Circulatory and Respiratory Anatomy

Which type of epithelial tissue would you suppose covers the gills of axolotls?

Which of the following is a function of the circulatory system?

An open circulatory system __________.

Why do larger animals, such as a bullfrog, require a circulatory system, while animals such as a planarian do not?

In which animal does the circulatory system include a heart and a system of closed vessels?

The function of the pulmonary circuit in a dog is to __________.

In a fish, blood circulates through __________, whereas in a mammal, it circulates through __________.

All known birds and mammals have __________.

Which of the following is an example of a portal vein?

What is unique about blood in pulmonary arteries compared with blood in other arteries?

What would you expect to see in an individual with low levels of blood protein in the capillaries?

A patient with which of the following conditions would probably benefit by injections of purified stem cells?

The primary sealant(s) that plug(s) leaks in damaged blood vessels is/are __________.

What is atherosclerosis?

An individual suffering from __________ has irregularly shaped erythrocytes and may suffer from severe pain and organ swelling.

Which of the following respiratory systems is not closely associated with a blood supply? a. the lungs of a vertebrate b. the gills of a fish c. the tracheal system of an insect d. the skin of an earthworm

Use the following diagram to review the flow of blood through a human cardiovascular system. Label the indicated parts, highlight the vessels that carry oxygen-rich blood, and then trace the flow of blood by numbering the circles from 1 to 10, starting with 1 in the right ventricle. (When two locations are equivalent in the pathway, such as right and left lung capillaries or capillaries of top and lower portion of the body, assign them the same number.)

Which of the following statements regarding the insect tracheal system is/are correct? Select True or False for each statement. T/F Tracheae dilate and constrict during flight or other types of movement, functioning as a “breathing” mechanism. T/F Spiracles open into the body cavity, allowing direct contact between the air and hemolymph. T/F Tracheae carry oxygen to alveoli; here the oxygen diffuses into the hemolymph to be delivered to tissues. T/F Spiracles can close to minimize water loss.

Blood returning to the mammalian heart in a pulmonary vein drains first into the a. left atrium. b. right atrium. c. left ventricle. d. right ventricle.

Label the parts of the human respiratory system. a. b. c. d. e. f. g.

Identify at least two advantages of breathing air instead of water.

Which of the following body systems facilitates (but doesn’t regulate) the functions of the other systems? respiratory system endocrine system digestive system circulatory system

Which of the following is the main difference between your cardiovascular system and that of a fish? a. Your heart has two chambers; a fish heart has four. b. Your circulation has two circuits; fish circulation has one. c. Your heart chambers are called atria and ventricles. d. Yours is a closed system; the fish’s is an open system.

Describe the disadvantages of an open circulatory system relative to a closed circulatory system.

One feature that amphibians and humans have in common is a. the number of heart chambers. b. a complete separation of circuits for circulation. c. the number of circuits for circulation. d. a low blood pressure in the systemic circuit.

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 a. the pulmonary vein. b. the trachea. c. the right atrium. d. the right ventricle.

In which of the following organisms does oxygen diffuse directly across a respiratory surface to cells, without being carried by the blood? a. a grasshopper b. a whale c. an earthworm d. a mous

What is the function of the cilia in the trachea and bronchi? a. to sweep air into and out of the lungs b. to increase the surface area for gas exchange c. to dislodge food that may have slipped past the epiglottis d. to sweep mucus with trapped particles up and out of the respiratory tract

What do the alveoli of mammalian lungs, the gill filaments of fish, and the tracheal tubes of insects have in common? a. use of a circulatory system to transport gases b. respiratory surfaces that are infoldings of the body wall c. countercurrent exchange d. a large, moist surface area for gas exchange

The diaphragm is a large sheet of muscle that helps move air in and out of your lungs. Breathing is automatically controlled by the brain, but you can choose to hold your breath or breathe deeper. What kind of muscle do you suppose makes up the diaphragm? (Explain your answer.)

Which of the following is not a true statement about open and closed circulatory systems? a. Both systems have some sort of a heart that pumps a circulatory fluid through the body. b. A frog has an open circulatory system; other vertebrates have closed circulatory systems. c. The blood and interstitial fluid are separate in a closed system but are indistinguishable in an open system. d. Some of the circulation of blood in both systems results from body movements.

Trace the path of blood starting in a pulmonary vein, through the heart, and around the body, returning to the pulmonary vein. Name, in order, the heart chambers and types of vessels through which the blood passes.

Predict how Antarctic icefish can transport enough oxygen in their blood to meet their needs even though they lack hemoglobin.

If blood were supplied to all of the body’s capillaries at one time, a. blood pressure would fall dramatically. b. resistance to blood flow would increase. c. blood would move too rapidly through the capillaries. d. the amount of blood returning to the heart would increase.

Why did separate systemic and pulmonary circulations evolve in species that have the high-pressure circulatory system required for rapid movement of blood?

Trace the path of an oxygen molecule in its journey from the air to a muscle cell in your arm, naming all the structures involved along the way.

If a blood clot forms inside a vein in the leg, it may travel through the circulatory system. What is the first capillary bed the clot would reach, where it might block blood flow?

Explain how the structure of capillaries relates to their function of exchanging substances with the surrounding interstitial fluid. Describe how that exchange occurs.

Here is a blood sample that has been spun in a centrifuge. List, as completely as you can, the components you would find in the straw-colored fluid at the top of this tube and in the dense red portion at the bottom.

Physiologists speculate about cardiovascular adaptations in dinosaurs—some of which had necks almost 10 m (33 feet) long. Such animals would have required a systolic pressure of nearly 760 mm Hg to pump blood to the brain when the head was fully raised. Some analyses suggest that dinosaurs’ hearts were not powerful enough to generate such pressures, leading to the speculation that long-necked dinosaurs fed close to the ground rather than raising their heads to feed on high foliage. Scientists also debate whether dinosaurs had a “reptile-like” or “bird-like” heart. Most modern reptiles have a three-chambered heart with just one ventricle. Birds, which evolved from a lineage of dinosaurs, have a four-chambered heart. Some scientists believe that the circulatory needs of these long-necked dinosaurs provide evidence that dinosaurs must have had a four-chambered heart. Why might they conclude this?

Which chamber(s) of a human heart receive(s) and pump(s) oxygenated blood?

Heart valves function to __________.

What is the physiological cause of a heart attack?

Blood leaves the inferior vena cava and flows directly into the __________.

Pressure is greatest in the ventricles when __________.

The SA node generates an electrical impulse from its location in __________.

A recording of the electrical activity of a patient's heart shows that the atria are contracting regularly and normally, but every few beats the ventricles fail to contract. Which of the following is probably functioning improperly?

Your blood pressure is 120/70. The "120" indicates __________, and the "70" indicates __________.

When we compare the structures and functions of arteries and veins, we find that the walls of arteries are __________, the blood pressure inside arteries is __________, and the blood in arteries is moving __________ the heart.

Which of the following decreases blood pressure?

A mutation that results in a nonfunctioning nitric oxide receptor would cause __________.

Blood pressure is highest in _________ , and blood moves most slowly in _________ . a. veins; capillaries b. arteries; capillaries c. veins; arteries d. arteries; veins

Pulse is a direct measure of a. blood pressure. b. stroke volume. c. cardiac output. d. heart rate.

When the doctor listened to Janet’s heart, he heard “lub-hiss, lub-hiss” instead of the normal “lub-dup” sounds. The hiss is most likely due to _________ . (Explain your answer.) a. a defective atrioventricular (AV) valve b. a damaged pacemaker (SA node) c. a defective semilunar valve d. high blood pressure

Paul’s blood pressure is 150/90. The 150 indicates _________ , and the 90 indicates _________ . a. pressure in the left ventricle; pressure in the right ventricle b. pressure during ventricular contraction; pressure during heart relaxation c. systemic circuit pressure; pulmonary circuit pressure d. pressure in the arteries; pressure in the veins

Which of the following initiates the process of blood clotting? a. damage to the lining of a blood vessel b. conversion of fibrinogen to fibrin c. attraction of white blood cells to a site of infection d. conversion of fibrin to fibrinogen

Blood flows more slowly in the arterioles than in the artery that supplies them because the arterioles a. have thoroughfare channels to venules that are often closed off, slowing the flow of blood. b. have sphincters that restrict flow to capillary beds. c. are narrower than the artery. d. collectively have a larger cross-sectional area than does the artery.

Explain why a person who survives a myocardial infarction might need to have an artificial pacemaker implanted.

During exercise, the cardiovascular system must supply muscles with large amounts of oxygen and fuel and get rid of a lot of wastes. How do the cardiovascular systems of athletes respond to prolonged exercise? Researchers used echocardiography, a sonogram of the heart, to estimate the mass of the left ventricle in current athletes, non-athletes, and ex-athletes. The data are graphed below (*** means P<0.001, and the P value comparing non-athletes and ex-athletes is >0.05). What conclusion can be drawn from the graph?

Some babies are born with a small hole in the wall between the left and right ventricles. How might this affect the oxygen content of the blood pumped out of the heart into the systemic circuit?

During exercise, the cardiovascular system must supply muscles with large amounts of oxygen and fuel and get rid of a lot of wastes. How do the cardiovascular systems of athletes respond to prolonged exercise? Explain the advantage of the observed difference between current athletes and non-athletes in the graph shown here.

Juan has a disease in which damaged kidneys allow some of his normal plasma proteins to be removed from the blood. How might this condition affect the osmotic pressure of blood in capillaries, compared with that of the surrounding interstitial fluid? One of the symptoms of this kidney malfunction is an accumulation of excess interstitial fluid, which causes Juan’s arms and legs to swell. Can you explain why this occurs?

During exercise, the cardiovascular system must supply muscles with large amounts of oxygen and fuel and get rid of a lot of wastes. How do the cardiovascular systems of athletes respond to prolonged exercise? Researchers have also observed that athletes and non-athletes have the same mean resting cardiac output, even though athletes have a far lower resting heart rate. How is this possible?

SCIENTIFIC THINKING The studies described in Module 23.6 were funded by both government agencies and major pharmaceutical and medical supply companies. NIH grants for research on heart disease total more than $1.2 billion per year. Gather more information and form an opinion on how heart disease research should be funded, whether by private enterprises such as pharmaceutical companies, donor-supported nonprofit organizations, or government agencies. Write an essay arguing your point of view.

During exercise, the cardiovascular system must supply muscles with large amounts of oxygen and fuel and get rid of a lot of wastes. How do the cardiovascular systems of athletes respond to prolonged exercise? Athletes are not the only people with enlarged hearts. Many patients with cardiovascular disease also have enlarged hearts. Suggest a cause of this enlargement.

How does myoglobin aid diving mammals such as the Weddell seal?

Which of the following would increase the release of oxygen from red blood cells?

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

What causes CO₂ in the blood to decrease?

When you exhale, __________.

In the alveoli and lung capillaries, carbon dioxide and oxygen are exchanged by means of __________.

Which structure in a human is most similar in function to the gill lamellae of a fish?

What happens when the CO₂ level from cellular respiration increases in the blood?

What is the major reason that land-dwelling mammals evolved lungs rather than gills as a primary respiratory organ?

What is the correct order of structures through which air passes as it is inhaled by a typical mammal?

Which of the following components of the mammalian gas exchange system has a surface covered by a thin film of fluid without cilia?

Countercurrent flow in the gills of a fish __________.

Which respiratory organ is most often found only in fully aquatic animals?

Gas exchange in the gills of a bony fish is maximized by which of the following?

For a body surface to be a respiratory surface, it must __________.

Complete the following concept map to review some of the concepts of gas exchange. a. b. c. d. e. f. g.

When you hold your breath, which of the following first leads to the urge to breathe? a. falling CO2 b. falling O2 c. falling pH of the blood d. rising pH of the blood

Which of the following promotes oxygen release from hemoglobin? a. a decrease in temperature b. an increase in O2 level c. a decrease in pH d. a decrease in carbonic anhydrase activity

When you hold your breath, which of the following blood gas changes first leads to the urge to breathe? a. rising O2 b. falling O2 c. rising CO2 c, falling CO2

Countercurrent gas exchange in the gills of a fish a. maintains a gradient that enhances diffusion. b. enables the fish to obtain oxygen without swimming. c. means that blood and water flow at different rates. d. allows O2 to diffuse against its partial pressure gradient

When you inhale, the diaphragm a. relaxes and moves upward. b. relaxes and moves downward. c. contracts and moves upward. d. contracts and moves downward.

Explain how each parameter in Fick’s law of diffusion is reflected in the structure of the mammalian lung.

Frog lungs have a smaller surface area for gas exchange than mammalian lungs. How do frogs compensate for this difference? a. Frog tissue absorbs more oxygen from the blood than mammalian tissue does. b. Frogs breathe more quickly than mammals. c. Frogs also obtain oxygen via diffusion across the skin. d. Frog lung tissue has a greater density of capillary beds than mammalian lung tissue.

Compared with the interstitial fluid that bathes active muscle cells, blood reaching these cells in arterioles has a a. higher PO2. b. higher PCO2. c. greater bicarbonate concentration. d. lower pH.

Carp are fishes that thrive in stagnant-water habitats with low oxygen partial pressure. Compared with the hemoglobin of many other fish species, carp hemoglobin has an extremely high affinity for O2. Draw an oxygen–hemoglobin equilibrium curve showing separate lines for carp and a fish that lives in water with a higher oxygen partial pressure. Explain why they differ.

What is the primary feedback used by the brain to control breathing? a. heart rate b. partial pressure of O2 c. blood pH, which indicates O2 level d. blood pH, which indicates CO2 level

What are two advantages of breathing air, compared with obtaining dissolved oxygen from water? What is a comparative disadvantage of breathing air?

During exercise, the cardiovascular system must supply muscles with large amounts of oxygen and fuel and get rid of a lot of wastes. How do the cardiovascular systems of athletes respond to prolonged exercise? During athletic training, the oxygen–hemoglobin dissociation curve a. shifts to the right, unloading more oxygen to tissues. b. shifts to the right, unloading less oxygen to tissues. c. shifts to the left, unloading more oxygen to tissues. d. shifts to the left, unloading less oxygen to tissues.

Carbon monoxide (CO) is a colorless, odorless gas found in furnace and automobile engine exhaust and cigarette smoke. CO binds to hemoglobin 210 times more tightly than does O2. CO also binds with an electron transport protein and disrupts cellular respiration. Explain why CO is such a deadly gas.

During exercise, the cardiovascular system must supply muscles with large amounts of oxygen and fuel and get rid of a lot of wastes. How do the cardiovascular systems of athletes respond to prolonged exercise? When athletes exercise, what is the primary physiological variable responsible for their sustained increase in ventilation rate? a. decreased blood PO2 b. increased blood PCO2 c. increased blood pH d. increased body temperature

Partial pressure reflects the relative amount of gas in a mixture and is measured in millimeters of mercury (mm Hg). Llamas are native to the Andes Mountains in South America. The partial pressure of O2 (abbreviated PO2) in the atmosphere where llamas live is about half of the PO2 at sea level. As a result, the PO2 in the lungs of llamas is about 50 mm Hg, whereas that in human lungs at sea level is about 100 mm Hg. A dissociation curve for hemoglobin shows the percentage of saturation (the amount of O2 bound to hemoglobin) at increasing values of PO2 As you see in the graph below, the dissociation curves for llama and human hemoglobin differ. Compare these two curves and explain how the hemoglobin of llamas is an adaptation to living where the air is “thin.”

Mountain climbers often spend weeks adjusting to the lower partial pressure of oxygen at high altitudes before and during their ascent of high peaks. During that time, their bodies begin to produce more red blood cells. Some runners and cyclists prepare for competition by training at high altitudes or by sleeping in a tent in which PO2 is kept artificially low. Explain why this training strategy may improve an athlete’s performance.

One of the many mutant opponents that the movie monster Godzilla contends with is Mothra, a giant mothlike creature with a wingspan of 7–8 m. Science fiction creatures like these can be critiqued on the grounds of biomechanical and physiological principles. Focusing on the principles of gas exchange that you learned about in this chapter, what problems would Mothra face? Why do you think truly giant insects are improbable?

SCIENTIFIC THINKING E-cigarettes pose a dilemma for public health officials. Because e-cigarettes produce fewer toxic chemicals than regular cigarettes, they may be a safer alternative for people who want to quit smoking but still crave nicotine. On the other hand, e-cigarettes may encourage nicotine addiction among teenagers. Evaluate the scientific evidence. Are e-cigarettes an effective aid for quitting cigarettes? What evidence supports the assertion that e-cigarettes are especially harmful to adolescents?