The Digestive System

What Happens During Digestion Three Main Processes ◊ Digestion: is the mechanical and chemical breakdown of foods within the stomach and intestines for use by the body’s cells. ◊ Absorption: is the passage of digested food from the digestive tract into the cardiovascular system. ◊ Elimination: is the body’s expulsion of un digested food or body waste.

How Digestion Works Digestion includes two processes  Mechanical: involves chewing, mashing and breaking down food  Chemical: involves secretions produced by digestive organs

How Digestion Works Starts in mouth Starts in mouth goes down the esophagus to stomach goes down the esophagus to stomach then goes through the small and large intestines [90% of all nutrients are absorbed] then goes through the small and large intestines [90% of all nutrients are absorbed] large intestine takes care of the rest. large intestine takes care of the rest.

The Mouth & The Esophagus  Teeth- break food down with mastication (process of chewing)  Salivary Glands- produce gastric juices that help break down food  Tongue- prepares chewed food for swallow, by shaping –Uvula; small flap of tissue in the back of the mouth helps prevent food from entering nasal passages –Epiglottis- cover throat, prevents food from entering the respiratory system

The Mouth & The Esophagus Continued Esophagus: when food is swallowed it enter the Esophagus. The Esophagus is a muscular tube; 10 inches long that connects to the pharynx w/stomach Esophagus: when food is swallowed it enter the Esophagus. The Esophagus is a muscular tube; 10 inches long that connects to the pharynx w/stomach Peristalsis: is a series of muscle contractions that moves food through the Esophagus. Peristalsis begins as soon as food is swallowed. Peristalsis: is a series of muscle contractions that moves food through the Esophagus. Peristalsis begins as soon as food is swallowed. Sphincter Muscle: Is a circular muscle at the entrance of stomach. Allows food to move from Esophagus to stomach. Sphincter Muscle: Is a circular muscle at the entrance of stomach. Allows food to move from Esophagus to stomach.

The Stomach The stomach is a hollow The stomach is a hollow Sac-like organ with wall of muscles Sac-like organ with wall of muscles Those muscles are flexible, allows stomach to expand when you eat Those muscles are flexible, allows stomach to expand when you eat

The Stomach Continued The stomach has three tasks. 1.Mixing foods with gastric juices The hydrochloric acid kills bacteria The hydrochloric acid kills bacteria Mucus produced by stomach protects it from the acid Mucus produced by stomach protects it from the acid Secretions from stomach lining contain hydrochloric acid an pepsin an enzyme that digests protein Secretions from stomach lining contain hydrochloric acid an pepsin an enzyme that digests protein 2.Storing partially digested food & liquid Holds food for further digestion before it is moved into the small intestine Holds food for further digestion before it is moved into the small intestine 3.Moving food into the small intestine Food is covered in chyme, a creamy fluid mixture of food & gastric juices. Peristalsis moves chyme into small intestine Food is covered in chyme, a creamy fluid mixture of food & gastric juices. Peristalsis moves chyme into small intestine

The Pancreas, Liver, and Gallbladder –In small intestine chyme mix with 2 juices of 2 other organs –Pancreas produces enzymes that breakdown carbohydrates, fats, and proteins in food. –Liver-;other digestive juice - bile Bile- yellow-green bitter fluid; absorbs fat. Bile is stored in the gallbladder between meals. Bile- yellow-green bitter fluid; absorbs fat. Bile is stored in the gallbladder between meals.

Large & Small Intestine Small intestine 20-23ft. Long. &1 inch. in diameter ft. Long. &1 inch. in diameter. Small intestine has three parts. Small intestine has three parts.  Duodenum, jejunum, and ileun  Lined with villi that absorb nutrients.  Villi are fingerlike projections Large intestine (colon) 5-6ft. Long & 2.5 inch. in diameter. 5-6ft. Long & 2.5 inch. in diameter. Undigested parts of food and fiber pass into the colon. Undigested parts of food and fiber pass into the colon. Absorbs water, vitamins,and salts, and eliminates waste. Absorbs water, vitamins,and salts, and eliminates waste.

Digestive System Problems Digestive problems range from indigestion to acute conditions that require immediate medical attention. Digestive problems range from indigestion to acute conditions that require immediate medical attention. Eat variety of low fat, high fiber foods, & wash hands before cook or eat, eat slow, drink 8,8 oz. glass of water a day. Eat variety of low fat, high fiber foods, & wash hands before cook or eat, eat slow, drink 8,8 oz. glass of water a day.

Functional Problems Affect by illness, stress, or eating particular food Affect by illness, stress, or eating particular food Indigestion: Discomfort in upper abdomen Indigestion: Discomfort in upper abdomen  Gas or Nausea  Too much food  Eat to fast  Eat spicy/high fat  Stomach disorder  stress o Constipations: feces becomes to dry & hard o Not drinking enough water o Not consuming enough fiber o Heartburn: burning sensation in center of chest o Acid reflex o Using tobacco, alcohol, aspirin o Eating spicy or greasy food

Functional Problems  Nausea: feeling of discomfort makes vomit  Motion sickness  Some medication  Pathogens  Dehydration  Diarrhea: passage of watery feces  Bacterial  Viral infection  Change in eating  Over ate

Structural Problem  Tooth decay: difficult to chew  Brush and Floss  Dental Checks  Gastritis: inflammation of mucus membrane line in stomach  Gallstone: cholesterol in bile crystallizes. Blocks bile duct  Lactose Intolerance: cant digest lactose: sugar in milk

The Excretory System

How Excretory works…  Process of removing waste from body  Several organs involved

Lungs, Skin, & Large Intestine Lungs expel carbon dioxide when breathing Lungs expel carbon dioxide when breathing Sweat is another form Sweat is another form Removes water & salt Removes water & salt Regulates body’s temp. Regulates body’s temp. Too much = dehydration Too much = dehydration Large intestine = solid waste Large intestine = solid waste

Urinary System Uses Kidneys, bladder, ureter, urethra, & liver Uses Kidneys, bladder, ureter, urethra, & liver Filters waste & extra fluid from blood Filters waste & extra fluid from blood Urine; Liquid waste Urine; Liquid waste Contains Nitrogen Contains Nitrogen

Kidneys & Ureter  Kidneys  Bean shape; vary in size  Near middle of back  Removes waste through filters  Nephrons  Monitors acid-base & water  Ureter  Single tube  Used to travel from kidneys to bladder  8 to 10 inches long

Bladder & Urethra  Hollow & Muscular  Sphincter muscle: keep from leaks  Leads to the urethra  Urethra  Tube leads outside

Maintain Excretory Health Remove waste that can become toxic Remove waste that can become toxic Drink at least 8 of 8 oz. of water Drink at least 8 of 8 oz. of water Limit caffeine and soft drink Limit caffeine and soft drink Regular check ups Regular check ups Well balance eating plan Well balance eating plan

Excretory & Kidney Problems Excretory Infection or blockage Infection or blockage Cystilis Cystilis Inflamed bladder Inflamed bladder Urethristis Urethristis Inflamed urethra Inflamed urethraKidney Nephris Nephris Salts in urine crystillize to stones Uremia Uremia Serious condition Decrease blood filtration by kidney

Kidney Failure Hemodialysis Hemodialysis Machine to remove waste Machine to remove waste Peritoneal dialysis Peritoneal dialysis Use thin membrane Use thin membrane Surround digestive organs Surround digestive organs Kidney transplant Kidney transplant Replace non-working kidney Replace non-working kidney