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Respiration & Gas Exhange

Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

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Page 1: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Respiration & Gas Exhange

Page 2: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Respiration

• Two processes:1. Release of energy from breakdown of food molecules.

All living cells use oxygen to release energy. This process produces waste carbon dioxide.

2.The exchange of gases between the atmosphere and body’s cells.

We will focus on the exchange of gases.

Page 3: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

So what are the functions of the respiratory system?

• Bring oxygen into the body• Remove carbon dioxide (CO2) from the body• Clean, moisten and warm air• Enable speech

Page 4: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Gas exchange supplies oxygen for cellular respiration and removes CO2

Gas exchange – uptake of O2 from environment and discharge of CO2

Mitochondria need O2 to produce more ATP, CO2 is the by-product

C6H12O6 + 6O2 6CO2 + 6H2O + 36 ATP

DIFFUSION

…………………………………………………………………………………………………………………

Page 5: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

How Does Oxygen Get Into Cells?

• O2 and CO2 enter and leave the cells (gas exchange) by diffusion

• Different animals have different systems• Some examples:

Organism: Gas exchange between:one-celled cell membrane and outside

cellearthworm skin and capillariesinsects trachea and body cellsfish gill filaments and capillariesmammals air sacs (alveoli) and

capillaries

Page 6: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Respiratory surfaces and gas exchange

• Respiratory surface– Size of organism– Habitat– Metabolic demands

• Unicellular organisms– Entire surface area for

diffusion

• Simple invertebrates– Sponges, cnidarians,

flatworms– diffusion

Page 7: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Human Respiratory SystemOur own pathway, in order:

Mouth/Nasal Cavity

Pharynx

Larynx

Trachea

Bronchi

Bronchioles

Alveoli (tiny air sacs)

Page 8: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Mammalian respiration

Page 9: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Organs of the respiratory system

• Nose and sinuses • Q. List the advantages of breathing in from the

nose? (page 170 )1. Cleans dust and bacteria in the air by hair and mucus, 2. warms and moistens the air3. Detect harmful chemicals by sensory cells

Page 10: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Organs of the respiratory system

• Pharynx – short tube leading to larynx

• Epiglottis – cartilaginous flap covering opening to larynx (glottis)

• Larynx – voicebox containing vocal cords

Hyoid Bone Epiglottis

ThyrohyoidMembrane

CricothyroidLigament

CricothyroidMuscles

CricothyroidCartilage

Trachea

ThyroidCartilage

Page 11: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Organs of the respiratory system

• Trachea – tubes leading into lungs.

• These branch into primary bronchi then into bronchioles

mouth

trachea

bronchi

alveoli

Page 12: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

larynxbronchiole

sinuses

pharynx

trachea

alveoli

bronchialtube

Page 13: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Organs of the respiratory system

• Bronchioles end in sac like structures called Alveoli

• Gas exchange occurs between the alveoli and capillaries

Primarybronchus

AlveoliTerminalbronchiole

Bronchiole

Tertiarybronchus

Secondarybronchus

Page 14: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Bronchial Tubes

Page 15: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Gas Exchange

• Capillaries surround the alveoli• Gases are exchanged between the thin walls of the

alveoli and capillaries

Page 16: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

How Does O2 Get Into the Blood?

Alveolus(air sac)

Pulmonary capillary

O2 CO2

Fromheart

Toheart

A i r

A i r

Page 17: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

How Does O2 Get Into the Blood?• Blood needs a special chemical to “carry” the oxygen:

– Hemoglobin• oxygen “sticks to” or binds with hemoglobin in red blood cells• hemoglobin contains iron which binds with oxygen

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

• Oxygen diffuses from the air in the alveoli into capillaries• Oxygen passes into red blood cells and binds with hemoglobin• In the blood, oxygen remains bound to hemoglobin until it reaches your

cells– At your cells:

• CO2 diffuses from cells into capillaries• Hemoglobin releases oxygen and binds with CO2• Oxygen diffuses from red blood cells into your body cells

Page 18: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

How Air Moves in and Out• Inhaling: getting air with oxygen in• Exhaling: getting air with carbon dioxide out• Air is forced into and out of your lungs.

But how?

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

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

• This is because of an important law of how gases work: Boyle’s Law

Page 19: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Boyle’s Law

• Robert Boyle discovered that if:– volume decreases, pressure increases– volume increases, pressure decreases

• Pressure and volume are inversely related:– If one increases, the other decreases– This is called an inverse relationship

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

lungs !

Page 20: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

1. Diaphragm & rib muscles (external intercostal muscles) contract

2. 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?

Page 21: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Lung ventilation through breathing• Negative pressure breathing in reptiles and mammals• Rib muscles and diaphragm change lung volume and pressure

Page 22: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Lung volumes• Factors• Smoking, increase due to CO• Anxiety, increase due to the effect of adrenaline• Drugs, some may cause an increase• Environmental factors, increased by high CO2

concentration in the atmosphere• Altitude, increased by low O2 conc. In the atmosphere• Weight, can increase because fat makes lung

ventilation harder (i.e tidal volume falls),

• Tidal volume– Volume of air inhaled and

exhaled with each breath• Vital capacity

– Maximum volume inhaled and exhaled during forced breathing

• Residual volume– Air left in alveoli after forced

exhalation

Page 23: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Control centers in the brain

regulate breathing

Page 24: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Gases diffuse down pressure

gradients

concentration and pressure drives the movement of gases

into and out of blood

Page 25: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Respiratory System Problems• Dirt, pollen, dust, and smoke damage the system and

interrupt the flow of oxygen to your cells

• Respiratory System Defenses:– White blood cells

• Surround, consume, and digest bacteria• Cannot consume asbestos

– Cilia• Tiny hairs lining trachea• Hairs “wave” upward to expel foreign particles• Cigarette smoke paralyzes cilia

• Defense against choking:– The epiglottis– Flap of tissue that closes trachea when you swallow– Makes certain food travels through esophagus instead

Page 26: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

Respiratory Disorders• Asthma

– Bronchial tubes become constricted– Symptoms: shortness of breath, wheezing, coughing– Causes: environmental factors: allergies, stress, certain foods

• Emphysema– Alveoli lose ability to expand and contract when breathing– Alveoli stretch and rupture; scar tissue develops– Less oxygen to cells + buildup of CO2

• Lung cancer– Caused by “tars” and other carcinogens in cigarette smoke– Cancerous tumors destroy lung tissue

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

Page 27: Respiration & Gas Exhange. Respiration Two processes: 1. Release of energy from breakdown of food molecules. All living cells use oxygen to release energy

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

– gills, alveoli, diaphragm, trachea – asthma, respiration, emphysema, lung cancer– gills, lungs, hemoglobin – lung cancer, asthma, emphysema– alveoli, diaphragm, trachea

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

3. What are the reactants and products of cell respiration?4. Use Boyle’s Law to explain inhaling, exhaling, and why the Heimlich

Maneuver works.5. Describe how gas exchange occurs in the lungs. 6. Why is your trachea lined with cartilage? 7. What is the function of your nasal cavity? 8. What is your epiglottis and what is it for?9. Why do you have cilia inside your trachea?10. Which respiratory condition can be the result of allergies?