Physiology

Question 1

The intracellular mechanisms and processes that consume oxygen and produce carbon dioxide.

Answer 1

Internal respiration

Question 2

At a constant temperature, the pressure exerted by a gas varies inversely with the volume of the gas.

Answer 2

Boyle’s Law

Question 3

P=2T/r describes the relationship between alveolar radius and the tendency to collapse. A smaller alveolar radius means a higher tendency to collapse.

Answer 3

Law of LaPlace

Question 4

The processes that exchange oxygen and carbon dioxide between the external environment and the cells of the body.

Answer 4

External respiration

Question 5

Comprises ventilation, gas exchange between the alveoli and blood, gas transport, and gas exchange at the tissues.

Answer 5

External respiration

Question 6

Maintains alveolar patency through the elastic recoil of surrounding alveoli preventing alveolar collapse.

Answer 6

Alveolar interdependence

Question 7

A product of Type II alveolar cells that opposes alveolar surface tension.

Answer 7

Alveolar surfactant

Question 8

Keeps the visceral and parietal pleurae closely opposed and can be overcome by a pneumothorax.

Answer 8

Transmural pressure gradient

Question 9

Keeps the visceral and parietal pleurae closely opposed. Dependent on water molecule polarity.

Answer 9

Intrapleural fluid

Question 10

Fick’s law of diffusion

Answer 10

Gas diffusion across a surface is inversely proportional to surface thickness and proportional to area

Question 11

Dalton’s law

Answer 11

The total pressure of a mixture of gases equals the sum of the partial pressures of each component gas

Question 12

The law of LaPlace

Answer 12

Smaller alveoli have a greater tendency to collapse

Question 13

The volume of air breathed in and out per minute

Answer 13

Pulmonary ventilation

Question 14

The volume of air exchanged between the atmosphere and alveoli per minute

Answer 14

Alveolar ventilation

Question 15

The inspired air that is available for gas exchange

Answer 15

Alveolar ventilation

Question 16

Those alveoli who are well ventilated but not adequately perfused.

Answer 16

Alveolar dead space

Question 17

The parts of the bronchial tree not available for airway exchange.

Answer 17

Anatomical dead space

Question 18

The factor that most increases pulmonary ventilation.

Answer 18

Tidal volume

Question 19

The myoglobin dissociation curve

Answer 19

A hyperbolic curve

Question 20

The haemoglobin dissociation curve

Answer 20

A sigmoid curve

Question 21

The Bohr effect on the haemoglobin dissociation curve

Answer 21

A sigmoid curve, shifted right

Question 22

The Bohr effect

Answer 22

The oxygen dissocation curve is shifted right due to conditions in the tissues, meaning more oxygen is released

Question 23

The Haldane effect

Answer 23

As O2 is removed from Hb, Hb’s ability to pick up CO2 and CO2-generated H+ ions is increased

Question 24

Henry’s Law

Answer 24

The amount of a gas dissolved in a given type and volume of liquid at constant temperature is proportional to the partial pressure of the gas in equilibrium with the liquid

Question 25

Most O2 is transported...

Answer 25

Bound to haemoglobin

Question 26

Most CO2 is transported...

Answer 26

As bicarbonate

Question 27

A small proportion of O2 is transported...

Answer 27

In solution

Question 28

The volume of air in the lungs after a maximal expiration.

Answer 28

Residual volume

Question 29

Equals inspiratory reserve volume plus tidal volume plus expiratory reserve volume

Answer 29

Vital capacity

Question 30

The volume of air in the lungs at the end of a normal, passive expiration

Answer 30

Functional residual capacity

Question 31

Equals expiratory reserve volume plus residual volume.

Answer 31

Functional residual capacity

Question 32

Equals inspiratory reserve volume plus tidal volume.

Answer 32

Inspiratory capacity

Question 33

The maximum total volume of air that can be inspired at the end of a normal, quiet respiration.

Answer 33

Inspiratory capacity

Question 34

The maximum volume of air that can be expired in a single breath following maximum inspiration.

Answer 34

Vital capacity

Question 35

The volume of air entering or leaving the lungs in a single breath.

Answer 35

Tidal volume

Question 36

Equals vital capacity plus residual volume

Answer 36

Total lung capacity

Question 37

Results in increased pulmonary compliance, produces hyperinflated lungs and will show an obstructive defect on spirometry.

Answer 37

Emphysema

Question 38

Causes shortness of breath on exertion, a restrictive defect on spirometry and reduced pulmonary compliance but no sign of infection.

Answer 38

Pulmonary fibrosis

Question 39

Will show a low FVC, a low FEV1 and a low FEV1/FVC% on spirometry.

Answer 39

Combined restrictive-obstructive lung disease

Question 40

Normal expiration

Answer 40

Is a passive process, controlled by the gaps in firing of dorsal neurons within the medulla

Question 41

Forceful expiration

Answer 41

Is an active process, controlled by the firing of ventral neurons in the medulla

Question 42

Normal inspiration

Answer 42

Is an active process, controlled by the firing of dorsal neurons within the medulla

Question 43

These chemoreceptors detect arterial oxygen partial pressure. When stimulated, they cause hyperventilation and increased cardiac output.

Answer 43

Peripheral chemoreceptors

Question 44

These chemoreceptors are found in the brainstem. They respond to CSF [H+].

Answer 44

Central chemoreceptors in the medulla

Question 45

These chemoreceptors, when stimulated, can compensate for metabolic acidosis by triggering increased elimination of CO2.

Answer 45

Peripheral chemoreceptors

Question 46

Chronic adaptation caused by hypoxia

Answer 46

Increased mitochondria, 2,3-BPG, capillaries and polycythaemia with a metabolic acidosis.

Question 47

Acute mountain sickness

Answer 47

Fatigue, headache, tachycardia, dizziness and shortness of breath, slipping into unconsciousness.

Question 48

Diabetic ketoacidosis

Answer 48

Hyperventilation with a severe metabolic acidosis.