THE HUMAN THE HUMAN RESPIRATORYRESPIRATORYSYSTEMSYSTEM

•AimAim: How do the structures of the : How do the structures of the respiratory system exchange gases respiratory system exchange gases with the environment?with the environment?

•Do NowDo Now: What is the purpose of : What is the purpose of having a respiratory system? having a respiratory system?

•HomeworkHomework: Read 574-576; do Self : Read 574-576; do Self Check Questions # 1-4.Check Questions # 1-4.

What is Respiration?What is Respiration?

RespirationRespiration: :

the process of the process of exchanging exchanging gases between gases between the body and the body and the the environment.environment.

What is a Respiratory What is a Respiratory Surface?Surface?

• In all organisms, the exchange of In all organisms, the exchange of gases must occur across a gases must occur across a respiratory surfacerespiratory surface. . – Must be Must be moistmoist – Must be Must be very thinvery thin so that gases so that gases

are able to pass throughare able to pass through– Must be a Must be a supply of oxygensupply of oxygen– Must be closely Must be closely connected to the connected to the

transporttransport system to deliver gases system to deliver gases to and from cellsto and from cells

The Human Respiratory The Human Respiratory SystemSystem

Organs of the Organs of the Respiratory SystemRespiratory System

The NoseThe Nose

•The nose serves The nose serves to to filterfilter, , moistenmoisten, and , and warmwarm inhaled inhaled air before it air before it reaches the reaches the lungs. lungs.

What is the What is the Pharynx?Pharynx?

•Pharynx – “throat”Pharynx – “throat”

•Air moves from the nasal Air moves from the nasal passage passage the pharynx the pharynx

• EpiglottisEpiglottis – flap of tissue covering the – flap of tissue covering the trachea during swallowing preventing trachea during swallowing preventing food from entering the lungs.food from entering the lungs.

The LarynxThe Larynx• ““voice box”voice box”

• Larynx contains vocal cords used to Larynx contains vocal cords used to speak.speak.

• AirAir passes from the pharynx passes from the pharynx larynx larynx

• FoodFood passes from the pharynx passes from the pharynx esophagus esophagus

The TracheaThe Trachea•““the windpipe”the windpipe”

•Kept open by Kept open by rings of rings of cartilagecartilage

•Lined with Lined with ciliacilia and and mucous mucous membranesmembranes

•AimAim: How do the structures : How do the structures of the respiratory system of the respiratory system allow you to breathe?allow you to breathe?

•Do NowDo Now: What does the nose : What does the nose do to the air that you do to the air that you breathe? What is the role of breathe? What is the role of the cilia that line the trachea?the cilia that line the trachea?

•HomeworkHomework::

The BronchiThe Bronchi•Trachea divides Trachea divides

into tubes called into tubes called the the bronchibronchi

•Bronchi enter Bronchi enter lungs and lungs and branch off into branch off into tiny tubes called tiny tubes called bronchial bronchial tubestubes

The The BronchiolesBronchioles

•AKA: Bronchial TubesAKA: Bronchial Tubes•Thin network of microscopic tubes Thin network of microscopic tubes

found inside the lungs.found inside the lungs.

Alveoli: The Air Alveoli: The Air SacsSacs

Alveoli: The Air Alveoli: The Air SacsSacs• Found in the Found in the LUNGSLUNGS

• Each bronchiole ends in a tiny alveoliEach bronchiole ends in a tiny alveoli

• ““cluster of grapes”cluster of grapes”

• The alveoli are the The alveoli are the respiratory respiratory surfacesurface

• Exchange of OExchange of O2 2 and COand CO2 2 occurs occurs HERE!HERE!

• Alveoli are surrounded by capillaries Alveoli are surrounded by capillaries (so O2 enters blood). (so O2 enters blood).

Gas ExchangeGas Exchange

•Aim: How do the structures of Aim: How do the structures of the respiratory system work the respiratory system work together to allow you to together to allow you to breathe?breathe?

•Do Now: Explain how gas Do Now: Explain how gas exchange occurs in the lungs exchange occurs in the lungs

•Homework: Homework:

How do we How do we Breathe?Breathe?

What is Going What is Going on Inside When on Inside When You Breathe?You Breathe?

•Composed of two phases:Composed of two phases:–InhalationInhalation – draws air into – draws air into lungslungs

–ExhalationExhalation – expels air – expels air from lungsfrom lungs

What is the What is the Diaphragm?Diaphragm?

•Muscle that Muscle that contracts and contracts and relaxes to relaxes to move gas move gas into and out into and out of the lungs.of the lungs.

InhalationInhalation

•Ribs are Ribs are pulled up and outpulled up and out

•Diaphragm is pulled Diaphragm is pulled downwarddownward

•Chest cavity is Chest cavity is enlargedenlarged

•Lungs Lungs expandexpand

•Air pressure in chest Air pressure in chest decreasesdecreases

ExhalationExhalation•Diaphragm Diaphragm relaxes and pushes relaxes and pushes

upwardupward•Rib muscles Rib muscles relaxrelax – ribs – ribs dropdrop•Size of chest cavity Size of chest cavity decreasesdecreases•Air is Air is squeezed outsqueezed out of lungs of lungs •Air pressure in chest Air pressure in chest increasesincreases

BreathingBreathing

Rate of BreathingRate of Breathing•If COIf CO2 2 levels in the blood levels in the blood increaseincrease, your breathing , your breathing rate rate INCREASESINCREASES..

•If COIf CO22 levels levels decreasedecrease, , breathing rate breathing rate DECREASESDECREASES..

• AimAim: What are the malfunctions of : What are the malfunctions of the human respiratory system?the human respiratory system?

• Do NowDo Now: Is it INHALATION or : Is it INHALATION or EXHALATION?EXHALATION?– The ribs are pulled up and out, the The ribs are pulled up and out, the

diaphragm is pulled down. ___________diaphragm is pulled down. ___________– The lungs decrease in size, the The lungs decrease in size, the

diaphragm is pushed upward. diaphragm is pushed upward. ____________________________________

– The chest cavity decreases in size, the The chest cavity decreases in size, the pressure inside the chest increases. pressure inside the chest increases. ________________________________

• HomeworkHomework: :

DISEASES OF THE DISEASES OF THE RESPIRATORY SYSTEMRESPIRATORY SYSTEM

AsthmaAsthma•Severe allergic reaction where Severe allergic reaction where

muscles surrounding bronchial muscles surrounding bronchial tubes contract and make breathing tubes contract and make breathing extremely difficult.extremely difficult.

AsthmaAsthma

BronchitisBronchitis•Inflammation of the bronchial Inflammation of the bronchial

tubestubes

•Passageways become swollen Passageways become swollen and clogged with mucusand clogged with mucus

•Results in severe coughing Results in severe coughing and difficulty in breathingand difficulty in breathing

BronchitisBronchitis

EmphysemaEmphysema

• Walls of alveoli breakdown Walls of alveoli breakdown decreasing the respiratory surfacedecreasing the respiratory surface

• Causes shortness of breath, difficulty Causes shortness of breath, difficulty exhaling and decreased lung capacityexhaling and decreased lung capacity

**Smokers run a greater risk of Smokers run a greater risk of developing emphysema*developing emphysema*

EmphysemaEmphysema

PneumoniaPneumonia•Alveoli become Alveoli become

filled with fluidfilled with fluid

•Caused by a Caused by a bacterial or bacterial or viral infectionviral infection

Lung CancerLung Cancer•Disease in Disease in

which tumors which tumors form in the form in the lungs from lungs from irregular and irregular and uncontrolled uncontrolled cell growthcell growth

Let’s Summarize…Let’s Summarize…1.1. What happens during respiration in What happens during respiration in

all animals?all animals?2.2. What are the requirements of a What are the requirements of a

respiratory surface?respiratory surface?3.3. How are dirt and other small How are dirt and other small

particles removed from the air particles removed from the air humans breathe?humans breathe?

4.4. List in order the structures that air List in order the structures that air passes through as it travels from the passes through as it travels from the external environment to the lungs. external environment to the lungs.

Let’s Summarize…Let’s Summarize…

5. Why are cilia important to the 5. Why are cilia important to the function of the lungs?function of the lungs?

6.6. At what point does the oxygen that At what point does the oxygen that you inhale actually enter into your you inhale actually enter into your blood?blood?

7.7. What happens to the rib cage What happens to the rib cage during inhalation and exhalation?during inhalation and exhalation?

8.8. What happens to the diaphragm What happens to the diaphragm during inhalation and exhalation?during inhalation and exhalation?

Let’s SummarizeLet’s Summarize

9. What system of the body carries the 9. What system of the body carries the oxygen taken in by the respiratory oxygen taken in by the respiratory system to all cells in the body? system to all cells in the body?

10. What is the scientific term for the 10. What is the scientific term for the “back of the throat”?“back of the throat”?

11. What is the role of mucous in the 11. What is the role of mucous in the respiratory system?respiratory system?

What Should We Study?What Should We Study?• Be able to :Be able to :

– Define all Define all vocabularyvocabulary in the respiratory system in the respiratory system – including structures– including structures

– Trace a drop of airTrace a drop of air from environment to the from environment to the alveoli in the lungs.alveoli in the lungs.

– Label diagramsLabel diagrams of the respiratory system. of the respiratory system.– Explain a Explain a malfunctionmalfunction of the respiratory of the respiratory

system and what causes it.system and what causes it.– Explain the Explain the functionfunction of each of the structures of each of the structures

in the respiratory system.in the respiratory system.– Discuss what makes a Discuss what makes a good respiratory good respiratory

surfacesurface – and where our respiratory surface is – and where our respiratory surface is found.found.