Respiratory system

Question 1

Upper respiratory tract

Answer 1

Moistens and filters inspired air

Nasal cavity, pharynx and larynx

Question 2

Lower respiratory tract

Answer 2

Trachea, bronchi and bronchioles control air flow through lungs
Lung enables gaseous exchange

Question 3

Anatomical difference between the right and left lung

Answer 3

Both have superior and inferior lobe

Right has a middle lobe, but not left because of position of heart

Question 4

Trachea and respiratory airways have 3 layers

Answer 4

Outer layer - cartilage reducing from trachea to bronchi
Middle muscular layer
Inner epithelial layer with goblet cells

Question 5

How does the ANS cause bronchodilation?

Answer 5

Sympathetic nerve tone results in adrenaline binding to beta 2 receptors in smooth muscle

Question 6

How does the ANS cause bronchoconstriction?

Answer 6

Parasympathetic stimulation releases acetylcholine that binds to M3 receptors on smooth muscle

Question 7

Epithelial layer of bronchi

Answer 7

Made up of pseudo-stratified columnar epithelium
Lined with cilia - removes dust and small particles
Aided by mucous secreted by Goblet cells

Question 8

Type I alveoli

Answer 8

Form alveolar sac

Sites of gaseous exchange

Question 9

Type II alveoli

Answer 9

Form surfactant
Exoctyose lipo-protein surfactant which reduces water tension
Create pressure needed by alveoli
Scavange debris

Question 10

Pulmonary respiration and pressure

Answer 10

Movements in chest wall and lungs cause lungs to increase and decrease in volume - changes lung pressure relative to atmospheric pressure

Question 11

Tidal volume

Answer 11

Amount of air breathed in and out at rest

Question 12

Inspiratory reserve

Answer 12

Extra air that can be inhaled in a deep breath

Question 13

Expiratory reserve

Answer 13

Extra air that can be expired in one breath

Question 14

Residual volume

Answer 14

Air left in lungs after expiration (cant be exhaled)

Question 15

Vital capacity

Answer 15

Amount of air that can be forcefully inhaled and exhaled

Question 16

Functional residual capacity

Answer 16

Expiratory reserve + residual volume

Question 17

External respiration

Answer 17

Oxygen diffuses from alveoli (p=100) to pulmonary capillary (p=40)
Carbon dioxide diffuses from capillary (p=45) to alveoli (p=40)

Question 18

Role of haeomoglobin

Answer 18

1. Oxygen carried in blood to haemoglobin
2. Iron in subunit binds oxygen, promoted by increased partial pressure and increased pH
3. When all 4 haemoglobin subunits have bound with oxygen, it is fully saturated

Question 19

Oxygen saturation curve

Answer 19

• Oxygen partial pressure in blood drops as blood travels away from lung
• Haemoglobin drops oxygen as pressure decreases
• 75% saturated when it reaches tissue

Question 20

Internal respiration

Answer 20

Oxygen diffuses from blood (p=95) to cells (p=40)

Carbon dioxide diffuses from cells (p=45) to blood (p=40)

Question 21

Involuntary regulation of respiration

Answer 21

Moderated by medulla oblongata in response to carbon dioxide levels
Normal tiding breathing - Hering Breuer reflex s when expansion stretch receptors signal to the medulla to inhibit further expansion

Question 22

Voluntary regulation of respiration

Answer 22

Cerebral cortex

Limbic system - emotions like fear and anger

Question 23

SNS receptors

Answer 23

Beta 2

Adrenaline binds and causes bronchial relaxation

Question 24

PSNS receptors

Answer 24

Muscarinic

Acetylcholine binds and causes bronchial constriction

Question 25

pH

Answer 25

Power of Hydrogen

Measure of the activity of hydrogen ions in a solution

Question 26

As the pH number goes up, the activity of hydrogen ions…

Answer 26

Decreases

Question 27

What happens if the body’s pH drops?

Answer 27

Hydrogen ions bind with bicarbonate, making carbonic acid
Carbonic acid is unstable so dissociates to carbon dioxide and water
Neutralisation of hydrogen ions by bicarbonate maintains a stable pH in the blood stream

Question 28

Increased carbon dioxide in the blood means…

Answer 28

Increased hydrogen ions, because carbon dioxide and water make carbonic acid which dissociates to bicarbonate and hydrogen