LRA 222 FINAL EXAM LATEST 2 ACTUAL EXAM VERSIONS

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LRA 222 FINAL EXAM LATEST 2 ACTUAL EXAM VERSIONS

AND BONUS PRACTICE EXAM ALL 250 QUESTIONS AND

CORRECT DETAILED ANSWERS ALREADY GARED A+

LRA 222 FINAL EXAM ACTUAL EXAM A

In order for blood to always flow unidirectionally through a closed circulatory system, the

________.

• blood vessels farthest from the heart must have valves.
• capillaries must have a thick endothelium.
• arteries must be elastic.
• pressure in all vessels must be equal. - ANSWER-A. blood vessels farthest from the heart

must have valves.

Large blood proteins such as albumin remain in capillaries rather than diffusing out, resulting in the ________.

• loss of osmotic pressure in the capillaries.
• loss of fluid from capillaries.
• development of an osmotic pressure difference across capillary walls.
• None of the above - ANSWER-C. development of an osmotic pressure difference across

capillary walls.

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2 Blood cells that function to fight infection are called ________.

• platelets
• leukocytes
• thrombi
• erythrocytes - ANSWER-B. leukocytes

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?

• Mast cells are not releasing their chemical messengers.
• There are too many antigens to allow clotting.
• Hemoglobin levels are too high to allow clotting.
• Platelets are not functioning properly, or there are too few to be effective. - ANSWER-D.

Platelets are not functioning properly, or there are too few to be effective.

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

• right atrium.
• right ventricle.
• left atrium.
• left ventricle - ANSWER-C. left atrium. 2 / 4

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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.
• the veins from the right and left legs.
• the pulmonary artery and the inferior vena cava.
• the pulmonary vein and the aorta. - ANSWER-A. the pulmonary vein and the superior vena

cava.

To become bound to hemoglobin for transport in mammals, atmospheric molecules of oxygen must cross ________.

• one membrane—that of the lining in the lungs—and then bind directly to hemoglobin, a

protein dissolved in the plasma of the blood.

• two membranes—in and out of the cell lining the lung—and then bind directly to

hemoglobin, a protein dissolved in the plasma of the blood.

• four membranes—in and out of the cell lining the lung, in and out of the endothelial cell

lining an alveolar capillary—and then bind directly to hemoglobin, a protein dissolved in the plasma of the blood.

• 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—to bind with hemoglobin. - ANSWER-D.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—to bind with hemoglobin. 3 / 4

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

• trachea → bronchioles → bronchi → alveoli
• larnyx → trachea → bronchi → bronchioles → alveoli
• trachea → tracheoles → bronchi → alveoli
• alveoli → tracheoles → bronchi → trachea - ANSWER-B. larnyx → trachea → bronchi →

bronchioles → alveoli

Carbon dioxide levels in the blood and cerebrospinal fluid affect blood pH. This enables the organism to sense a disturbance in gas levels as ________.

• the brain directly measures and monitors oxygen levels and causes breathing changes

accordingly.

• the brain alters the pH of the cerebrospinal fluid to force the animal to retain more or less

carbon dioxide.

• the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses

this measure to control breathing.

• stretch receptors in the lungs cause the medulla oblongata to speed up or slow breathing. -

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

Most of the carbon dioxide produced by humans is ________.

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