The Human Respiratory System

What are the primary functions of the respiratory system?

Oxygen Is obtained from the air by diffusion across delicate exchange surfaces of lungs Is carried to cells by the cardiovascular system which also returns carbon dioxide to the lungs

What are the main parts of the respiratory system?

nasopharynx pharynx larynx trachea bronchial tube pleura bronchiole Lung alveoli diaphragm

Bronchial tubes (bronchi) STRUCTURE FUNCTION nose / nasal cavity  warms, moistens, & filters air as it is inhaled pharynx (throat)  passageway for air, leads to trachea larynx  the voice box, where vocal chords are located trachea (windpipe)  keeps the windpipe "open"  trachea is lined with fine hairs called cilia which filter air before it reaches the lungs Bronchial tubes (bronchi)  two branches at the end of the trachea, each lead to a lung bronchioles  a network of smaller branches leading from the bronchi into the lung tissue & ultimately to air sacs alveoli  the functional respiratory units in the lung where gases are exchanged

What controls the respiratory system?

Respiration rate is the number of breaths per minute Human respiration rate is controlled by a part of the brain called the medulla Sends signals to adjust levels of oxygen present in your body by changing your breathing rate Respiration rate is the number of breaths per minute

How does air get into the lungs?

How does O2 and CO2 get where it needs to go?

Alveoli Alveoli are tiny air sacs that fill up with air/oxygen when you breath in. Alveoli are surrounded by many tiny blood vessels called capillaries. The walls of alveoli (and capillaries) are so thin that the oxygen or carbon dioxide can pass through them, traveling right into, or out of your blood stream by diffusion

Diffusion of O2 and CO2 Red blood cells carry O2 and CO2 When a RBC carrying O2 nears tissue cells that are lacking in O2, diffusion will occur from the blood cell to the tissues. Those same tissue cells will have a high concentration of CO2. So CO2 diffuses from the tissues to the RBC.

Diffusion •RBC’s have the protein HEMOGLOBIN binds the oxygen tightly so that no diffusion occurs until the RBC. is near O2 deprived body cells

Summary of diffusion in the lungs and tissue

How are delicate respiratory exchange surfaces protected from pathogens, debris, and other hazards?

The Respiratory Defense System Removes particles and pathogens that are in the air we breath everyday, we do not want this stuff to get in! Consists of a series of filtration mechanisms

Components of the Respiratory Defense System Goblet cells and mucus glands: produce mucus that bathes exposed surfaces Cilia: sweep debris trapped in mucus toward the pharynx (mucus escalator) Filtration in nasal cavity removes large particles Alveolar macrophages engulf small particles that reach lungs

Next: The Cardio-Pulmonary System How do cells at a distance get oxygen needed?

Fun Facts * The right lung is slightly larger than the left. * At rest, the body takes in and breathes out about 10 liters of air each minute. * The right lung is slightly larger than the left. * The highest recorded "sneeze speed" is 165 km per hour. * The surface area of the lungs is roughly the same size as a tennis court. * The capillaries in the lungs would extend 1,600 kilometers if placed end to end. * We lose half a liter of water a day through breathing. This is the water vapor we see when we breathe onto glass. * A person at rest usually breathes between 12 and 15 times a minute. * The breathing rate is faster in children and women than in men.

The 4 steps of Respiration in Mammals Air or water, containing oxygen, is moved past a respiratory surface by bulk flow. 2. O2 and CO2 are exchanged through the respiratory surface by diffusion. O2 enters the capillaries and CO2 leaves. 3. Gases are transported between the respiratory system & the tissues by the bulk flow of blood (pumped by a heart) 4. Gas exchange between tissue and circulatory system. O2 diffuses out of capillaries and CO2 diffuses into them. Diffusion = movement of particles from a region of high concentration to one of low concentration. Bulk flow = movement of many particles from an area of higher pressure to one of lower pressure

To do : Read pages 282-290 Page 285# 1-6 Page 289 #1-3