PNB 2265 Exam 2 Quiz Review 2026 | Complete Q&A
Study Guide
1. What happens in response to acute hemorrhage?
decreased sympathetic activity to heart and blood vessels to bring
arterial pressure back down
increased sympathetic activity to heart and blood vessels to bring
arterial pressure back up
decreased parasympathetic activity to heart to bring arterial pressure
back down
increased parasympathetic activity to heart to bring arterial pressure
back down
2. Describe the role of the tunica media in regulating blood flow.
The tunica media is primarily responsible for nutrient exchange
between blood and tissues.
The tunica media is involved in the formation of blood clots.
The tunica media contains smooth muscle that allows for
vasoconstriction and vasodilation, thus regulating blood flow.
The tunica media provides structural support to the blood vessel.
3. Predict what would happen to the end systolic volume (ESV) if contraction
force (contractility) were to increase
it would increase
ESV is not affected by contraction force.
it would decrease
it would remain constant
,4. Describe how a decrease in end systolic volume (ESV) affects cardiac output.
A decrease in ESV has no effect on stroke volume or cardiac output.
A decrease in ESV decreases heart rate, thus reducing cardiac output.
A decrease in ESV causes the heart to work harder without affecting
cardiac output.
A decrease in ESV increases stroke volume, which can lead to an
increase in cardiac output.
5. Describe how increased cardiac output affects overall blood circulation in
the body.
Increased cardiac output reduces blood flow to vital organs.
Increased cardiac output enhances blood flow, delivering more
oxygen and nutrients to tissues.
Increased cardiac output has no significant effect on blood
circulation.
Increased cardiac output decreases the efficiency of gas exchange.
6. What is the name of the layer of blood vessels that facilitates changes in
vessel diameter?
Tunica media
Endothelium
Tunica externa
Tunica intima
7. Alveolar pressure ___________ .
Is always subatmospheric
, Increases (more positive) during inspiration
Changes between negative and positive during the ventilation cycle
Is the pressure holding the lungs open and is always positive
8. Compared to their partial pressures in air, the partial pressures of oxygen and
carbon dioxide in alveoli are ___ _.
higher (PO2) and lower (PCO2)
lower
higher
lower (PO2) and higher (PCO2)
9. The lungs expand in inhalation because:
the diaphragm contracts upward
the shoulder girdle moves upward
the lung tissue rebounds from exhalation
the volume of the thoracic cavity increases
10. Describe the process by which CO2 diffuses across the respiratory
membrane and why this is important for respiration.
CO2 diffuses from the alveoli into the blood to increase oxygen
levels.
CO2 remains in the blood and does not participate in gas exchange.
CO2 diffuses from the blood into the alveoli due to a concentration
gradient, allowing for its removal from the body.
CO2 is actively transported from the alveoli into the blood for
oxygenation.
Study Guide
1. What happens in response to acute hemorrhage?
decreased sympathetic activity to heart and blood vessels to bring
arterial pressure back down
increased sympathetic activity to heart and blood vessels to bring
arterial pressure back up
decreased parasympathetic activity to heart to bring arterial pressure
back down
increased parasympathetic activity to heart to bring arterial pressure
back down
2. Describe the role of the tunica media in regulating blood flow.
The tunica media is primarily responsible for nutrient exchange
between blood and tissues.
The tunica media is involved in the formation of blood clots.
The tunica media contains smooth muscle that allows for
vasoconstriction and vasodilation, thus regulating blood flow.
The tunica media provides structural support to the blood vessel.
3. Predict what would happen to the end systolic volume (ESV) if contraction
force (contractility) were to increase
it would increase
ESV is not affected by contraction force.
it would decrease
it would remain constant
,4. Describe how a decrease in end systolic volume (ESV) affects cardiac output.
A decrease in ESV has no effect on stroke volume or cardiac output.
A decrease in ESV decreases heart rate, thus reducing cardiac output.
A decrease in ESV causes the heart to work harder without affecting
cardiac output.
A decrease in ESV increases stroke volume, which can lead to an
increase in cardiac output.
5. Describe how increased cardiac output affects overall blood circulation in
the body.
Increased cardiac output reduces blood flow to vital organs.
Increased cardiac output enhances blood flow, delivering more
oxygen and nutrients to tissues.
Increased cardiac output has no significant effect on blood
circulation.
Increased cardiac output decreases the efficiency of gas exchange.
6. What is the name of the layer of blood vessels that facilitates changes in
vessel diameter?
Tunica media
Endothelium
Tunica externa
Tunica intima
7. Alveolar pressure ___________ .
Is always subatmospheric
, Increases (more positive) during inspiration
Changes between negative and positive during the ventilation cycle
Is the pressure holding the lungs open and is always positive
8. Compared to their partial pressures in air, the partial pressures of oxygen and
carbon dioxide in alveoli are ___ _.
higher (PO2) and lower (PCO2)
lower
higher
lower (PO2) and higher (PCO2)
9. The lungs expand in inhalation because:
the diaphragm contracts upward
the shoulder girdle moves upward
the lung tissue rebounds from exhalation
the volume of the thoracic cavity increases
10. Describe the process by which CO2 diffuses across the respiratory
membrane and why this is important for respiration.
CO2 diffuses from the alveoli into the blood to increase oxygen
levels.
CO2 remains in the blood and does not participate in gas exchange.
CO2 diffuses from the blood into the alveoli due to a concentration
gradient, allowing for its removal from the body.
CO2 is actively transported from the alveoli into the blood for
oxygenation.
