D1 B. Respiratory System

Question 1

Breathing (or ventilation)

Answer 1

The process by which air enters and leaves the lungs

Question 2

Respiration

Answer 2

All processes that supply oxygen to the cells of the body for the breakdown of glucose and the process by which CO₂ is transported to the lungs for exhalation

Question 3

3 Steps of Ventilation

Answer 3

1. Ventilation (gas exchange between atmosphere and lungs)
2. Gas exchange (transfer of gases between lungs and bloodstream)
3. Cell respiration (release of ATP from organic molecules)

Question 4

The Upper Respiratory System

Nasal Cavity

Answer 4

• Hair and mucus (filtering system)
• Mucus keeps cells lining the cavities moist
• Opens into the pharynx → branches into the treachea and esophagus

Question 5

The Lower Respiratory System

Larynx (voice box)

Answer 5

• Upper end of trachea
• Elastic ligaments form the vocal cords which vibrate as air is forced past them
• Protected by thick cartilage (Adam’s apple)

Question 6

The Lower Respiratory System

Trachea (wind pipe)

Answer 6

• Mucus (traps and filters)
• Ciliated cells (cilia - small hairs) sweep debris back to the pharynx
• Supported by rings of cartilage - keep trachea open

Question 7

The Lower Respiratory System

Bronchi

Answer 7

• Has cartilage rings
• Carry air into the right and left lungs
• Branch into smaller airways called bronchioles (no cartilage)

Question 8

The Lower Respiratory System

Alveoli

Answer 8

• Single layer of cells
• Surrounded by capillaries
• Gasses diffuse between thee air and blood according to the concentration gradients
• S.A. (150 million alveoli per lung)
• Lipoproteins prvents sacs from sticking to self during exhalation

Question 9

Alveoli - Pneumocytes

Type I Pneumocytes

Answer 9

• Mediate gas exchange with capillaries and over ~95% of the alveolar surface
• Squamous (flat) and thin - minimizes diffusion rate

Question 10

Alveoli - Pneumocytes

Type II Pneumocytes

Answer 10

• Secrete pulmonary surfacant which reduces surface tension in alveoli
• Cubodial in shape and possess granules (stores surfactant)

Question 11

Surfactant

Answer 11

Surface tension is the force created by a fluid surface that minimizes surface area

Without Surfactant:

• More pressure (due to small radius)

With Surfactant:

• Less tension

Question 12

Lung Lobes

Answer 12

The right lung has 3 lobes whereas the left lung has 2

Question 13

Bronchiole

Answer 13

A branch off the bronchi

Question 14

Diaphragm

Answer 14

• Dome shaped sheet of muscle
• Seperates thoracic (chest) cavity and abdominal cavity
• Inspiration - Muscle contracts and pulls downwards, chest volume increases, pressure in the lungs decreases
• Expiration - Diaphram relaxes and returns to its dome shape, chest volume decreases, and pressure increases

Question 15

Epiglottis

Answer 15

Small, cartilage that protects larynx and helps you swallow

Question 16

Pharynx

Answer 16

• Throat
• Passageway that is part of both the digestive and respiratory system

Question 17

Thoracic Cavity

Answer 17

Space that contains the heart, lungs and other organs

Question 18

Air flow through the respiratory system

Answer 18

1. Air enters your body through nose or mouth
2. Air travels down throat through larynx and trachea
3. Air goes into lungs through larger tubes called bronchi

There are two bronchi; one that leads to each lung

1. Air goes through bronchi into smaller bronchioles
2. Bronchioles end in tiny sacs (alveoli) where gas exchange occurs

Breathe out Carbon Dioxide

Question 19

Boyles Law

Answer 19

Pressure is inversely proportional to volume

• When volume in the thoracic cavity increase; pressure decreases (gas will flow in)
• When volume in the thoracic cavity decreases, pressure increases (gas will flow out)

Question 20

Intercostal Muscle

Answer 20

• Muscle between the ribs, which raise and lower the rib cage
• Nerve stimulation causes muscle to contract, pulling ribs upward and outward, thus raising volume of the chest

Question 21

Pleura of the lungs

Answer 21

2 thin layers of tissue that protect and cushion the lungs

• Inner layer wrapped around lungs
• Outer layer lines inside of chest wall

The fluid filled pleural cavity helps prevent friction as the lungs move agaisnt the walls of the thoracic cavity

Question 22

Tidal Volume

Answer 22

Volume of air inhaled and exhaled in a normal breath (about 500mL)

Question 23

Inspiratory Reserve Volume

Answer 23

The additional volume of air that can be inhaled

Question 24

Expiratory Reserve Volume

Answer 24

The additional volume of air that can be exhaled (must be forced out of lungs)

Question 25

Vital Capacity

Answer 25

Total volume of gas that can be moved in or out of lungs

Question 26

Inspiratory Reserve Volume + Tidal Volume + Expiratory Reserve Volume

Answer 26

Vital Capacity

Question 27

Residual Volume

Answer 27

Amount of air left in the lungs after max exhalation

Question 28

Passive diffusion of gases

Answer 28

Oxygen: High in alveoli; low in capillaries Carbon Dioxide: High in capillaries, low in alveoli

Question 29

Avogadro's Hypothesis

Answer 29

Equal volume of gases at the same temperature and pressure contain equal number of molecules * As a result, gas diffuses from area of high pressure to an area of low pressure

Question 30

Dalton's Law of Partial Pressure

Answer 30

Gases in a mixture behave as if the other isn't there exerting its own pressure (or partial pressure)

Question 31

Oxygen Transport (Plasma)

Answer 31

* Through partial pressures, oxygen moves from the atmosphere into the alveoli then into the blood * Plasma can only dissolve about 0.3 mL of oxygen/ 100 mL of blood

Question 32

Hemoglobin

Answer 32

Allows 20 mL of oxygen/ 100 mL

Question 33

# 3 Main Ways CO₂ is Transported Bicarbonate Ions

Answer 33

* Most CO₂ produced from CR enters the blood plasma and combines with water to form carbonic acid * Catalyzed by carbonic anhydrase * Carbonic acid then dissociates to form bicarbonate ions and hydrogen ions * Decrease the amount of CO₂ in plasma therefore maintaining a low partial pressure * H⁺ with hemoglobin, therefore buffering blood pH

Question 34

# 3 Main Ways CO₂ is Transported Bound to Hemoglobin

Answer 34

* CO₂ attaches to the globin part of the hemoglobin - carbaminohemoglobin * (O₂ carried on heme part so they don't interfere with each other)

Question 35

# 3 Main Ways CO₂ is Transported Dissolved in Plasma

Answer 35

CO₂ is 20% more soluble than oxygen. Inefficient way to carry CO₂

Question 36

Maintaining Gas Levels

Answer 36

* Chemoreceptors in the aortic body and carotid body detect high levels of CO₂ in the blood * Sends message to the medullaa oblongata (in the brain) * Message is sent to intercostal muscles and diaphragm to increase lung volume and breathing rate * When CO₂ levels return to normal breathing rate decreases

Question 37

Regulation of Breathing Movements

Answer 37

* Nerves from the medulla oblongata (in the brain) control breathing rates * Chemoreceptors detect changes in CO₂ and O₂, and acid levels in the blood Two Types * CO₂ and Acid Chemoreceptors are the msot sensitive & main regulators of breathing movements * O₂ Chemoreceptors: Found in carotid and aorta

Question 38

# Types of Respiration External Respiration

Answer 38

* In lungs * Involves exchange of O₂ and CO₂ molecules between air and blood * When you breathe in, partial pressure of O₂ is higher in the alveoli than in the capillaries → O₂ moves from the alveoli into the capillaries

Question 39

# Types of Respiration Internal Respiration

Answer 39

* Within body * Exchange of O₂ and CO₂ molecules between blood and tissue fluid * O₂ is used in cell resp. → Partial pressure gradient for O₂ is low → O₂ will go from the capillaries into the tissues