Grab a copy of the Lung Capacity Lab. Get a ruler. Get out your paper. Thursday, February 23, 2017

What are the forces that move air into and out of the lungs? LEQ What are the forces that move air into and out of the lungs?

Lab Set up Get out a sheet of paper, a PENCIL, and a ruler On your paper: Put your first & last name, date & period # in the upper right corner Center the lab title on the first line Copy the Purpose Answer both Hypothesis questions in COMPLETE SENTENCES (your team is the people you are sitting with)

Copy Data Table Trial Balloon Diameter (cm) Lung capacity (L) 1 2 3 Average

When you think you’re ready to begin Show your paper to Mrs. Glisson She will give you a balloon if your hypothesis & data table are correctly done Carry out the procedure Record YOUR data Calculate averages Throw away your balloon Get a book & read pgs. 448-452 wait for everyone else to finish

Record Average Lung capacity in class table Answer Analysis #1 only Write a Conclusion: Was each of your hypothesis correct? Use data to support your answer Turn in lab paper; return ruler Get out new sheet of paper

Pulmonary ventilation external respiration Define the following Pulmonary ventilation external respiration

Read pgs. 448-452 on Resp. Phys.

Four Events of Respiration Pulmonary ventilation—moving air in and out of the lungs (commonly called breathing) External respiration—gas exchange between pulmonary blood and alveoli Oxygen is loaded into the blood Carbon dioxide is unloaded from the blood

External Respiration Figure 13.6 (2 of 2)

Four Events of Respiration Respiratory gas transport—transport of oxygen and carbon dioxide via the bloodstream Internal respiration—gas exchange between blood and tissue cells in systemic capillaries

Mechanics of Breathing (Pulmonary Ventilation) Completely mechanical process that depends on volume changes in the thoracic cavity Volume changes lead to pressure changes, which lead to the flow of gases to equalize pressure

Mechanics of Breathing (Pulmonary Ventilation) Two phases Inspiration = inhalation flow of air into lungs Expiration = exhalation air leaving lungs

Inspiration Diaphragm and external intercostal muscles contract The size of the thoracic cavity increases External air is pulled into the lungs due to Increase in intrapulmonary volume Decrease in gas pressure

Inspiration Figure 13.7a

Inspiration Figure 13.8

Expiration Largely a passive process which depends on natural lung elasticity As muscles relax, air is pushed out of the lungs due to Decrease in intrapulmonary volume Increase in gas pressure Forced expiration can occur mostly by contracting internal intercostal muscles to depress the rib cage

Expiration Figure 13.7b

Expiration PLAY Respiration: Pressure Gradients Figure 13.8

Pressure Differences in the Thoracic Cavity Normal pressure within the pleural space is always negative (intrapleural pressure) Differences in lung and pleural space pressures keep lungs from collapsing

Nonrespiratory Air (Gas) Movements Can be caused by reflexes or voluntary actions Examples: Cough and sneeze—clears lungs of debris Crying—emotionally induced mechanism Laughing—similar to crying Hiccup—sudden inspirations Yawn—very deep inspiration

Crash Course Circulatory and Respiratory Copy on your paper How do the circulatory and respiratory systems work together to carry out their functions? Crash Course Circulatory and Respiratory

Spirometer

Respiratory Volumes Figure 13.9

Ticket out the door How do we breathe?