THE HUMAN RESPIRATORY SYSTEM

Aim: How do the structures of the respiratory system exchange gases with the environment? Aim: How do the structures of the respiratory system exchange gases with the environment? Do Now: What is the purpose of having a respiratory system? Do Now: What is the purpose of having a respiratory system? Homework: Read ; do Self Check Questions # 1-4. Homework: Read ; do Self Check Questions # 1-4.

What is Respiration? Respiration: the process of exchanging gases between the body and the environment. the process of exchanging gases between the body and the environment.

What is a Respiratory Surface? In all organisms, the exchange of gases must occur across a respiratory surface. In all organisms, the exchange of gases must occur across a respiratory surface. –Must be moist –Must be very thin so that gases are able to pass through –Must be a supply of oxygen –Must be closely connected to the transport system to deliver gases to and from cells

The Human Respiratory System

Organs of the Respiratory System

The Nose The nose serves to filter, moisten, and warm inhaled air before it reaches the lungs. The nose serves to filter, moisten, and warm inhaled air before it reaches the lungs.

What is the Pharynx? Pharynx – “throat” Air moves from the nasal passage  the pharynx Epiglottis – flap of tissue covering the trachea during swallowing preventing food from entering the lungs.

The Larynx “voice box” “voice box” Larynx contains vocal cords used to speak. Larynx contains vocal cords used to speak. Air passes from the pharynx  larynx Air passes from the pharynx  larynx Food passes from the pharynx  esophagus Food passes from the pharynx  esophagus

The Trachea “ the windpipe” “ the windpipe” Kept open by rings of cartilage Kept open by rings of cartilage Lined with cilia and mucous membranes Lined with cilia and mucous membranes

Aim: How do the structures of the respiratory system allow you to breathe? Aim: How do the structures of the respiratory system allow you to breathe? Do Now: What does the nose do to the air that you breathe? What is the role of the cilia that line the trachea? Do Now: What does the nose do to the air that you breathe? What is the role of the cilia that line the trachea? Homework: Homework:

The Bronchi Trachea divides into tubes called the bronchi Trachea divides into tubes called the bronchi Bronchi enter lungs and branch off into tiny tubes called bronchial tubes Bronchi enter lungs and branch off into tiny tubes called bronchial tubes

The Bronchioles AKA: Bronchial Tubes AKA: Bronchial Tubes Thin network of microscopic tubes found inside the lungs. Thin network of microscopic tubes found inside the lungs.

Alveoli: The Air Sacs

Alveoli: The Air Sacs Found in the LUNGS Each bronchiole ends in a tiny alveoli “cluster of grapes” The alveoli are the respiratory surface Exchange of O2 and CO2 occurs HERE! Alveoli are surrounded by capillaries (so O2 enters blood).

Gas Exchange

Aim: How do the structures of the respiratory system work together to allow you to breathe? Aim: How do the structures of the respiratory system work together to allow you to breathe? Do Now: Explain how gas exchange occurs in the lungs Do Now: Explain how gas exchange occurs in the lungs Homework: Homework:

How do we Breathe?

What is Going on Inside When You Breathe? Composed of two phases: Composed of two phases: –Inhalation – draws air into lungs –Exhalation – expels air from lungs

What is the Diaphragm? Muscle that contracts and relaxes to move gas into and out of the lungs. Muscle that contracts and relaxes to move gas into and out of the lungs.

Inhalation Ribs are pulled up and out Ribs are pulled up and out Diaphragm is pulled downward Diaphragm is pulled downward Chest cavity is enlarged Chest cavity is enlarged Lungs expand Lungs expand Air pressure in chest decreases Air pressure in chest decreases

Exhalation Diaphragm relaxes and pushes upward Diaphragm relaxes and pushes upward Rib muscles relax – ribs drop Rib muscles relax – ribs drop Size of chest cavity decreases Size of chest cavity decreases Air is squeezed out of lungs Air is squeezed out of lungs Air pressure in chest increases Air pressure in chest increases

Breathing

Rate of Breathing If CO 2 levels in the blood increase, your breathing rate INCREASES. If CO 2 levels in the blood increase, your breathing rate INCREASES. If CO 2 levels decrease, breathing rate DECREASES. If CO 2 levels decrease, breathing rate DECREASES.

Aim: What are the malfunctions of the human respiratory system? Aim: What are the malfunctions of the human respiratory system? Do Now: Is it INHALATION or EXHALATION? Do Now: Is it INHALATION or EXHALATION? –The ribs are pulled up and out, the diaphragm is pulled down. ___________ –The lungs decrease in size, the diaphragm is pushed upward. __________________ –The chest cavity decreases in size, the pressure inside the chest increases. ________________ Homework: Homework:

DISEASES OF THE RESPIRATORY SYSTEM

Asthma Severe allergic reaction where muscles surrounding bronchial tubes contract and make breathing extremely difficult. Severe allergic reaction where muscles surrounding bronchial tubes contract and make breathing extremely difficult.

Asthma

Bronchitis Inflammation of the bronchial tubes Inflammation of the bronchial tubes Passageways become swollen and clogged with mucus Passageways become swollen and clogged with mucus Results in severe coughing and difficulty in breathing Results in severe coughing and difficulty in breathing

Bronchitis

Emphysema Walls of alveoli breakdown decreasing the respiratory surface Walls of alveoli breakdown decreasing the respiratory surface Causes shortness of breath, difficulty exhaling and decreased lung capacity Causes shortness of breath, difficulty exhaling and decreased lung capacity *Smokers run a greater risk of developing emphysema*

Emphysema

Pneumonia Alveoli become filled with fluid Alveoli become filled with fluid Caused by a bacterial or viral infection Caused by a bacterial or viral infection

Lung Cancer Disease in which tumors form in the lungs from irregular and uncontrolled cell growth Disease in which tumors form in the lungs from irregular and uncontrolled cell growth

Let’s Summarize… 1. What happens during respiration in all animals? 2. What are the requirements of a respiratory surface? 3. How are dirt and other small particles removed from the air humans breathe? 4. List in order the structures that air passes through as it travels from the external environment to the lungs.

Let’s Summarize… 5. Why are cilia important to the function of the lungs? 6. At what point does the oxygen that you inhale actually enter into your blood? 7. What happens to the rib cage during inhalation and exhalation? 8. What happens to the diaphragm during inhalation and exhalation?

Let’s Summarize 9. What system of the body carries the oxygen taken in by the respiratory system to all cells in the body? 10. What is the scientific term for the “back of the throat”? 11. What is the role of mucous in the respiratory system?

What Should We Study? Be able to : Be able to : –Define all vocabulary in the respiratory system – including structures –Trace a drop of air from environment to the alveoli in the lungs. –Label diagrams of the respiratory system. –Explain a malfunction of the respiratory system and what causes it. –Explain the function of each of the structures in the respiratory system. –Discuss what makes a good respiratory surface – and where our respiratory surface is found.