BIOL 228 Exam II

1. Air consists of about 78.6% nitrogen, 20.9% oxygen, 0.04% carbon dioxide, and 0.5% water.  At sea level, (760 mmHg) what is the PCO₂? 

2. A) 597 mmHg

   1. B) 159 mmHg

   2. C) 0.3 mmHg

   3. D) 3.7 mmHg

   4. E) The correct answer is not listed above

• A) 597 mmHg

• B) 159 mmHg

• C) 0.3 mmHg

• D) 3.7 mmHg

• E) the correct answer is not listed above

1. If atmospheric pressure is 750mmHg and the atmosphere consists of 20% oxygen, what is the partial pressure of oxygen?

   1. A) 100mmHg

   2. B) 150mmHg

   3. C) 750mmHg

   4. D) 200mmHg

• A) 100 mmHg

• B) 150 mmHg

• C) 750 mmHg

• D) 200 mmHg

1. Which would occur during a hyperventilation state when the amount of oxygen in the alveoli is above a normal, resting state?

   1. A) Bronchiodilation of respiratory airways and vasodilation of respiratory arterioles

   2. B) Broncioconstriction of respiratory airways and vasoconstriction of respiratory arterioles

   3. C) Bronchioconstriction of respiratory airways and vasodilation of respiratory arterioles

   4. D) Bronchiodilation of respiratory airways and vasoconstriction of respiratory arterioles

   5. E) Increased oxygen concentration in the alveoli would have no effect on the diameter of the respiratory airways or the respiratory arterioles

• A

• B

• C

• D

• E

1. If the PO₂ of blood in a specific tissue’s capillaries is 75mmHg and the tissue is highly metabolizing (for example, skeletal muscle during exercise), which direction will oxygen move?

   A) Oxygen will not move into the tissue, but remain in blood as long as the tissue is highly metabolizing

   1. B) Oxygen will move into the tissues readily to meet the high metabolic needs of the tissue

2. C) Oxygen will move into the tissue and be directly exchanged for carbon dioxide created by tissue, molecule for molecule, leaving space on hemoglobin for carbon dioxide to bind

3. D)Oxygen will only move into the tissue if carbon monoxide is present in the tissue as carbon monoxide will take over oxgyen’s binding on hemoglobin, causing it to move into the tissue

• A

• B

• C

• D

1. The catecholamines (epinephrine, norepinephrine, and dopamine) are ________________ neurotransmitters:

   1. A) Neuropeptides

   2. B) Monoamines

   3. C) GABA

   4. D) ACh

   5. E) Substance P

• A

• B

• C

• D

• E

1. All of the following are typical characteristics of a neurotransmitter EXCEPT:

1. A) They are synthesized by the presynaptic neuron

2. B) They are released in response to stimulation

3. C) They are released into the bloodstream before reaching the postsynaptic cell

4. D) They bind to specific receptors on the postsynaptic cell

5. E) They alter the physiology of the postsynaptic cell

• A

• B

• C

• D

• E

1. Which of the following channels are stimulated to open when the action potential arrives at the axon terminal?

   1. A) Voltage gated calcium channels

   2. B) Chemically gated calcium channels

   3. C) Voltage gated chloride channels

   4. D) Chemically gated chloride channels

   5. E) The correct answer is not listed above

• A

• B

• C

• D

• E

The opening of chloride gates produces an ____.

1. A GABA-ergic synapse involves ____________ of the postsynaptic cell:

   1. A) Depolarization

   2. B) Hyperpolarization

   3. C) Excitation

   4. D) Inhibition 

   5. E) Both B and D above

• A

• B

• C

• D

• E

1. A cholinergic synapse uses _______________as its neurotransmitter:

1. A) Monoamine

2. B) Acetylcholine

3. C) Epinephrine

4. D) Norepinephrine

5. E) Catecholamine

• A

• B

• C

• D

• E