Respiratory Physiology

Question 1

What is dead space in the respiratory system?

Answer 1

Area where air travels but gas exchange does not occur

Question 2

What are the two primary functions of the respiratory system?

Answer 2

• Pulmonary respiration or ventilation
• Transport of gases between the atmosphere and the tissues

Question 3

What does respiration refer to?

Answer 3

All components of the interchange of gases between the atmosphere and the cell of the body

Question 4

What does ventilation refer to?

Answer 4

The transport of air to and from the lungs

Question 5

What does gas exchange refer to?

Answer 5

Transport of gases between the air in the lungs and the cells of the body

Question 6

What must occur for air to move into the lungs?

Answer 6

An area of lower pressure must be created

Question 7

How do you calculate the flow of air into the lungs?

Answer 7

F=Area of lower pressure/resistance

Question 8

What is the approximate air pressure in alveoli at rest?

Answer 8

Atmospheric pressure - 760mmHg

Question 9

How is an area of lower pressure created for ventilation?

Answer 9

The thoracic cavity expands causing a reduction in alveolar pressure

Question 10

What is the tidal volume?

Answer 10

The volume of air flowing through the airways during inspiration and expiration

Question 11

What is dead space volume made up of?

Answer 11

• Anatomical dead space
• Alveolar ventilation

Question 12

What is anatomical dead space?

Answer 12

The volume of the upper airways that are not involved in gas exchange

Question 13

What is alveolar ventilation?

Answer 13

The volume of air available for gas exchange in the alveoli per minute

Question 14

What is alveolar dead space?

Answer 14

The volume of alveoli that are not being perfuse by blood so do not participate in gas exchange

Question 15

How is alveolar ventilation calculated?

Answer 15

Alveolar ventilation = (tidal volume - anatomical dead space) x respiratory rate

Question 16

What is the expiratory reserve volume?

Answer 16

The amount of air that can be forcefully exhaled from the lungs after a normal exhalation

Question 17

What is the inspiratory reserve volume?

Answer 17

Maximum amount of air that can be inhaled after a normal breath

Question 18

What is the residual volume?

Answer 18

The amount of air remaining in the lungs after a maximal exhalation a volume that cannot be expelled

Question 19

What is the vital capacity?

Answer 19

Maximum amount of air a person can exhale from their lungs after a maximal inhalation

Question 20

What is total lung capacity?

Answer 20

The maximum amount of air the lungs can hold after a maximal inhalation

Question 21

What results in expiration?

Answer 21

The respiratory muscles relax and the lungs recoil and thoracic cage reduce thoracic volume

Question 22

Why does the pO2 decrease in the alveoli?

Answer 22

The air is moistened by the respiratory tract so that the partial pressure of water increases which means pO2 must decrease

Question 23

How does carbon dioxide move in between the alveoli and capillaries?

Answer 23

Moves from the capillaries to alveoli down concentration gradient

Question 24

How does oxygen move in between the alveoli and capillaries?

Answer 24

Moves from the alveoli to capillaries down the concentration gradient

Question 25

How much of air is exchanged with each breath in an alvieoli?

Answer 25

15%

Question 26

What is meant by perfusion in the lungs?

Answer 26

Where blood goes in the lungs

Question 27

What is the perfusion of the lungs?

Answer 27

Less blood flows to the highest part of the lungs due to gravity

Question 28

Where does air usually go to in the lungs?

Answer 28

The more dependent parts (lower parts) of the lungs

Question 29

What are the two ways oxygen can be transported in the body?

Answer 29

- Dissolved in the blood plasma - Bound to haemoglobin in RBCs

Question 30

How much O2 is in plasma?

Answer 30

3mL/L of blood

Question 31

How much O2 is in blood with a haemoglobin concentration of 150mL/L?

Answer 31

200mL/L of blood

Question 32

How many oxygen molecules can one haemoglobin molecule bind?

Answer 32

4 as it contains 4 heme groups

Question 33

What is oxygen association in relation to haemoglobin?

Answer 33

The process of oxygen binding to haemoglobin in the lungs where the pO2 is high

Question 34

What is oxygen dissociation from haemoglobin?

Answer 34

Is the release of oxygen from haemoglobin in the tissues where the pO2 of oxygen is low

Question 35

Why is pO2 significant in oxygen transport?

Answer 35

pO2 determines how readily oxygen binds to or dissociates from haemoglobin

Question 36

What is the oxyhaemoglobin dissociation curve?

Answer 36

Is a graph showing the relationship between haemoglobin saturation and pO2 indicating cooperative binding of oxygen

Question 37

What is cooperative binding in haemoglobin?

Answer 37

The process where the binding of one oxygen molecule to haemoglobin increases its affinity for the next oxygen molecule

Question 38

What causes the oxyhaemoglobin dissociation curve to shift to the right?

Answer 38

Conditions such as high CO2, low pH, increased temp and exercise making haemoglobin more likely to release oxygen

Question 39

What is the Bohr effect on the oxyhaemoglobin dissociation curve?

Answer 39

Is the rightward shit of the cure in response to increased CO2 and decreased pH

Question 40

What are the three ways carbon dioxide is transported in the blood from lowest to highest?

Answer 40

- Plasma - Bound to Haemoglobin - Bicarbonate ions

Question 41

How does CO2 bind to haemoglobin?

Answer 41

Bind to the amino groups of the globin part of haemoglobin

Question 42

What happens to CO2 when it enters red blood cells in tissues?

Answer 42

CO2 reacts with water to form carbonic acid, which then dissociates into hydrogen ions and bicarbonate ions

Question 43

How does the pCO2 affect carbon dioxide transport?

Answer 43

High pCO₂ in tissues promotes CO₂ binding to haemoglobin, while low pCO₂ in the lungs promotes CO₂ release and exhalation

Question 44

Where is the respiratory centre located?

Answer 44

Medulla oblongata and pons

Question 45

What does the inspiratory centre control?

Answer 45

Baseline rhythm of breathing

Question 46

When is the expiratory centre active?

Answer 46

Only during forced expiration

Question 47

What is the function of the pneumotaxic centre?

Answer 47

Limits inspiration

Question 48

What is the Hering-Breuer Reflex

Answer 48

Stretch receptors inhibit inspiration to prevent over inflation

Question 49

Which receptors stimulate respiration during exercise?

Answer 49

Proprioceptros in limbs

Question 50

What are the two types of chemoreceptors related to respiration?

Answer 50

Central and peripheral

Question 51

Where are central chemoreceptors in relation to respiration?

Answer 51

The medulla

Question 52

Where are peripheral chemoreceptors in relation to respiration?

Answer 52

In the carotid and aortic bodies

Question 53

What does pCO2 primarily affect?

Answer 53

Ventilation rate and depth

Question 54

Which receptor is more sensitive to pCO2?

Answer 54

Central chemoreceptors

Question 55

When does pO2 begin to affect respiration?

Answer 55

Only when less than 60mmHg

Question 56

How is H+ concentration detected by peripheral and central chemoreceptors?

Answer 56

- Peripheral detects arterial H+ conc - Central detects cerebrospinal fluid H+ conc from pCO2

Question 57

How does panting help thermoregulation?

Answer 57

Increases dead space ventilation and evaporative heat loss

Question 58

Why might cats purr when in pain?

Answer 58

To prevent alveolar collapse

Question 59

What immunological component removes particles in alveoli?

Answer 59

Alveolar macrophages

Question 60

What is the mucociliary escalator?

Answer 60

Cilia move mucus and trapped particles toward the pharynx

Question 61

How are large particles trapped in the respiratory system?

Answer 61

By impaction in the nasopharynx

Question 62

How are medium particles trapped in the respiratory system?

Answer 62

By sedimentation in small airways

Question 63

How are small particles trapped in the respiratory system?

Answer 63

By diffusion or exhalation in the alveoli

Question 64

What causes bronchoconstriction?

Answer 64

Parasympathetic stimulation and inflammatory mediators

Question 65

What is the respiratory pumo?

Answer 65

Inspiration reduces thoracic pressure and pumps venous blood towards the heart

Question 66

What are the four steps to the cough reflex?

Answer 66

- Deep breath - Epiglottis closes - Pressure builds - Sudden release expels air

Question 67

How is sneezing different from coughing?

Answer 67

Triggered from nasal passages and air is expelled through the nose