Resp true or false Flashcards Preview

Yr1 - S2 - Formatives > Resp true or false > Flashcards

Flashcards in Resp true or false Deck (40):
1

Concerning gas transport. Shift of the oxygen dissociation curve of blood to the right may be caused by hyperventilation

False


hyperventilation would lower PCO2 and therefore increase in pH. this is the opposite effect seen in active tissues where pH falls and favours increased unloading of oxygen

2

Concerning the mechanics of breathing, ventilation and perfusion. Air in the pleural cavity (pneumothorax) makes the intrapleural pressure less negative

True

3

Concerning the mechanics of breathing, ventilation and perfusion. Air in the pleural cavity (pneumothorax) results when the cavity if opened to air at atmospheric pressure

true

4

Concerning gas transport. The haemoglobin-O2 saturation curve is moved to the left by a rise in pH

true

5

regarding airway and breathing: expiration at rest is essentially passive process

true


6

during the control of respiration. The carotid bodies are stretch receptors in the wall of the internal carotid artery

false


those are baroreceptors in the carotid sinus


the carotid bodies contain peripheral receptors

7

concerning the mechanic of breathing. ventilation and perfusion: air in the pleural cavity (pneumothorax) reduced vital capacity

true

8

the cuboidal epithelium found in the alveolar lining functions as the membrane across which gas exchange occurs

false




The membrane across which gas exchange occurs consists of squamous epithelial cells - the type I alveolar cells. These from the majority of cells lining the alveoli but there are also some rounded (cuboidal) cells - these are the type II alveolar cells, which secrete surfactant.

9

Concerning the mechanics of breathing, ventilation and perfusion: Peak expiratory flow rate is a useful clinical measure of lung function.

true


Concerning the mechanics of breathing, ventilation and perfusion: Peak expiratory flow rate is a useful clinical measure of lung function.

10

Concerning gas exchange and gas transport: Increases in carbon dioxide in the blood enhance the oxygen binding power of haemoglobin.

True



Carbon dioxide shifts the oxygen-haemoglobin dissociation curve to the right and favours the off-loading of oxygen. This can be considered as a physiological adaptation to ensure that the haemoglobin does not hang on to its oxygen once it reaches peripheral tissues.

11

Regarding the respiratory system: The costophrenic angle (costodiaphragmatic recess) provides space into which the lungs can expand in inspiration.

true


12

Concerning lung volumes and capacities: The total volume of both lungs is called the vital capacity.

false

Correct. The total lung volume is equal to the vital capacity plus the residual volume.

13

Concerning the mechanics of breathing, ventilation and perfusion: The volume of blood flowing through the pulmonary circulation per minute is less than in the systemic circulation.

False


Both receive an equal cardiac output. The right and left ventricles are arranged in series therefore the blood flow through the pulmonary and systemic circulations must be equal.

14

Concerning the control of respiration: Activity in the inspiratory neurones in the medulla is increased by lung inflation.

false



The spontaneous activity of the medullary inspiratory neurones is inhibited by feedback from stretch receptors in the lung parencyhma whose afferents travel in the vagus nerve. Section of the vagi therefore leads to an increase in the depth and a decrease in the rate of respiration.

15

Regarding airways and breathing: Pulmonary blood flow is unaffected by gravity in the upright posture.

FALSE


The effect of gravity increase filling of blood vessels at the bottom (base) of the lung and means that many capillaries at the top (apex) of the lung are closed at rest. They only get perfused when pulmonary perfusion pressure rises, eg during exercise.

16

Concerning the mechanics of breathing, ventilation and perfusion: Air in the pleural cavity (pneumothorax) increases the functional residual capacity.

False

17

Concerning lung volumes and capacities: Alveolar ventilation volume is more than minute ventilation volume.

false


. Minute ventilation volume describes the volume of gas entering the lungs each minute. Not all of this will reach the alveoli and so alveolar ventilation will be smaller than the minute ventilation volume.

18

Concerning gas exchange and gas transport: The term shunt describes the passage of blood through the lungs where the opportunity for gas exchange does not occur.

false

. The end result is to lower PO2 in the systemic arteries.

19

Regarding airways and breathing: Inspiratory movement of the chest wall expands the thoracic cavity.

true

. Thereby reducing the intrapleural pressure, thus causing air to flow in from the atmosphere.

20

Regarding the respiratory system: The right lung is divided by a fissure into the upper and lower lobes.

false


The right lung is normally divided into 3 lobes, the inferior, middle, and superior lobes. These are separated by the oblique and the horizontal fissures.

21

Gas exchange at rest is normally complete within a third of the time for which the blood is in the capillaries

true

22

Air in the pleural cavity (pneumothorax) reduced the vital capacity

true

23

alveolar ventilation is defined as the total volume of gas breathed per minute

false

. Alveolar ventilation is defined as the volume of gas that reaches the respiratory zone per minute.

24

Concerning the mechanics of breathing, ventilation and perfusion: Air in the pleural cavity (pneumothorax) increases the functional residual capacity.

False

25

Concerning the mechanics of breathing, ventilation and perfusion: The volume of blood flowing through the pulmonary circulation per minute is less than in the systemic circulation.

False


Both receive an equal cardiac output. The right and left ventricles are arranged in series therefore the blood flow through the pulmonary and systemic circulations must be equal.

26

Regarding the respiratory system: The intercostal artery and nerve are situated at the inferior margin of the rib.

True


this makes an important difference to where between the ribs you would choose to stick a needle

27

Regarding airways and breathing: Forced vital capacity is the maximum amount of gas that can be breathed out of the lungs from full inspiration in one second.

False

Forced vital capacity is the vital capacity measured with the subject exhaling as rapidly as possible. The volume breathed out in one second is the FEV1. FEV1 should be about 80% of FVC in healthy lungs.

28

Concerning gas transport: Shift of the oxygen dissociation curve of blood to the right decreases the oxygen content of blood at a given oxygen pressure.

False

. Shifting the curve to the right decreases the affinity of haemoglobin for oxygen and so less can be carried. This has the effect of unloading oxygen into tissues.

29

Concerning gas exchange and gas transport: Only 25% of the oxygen carried by haemoglobin is actually used by the tissues of the body at rest.

True


HbO2 saturation of venous blood varies between tissues, but HbO2 saturation of mixed venous blood at rest is about 75%.

30

Concerning lung volumes and capacities: The volume which may be forcibly exhaled in one second is greater than 70% of the vital capacity in a healthy adult.

True


(this describes the ratio)

31

Concerning gas transport: Shift of the oxygen dissociation curve of blood to the right is seen in foetal blood, as compared with adult blood.

False



Foetal blood has to pick oxygen up from the maternal placental blood. A shift in the foetal oxygen dissociation curve to the left enables it to do this.

32

Concerning the control of respiration: The carotid bodies are stretch receptors in the wall of the internal carotid artery.

False



This refers to the baroreceptors in the carotid sinus. The carotid bodies contain the peripheral chemoreceptors, which are stimulated by a decrease in arterial PO2 and an increase in arterial H+ concentration.

33

Concerning the control of respiration: At the onset of inspiration, action potential frequency in the phrenic motoneurones decreases.

False


Phrenic motor neurnones innervate the diaphragm and activity in these nerves initiate inspiration.

34

The pulmonary circulation is described as being a low-flow high-pressure system.

False


It is a high-flow low-pressure system. The MAP in the pulmonary circulation is only about 1/5th of that in the system circulation, but the blood flow is the same.

35

Concerning the control of respiration: The carotid bodies are stimulated by increased blood acidity.

True



acidosis stimulates ventilation

36

Concerning the mechanics of breathing, ventilation and perfusion: Air in the pleural cavity (pneumothorax) makes the intrapleural pressure less negative.

True

37

Regarding airways and breathing: Surfactant reduces the surface tension within alveoli.

True


. It decreases surface tension making it easier to inflate the lung and thus more compliant. It also prevents alveolar collapse on deflation.

38

Concerning gas exchange and gas transport: CO2 in the blood is mainly carried in the form of carbamino compounds.

False




Correct. Only about 30% of the CO2 in the blood reacts with amino groups of haemoglobin and is carried as carbamino haemoglobin. About 60% of the CO2 in the blood forms carbonic acid (H2CO3) inside red blood cells. H+ ions from the carbonic acid are buffered by Hb in the red cells. The HCO3- ions enter the plasma via a transporter in exchange for Cl- ions to maintain electroneutrality.

39

Regarding the respiratory system: The costophrenic angle (costodiaphragmatic recess) provides space into which the lungs can expand in inspiration.

true

40

Regarding the respiratory system: The right lung is divided by a fissure into the upper and lower lobes.

false


The right lung is normally divided into 3 lobes, the inferior, middle, and superior lobes. These are separated by the oblique and the horizontal fissures.