The Respiratory System https://www.youtube.com/watch?v=qGiPZf7njqY

Inhalation vs. Exhalation

Respiration- Exchange of gases between your body and the environment; inhalation and exhalation Structure and Function: 1. Inhalation- Muscles between ribs and diaphragm (separates the chest cavity and the abdominal cavity) contract to make chest bigger; air rushes in from higher pressure outside to lower pressure inside -Air enters either through the nose or mouth

Nose is better because air is filtered, cleaned, and warmed by mucous membranes and cilia -After the nose, air goes through the pharynx (throat) and into the trachea (windpipe), which also has mucous membranes and cilia -At the beginning of the trachea is the larynx (voice box)

Food pipe (esophagus) vs. Wind pipe (trachea)

-The trachea branches into two bronchi that lead into the lungs -The trachea branches into two bronchi that lead into the lungs *bronchus= singular; bronchi= plural -The bronchi are divided into a network of bronchioles -At the end of each bronchiole is a cluster of alveoli. These are covered with capillaries that allow exchange of O2 and CO2 (where the magic happens!) https://www.youtube.com/watch?v=EtrsdmuhcT8&feature=related 2. Exhalation- Rib muscles/diaphragm relax making the chest smaller; this creates higher pressure on inside forcing air outside

Common Problems of the Respiratory System Common place for infection due to easy access 1. bronchitis- inflammation of bronchi (wheezing, shortness of breath, cough, mucus); caused by irritants such as second hand smoke or pollution 2. asthma- trachea, bronchi, and bronchioles become narrowed, causing difficulty breathing; inhaler dispenses medication that dilates airways 3. pneumonia- inflammation of lungs caused by bacterial or viral infection; fluid fills alveoli; cough, fever, chills, chest pain 4. emphysema- disease that progressively destroys the walls of the alveoli; tissue damage is permanent; caused by firsthand smoking 5. sinusitis- sinus infection; inflammation of (-itis) the sinus tissues; can result from allergies or fever; caused by bacteria, usually cured with antibiotics

https://www.youtube.com/watch?v=ydmPh4MXT3g

Smoking may lead to emphysema and/or lung cancer

The Digestive System https://www.youtube.com/watch?v=s06XzaKqELk

3 Functions of the Digestive System Digestion- the physical (chewing) and chemical (acids and enzymes) breakdown of food Absorption- nutrients go from the digestive system into the circulatory system (bloodstream) Elimination- getting rid of body waste (going to the bathroom)

Structures and Processes of the Digestive System Ingestion- Taking food into the mouth/consuming Mastication- Chewing; done by teeth Saliva- Starts the digestive process; starts to dissolve and lubricate the food to be swallowed (has enzymes to begin the chemical breakdown) Tongue- Forms food into a ball to be swallowed Enzyme- a substance produced by a living organism that acts as a catalyst to bring about a specific biochemical reaction

Epiglottis- Tissue (flap) that covers the throat; prevents food from entering trachea Esophagus- Tube that takes the food from the mouth to the stomach Peristalsis- Involuntary wave-like muscle contractions that move food along the digestive tract

Epiglottis helps food from going down the trachea (wrong pipe)

Trachea vs. Esophagus

Stomach- Continues the breakdown of food by mixing it with gastric juices; stores food temporarily until ready to enter small intestine Chyme- soupy mixture of food and gastric juices; this is what moves from stomach to small intestine

Small intestine- 20-30 ft long, but only about an inch in diameter; peristalsis moves the chyme through Villi- Lines the small intestine; absorbs nutrients into the circulatory system (to be used by the body) Large intestine- 5-6 feet long; 2.5 inches in diameter; where unabsorbed chyme enters; water, vitamins, and minerals are absorbed into circulatory system; what is left is eliminated as waste/feces

Organs That Assist Digestion Liver- Regulates the levels of chemicals in blood and absorbs drugs and other poisonous substances (ex: alcohol and medicine); changes them into bile which goes to gall bladder Gall bladder- Stores bile until it is needed to be released into the small intestine to help breakdown of fats bile- a bitter greenish-brown alkaline fluid that aids digestion; is secreted by the liver and stored in the gallbladder Pancreas- Part of the endocrine (think: hormones) system; produces insulin as well as three digestive enzymes to break down carbs, fats, and proteins

Common Problems of the Digestive System Heartburn- acid reflux; acid from the stomach rushes up into the esophagus; does NOT involve the heart, but it is in the chest area; burning sensation Diarrhea- watery, loose feces Constipation- dry, hard feces; difficult to go “number 2” Appendicitis- inflammation of the appendix; a 3 1/2-inch-long tube of tissue that extends from the large intestine. No one is absolutely certain what the function of the appendix is. One thing we do know: We can live without it, without apparent consequences. Ulcer- a sore in the lining of the stomach