CHAPTER 7.1 – STRUCTURES OF THE RESPIRATORY SYSTEMPages 244 - 247

DO NOW

○ What structures, do you think, are active participating in the breathing process?

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WHAT ARE WE DOING IN TODAY’S CLASS

○ Finishing Digestion Notes

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○ The main functions of the respiratory system: ● bring oxygen to cells ● remove carbon dioxide from cells

○ Respiration is the general term used to describe gas exchange

○Main requirements for respiration: ●Large surface area for gas exchange

●Moist environment allows oxygen and carbon dioxide to dissolve in water

○ Stages of respiration: 1. Breathing

2. External respiration

3. Internal respiration

4. Cellular respiration

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THE STAGES IN RESPIRATION

1. Breathing: ● Inspiration – breathing

in; inhaling. Moves air from the external environment to lungs inside body

● Expiration – breathing out; exhaling. Moves air from lungs back to external environment

THE STAGES IN RESPIRATION

2. External respiration: exchange of oxygen and carbon dioxide between air and blood

3. Internal respiration: exchange of oxygen and carbon dioxide between cells and blood

4. Cellular respiration: energy releasing reactions taking place in the cells; sole means of providing energy for all cellular activities

THE RESPIRATORY TRACT

CHECK-IN QUESTION

○ What is the main function of the human respiratory system?

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THE UPPER RESPIRATORY TRACT

○The nasal passages: ● beginning of respiratory tract

warms, moistens and cleans incoming air

●Specialized cells secrete mucous and trap foreign particles

○ Ciliated cells sweep mucous and foreign particles back up to nose and throat where they are expelled via coughing or sneezing

○ Pharynx (throat): ● passage way for air into the respiratory

system

○ Epiglottis: ● flap of cartilage behind tongue and

larynx

● closes over trachea when swallowing

● prevents food from entering lungs

●when epiglottis is at rest, allows air to pass into lower respiratory tract

○Larynx (voice box): ●made from cartilage

● contains vocal cords ● large gap between the vocal cords

with normal breathing

● larynx contracts and the vocal cords are drawn together when speaking

●Air passing through narrow space causes the vocal cords to vibrate and make a sound

Vocal cords in action…

CHECK-IN QUESTION

○ What are the different parts of the upper respiratory tract?

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THE LOWER RESPIRATORY TRACT

○The trachea (windpipe) branches into the left and right bronchi (singular – bronchus)

○ Each bronchus subdivides to create branching network of bronchioles

○ Bronchi are supported by “C-shaped” cartilaginous rings that surround bronchus wall

○ Each lung divided into lobes ○ The right lung has 3 lobes ○ The left lung has 2 lobes, leaving space for heart ○ Each lung made up of smaller lobules extending

from each bronchiole

○Lungs surrounded by thin, double-layered membrane called pleural membrane

○Outer layer of membrane attaches to inside of chest cavity

○ Inner layer of the membrane attaches to lungs

○Fluid fills space between two membranes, adhering them together

Connection between the two membranes allows for lungs to expand and contract with thoracic cavity

○Each bronchiole ends in a cluster of tiny sacs called alveoli (singular – alveolus)

○Gas exchange occurs within alveoli during external respiration

○Each alveolus is contained within a membrane called an alveolar wall

○The alveolar wall is one cell thick and is surrounded by network of tiny capillaries

○Alveoli are lined with lubricating film (surfactant) that prevents alveoli from collapsing

EXIT SLIP

○ Answer the following questions on a sheet of paper and place it in the biology 20 hand-in folder:

○ How is external respiration different from internal respiration? ○ Describe the roles of mucous and cilia in the upper respiratory tract. ○ Identify the structures that make up the upper respiratory tract. Briefly describe

the function of each structure.

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7.2 – BREATHING AND RESPIRATION

Pages 249 - 254

WHAT ARE WE DOING IN TODAY’S CLASS

○ - objectives and the I can statements (should be in their notes as well)

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THE STRUCTURES○The diaphragm and intercostal muscles

(rib muscles) control movement of air in and out of lungs

○Diaphragm – domed shaped muscle separating the thoracic and abdominal cavity

○ Intercostal muscles–found between and along ribs

THE MECHANICS OF BREATHING

○ Inhalation: 1. External rib muscles and

diaphragm contract. 2. Rib cage expands upward and

outward 3. The volume of the thoracic cavity

increases

4. The density of gas in the cavity decreases – air pressure in the cavity decreases

5. Air moves from area high to low pressure (outside lungs to inside lungs)

6. Air rushes into lungs

THE MECHANICS OF BREATHING

○ Exhalation: 1. External rib muscles and diaphragm relax 2. The volume of thoracic cavity decreases 3. The density of gas in the cavity increases

– air pressure in the cavity increases 4. Air moves from areas of high to low

pressure (inside the lungs to outside the lungs)

5. Air rushes out of the lungs

Mechanics of Breathing

RESPIRATORY VOLUME○Under normal circumstances regular

breathing does not use full lung capacity

○When your body needs more oxygen the volume of lungs can increase

○A spirograph is used to represent the amount of air that moves into and out of lungs with each breath

DO NOW

Turn to your desk partner and discuss the following: Summarize the series of events that leads to the inhalation and exhalation of air.

** Please be ready to share your answer with the class! **

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The following terms are used in a spirograph:

○Tidal volume – volume of air inhaled and exhaled in a normal breathing movement when body is at rest

○ Inspiratory volume –additional volume of air taken into the lungs, beyond a regular breath

○Expiratory reserve volume –additional volume of air that can be forced out of lungs, beyond a regular breath

○ Vital capacity –total lung capacity; total volume of gas that can be moved into or out of the lungs. ●Vital capacity = tidal volume + inspiratory

reserve + expiratory reserve volume

○ Residual volume –amount of air that remains in lungs and passageways after a full exhalation. If this gas left the system, the lungs and passageways would collapse.

○ The residual volume has little value for gas exchange because it is not exchanged with external environment

THE SPIROGRAPH

BALLOON DEMO

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DEMO FOLLOW-UP QUESTIONS

With your desk partner, discuss the following questions:

1. When a student takes a deep breath and inflates a balloon, what lung volume does the air in the balloon represent? Explain.

2. Is it possible to measure an individual’s total lung volume by inflating a balloon? Explain why or why not.

3. Do you think that everybody can inflate a balloon to its fullest size? Why or why not?

** Please be ready to share your answer with the class! **

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EXTERNAL RESPIRATION○External respiration takes place in lungs

○During external respiration, gases are exchanged between alveoli and blood in capillaries

○The walls of alveoli and capillaries are each one cell thick

○Gases easily diffuse through cell walls

○Diffusion occurs from high ! low concentration

○The air entering alveoli have a higher oxygen concentration than blood in the capillaries, oxygen diffuses from alveoli into capillaries

○Blood in capillaries has higher concentration of carbon dioxide because it is returning from body tissues

○The carbon dioxide diffuses from capillaries into alveoli

○The carbon dioxide is exhaled into air

INTERNAL RESPIRATION

○Once oxygen and carbon dioxide have been exchanged, the blood moves through the heart and back to body tissues

○Oxygen and carbon dioxide are transported differently

○ 99% of oxygen is carried by hemoglobin

○ 1% is dissolved in blood plasma

⦿ Carbon dioxide is carried via: ⦿ 23% by hemoglobin ⦿ 7% in the plasma ⦿ 70% is dissolved and carried in the

blood as bicarbonate ion (HCO3-)

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⦿ The carbon dioxide reacts with water in the blood to form carbonic acid (H2CO3)

⦿ The reaction is reversed once the carbonic acid reaches the lung tissues

⦿ CO2 + H2O ! H2CO3 ! CO2 + H2O

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How can increased exercise causes an increase in breathing rate?

WHAT TO DO

○Answer the following questions on page 254 of the text:

○ 1- 4 a,c, 6, 8

THE SPIROGRAPH

Term Definitiontidal volume Volume of air that is inhaled and exhaled in a

normal breath.

inspiratory reserve volume

Additional volume of air that can be taken into lungs beyond tidal inhalation.

expiratory reserve volume

Additional volume of air that can be forced out of the lungs beyond tidal inhalation.

vital capacity Total volume of gas that can be taken into and forced out of the lungs. It is calculated by adding the tidal volume + inspiratory reserve volume + expiratory reserve volume.

residual volume Amount of gas that remains in the lungs and respiratory system passageways even after full exhalation. Is necessary so lungs do not collapse.

•The typical tidal volume for humans is 500 mL.

•The typical expiratory reserve volume for humans is 1200 mL.

•The typical vital capacity for humans is 4800 mL.

7.3 – RESPIRATORY HEALTHPages 256 - 262

○Upper Respiratory Tract Disorders: ●Tonsillitis

●Laryngitis

○Lower Respiratory Tract Disorders ●Bronchitis

●Pneumonia

●Pleurisy

●Asthma

●Emphysema

TONSILLITIS

○ Viral infection of the tonsils ○ Symptoms include swollen and red

tonsils

○ Treatment: ● Removal of tonsils in extreme cases

● Over the counter medication to treat for symptoms

LARYNGITIS

○ Inflammation of the larynx (voice box) due to viral infection, allergies or over-use of voice

○ Symptoms include sore throat and voice loss

○Treatment: ●Over the counter medication to treat for

symptoms

BRONCHITIS

○ Acute bronchitis: ● Bacterial infection

● Treated with antibiotics

○ Chronic bronchitis: ● Due to exposure to irritants and foreign bodies

● Loss of cilia increases risk of infection

● Treatment includes reduction to irritants (ie. quitting smoking)

○ Symptoms include: inflamed airways, wet cough, wheezing

PNEUMONIA○ Alveoli become inflamed and fill with fluids

○ Lobular pneumonia: ● Due to bacterial infection

● Affects an entire lobe of lung

● Treated with antibiotics

○ Bronchial pneumonia: ● Due to viral infection

● Affects patches throughout lungs

● Treated with anti-viral medication

○ Symptoms include: difficulty breathing, low energy due to loss of gas exchange

PLEURISY

○ Swelling and irritation of the pleural membranes

○ May be due to viral or bacterial infection ○ Symptoms include a sharp stabbing pain in

the chest in one region

○ Treatment: ● antibiotics or anti-virals ● Reduce swelling and irritation

EMPHYSEMA

○ Alveolar wall loses elasticity ○ Surface area for gas exchange is reduced ○ Moist common cause is smoking ○ Symptoms include: difficulty breathing ○ Treatment includes use of a low flow

oxygen tank

ASTHMA

○ Reduced air flow due to inflammation of bronchi and bronchioles

○ Varies from mild to extreme ○ Inflammation may be triggered by

allergens, exercise, and stress ○ Symptoms include difficulty breathing

○ Treatment includes: ● Steroids and inhalers to reduce inflammation

● A nebulizer is often used in young patients

CYSTIC FIBROSIS

○ Genetic disorder affecting body’s ability to control salt balance

○ Thin fluid in lungs becomes thick mucous ○ Sufferers are more prone to infection ○ Results in low gas exchange

○ Treatment: ● Medications to thin mucous

● Gene therapy – healthy gene is inhaled deep into lungs

LUNG CANCER

○ Due to carcinogens – cancer causing agents ○ Most common source of carcinogens are

cigarettes ○ Rapid growth of carcinoma (tumor) reduces

surface area for gas exchange

○ Other causes: ● Asbestos

● Radon

○ Treatment may include removal of tumor depending on stage of cancer