Module 5: Gas Exchanges

Question 1

When inhaled, the diaphragm and rip muscles are

Answer 1

contracts to increase the volume of the lungs

Question 2

When inhaled, the diaphragm and rip muscles are

Answer 2

contract to increase the volume of the lung

Question 3

Gas exchange occurs _____ in the lungs

Answer 3

Alveolus. Each Alveolus is surrounded by capillaries. Oxygen diffuses from the alveolus to the blood, and Co2 diffuses from the blood to the alveolus, and it becomes rich in oxygen

Question 4

Gas exchange occurs across specialised respiratory surfaces by

Answer 4

passive diffusion
=> gas itself cannot get across the cell membrane

Question 5

Gas exchange: Partial pressures of gases

Answer 5

the pressure excerted by particular gas in a mixture of gases

Question 6

Quiz II - Organisms in which a circulating body fluid is distinct from the fluid that directly surrounds the body’s cells are likely to have which of the following?

Answer 6

a closed circulatory system

Question 7

A human red blood cell in an artery of the left arm is on its way to deliver oxygen to a cell in the thumb. From this point in the artery, how many capillary beds must this red blood cell pass through before it returns to the left ventricle of the heart?

Answer 7

two

Question 8

What is the function of a circulatory system?

Answer 8

It brings a transport liquid into close contact with all cells in the body.
=> This transport liquid exchanges gases, nutrients, and wastes with the cells in the body.

Question 9

voice sounds are produced by the ____

Answer 9

larynx

Question 10

the primary functions of the ____ are to warm, filter, and humidify air

Answer 10

nasal cavity

Question 11

Why do the circulatory systems of land vertebrates have separate circuits to the lungs and to the rest of the body?

Answer 11

The large decrease in blood pressure as blood moves through the lungs may prevent efficient circulation through the rest of the body.
=> The changes in blood pressure as blood moves through the lungs of land-dwelling vertebrates make it necessary to have separate circuits to the lungs and the rest of the body.

Question 12

True or false? The circulatory systems of land-dwelling vertebrates are composed of two pumping circuits: the systemic circulation, which is a lower-pressure circuit to the lung, and the pulmonary circulation, which is a higher-pressure circuit to the rest of the body.

Answer 12

F
=> The pulmonary circulation is the lower-pressure circuit to the lung, whereas the systemic circulation is the higher-pressure circuit to the rest of the body.

Question 13

in negative pressure breathing, inhalation results from

Answer 13

contracting diaphragm

Question 14

What is the function of the left ventricle?

Answer 14

It pumps oxygenated blood around the body via the systemic circulation.

Question 15

Which of the following statements about blood circulation in the body is true?

Answer 15

Valves are flaps of tissue that close when the ventricles contract to prevent the backflow of blood into the atria and also when the ventricles relax to prevent the backflow of blood from exiting vessels to the ventricles.

Question 16

Which event occurs first during atrial and ventricular diastole?

Answer 16

The atria and ventricles are relaxed, and blood flows into the atria.
=> Diastole is the relaxation phase of the cardiac cycle during which the chambers of the heart are relaxed and blood can enter them passively.

Question 17

when you hold your breath, which of the following blood gas changes first leads to the urge to breathe?

A) rising CO2
B) rising O2
C) falling CO2
D) rising CO2 and falling O2
E) falling O2

Answer 17

A

Question 18

Which event of the cardiac cycle occurs when systolic blood pressure is measured?

Answer 18

The ventricles contract, carrying blood into the aorta, and blood flows into the relaxed atria.
=> The systolic blood pressure is the peak blood pressure, resulting from contraction of the ventricles.

Question 19

If the atrioventricular node could be surgically removed from the heart without disrupting signal transmission to the Purkinje fibres, what would be the effect?

Answer 19

Atria and ventricles would contract at about the same time.

Question 20

Average blood pressure is lowest in which structure(s)?

Answer 20

venae cavae

Question 21

Which of the following is correct for a blood pressure reading of 130/80?
I. The systolic pressure is 130.
II. The diastolic pressure is 80.
III. The blood pressure during heart contraction is 80.

Answer 21

I and II only

Question 22

What is the reason that fluid is forced from the bloodstream to the surrounding tissues at the arteriole end of systemic capillaries?

Answer 22

The hydrostatic pressure of the blood is greater than the osmotic pressure of the blood.

Question 23

What would be the long-term effect if the lymphatic vessels associated with a capillary bed were to become blocked?

Answer 23

Fluid would accumulate in interstitial areas.

Question 24

Human plasma proteins include which of the following?

Answer 24

Immunoglobulin, fibrinogen

Question 25

Which of these speed up heart rate?

Answer 25

epinephrine (adrenaline)

Question 26

Which of the following is a normal event in the process of blood clotting?

Answer 26

activation of prothrombin to thrombin

Question 27

The average resting stroke volume of the heart is 70 mL and it beats ~72 times per minute. This would result in which cardiac output?

Answer 27

To calculate the cardiac output, you need to multiply the stroke volume (SV) by the heart rate (HR). In this case, the stroke volume is given as 70 mL, and the heart rate is approximately 72 beats per minute.

Cardiac Output = Stroke Volume × Heart Rate

Cardiac Output = 70 mL/beat × 72 beats/minute

Cardiac Output = 5040 mL/minute

The cardiac output would be 5040 mL/minute.

5L/min

Question 28

Which sequence of blood flow can be observed in either a reptile or a mammal?

Answer 28

vena cava→right atrium→ventricle→pulmonary circuit

Question 29

Which of these are involved in the early stages of blood clotting?

Answer 29

platelets

Question 30

Voice sounds are produced by the _____.

Answer 30

larynx

Question 31

The primary functions of the _____ are to warm, filter, and humidify air.

Answer 31

nasal cavity

Question 32

Why is gas exchange more difficult for aquatic animals with gills than for terrestrial animals with lungs?

Answer 32

Water contains much less O2 than air per unit volume.

Question 33

Which of the following is an example of countercurrent exchange?

Answer 33

the flow of water across the gills of a fish and that of blood within those gills

Question 34

Atmospheric pressure at sea level is equal to a column of 760 mm Hg.
Oxygen makes up 21% of the atmosphere by volume.

Answer 34

21/100 x 760 = 160 mmHg

Question 35

Which of the following occurs with the exhalation of air from human lungs?

Answer 35

The volume of the thoracic cavity decreases.

Question 36

Most carbon dioxide is carried from the body tissues to the lungs _____.

Answer 36

as bicarbonate ions (HCO3 -)

Most carbon dioxide released from body tissues combines with water to form carbonic acid, which then breaks up into hydrogen and bicarbonate ions.

Question 37

By picking up hydrogen ions, hemoglobin prevents the blood from becoming too _____.

Answer 37

acidic
=> If not carried by hemoglobin, hydrogen ions would reduce the pH, or increase the acidity, of the blood.

Question 38

In the blood most of the oxygen that will be used in cellular respiration is carried from the lungs to the body tissues _____.

Answer 38

combined with hemoglobin

In the blood most oxygen is transported attached to hemoglobin.

Question 39

Tidal volume in respiration is analogous to what measurement in cardiac physiology?

Answer 39

stroke volume

Question 40

Which of the following occurs with the exhalation of air from human lungs?

Answer 40

The volume of the thoracic cavity decreases

Question 41

A person with a tidal volume of 450 mL, a vital capacity of 4,000 mL, and a residual volume of 1,000 mL would have a potential total lung capacity of

Answer 41

To calculate the potential total lung capacity, we can sum up the vital capacity and the residual volume.

Given:
Tidal volume = 450 mL
Vital capacity = 4,000 mL
Residual volume = 1,000 mL

Total Lung Capacity = Vital Capacity + Residual Volume

Total Lung Capacity = 4,000 mL + 1,000 mL

Total Lung Capacity = 5,000 mL

Therefore, the potential total lung capacity would be 5,000 mL.

Question 42

The Bohr shift on the oxygen-haemoglobin dissociation curve is produced by changes in

Answer 42

pH

Question 43

Hydrogen ions produced in human red blood cells are prevented from significantly lowering pH by combining with

Answer 43

Haemoglobin.