1. What is the function of the organ shown below? C. Produces enzymes that break down carbohydrates, proteins, and fats What is the name for the muscular contractions that push food through the digestive system? 2. B. Peristalsis 3. The small intestine shown below contains lymphatic vessels but no capillaries. Which nutrient will be absorbed by this small intestine? C. Fatty acids 4. A diagram of the human digestive system is shown below. Removing which organ would have the smallest impact on digestion, absorption, and elimination? (Assume the system will remain connected if a large organ is removed.) A. Esophagus No major role in digestion other than being a passageway
5. The digestive system below contains a mouth, a salivary gland, a stomach, a duodenum, and a pancreas. Which of the following foods will digest most completely in this system? D. Pasta - No chief cells (make pepsin), no parietal cells (acid) and no gall bladder (bile). Proteins and fats won’t be digested well PASTA is mostly carbs which are digested by amylase in mouth and pancreatic enzymes in small intestine.
How does the Respiratory System work? • YouTube clip: The Respiratory System http://www.youtube.com/watch?v=hc1YtXc_84A
Learning Goals • I understand the purpose and process of gas exchange. • I know the structure and function of the parts of the respiratory system. • I know the diseases associated with the respiratory system.
The Respiratory System • Takes up oxygen and eliminates the carbon dioxide produced when your body uses energy for growth, repair and reproduction.
Breathing How many times do you breath a day? - 21, 600 times! Breathing: involuntary – part of the brain detects the concentration of CO2 in the blood. • Inhalation: Air goes into the lungs (volume increases) • Exhalation: Air goes out of the lungs (volume decreases) Diaphragm - muscle located beneath the lungs • Contraction: Flattens down to increase the lung volume – air rushes in • Relaxation: Moves up to decrease the lung volume – air is forced out
What would happen if the concentration of CO2 in your blood got too high? • Brain send a signal to the diaphragm, the muscles between the ribs (intercostal muscles) and the heart. • Heart rate and breathing rate both increase. More oxygen in, and CO2 out
Gas Exchange Alveoli: Bronchi bronchioles in the lungs air sacs called alveoli (bunch of grapes). • Surrounded by networks of capillaries • Circulatory system provides constant blood flow through the capillaries in the lungs: - CO2 from the blood diffuses into the alveoli - O2 from the alveoli diffuses into the blood * Gases diffuse across two membranes
The Respiratory System in Fish • Fish have GILLS for gas exchange • Gills contain many capillaries that are close to the surface. This allows O2 from the surrounding water to diffuse into the capillaries and CO2 from the capillaries to diffuse into the surrounding water. • Fish open their mouths or swim constantly to keep a flow of water over their gills.
Summary • Gas exchange occurs in the alveoli which are surrounded by networks of capillaries. O2 diffuses into the blood and CO2 diffuses into the lungs • The circulatory system delivers oxygen to the cells and removes carbon dioxide. • Main parts - nose, mouth, trachea, bronchi, lungs and diaphragm. • Many diseases are associated with the respiratory system including TB, cancer, asthma and SARS. • Some organisms have different respiratory systems.
Homework • 2 page worksheet: What is the Respiratory System? Due Monday in class • QUIZ TUESDAY