratory Infections -cold, flu, pneumonia 2. Chronic Bronchitis -bronchial tubes are irritated and swell 3. Emphysema -alveoli enlarge and fail 4. Lung Cancer -uncontrolled cell growth in lung tissue 5. Asthma -shortness of breath and wheezing

14.4 Excretory System Function- removes waste Kidney

IN OUT Digestive Respiratory Skin Urinary Food & liquid Water & undigested food Respiratory oxygen Carbon dioxide Skin nothing Salt, organic substances Urinary Water salts Excess water, salts

A. Urinary System 1. Functions -gets rid of cell waste -controls blood volume -filters blood -produces & releases waste

2. Organs a. Kidneys- bean shaped, red-brown color - filters blood every 5 minutes b. Nephrons- filtering units inside kidneys c. Ureters- tubes connecting kidneys to bladder d. Bladder- elastic muscle, stores urine e. Urethra- tube that allows urine to pass outside of body

3. Diseases & Disorders a. Infections often occur in the bladder and spread to the kidneys ***treat with cranberry juice and water*** b. Ureters and urethra can become blocked; interrupting urine flow and damaging kidneys c. Kidney failure- if both kidneys fail, a person would need to undergo dialysis ( a machine used to filter the blood)