Human Digestive System

Image of the Digestive System An Introduction to the Human Digestive System. The Parts of the Human Digestive System

Functions Supplies energy to body cells: Ingest food Breaks down food – chemical/physical Move through digestive tract – muscular action in the esophagus pushes food to the stomach squeezing by the esophagus Absorb digested food and water Converts food to useable molecules Nutrients made available to body cells

Mouth Breaks down food into small pieces Chewing = chemical & physical change phy = changes shape of food chem = Saliva breaks down food Moves food into esophagus Epiglottis covers trachea

Salivary Glands Glands in the mouth and throat Produce chemicals (saliva) which lubricate food and begin the chemical digestive process Breakdown of starch into glucose by saliva is a chemical change

Esophagus Tube connecting the mouth to stomach Food is squeezed by the esophagus into stomach. This is called peristalsis. Through the Esophagus

Stomach Muscles churn food = physical digestion. Reaction of stomach acid & bile = chemical digestion Stomach is shaped like a pouch and is a property of the stomach that is NOT a property of the system as a whole Enzymes break down fats and proteins and is a chemical change

Pancreas produces insulin that regulates blood sugar levels helps neutralize stomach acid releases enzymes into the small intestine to break down the food

Gallbladder organ that stores bile for future use When there is no food in the small intestine bile from the liver is sent to the gall bladder where it is stored, to be released when food enters the digestive tract.

Liver processes and distributes nutrients. creates bile, which is important in chemically breaking down the food in the small intestine. processes damaged red blood cells and stores vitamins A and D.

Small Intestine! Digestion is finished here Most chemical digestion occurs here Pancreatic juice produces enzymes to finish chemical digestion of fats, proteins and carbohydrates In the Small Intestine

Large Intestine Absorbs water Stores solid waste in rectum until elimination. Final stage of digestion The Large Intestine

Fun Facts The circulatory and the digestive systems work together to obtain important vitamins and nutrients and transport them to the cells all over the body. Your intestines are at least 25 feet in an adult. Be glad you're not a full-grown horse -- their coiled-up intestines are 89 feet long! Chewing food takes from 5-30 seconds Swallowing takes about 10 seconds Food sloshing in the stomach can last 3-4 hours It takes 3 hours for food to move through the intestine Food drying up and hanging out in the large intestine can last 18 hours to 2 days! In your lifetime, your digestive system may handle about 50 tons The lining of your digestive system is shed every 3 days 1.7 litres of saliva is produced each day

The Excretory System and The Digestive System are mainly responsible for taking in nutrient food molecules and getting rid of waste products.

The Excretory System The Urinary System

The Excretory System Functions: to rid the body of wastes, including excess water and salts dispose of waste and control body fluid Directly responsible for maintaining the volume and composition of most body fluids

The Excretory System Major Organs Kidneys Ureters Urinary Bladder Skin & lungs

Kidney Located behind the intestines Remove waste (urine, toxins, urea, water and mineral salts) from your body Filter blood that has collected wastes from your body's cells Regulates chemical composition of blood Maintains homeostasis

Kidney Filtration The kidney is a two stage filter It is made up of 1 million nephrons Stage 1 occurs when water, sugar, salt and waste from blood pass into a cup like structure Stage 2 occurs as the liquid in the cuplike structure is squeezed into a narrow tubule capillaries perform the next filtration and return purified blood to main circulatory system and the waste water (called urine) is moved to the bladder

Functions of the Urinary System Regulates water and other substances in the blood Removes metabolic waste Removes nitrogenous waste

Ureters Tubes that lead from each kidney and connects to the bladder Urine travels through this tube to the bladder

Urinary Bladder Elastic, muscular organ that holds urine until it leaves the body Can hold up to 0.5 L A tube called the urethra carries urine from the bladder out of the body

The Role of the Kidney in Homeostasis The kidney is essential in maintaining the correct amount of water in the blood.   

Urinary Diseases Problems in the urinary system include kidney failure, urinary tract infections, kidney stones, prostate enlargement, and bladder control problems. Cancer can affect both the kidney and the bladder

When kidneys go wrong People can live healthily with one functioning kidney. However, when about 90% of kidney function has been lost, a person can only survive by having dialysis. Dialysis works by using a machine that replicates the blood-cleaning function of healthy kidneys. In the most extreme cases of kidney failure, survival depends on the person receiving a donor organ

Fun Facts Your blood passes through the kidneys 300 times a day. Your kidneys have about a million structures that filter out liquids and wastes. About 440 gallons of blood flow through the kidneys each and every day! The nephrons clean all your blood in 45 minutes.  Every day the nephrons send about six cups of urine to the bladder

Extras Facts about pee Facts about poop Kidney animation Printable worksheets and online quiz No Sweat Scavenger Hunt Black line masters from United Streaming