BIO152 Unit 8 O'Quin

Most carbon dioxide is carried from the body tissues to the lungs _____. as bicarbonate ions (HCO3 -) combined with hemoglobin by the trachea as hydrogen ions (H+) dissolved in blood plasma

as bicarbonate ions (HCO3 -)

What type of blood vessels has the slowest velocity of blood flow? veins arteries arterioles capillaries

capillaries

A shift to the right of the oxygen-hemoglobin equilibrium curve represents _____. cooperative binding noncooperative binding increased oxygen delivery to a tissue decreased oxygen delivery to a tissue

increased oxygen delivery to a tissue

The Bohr shift on the oxygen-hemoglobin dissociation curve is produced by changes in _____. pH the partial pressure of oxygen hemoglobin concentration temperature the partial pressure of carbon monoxide

pH

Damage to the sinoatrial node in humans _____. would disrupt the rate and timing of cardiac muscle contractions would have a negative effect on peripheral resistance would have a direct effect on blood pressure monitors in the aorta is a major contributor to heart attacks would block conductance between the bundle branches and the Purkinje fibers

would disrupt the rate and timing of cardiac muscle contractions

Which of the following is most likely to be found in a terrestrial animal with high activity rates? A four-chambered heart An open circulatory system A two-chambered heart A three-chambered heart

A four-chambered heart

Based on the figure above, showing fetal (A) and adult (B) oxygen-hemoglobin saturation curves, which of the following conclusions is true? At 50 percent saturation, fetal blood will have a higher affinity for oxygen than adult blood will. The mother binds oxygen with greater affinity than the fetus. Adult saturation occurs at lower partial pressures of oxygen than fetal saturation does. As the partial pressure of oxygen increases, adult hemoglobin approaches saturation faster than fetal hemoglobin does.

At 50 percent saturation, fetal blood will have a higher affinity for oxygen than adult blood will.

Which of the following does NOT correctly represent blood flow through the heart? From the right ventricle to the left ventricle From the vena cava to the right atrium From the left ventricle to the aorta From the right atrium to the right ventricle

From the right ventricle to the left ventricle

In what way does hemoglobin act as a buffer against changes in blood pH? Hemoglobin removes excess protons from the red blood cells so that they can be excreted through the kidneys. Hemoglobin produces protons or hydroxide ions as needed to alter the blood pH. Subsequent binding of oxygen is drastically reduced after the first one is bound. Hemoglobin binds some of the excess protons released by carbonic acid.

Hemoglobin binds some of the excess protons released by carbonic acid.

The oxygen content of water increases linearly with an increase in oxygen partial pressure, while the oxygen content of blood increases in a sigmoidal (S-shaped) fashion. Why? The Bohr shift is stronger in water than in blood. Oxygen is transported equally by hemoglobin and blood plasma. Hemoglobin shows cooperative oxygen binding. Carbonic anhydrase contributes to carbon dioxide release in blood, but not water.

Hemoglobin shows cooperative oxygen binding.

When you are jogging, your muscles are using more oxygen and releasing more carbon dioxide into the blood than when you are at home on the couch. Which of the following would occur during your jog? The volume of the dead air space would decrease. The concentration of bicarbonate ions (HCO3-) in the blood would decrease. The medullary respiratory center would detect rising carbon dioxide levels. Blood pH would become more basic.

The medullary respiratory center would detect rising carbon dioxide levels.

Which of the following occurs in response to a drop in blood pressure? Sympathetic nervous system activity decreases. Veins constrict. Heart rate decreases. Blood flow to the intestines increases.

Veins constrict.

You are a physician, and you are seeing a patient who complains of abnormal fatigue during exercise. You find that the immediate problem is a buildup of carbon dioxide in the tissues. What is the most likely cause? abnormal carbonic anhydrase not enough hemoglobin abnormal hemoglobin abnormally shaped platelets

abnormal carbonic anhydrase

By picking up hydrogen ions, hemoglobin prevents the blood from becoming too _____. acidic basic thick low in oxygen concentration red

acidic

In mammals, most gas exchange between the atmosphere and the pulmonary blood occurs in the _____. bronchioles bronchi larynx trachea alveoli

alveoli

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 most closely related to alligators and crocodiles animal was endothermic and had a high metabolic rate animal was likely an invertebrate animal species had little to no need to regulate blood pressure animal had evolved from birds

animal was endothermic and had a high metabolic rate

Breathing is primarily regulated by _____. erythropoietin levels in the blood hemoglobin levels in the blood the concentration of red blood cells carbon dioxide concentration and pH-level sensors the lungs and the larynx

carbon dioxide concentration and pH-level sensors

What is present in arterioles that is NOT present in capillaries? circular smooth muscle cells a lining of endothelial cells carbon dioxide white blood cells and platelets

circular smooth muscle cells

In the blood most of the oxygen that will be used in cellular respiration is carried from the lungs to the body tissues _____. as bicarbonate ions (HCO3 -) combined with hemoglobin by the trachea water (H2O) dissolved in blood plasma

combined with hemoglobin

Most of the carbon dioxide produced by humans is _____. converted to bicarbonate ions by an enzyme in red blood cells simply dissolved in the plasma bound to hemoglobin transported in the erythrocytes as carbonic acid bicarbonate ions bound to hemoglobin

converted to bicarbonate ions by an enzyme in red blood cells

The only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart are the _____. fishes mammals reptiles birds amphibians

fishes

Which of the following animals has a three-chambered heart? frog crocodile fish bird

frog

An decrease from pH 7.4 to pH 7.2 causes hemoglobin to _____. release all bound carbon dioxide molecules denature give up more of its oxygen molecules increase its binding of H+ bind more oxygen molecules

give up more of its oxygen molecules

Why is the pharmacological reactivation of fetal hemoglobin in a patient with sickle-cell anemia often a successful treatment? Fetal hemoglobin _____. has a higher affinity for carbon dioxide than does adult hemoglobin is better able to release oxygen than is adult hemoglobin is better able to release carbon dioxide than is adult hemoglobin binds more carbon dioxide molecules than adult hemoglobin has a higher affinity for oxygen than does adult hemoglobin

has a higher affinity for oxygen than does adult hemoglobin

The fluid that moves around in the circulatory system of a typical arthropod is _____. hemolymph cytosol blood plasma digestive juices

hemolymph

Blood returning to the mammalian heart in a pulmonary vein drains first into the _____. right ventricle left atrium vena cava left ventricle right atrium

left atrium

Which of the following does blood not do? buffer against pH changes produce new red blood cells and other formed elements distribute body heat transport O2 and CO2

produce new red blood cells and other formed elements

Which of the four muscular chambers of the human heart directly propels blood into the pulmonary circulation? right atrium left ventricle left atrium right ventricle

right ventricle

Electrical impulses that trigger contraction of cardiac muscle cells in vertebrates originate in the _____. sinoatrial node intercalated discs atrioventricular node ventricles

sinoatrial node

One feature that amphibians and humans have in common is _____. a complete separation of circuits for circulation a low blood pressure in the systemic circuit the number of circuits for circulation the type of gas exchange tissues the number of heart chambers

the number of circuits for circulation

Circulatory systems compensate for _____. the slow rate at which diffusion occurs over large distances the need to cushion animals from trauma the need that fetal organisms have for maintaining an optimal body temperature temperature differences between the lungs and the active tissue the problem of communication systems involving only the nervous system

the slow rate at which diffusion occurs over large distances

The velocity of blood flow is the lowest in capillaries because _____. the diastolic blood pressure is too low to deliver blood to the capillaries at a high flow rate the capillary walls are not thin enough to allow oxygen to exchange with the cells 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 the capillaries have internal valves that slow the flow of blood the systemic capillaries are supplied by the left ventricle, which has a lower cardiac output than the right ventricle

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

A blood vessel that takes blood to the heart is a(n) _____. artery lymphatic vessel capillary vein

vein

A blood vessel that takes blood to the heart is a(n) _____. lymphatic vessel artery capillary vein

vein

Which of the following is the correct sequence of blood flow in birds and mammals? vena cava → right atrium → right ventricle → pulmonary vein pulmonary vein → left atrium → left ventricle → pulmonary circuit left ventricle → aorta → lungs → systemic circulation vena cava → right atrium → right ventricle → pulmonary artery right atrium → pulmonary artery → left atrium → ventricle

vena cava → right atrium → right ventricle → pulmonary artery