Respiratory

Question 1

What other body system does the respiratory system work closest with?

Answer 1

The cardiovascular system

Question 2

What defines the lungs into lobes?

Answer 2

Fissures

Question 3

How many lobes does the left lung have and what are they called?

Answer 3

Two

Superior and Inferior lobe (due to cardiac notch)

Question 4

How many lobes does the right lung have and what are they called?

Answer 4

Three

• Superior
• Middle
• Inferior

Question 5

Which primary bronchus is the largest?

Answer 5

The right

Question 6

List the bronchial tree

Answer 6

Trachea > Primary Bronchi > Secondary > Tertiary > Bronchioles > Terminal Bronchioles

Question 7

What epithelium is the trachea made up of?

Answer 7

pseudostratified columnar epithelium with goblet cells

Question 8

What supports the trachea and what are the 2 main functions?

Answer 8

C rings of hyaline cartilage

• Prevents collapse
• Allows for expansion

Question 9

What epithelium are the bronchial airways made up of?

Answer 9

Ciliated columnar epithelium with goblet cells

Question 10

What do the bronchial airways do?

Answer 10

Conduct air deep into lungs

Question 11

What do the terminal bronchioles branch/subdivide into?

Answer 11

Respiratory bronchioles

Question 12

What two epithelium are the terminal bronchioles made of?

Answer 12

Simple cuboidal

Simple squamous

Question 13

What are alveoli?

Answer 13

Microscopic air sacs where gas exchange occurs

Question 14

What are the two types of cell in the alveoli?

Answer 14

Type I and Type II

Question 15

What function do type I cells in the alveoli serve?

Answer 15

They form a continuous lining and are the main site of gas exchange

Question 16

What function do type II cells in the alveoli serve?

Answer 16

These are septal cells that secrete alveolar fluid (including surfactant) which reduces surface tension preventing alveolar collapse

Question 17

How thick is the respiratory membrane?

Answer 17

0.5 micrometres

Question 18

What 3 things is the respiratory membrane made up of?

Answer 18

Alveolar cells 
Endothelium 
Connective Tissue (CT)

Question 19

What happens at the respiratory membrane?

Answer 19

Gas exchange

Question 20

What is ventilation?

Answer 20

The process of breathing

Question 21

What are the two parts of ventilation?

Answer 21

• Inhalation (atmosphere to lungs)

- Exhalation (lungs to atmosphere)

Question 22

How is ventilation achieved?

Answer 22

Due to pressure differences and the contraction and relaxation of respiratory muscles

Question 23

How is inhalation achieved (rib cage and diaphragm)?

Answer 23

Rib cage up and out
Diaphragm down
To expand thoracic volume

Question 24

How is exhalation achieved (rib cage and diaphragm)?

Answer 24

Rib cage down and in 
Diaphragm up (relaxes) 
To decrease thoracic volume

Question 25

How does pressure change as volume increases?

Answer 25

Pressure decreases

Question 26

What law governs pressure and volume?

Answer 26

Boyles law (pressure x volume = constant)

Question 27

What is the equation for Boyles law?

Answer 27

``` P1V1 = P2V2 OR PV = K ```

Question 28

What three factors affect ventilation?

Answer 28

1. Alveolar surface tension 2. Lung compliance 3. Airway resistance

Question 29

How does alveolar surface tension affect ventilation?

Answer 29

Fluid/surfactant reduces surface tension to allow for easier alveolar inflation

Question 30

How does lung compliance affect ventilation?

Answer 30

High compliance is normal allowing for easy ventilation | Low compliance in disease states

Question 31

How does airway resistance affect ventilation?

Answer 31

As diameter decreases, airflow resistance increases and leads to reduction in ventilation.

Question 32

What conditions can cause increased airway resistance?

Answer 32

- Asthma (smooth muscle contraction) - Bronchitis (inflammation and musuc) - Emphysema (loss of elastic tissues)

Question 33

What is a normal tidal volume Vt?

Answer 33

500ml

Question 34

How much air is contained within 'dead space' each breath?

Answer 34

150ml

Question 35

How do gases move from the air to blood and back?

Answer 35

Diffusion

Question 36

What is partial pressure?

Answer 36

The pressure exerted by gases in air

Question 37

~ how much of air is made up of oxygen?

Answer 37

21%

Question 38

What does partial pressure difference determine?

Answer 38

The direction gases move in

Question 39

What is the PO2 in venous blood compared to arterial blood?

Answer 39

Venous - 40mmHg | Arterial - 100mmHg

Question 40

What is the PO2 in the atmosphere compared to the alveoli?

Answer 40

Atm - 159mmHg | Alveoli - 105mmHg

Question 41

What is the PCO2 in the atmosphere compared to the alveoli?

Answer 41

atm - 0.3mmHg | Alveoli - 40mmHg

Question 42

What is the PCO2 in venous blood compared to arterial blood?

Answer 42

Venous - 45mmHg | Arterial - 40mmHg

Question 43

What two ways are oxygen carried around in the blood?

Answer 43

Dissolved in water (3ml/l) | Bound to haemoglobin (197ml/l)

Question 44

What are the two components of haemoglobin?

Answer 44

Haem (pigment) | Globin (protein)

Question 45

What is at the centre of each haem molecule?

Answer 45

Iron

Question 46

How many oxygen molecules can potentially be carried by one Hb molecule

Answer 46

Four

Question 47

What is the compound called when oxygen and haemoglobin are bound together?

Answer 47

Oxyhaemoglobin

Question 48

What determines the level of oxygen saturation in the blood?

Answer 48

PO2 in the blood

Question 49

What happens to O2 binding when pH becomes more acidic?

Answer 49

Less O2 binds to haemoglobin

Question 50

What does the acidic environment at the tissues allow?

Answer 50

Delivery of O2 to the tissues

Question 51

Where in the body is less acidic and what does it allow?

Answer 51

Lungs | Allows O2 to be picked up

Question 52

What 3 ways are CO2 molecules transported in the blood?

Answer 52

- Dissolved in water (8%) - Bound to Hb (carbaminohaemoglobin) (25%) - Transported by HCO3 in plasma (67%)

Question 53

What do central chemoreceptors respond to?

Answer 53

Changes in PCO2

Question 54

What do peripheral chemoreceptors respond to?

Answer 54

Changes in PO2

Question 55

Where is the respiratory control centre?

Answer 55

Brainstem

Question 56

Where is the central chemoreceptor?

Answer 56

Medulla (brainstem)

Question 57

Where are the peripheral chemoreceptors?

Answer 57

``` Aortic bodies (aortic arch) Carotid bodies ```

Question 58

What does the respiratory centre end up doing?

Answer 58

Changing the activity of respiratory muscles