Respiratory SystemRespiratory System

Every animal needs a system to take in Every animal needs a system to take in oxygenoxygen from the environmentfrom the environment

Why is Why is oxygenoxygen needed? needed? Oxygen is required for Oxygen is required for cell respirationcell respiration Oxygen and Oxygen and nutrientsnutrients are combined to release are combined to release energyenergy

Remember cell respiration?Remember cell respiration?Reactants:Reactants: Products: Products:

GlucoseGlucose + + OO22 CO CO22 + H + H22O + O + EnergyEnergy

How Does Oxygen Get Into Cells?How Does Oxygen Get Into Cells?

OO22 and CO and CO22 enter and leave the cells enter and leave the cells

((gas exchangegas exchange) by ) by diffusiondiffusion Different animals have different systemsDifferent animals have different systems Some examples:Some examples:

Organism:Organism: Gas exchange between:Gas exchange between:one-celledone-celled cell membrane and outside cellcell membrane and outside cellearthwormearthworm skin and capillariesskin and capillariesinsectsinsects trachea and body cellstrachea and body cellsfishfish gill filaments and capillariesgill filaments and capillariesmammalsmammals air sacs (alveoli) and air sacs (alveoli) and

capillariescapillaries

Human Respiratory SystemHuman Respiratory System

Our own pathway, in order:

Mouth/Nasal Cavity

Pharynx

Larynx

Trachea

Bronchi

Bronchioles

Alveoli (tiny air sacs)

Respiratory System TissuesRespiratory System TissuesMouth/nasal cavity:Mouth/nasal cavity:

Air enters the bodyAir enters the body Nasal hairs and mucus warm and clean the airNasal hairs and mucus warm and clean the air

Pharynx and larynx:Pharynx and larynx: Pharynx is the back of your mouth (say aaaaah)Pharynx is the back of your mouth (say aaaaah) Larynx is lower – this is your throat (voice box)Larynx is lower – this is your throat (voice box)

Trachea:Trachea: Air passageway leading to lungsAir passageway leading to lungs Lined with C-shaped rings of cartilageLined with C-shaped rings of cartilage

Bronchi, bronchioles, alveoli:Bronchi, bronchioles, alveoli: Air pathway into each lung branches down and ends in millions Air pathway into each lung branches down and ends in millions

of of microscopicmicroscopic air sacs (alveoli) air sacs (alveoli) An adult human lung has several hundred An adult human lung has several hundred millionmillion alveoli, alveoli,

each one surrounded by capillaries of your circulatory systemeach one surrounded by capillaries of your circulatory system

How Air Moves in and OutHow Air Moves in and Out

Inhaling: Inhaling: getting getting oxygenoxygen in in Exhaling: Exhaling: getting getting carbon dioxidecarbon dioxide out out Air is Air is forcedforced into and out of your lungs. into and out of your lungs.

But how?But how?

When you squeeze a plastic bottle, what does the air do? When you squeeze a plastic bottle, what does the air do? Which direction does it move?Which direction does it move?

When you let the plastic bottle spring back into shape, When you let the plastic bottle spring back into shape, what does the air do? Which direction does it move now?what does the air do? Which direction does it move now?

This is because of an important law of how This is because of an important law of how gasesgases work: work: Boyle’s LawBoyle’s Law

Boyle’s LawBoyle’s Law

Robert Boyle discovered that if:Robert Boyle discovered that if: volume decreases, pressure increasesvolume decreases, pressure increases volume increases, pressure decreasesvolume increases, pressure decreases

Pressure and volume are inversely related:Pressure and volume are inversely related: If one increases, the other decreasesIf one increases, the other decreases This is called an This is called an inverseinverse relationship relationship

Gases always move from:Gases always move from: areas of higher pressure to areas of lower pressureareas of higher pressure to areas of lower pressure Boyle’s Law explains how air is forced into and out of Boyle’s Law explains how air is forced into and out of

your lungs !your lungs !

1. Diaphragm & rib muscles contract2. Rib cage expands3. Volume in lungs increases4. Pressure in lungs decreases5. Air pressure outside is greater6. Air rushes into lungs

1.2.3.4.5.6.

Can you fill in steps 1- 6 for exhaling?

How Does OHow Does O22 Get Into the Blood? Get Into the Blood?

Alveolus(air sac)

Pulmonary capillary

O2 CO2

Fromheart

Toheart

A i r

A i r

How Does OHow Does O22 Get Into the Blood? Get Into the Blood? Blood needs a special chemical to “carry” the oxygen: Blood needs a special chemical to “carry” the oxygen:

HemoglobinHemoglobin oxygenoxygen “sticks to” or binds with “sticks to” or binds with hemoglobin hemoglobin in red blood cellsin red blood cells hemoglobin contains hemoglobin contains ironiron which binds with which binds with oxygenoxygen

Can you follow the oxygen? Can you follow the oxygen? In the lungs:In the lungs:

OxygenOxygen diffuses from the air in the diffuses from the air in the alveolialveoli into capillaries into capillaries OxygenOxygen passes into red blood cells and binds with passes into red blood cells and binds with hemoglobinhemoglobin In the blood, oxygen remains bound to hemoglobin until it reaches In the blood, oxygen remains bound to hemoglobin until it reaches

your cellsyour cells At your cells:At your cells:

COCO22 diffuses from cells into capillaries diffuses from cells into capillaries HemoglobinHemoglobin releases releases oxygenoxygen and binds with and binds with COCO22

Oxygen diffuses from red blood cells into your body cellsOxygen diffuses from red blood cells into your body cells

Respiratory System ProblemsRespiratory System Problems DirtDirt, , pollenpollen, , dustdust, and , and smokesmoke damage the system and damage the system and

interrupt the flow of oxygen to your cellsinterrupt the flow of oxygen to your cells

Respiratory System Defenses:Respiratory System Defenses: White blood cellsWhite blood cells

Surround, consume, and digest Surround, consume, and digest bacteriabacteria Cannot consume Cannot consume asbestosasbestos

CiliaCilia Tiny hairs lining tracheaTiny hairs lining trachea Hairs “wave” upward to expel foreign particlesHairs “wave” upward to expel foreign particles Cigarette smoke paralyzes ciliaCigarette smoke paralyzes cilia

Defense against choking:Defense against choking: The The epiglottisepiglottis Flap of tissue that closes trachea when you swallowFlap of tissue that closes trachea when you swallow Makes certain food travels through esophagus insteadMakes certain food travels through esophagus instead

Respiratory DisordersRespiratory Disorders Asthma Asthma

Bronchial tubes become constrictedBronchial tubes become constricted Symptoms: shortness of breath, wheezing, coughingSymptoms: shortness of breath, wheezing, coughing Causes: Causes: environmentalenvironmental factors: allergies, stress, certain foods factors: allergies, stress, certain foods

EmphysemaEmphysema Alveoli lose ability to expand and contract when breathingAlveoli lose ability to expand and contract when breathing Alveoli stretch and rupture; scar tissue developsAlveoli stretch and rupture; scar tissue develops Less oxygen to cells + buildup of COLess oxygen to cells + buildup of CO22

Lung cancerLung cancer Caused by “tars” and other Caused by “tars” and other carcinogenscarcinogens in cigarette smoke in cigarette smoke Cancerous tumors destroy lung tissueCancerous tumors destroy lung tissue

Effects of smoking:Effects of smoking: Short term: carbon Short term: carbon monoxidemonoxide (CO) replaces oxygen in blood (CO) replaces oxygen in blood Long term: heart disease, emphysema, lung cancerLong term: heart disease, emphysema, lung cancer Without smoking, these disorders are a Without smoking, these disorders are a minorminor problem in society problem in society

Review QuestionsReview Questions1.1. Which term does not belong with the others and why not?Which term does not belong with the others and why not?

gills, alveoli, diaphragm, trachea gills, alveoli, diaphragm, trachea asthma, respiration, emphysema, lung cancerasthma, respiration, emphysema, lung cancer gills, lungs, hemoglobin gills, lungs, hemoglobin lung cancer, asthma, emphysemalung cancer, asthma, emphysema alveoli, diaphragm, tracheaalveoli, diaphragm, trachea

2.2. Explain what happens to your diaphragm and ribcage when you Explain what happens to your diaphragm and ribcage when you inhale and exhale. inhale and exhale.

3.3. What are the reactants and products of cell respiration?What are the reactants and products of cell respiration?4.4. Use Boyle’s Law to explain inhaling, exhaling, and why the Use Boyle’s Law to explain inhaling, exhaling, and why the

Heimlich Maneuver works.Heimlich Maneuver works.5.5. Describe how gas exchange occurs in the lungs. Describe how gas exchange occurs in the lungs. 6.6. Why is your trachea lined with cartilage? Why is your trachea lined with cartilage? 7.7. What is the function of your nasal cavity? What is the function of your nasal cavity? 8.8. What is your epiglottis and what is it for?What is your epiglottis and what is it for?9.9. Why do you have cilia inside your trachea?Why do you have cilia inside your trachea?10.10. Which respiratory condition can be the result of allergies?Which respiratory condition can be the result of allergies?