bio ch 42

What is the theoretical cardiac output of a patient with a heart rate of 70 beats per minute and a stroke volume of 70 mL/beat?

4,900 mL/minute

What is the partial pressure of oxygen (PO2) when the air in a testing chamber is mixed so that its oxygen content is 10% and its overall air pressure is 400 mm Hg?

40 mm Hg

What is a person's total lung capacity if they have a tidal volume of 450 mL (milliliters), a vital capacity of 4,000 mL, and a residual volume of 1,000 mL?

5,000 mL

Atmospheric pressure at the summit of Mount Everest is about one third the pressure at sea level, which is 760 mm Hg. What is the partial pressure of oxygen (PO2) at the summit of Mount Everest if oxygen makes up 21% of the atmosphere by volume at both locations?

53 mm Hg

Chambers A and B are separated by a membrane permeable to substance X. The concentration of X is 5% in A and 15% in B. The volume of A is three times that of B. Which of the following will occur?

Although diffusion is random, the result will be the net movement of X from B to A.

__________ in carbon dioxide in your tissues leads to __________ in pH of cerebrospinal fluid and blood, which ultimately causes your breathing to speed up.

An increase, a drop

Which of the following statements best describes an artery?

Arteries carry blood away from the heart.

Why does the velocity of blood slow greatly as blood flows from arterioles into capillaries?

Because capillary beds have a total cross-sectional area much greater than the total cross-sectional area of the arterioles.

Select the correct statement about capillary beds.

Capillary beds are the site of nutrient and oxygen delivery to tissues.

Which statement best describes how diving mammals are different than mammals that are not adapted for diving?

Diving mammals can store more oxygen in their muscles

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.

False

Which of the following is an adaptation of the avian lung that best helps meet the metabolic demands of flight?

Gas exchange occurs during both inhalation and exhalation.

Which statement about lipoproteins is correct?

High-density lipoproteins are cholesterol transporters in the blood.

Which of the following mechanisms are used to regulate blood pressure in the closed circulatory system of vertebrates? I)changing the strength of heart contraction II)constricting and relaxing smooth muscle in the walls of arterioles III)opening or closing precapillary sphincters

I, II, and III

Which of the following statements regarding the mammalian heart is correct?

In the adult heart, blood in the right chambers of the heart cannot enter the left chambers without passing through the lungs.

How are gases transported in insect bodies?

In tracheal systems

What is the function of a circulatory system?

It brings a transport liquid into close contact with all cells in the body.

Which statement about the gas exchange system in fish is correct?

It enables oxygen to diffuse from the water into the blood over the entire length of the gill capillaries.

Which statement best describes what happens to the carbon dioxide produced by humans?

It is converted to bicarbonate ions.

What is the function of the left ventricle?

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

Which of the following statements about human blood vessels is correct?

Pulmonary veins carry oxygen-rich blood to the heart.

Which event occurs first during atrial and ventricular diastole?

The atria and ventricles are relaxed, and blood flows into the atria.

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

The large decrease in blood pressure as blood moves through the lungs may prevent efficient circulation through the rest of the body.

Which of the following statements correctly compares respiration in fish and in mammals?

The movement of the respiratory medium in mammals is bidirectional, but in fish it is unidirectional.

Which statement about oxygen in fish gills is correct?

The partial pressure of oxygen in blood increases as it flows through gill capillaries.

A rabbit taken from a meadow near sea level and moved to a meadow high on a mountainside would have some trouble getting adequate oxygen delivery. Which statement best explains why this would occur?

The partial pressure of oxygen in the air at high elevations is lower than at sea level.

Which of the following features of the mammalian circulatory system helps to prevent damage to capillaries from high arterial blood pressure?

The total cross-sectional diameter of the blood vessels increases with progression from artery to arteriole to capillary, leading to a reduced blood pressure.

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

The ventricles contract, carrying blood into the aorta, and blood flows into the relaxed atria.

While jogging, a person has a stroke volume of 130 mL/beat and a heart rate of 120 beats per minute. Their resting stroke volume is 70 mL/beat and resting heart rate is 60 beats per minute. Which answer best describes the effect of jogging on the person's cardiac output?

Their cardiac output increased from 4,200 mL/minute to 15,600 mL/minute when jogging.

The partial pressure of oxygen at a particular point in the bloodstream is 100 mm Hg. Under what circumstance will there be a net diffusion of oxygen from the water into the bloodstream at this location?

There will be a net diffusion of oxygen from the water into the bloodstream only if the partial pressure of oxygen in the water is greater than 100 mm Hg.

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

Valves prevent the back flow of blood into the atria and ventricles.

Although having evolved independently, the tracheal tubes of mammals and insects are both supported by rigid tissues. The trachea of a mammal are supported by cartilage, and the tracheae of an insect are supported by chitin. Which of the following is a selective pressure that most likely led to the convergent evolution of these respiratory structures?

When breathing air, there is a risk that trachea and tracheal tubes will collapse.

Stroke occurs when __________.

a blood clot enters the cerebral circulation, blocking an artery and causing the death of brain tissue

Which type of circulatory system is most likely present in organisms with a circulating body fluid that is distinct from the fluid that directly surrounds the body's cells?

a closed circulatory system

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

activation of prothrombin to thrombin

A decrease of blood pH from 7.4 to 7.2 would cause hemoglobin to ________.

bind fewer oxygen molecules

Which of the following indicates a diagnosis of hypertension in adults?

blood pressure being greater than 140 mm Hg systolic and/or greater than 90 mm Hg diastolic

The smallest airway through which inspired air passes before gas exchange occurs in the mammalian lungs is the __________.

bronchiole

The human respiration rate is most closely correlated to the blood levels of which compound during most daily activities?

carbon dioxide

During aerobic exercise, the partial pressure of oxygen in muscle cells will ________, thus the rate of diffusion of oxygen into the muscle tissue from the blood will ________.

decrease; increase

Countercurrent exchange in the fish gill helps to maximize ________.

diffusion

Damage to the SA node in humans is most likely to result in a ________.

disruption on the rate and timing of cardiac muscle contractions

Which of the following organisms has no specialized respiratory structures? See Concept 42.5 (Page)

earthworms

Which of the following are the only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart?

fishes

Which biological membranes must atmospheric molecules of oxygen cross to become bound to hemoglobin for transport in mammals?

five membranes (in and out of the cell lining the lung, in and out of the endothelial cell lining an alveolar capillary, and into the red blood cell)

Which of the following examples illustrates the process of countercurrent exchange?

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

Which of the following would an organism need to adjust blood pressure independently in the blood vessels of the gas-exchange surface and in the blood vessels of the general body circulation?

four-chambered heart

In which of the following organisms does blood flow from the pulmocutaneous circuit to the heart before circulating through the rest of the body?

frogs

Which one of the following organisms likely has the highest systolic pressure in its aorta?

giraffe

In which of the following animals are the blood and the interstitial fluid considered to be the same body fluid?

grasshoppers

Pulse is a direct measure of

heart rate.

Compared with the interstitial fluid that bathes active muscle cells, blood reaching these cells in arterioles has a

higher PO2

The amount of oxygen bound to hemoglobin _____.

increases in the presence of high concentrations of oxygen

From the capillaries of the abdominal organs and hind limbs, blood flows to the _____.

inferior vena cava

Organisms belonging to a species with a high resting cardiac output are most likely to have which of the following characteristics?

large distance between its heart and its brain

Which of the following represents the correct flow of air into the lung of a mammal?

larnyx →→ trachea →→ bronchi →→ bronchioles →→ alveoli

Voice sounds are produced by the _____.

larynx

Blood returning to the mammalian heart in a pulmonary vein drains first into the

left atrium

From the pulmonary veins, blood flows to the _____.

left atrium

Some human infants, especially those born prematurely, suffer serious respiratory failure because of ________.

lung collapse due to inadequate production of surfactant

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

nasal cavity

Atrial systole ________.

occurs at the same time as ventricular diastole

As a property of enzymes, cooperativity refers to

one enzyme subunit altering the behavior of others.

Cellular respiration

produces CO2CO2 and ATP.

Blood returns to the heart via the..

pulmonary veins

An advantage of gas exchange in water, compared with gas exchange in air, is that __________.

respiratory surfaces remain moist

From the superior vena cava, blood flows to the _____.

right atrium

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

rising CO2

Which of the following results in the greatest blood pressure in the mammalian aorta?

systole of the left ventricle

Consider the following reaction. Which of the following would happen if the pH of the blood was decreased?CO2 + H2O ⇐ H2CO3 ⇐ HCO3- + H+

the amount of carbon dioxide would increase

A paleontologist discovers the fossilized heart of an extinct animal. The evidence indicates that the organism's heart was large, was well-formed, and had four chambers, with no connection between the right and left sides. Which of the following conclusions is best supported by these observations?

the animal was endothermic and had a high metabolic rate

Which of the following would be the consequence if the direction of water flow over the gills of a fish was reversed, moving water inward past the operculum, past the gills, then out the mouth?

the efficiency of gas exchange would be reduced

Which of the following best describes how an organism senses a disturbance in gas levels?

the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing

One feature that amphibians and humans have in common is

the number of circuits for circulation.

The sun shining on a tidal pool during a hot day heats the water, causing some water to evaporate. Which of the following is most likely to occur because the water has become warmer and saltier?

the oxygen content will decrease

Which of the following is most analogous in structure and function to the circulatory systems of bony fishes, rays, and sharks?

the portal systems of mammals, where two capillary beds occur sequentially, without passage of blood through a pumping chamber

The greatest difference in the concentration of respiratory gases is found in which of the following pairs of mammalian blood vessels?

the pulmonary vein and the superior vena cava Submit

A molecule of CO2 released into the blood in your left toe can be exhaled from your nose without passing through which of the following structures?

the pulmonary vein.

An electrocardiogram (ECG) provides information about ________.

the rhythm of heart contractions

Circulatory systems help to overcome which of the following physiological challenges?

the slow rate at which diffusion occurs over large distances

The velocity of blood flow lowest in capillaries because ________.

the total cross-sectional area is greater in the capillaries than in any other part of the circulatory system

Which of the following respiratory systems is independent from a fluid-based circulatory system?

the tracheal system of an insect

How many capillary beds must a red blood cell pass through to move from an artery in the left arm to the left ventricle of the heart?

two

Which of the following is the correct sequence of blood flow in birds and mammals?

vena cava →→ right atrium →→ right ventricle →→ pulmonary artery