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Respiratory System Gas Exchange

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Respiratory System. Gas Exchange. Introduction. What is our atmosphere made of? Nitrogen 78%, Oxygen 21%, Other 1% Why is breathing important? Exchange of O 2 and CO 2 b/t environment and our bodies What is the O 2 used for? All cells require O 2 for cellular respiration energy - PowerPoint PPT Presentation

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Page 1: Respiratory System

Respiratory System

Gas Exchange

Page 2: Respiratory System

Introduction

• What is our atmosphere made of?• Nitrogen 78%, Oxygen 21%, Other 1%

• Why is breathing important?– Exchange of O2 and CO2 b/t environment

and our bodies• What is the O2 used for?

– All cells require O2 for cellular respiration• energy

• Other gasses?– CO2 + H2O– Expelled as waste

Page 3: Respiratory System

General Functions

– Intake of oxygen• For Cellular Respiration

– Exhale carbon dioxide– Preservation of life

Page 4: Respiratory System

Terminology• Breathing: to take air into

the lungs and let it out again (inhale and exhale).

• Gas Exchange: the process of diffusion that allows for carbon dioxide to leave the capillaries surrounding the alveoli while facilitating the entrance of oxygen into the capillary. (Carbon dioxide-out: oxygen in)

Page 5: Respiratory System

• Cellular Respiration: when cells oxidize organic carbon to obtain energy. This is different from just respiration or the respiratory system. Note: the start product (oxygen) and end product (carbon dioxide) necessitate the need for the respiratory system.

Page 6: Respiratory System

Breathing vs. Respiration (Terminology)• Breathing

– Intake of O2

– Exhale CO2

– Gasses exchanged in alveoli in lungs• Respiration

– C6H12O6 + 6O2 = 6CO2 + 6H2O– Breakdown of sugar into energy– Takes place in all cells

• Gas Exchange:– Diffusion allowing for carbon dioxide to leave the

capillaries and oxygen to come in. (Carbon dioxide-out: oxygen in)

Page 7: Respiratory System
Page 8: Respiratory System
Page 9: Respiratory System

Respiratory Structures and their Functions

• Mouth and nostrils– Air enters respiratory system– Allows a larger volume of air to be

transferred• Nasal cavities

– Provide moisture– Filter and trap particles

• Hair and mucous

Page 10: Respiratory System

Respiratory Structures and their Functions

• Pharynx– In mouth– connect to the

back of the oral and nasal cavities. The pharynx is also connected to the trachea and esophagus

– Passage for food and air (digestion and gas exchange

– Lined with ciliate epithelial cells to trap fine particles

– Contains tonsils and adenoids

Page 11: Respiratory System

• Epiglottis– A leaf-like flap of tissue– prevents food from entering the trachea.

Respiratory Structures and their Functions

Page 12: Respiratory System

Respiratory Structures and their Functions

• Larynx– Voice box– Ligaments– Air passes, vibrate ligaments, sound

produced• Vocal chords

Page 13: Respiratory System

• Vocal chords: two elastic ligaments that produce sounds depending on various tensions.

Respiratory Structures and their Functions

Page 14: Respiratory System

Respiratory Structures and their Functions

• Adam’s apple– cartilage that protects the larynx.

Page 15: Respiratory System

Respiratory Structures and their Functions

• Trachea– Windpipe– Takes air into the lungs. – Lined with cilia

• Mucus• Filter extra particles

– Cartilage rings• Provide support • Keep trachea open

Page 16: Respiratory System

Respiratory Structures and Their Function• Cilia: small hairs that trap particles. Cilia move

upwards to move particles back upwards so that they can be spit out.

Trachea Pharynx

Page 17: Respiratory System

Respiratory Structures and their Functions

• Bronchi– Two branches of the

trachea– Contain cartilage– Go to R & L lungs

• Bronchioles– Smaller branches

inside each lung that are less than 1mm in diameter

– No cartilage– Rings of muscle –

change diameter

Page 18: Respiratory System

Respiratory Structures and their Functions• Alveoli

– The point of gas exchange– The overall purpose of alveoli

is to increase surface area for gas exchange.

– Very thin air sacs– Surrounded by capillaries– Site of gas diffusion

• Concentration gradient– One cell thick– Each lung - ~ 150 million– Film of lipoprotein – prevents

alveoli from sticking together

Page 19: Respiratory System
Page 20: Respiratory System

• Lungs– Two cone shaped

organs – right has 3 lobes – left has 2 lobes

• shares space with heart

– Located in thoracic cavity -base contacts diaphragm and top above the clavicles

Respiratory Structures and their Functions

Page 21: Respiratory System

Respiratory Structures and their Functions

• Pleural Membrane– Outer surface of lungs– Inner wall of chest cavity– Reduced friction

Page 22: Respiratory System

• Diaphragm– Band of muscle shaped like a dome– Separates thoracic cavity from abdominal

cavity– Helps in breathing

Respiratory Structures and their Functions

Page 23: Respiratory System

• Ribs: bones that protect the thoracic cavity.

Respiratory Structures and their Functions

Page 24: Respiratory System

Respiratory Structures and their Functions

• Intercostal muscles– muscles between the ribs that aid in breathing.

Page 25: Respiratory System

Human Gas Exchange System

Page 26: Respiratory System

Section of head and thorax to show respiratory system. left lung (surface) view Right lung (section)

1 Nasal cavity

2 Pharnyx

3 Epiglottis

4 esophagus

5 Cartilage rings

6 Bronchi

7 Lung

Diagram Answers

8 Heart9 Pleural membranes10 Diaphragm11 Alveoli12 Pleural membranes13 Bronchioles14 Intercostal muscles15 Ribs16 Trachea17 Larynx

Page 27: Respiratory System

Mechanism of Breathing

Page 28: Respiratory System

BREATHING MOVEMENTS

• Oxygen continuously moves from alveoli into blood

• Carbon dioxide from blood to alveoli

• Air in alveoli must, therefore, be continuously replaced with fresh air

Page 29: Respiratory System

INHALATION

1. diaphragm contracts2. intercostal muscles

contract3. increase in lung

volume4. environmental air

pressure is greater than the lung pressure

5. air rushes in to equalize pressure

Page 30: Respiratory System

EXHALATION

1. diaphragm relaxes up2. intercostal muscles

relax3. decrease in lung

volume4. lung pressure is

greater than environmental air pressure

5. air rushes out to equalize pressure

Page 31: Respiratory System
Page 32: Respiratory System

Inhalation and Exhalation

Page 33: Respiratory System

Inhalation and Exhalation

Page 34: Respiratory System

Role of Diaphragm• During inhalation

– regulates pressure in chest cavity• Contract – flattens, moves down• Volume increases, pressure decreases• Air moves into lungs

• During exhalation• Relaxes – dome shaped, moves up • Chest volume decreases, pressure increases• Air moves out

Page 35: Respiratory System

Role of the Intercostal Muscles

– Intercostal muscles are located between the ribs

– Inspiration: Muscles contract, pulls ribs up and out

– Expiration: Muscles relax, ribs move down

Page 36: Respiratory System

Diffusion Across Alveoli

• In LUNGS –

– Higher concentration of oxygen than in blood.

– Lower concentration of carbon dioxide than in blood.

Page 37: Respiratory System

RESULTS

Diffusion Across Alveoli

• Oxygen moves from the air in the lungs across the alveoli and into the capillary where it becomes attached to hemoglobin.

• Carbon dioxide moves from the blood across the alveoli and into the air of the lungs.

Page 38: Respiratory System

Alveoli

• Characteristics that facilitate diffusion:– have thin walls– kept moist– richly supplied with blood vessels– large surface area

Page 39: Respiratory System

REGULATION & CONTROL– Medulla Oblongata -- breathing center

• controls rate and depth of breathing• the medulla is sensitive to CO2 levels in the blood• If CO2 (carbonic acid) level too high...

– medulla tells diaphragm and intercostals to increase activity

• once CO2 levels drop into normal range...– medulla stops sending “increase activity” message

Page 40: Respiratory System

REGULATION & CONTROL

• Chemoreceptors –– If stimulated –

• Diaphragm begins breathing movements• More breathing, lower CO2 levels

• Can be controlled – Medulla will take over if CO2 builds up

Page 41: Respiratory System

QUANTITIES OF AIR

• TIDAL VOLUME – amount air exchanged with each normal breath

• INSPIRATORY RESERVE – additional air that can be inhaled over and above the tidal volume

• EXPIRATORY RESERVE – extra air that can be forcibly exhaled in excess of the tidal volume

Page 42: Respiratory System

• VITAL CAPACITY – the maximum amount of air that can be forcibly exchanged

• RESIDUAL VOLUME – amount of air that remains in lungs after forceful expiration.

QUANTITIES OF AIR

Page 43: Respiratory System

VITAL CAPACITY

INSPIRATORY RESERVE VOLUME (3 L)

TIDAL VOLUME (1/2 L)

EXPIRATORY RESERVE VOLUME (1 L)

RESIDUAL VOLUME (1.2L)

QUANTITIES OF AIR

Page 44: Respiratory System
Page 45: Respiratory System

Transport of Gases• OXYGEN TRANSPORT

– hemoglobin transports about 97% of the oxygen

– 3% will diffuse into the plasma

– the hemoglobin molecule is composed of 4 peptide chains with an iron center

– oxygen attaches to hemoglobin to form oxyhemoglobin

– oxygen is released in the tissues

Page 46: Respiratory System

Carbon Dioxide in the Blood• Approximately

– 64% of CO2 – bicarbonate ion in plasma– 27% of CO2 – combines with hemoglobin– 9% of CO2 – is dissolved in plasma

Page 47: Respiratory System

Transport of Gases• CARBON DIOXIDE TRANSPORT • CO2 moves away from muscle

– CO2 continually diffuses into the blood plasma. – an enzyme (carbonic anhydrase) in red blood cells

converts some CO2 and water (from plasma) into carbonic acid

– carbonic acid breaks into H+ and bicarbonate ions (hydrogen carbonate)

– the H+ combines with hemoglobin • helps avoid significant pH change in blood

– the bicarbonate ion stays in the plasma

Page 48: Respiratory System

Transport of Gases• When this blood reaches lungs:

– new O2 will combine with hemoglobin displacing H+ into plasma.

– H+ recombines with bicarbonate ion producing H2O and CO2 which diffuses into alveoli to be exhaled

Page 49: Respiratory System

Factors Affecting Breathing Rate

Page 50: Respiratory System

1. Exercise• When exercise occurs carbon dioxide levels

accumulate faster than normal.• As a result, your breathing rate and depth

increase.

Page 51: Respiratory System

2. Hormones• Hormones such adrenaline increases

breathing rate

Page 52: Respiratory System

3. High Altitude• At higher altitudes there is less oxygen present in the

atmosphere.• This does not have a great effect on carbon dioxide

receptors.• Receptors in the arteries will increase the breathing

rate.

Page 53: Respiratory System

4. Carbon Monoxide• CO acts as a competitive inhibitor in the red blood

cell• CO attaches to the hemoglobin molecule 200

times stronger (and faster) than O2 or CO2• This makes the hemoglobin unavailable for O2 or

CO2

Page 54: Respiratory System

Holding Your Breath

• When you hold your breath carbon dioxide levels begin to build.

• As a result, when breathing is resumed it occurs at a faster rate and with greater depth than normal.

Page 55: Respiratory System

Hyperventilation

• When you hyperventilate your carbon dioxide levels temporarily decrease.

• This temporary carbon dioxide decrease would allow you to hold your breath for longer periods of time.

Page 56: Respiratory System

DISORDERS

Page 57: Respiratory System

Disorders

• Bronchitis– Inflammation of bronchioles– Air passages get smaller– Excess mucus– Harder to exhale than inhale– Can lead to asthma and emphysema

Page 58: Respiratory System

• Emphysema– Increased resistance to airflow– Over-inflation of the lungs– Alveoli cannot handle pressure

• Rupture• Less SA for gas exchange• Lowers O2 levels

Page 59: Respiratory System

• Lung Cancer– Uncontrolled growth of cells– Less surface area for diffusion– Blockages may occur

Page 60: Respiratory System
Page 61: Respiratory System

Tobacco

• People have smoked tobacco for centuries• How is related to this class?• Lung cancer

– Most common type of death from cancer– 50% OF SMOKERS WILL DIE FROM

SMOKING RELATED CAUSES

Page 62: Respiratory System
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Healthy vs. Unhealthy

Page 64: Respiratory System

The effects of chewing tobacco on a Man.

Page 65: Respiratory System

1. hair loss 2. cataracts 3. wrinkling 4. hearing loss :6. tooth decay :7. lung ailments :9. heart disease :16. cancer : a)of the

lungs b)of the tongue c) of the mouth, salivary glands and pharynx.

Other Effects of Smoking