Respiratory System

What Happens During Respiration In external respiration, oxygen moves from the lungs into the blood, and carbon dioxide moves from the blood into the lungs. In internal respiration, oxygen moves from the blood into the cells, and carbon dioxide moves from the cells into the blood.

How Respiration Works As you inhale, the diaphragm and the muscles between your ribs contract, expanding your chest cavity and your lungs. Diaphragm A muscle that separates the chest from the abdominal cavity

Respiratory Pathway Nasal Cavity- Nose or mouth Pharynx - Throat Larynx - Voice Box Trachea- Lined with cilia Bronchus 2 bronchi; one for each lung; they reach into lungs Bronchiole many tiny branches Alveoli tiny bundles of air sacs where the capillaries are located Capillaries Gases are exchanged here

Respiratory System Problems An inflammation of the tissues that line the sinuses, air-filled cavities above the nasal passages and throat. Sinusitis An inflammation of the bronchi caused by infection or exposure to irritants such as tobacco smoke or air pollution. Bronchitis An inflammation of the lungs commonly caused by a bacterial or viral infection. Pneumonia

Respiratory System Problems During an asthma attack, an involuntary contraction of smooth airway muscles leads to chest tightness and breathing difficulty. Asthma An inflammatory condition in which the trachea, bronchi, and bronchioles become narrowed, causing difficulty breathing

Respiratory System Problems Emphysema, which is almost always caused by smoking, causes breathing difficulty, chronic cough, and permanent tissue damage. Emphysema A disease that progressively destroys the walls of the alveoli

The Digestive System

What Happens During Digestion Three Main Processes of the Digestive System The mechanical and chemical breakdown of foods within the stomach and intestines for use by the body’s cells. Digestion The passage of digested food from the digestive tract into the cardiovascular system. Absorption The body’s expulsion of undigested food or body wastes. Elimination

DIGESTIVE PATHWAY Oral Cavity (mouth) Esophagus Stomach Small Intestine Large Intestine Rectum Anus Be sure to include the various things that also happen: teeth, gastric juices, chyme, pancreas, bile, liver, colon, carbohydrates, fats, proteins, etc.

How Digestion Works The digestive system consists of the mouth, esophagus, stomach, and intestines. Carbohydrates begin digesting in the mouth, protein begins digesting in the stomach, and fats begin digesting in the small intestines.

How Digestion Works Digestion includes two processes. Mechanical Processes Chewing, mashing, and breaking food down. Chemical Processes Secretions produced by digestive organs.

How Digestion Works The teeth break the food you eat into smaller pieces. Mastication prepares food to be swallowed. Salivary glands produce saliva, which contains an enzyme that begins to break down the starches and sugars in food into smaller particles. The tongue prepares chewed food for swallowing by shaping it.

The Esophagus When food is swallowed, it moves through the esophagus, stomach, and intestine through peristalsis. Peristalsis A series of involuntary muscle contractions that moves food through the digestive tract

The Stomach The stomach has three tasks: Storing partially digested food and liquid Mixing foods with gastric juices Moving food into the small intestine

The Stomach The hydrochloric acid in gastric juices kills bacteria taken in with food and creates an acidic environment for pepsin to do its work. Gastric juices Secretions from the stomach lining that contain hydrochloric acid and pepsin, an enzyme that digests protein

The Stomach The stomach holds the food for further digestion before it is moved into the small intestine. As food is digested in the stomach, it is converted to chyme, a creamy, fluid mixture of food and gastric juices, which is moved into the small intestine.

The Stomach The three layers of stomach muscles each move in different directions to aid both mechanical and chemical digestion.

The Pancreas, Liver, and Gallbladder The liver produces bile and the pancreas produces other enzymes that break down the carbohydrates, fats, and proteins in food in the small intestine. Bile A yellow-green, bitter fluid important in the breakdown and absorption of fats

The Small and Large Intestines About 90 percent of all nutrients are absorbed through the small intestine. Unabsorbed material leaves the small intestine in the form of liquid and fiber and moves by peristalsis into the large intestine.

The Small and Large Intestines The inner wall of the small intestine contains millions of fingerlike projections called villi that are lined with capillaries that absorb the nutrients.

The Small and Large Intestines The undigested parts of the food—fiber, or roughage—pass into the colon, or large intestine. Its function is to absorb water, vitamins, and salts, and to eliminate waste.

Digestive System Problems Tips for Maintaining Digestive Health Eat a variety of low-fat, high-fiber foods. Wash your hands before preparing or eating meals. Eat slowly and chew your food thoroughly. Drink at least eight 8-ounce glasses of water a day. Avoid using food as a way of dealing with your emotions.

Functional Problems Indigestion Constipation Heartburn Gas Nausea Discomfort in the abdomen, sometimes with gas and nausea. Indigestion Feces become dry and hard, making bowel movements difficult. Constipation A burning sensation in the chest that may rise up to the throat. Heartburn Cramps or an uncomfortable feeling of fullness in the abdomen. Gas A feeling of discomfort that sometimes precedes vomiting. Nausea Diarrhea The frequent passage of watery feces.

Structural Problems Tooth decay Gastritis Gallstones Makes it difficult to chew foods thoroughly. Inflammation of the mucous membrane that lines the stomach Gastritis Blockage of the bile duct between the gallbladder and the small intestine. Gallstones Lactose Intolerance An inability to digest lactose, a type of sugar found in milk and other dairy products. Colitis Inflammation of the large intestine, or colon.

Structural Problems Colon cancer Hemorrhoids Crohn’s Disease Cirrhosis Cancer that usually develops in the lowest part of the colon, near the rectum. Colon cancer Veins in the rectum and anus that may become swollen and inflamed. Hemorrhoids Inflammation of the lining of the digestive tract. Crohn’s Disease Scarring of the liver tissue caused by prolonged heavy alcohol use. Cirrhosis

Structural Problems Appendicitis can cause the appendix to burst, spreading infection throughout the abdomen, which can lead to death. Peptic ulcers can be caused by a bacterial infection or the overuse of aspirin. They can cause stomach bleeding.

Structural Problems Cirrhosis is caused by prolonged heavy alcohol use. It can lead to liver failure and may cause death.