Biology 102 Final ( Chapter 42)
A patient with a heart rate of 70 beats per minute and a stroke volume of 70 mL/beat will have a cardiac output of
4,900 mL/minute
When the air in a testing chamber is specially mixed so that its oxygen content is 10% and its overall air pressure is 400 mm Hg, then PO2 is
40 mm Hg
A person with a tidal volume of 450 mL (milliliters), a vital capacity of 4000 mL, and a residual volume of 1000 mL would have a potential total lung capacity of
5000 mL
Which of the following best describes an artery?
Arteries carry blood away from the heart
capillary beds
Capillary beds are the site of nutrient and oxygen delivery to tissues.
_ is a hormone that is released from the ________ to stimulate the production of red blood cells.
Erythropoietin; kidney
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 force 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 statement 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
Hyperventilation (rapid inhalation and exhalation) can result in respiratory alkalosis (increased blood pH). Why?
Rapid breathing depletes the blood of carbon dioxide, thus the blood pH increases.
Which of the following would you expect of a species that has a high resting cardiac output?
The animal likely has a very long distance between its heart and its brain.
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.
Blood is pumped at high pressures in arteries from the heart to ensure that all parts of the body receive adequate blood flow. Capillary beds, however, would hemorrhage under direct arterial pressures. How does the design of the circulatory network contribute to reducing blood pressure to avoid this scenario?
The total cross-sectional diameter of the arterial circulation 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.
Humans infected with some types of parasitic worms develop a condition called elephantiasis, which is characterized by swelling of the limbs. Which of the following would be the most likely cause of elephantiasis?
The worms are blocking the lymph vessels.
While jogging, a person has a stroke volume of 130 ml/beat and a heart rate of 120 beats per minute. If their resting stroke volume was 70 ml/beat and resting heart rate was 60 beats per minute, how did this person's cardiac output change?
Their cardiac output increased from 4,200 ml/minute to 15,600 ml/minute after jogging.
Although having evolved independently, the tracheal tubes of mammals and insects are both supported by rigid tissues. The trachea of a mammal is supported by cartilage, and the tracheae of an insect are supported by chitin. What selective pressure most likely led to the convergent evolution of these respiratory structures?
When air is the respiratory medium, there is a greater risk that the tracheal tubes will collapse.
Stroke occurs when
a blood clot enters the cerebral circulation, blocking an artery and causing the death of brain tissue
Organisms with a circulating body fluid that is distinct from the fluid that directly surrounds the body's cells are likely to have _____.
a closed circulatory system
A normal event in the process of blood clotting is the
activation of prothrombin to thrombin
Consider the following reaction. If the pH of the blood was decreased, then the ________.CO2 + H2O ↔ H2CO3 ↔ HCO3- + H+
amount of carbon dioxide would increase
Cyanide poisons mitochondria by blocking the final step in the electron transport chain. Human red blood cells placed in an isotonic solution containing cyanide are likely to _____.
be unaffected
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
An oil-water mixture works as an insecticidal spray against mosquitoes and other insects because it _
blocks the openings into the tracheal system
The diagnosis of hypertension in adults is based on the
blood pressure being greater than 140 mm Hg systolic and/or greater than 90 mm Hg diastolic
In order for blood to always flow unidirectionally through a closed circulatory system, the
blood vessels farthest from the heart must have valves
the smallest airway through which inspired air passes before gas exchange occurs in the mammalian lungs is the
bronchiole
Which of the following conditions would most likely be due to high blood pressure in a mammal?
bursting of blood vessels in capillary beds
Compared to mammals that are not adapted for diving, diving mammals
can store more oxygen in their muscles
During most daily activities, the human respiration rate is most closely linked to the blood levels of
carbon dioxide
Most of the carbon dioxide produced by humans is
converted to bicarbonate ions
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
Large proteins such as albumin remain in capillaries rather than diffusing out, resulting in the
development of an osmotic pressure difference across capillary walls
Countercurrent exchange in the fish gill helps to maximize
diffusion
which of the following organisms has no specialized respiratory structures?
earthworms
The only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart are the _____.
fishes
To become bound to hemoglobin for transport in mammals, atmospheric molecules of oxygen must cross
five membranesin and out of the cell lining the lung, in and out of the endothelial cell lining an alveolar capillary, and into the red blood cellto bind with hemoglobin
If the osmotic pressure on the venous side of capillary beds is lower than the hydrostatic pressure, then
fluid will tend to accumulate in tissues
To adjust blood pressure independently in the capillaries of the gas-exchange surface and in the capillaries of the general body circulation, an organism would need a(n)
four-chambered heart
In which of the following organisms does blood flow from the pulmocutaneous circulation to the heart before circulating through the rest of the body?
frog
Among the following choices, which organism likely has the highest systolic pressure?
giraffe
A decrease of blood pH from 7.4 to 7.2 causes hemoglobin to
give up more of its oxygen molecules
Under identical atmospheric conditions, freshwater
has more dissolved oxygen than seawater
Compared with the interstitial fluid that bathes active muscle cells, blood reaching these cells in arteries has a
higher P(O2)
Small swollen areas in the neck, groin, and axillary region are associated with
increased activity of the immune system
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
What is the function of the left ventricle?
it pumps oxygenated blood around the body via the systemic circulation.
Which of the following represents the correct flow of air into the lung of a mammal?
larnyx → trachea → bronchi → bronchioles → alveoli
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
Blood cells that function to fight infection are called
leukocytes
Some human infants, especially those born prematurely, suffer serious respiratory failure because of
lung collapse due to inadequate production of surfactant
In an open circulatory system, blood is
not always confined to blood vessels and is under lower pressure than in closed circulatory systems
Atrial systole
occurs at the same time as ventricular diastole
You cut your finger, and after putting pressure on the wound for several minutes, you notice that it is still bleeding profusely. What may be the problem?
platelets are not functioning properly, or there are too few to be effective
Blood returns to the heart via the
pulmonary veins
Which statement about human blood vessels is correct?
pulmonary veins carry oxygen-rich blood to the heart.
What would be the consequence if we were to reverse the direction of water flow over the gills of a fish, moving water inward past the operculum, past the gills, then out the mouth? This reversal of water flow would
reduce efficiency of gas exchange
From the superior vena cava, blood flows to the
right atrium
Which of the following develops the greatest pressure on the blood in the mammalian aorta?
systole of the left ventricle
Carbon dioxide levels in the blood and cerebrospinal fluid affect pH. This enables the organism to sense a disturbance in gas levels as _____.
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. Because the water has become warmer and saltier,
the oxygen content will decrease
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
An electrocardiogram (ECG) provides information about
the rhythm of heart contractions
The velocity of blood flow is the lowest in capillaries because
the total cross-sectional area of the capillaries is greater than the total cross-sectional area of the arteries or any other part of the circulatory system
Which of the following respiratory systems is not closely associated with a blood supply?
the tracheal system of an insect
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. To travel from the artery to the thumb and then back to the left ventricle, this red blood cell must pass through _____.
two capillary beds
Which of the following statements about blood circulation in the body is true?
valves prevent the backflow of blood into the atria and ventricles.
Which of the following is the correct sequence of blood flow in birds and mammals?
vena cava → right atrium → right ventricle → pulmonary artery
Countercurrent exchange is evident in the flow of
water across the gills of a fish and the blood within those gills
An advantage of gas exchange in fresh water, compared with gas exchange in air, is that
water loss through evaporation across the respiratory surface can be minimized
Atmospheric pressure at the summit of Mount Everest is about one third the pressure at sea level, which is 760 mm Hg. If oxygen makes up 21% of the atmosphere by volume, the partial pressure of oxygen (PO2) on Mount Everest is approximately __
53 mm Hg
How does the dissociation curve for fetal hemoglobin compare to that for maternal hemoglobin?
Fetal hemoglobin has a higher affinity for oxygen than maternal hemoglobin at any partial pressure of oxygen
Which hypothesis best explains this difference?
Fetal hemoglobin higher affinity for oxygen helps promote the movement of oxygen from mother to fetus.
How has the avian lung adapted to the metabolic demands of flight?
Gas exchange occurs during both inhalation and exhalation
Which of the following events would you predict as carbon dioxide is released from your muscles into the surrounding capillary bed?
Oxygen delivery to muscle is increased when more carbon dioxide is produced by the muscle.
Which of the following statements comparing respiration in fish and in mammals is correct?
The movement of the respiratory medium in mammals is bidirectional, but in fish it is unidirectional.
A rabbit taken from a meadow near sea level and moved to a meadow high on a mountainside would have some trouble breathing. Why?
The partial pressure of oxygen in the air at high elevations is lower than at sea level.
in carbon dioxide in your red blood cells, which causes _____ in pH, causes your breathing to speed up
an increase.. a drop
An anthropologist 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. A reasonable conclusion supported by these observations is that the
animal was endothermic and had a high metabolic rate
Most carbon dioxide is carried from the body tissues to the lungs
as bicarbonate ions (HCO3 -)
Damage to the sinoatrial node in humans would
disrupt the rate and timing of cardiac muscle contractions
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
When you hold your breath, which of the following blood gas changes first leads to the urge to breathe?
rising CO2
The circulatory systems of bony fishes, rays, and sharks are most similar to
the portal systems of mammals, where two capillary beds occur sequentially, without passage of blood through a pumping chamber
If a molecule of CO2 released into the blood in your left toe is exhaled from your nose, it must pass through all of the following except
the pulmonary vein