Question 1

Olympic wrestlers grapple with each other for relatively short but intense periods, relying on powerful skeletal muscles in their arms and legs to pin their opponents.What changes might you expect to see in their circulatory systems during the match?

Accepted Answer

During intense physical activity, such as wrestling, the body increases blood flow to active muscles (in this case, in the arms and legs) to meet the increased demand for oxygen and nutrients. This is achieved by the relaxation of arterioles serving the capillaries in those muscles, allowing more blood to flow through them.

Question 2

Turtles can largely bypass the lung circuit and pump blood around the body because of the incomplete division of their _______.

Accepted Answer

The answer of Turtles can largely bypass the lung circuit...

Question 3

In the circulatory system of fishes, blood returning from the body flows through the heart by first entering the sinus venosus and then flowing through the _______.

Accepted Answer

The answer of In the circulatory system of fishes, blood...

Question 4

People who have a strong allergic reaction to a bee sting or other allergen often carry an EpiPen, which delivers a single dose of epinephrine to prevent the reaction.The product carries a warning label from the manufacturer cautioning those users who also have high blood pressure.Why is this warning necessary?

Accepted Answer

Epinephrine is part of the sympathetic response and can cause an increase in blood pressure. People with high blood pressure are already at risk of experiencing a sudden increase in blood pressure, so the caution is necessary to ensure they do not experience any adverse reactions from using the EpiPen.

Question 5

In open circulatory systems of arthropods, fluid enters the _______ through holes called ostia.

Accepted Answer

The answer of In open circulatory systems of arthropods, fluid...

Question 6

In organisms with a closed circulatory system, the liquid outside of the circulatory system surrounding cells in the body is called _______ fluid.

Accepted Answer

The answer of In organisms with a closed circulatory system,...

Question 7

In open circulatory systems, the fluid called _______ leaves the vessels of the circulatory system before flowing over the organs.

Accepted Answer

The answer of In open circulatory systems, the fluid called...

Question 8

The complexity and number of atria and ventricles in the heart increase from fishes to amphibians to nonavian reptiles to mammals and birds.An important consequence of this increased complexity is the gradual separation of the circulatory system into two independent circuits: the pulmonary involving the lungs and the _______ involving the body.

Accepted Answer

The answer of The complexity and number of atria and...

Question 9

Arteries are vessels that carry blood away from the heart, whereas _______ are vessels that carry blood back to the heart.

Accepted Answer

The answer of Arteries are vessels that carry blood away...

Question 10

Arthropods, mollusks, and some other invertebrates have a(n) _______ circulatory system.

Accepted Answer

The answer of Arthropods, mollusks, and some other invertebrates have...

Question 11

Baroreceptors in the aorta and carotid arteries

Accepted Answer

Baroreceptors in the aorta and carotid arteries are activated when blood pressure rises. They are part of the body's natural blood pressure regulation system, and when they detect a rise in blood pressure, they send signals to the brain to decrease the heart rate and dilate blood vessels. This helps to bring blood pressure back down to a normal level.

Question 12

Blockage of a coronary artery can cause

Accepted Answer

Blockage of a coronary artery can cause a lack of blood flow to the heart muscle, leading to a heart attack. Choices B, C, D, and E are not directly related to coronary artery blockage.

Question 13

Which of the following is not one of the risk factors for developing atherosclerosis?

Accepted Answer

Living at a high altitude is not a risk factor for developing atherosclerosis. The other options can all contribute to the development of this condition.

Question 14

In humans, blood is pumped from the heart to the lungs and back through the _______ circuit.

Accepted Answer

The answer of In humans, blood is pumped from the...

Question 15

Which situation is most likely to facilitate a parasympathetic response and cause heart rate and arterial pressure to decrease?

Accepted Answer

A relaxing massage is likely to facilitate the parasympathetic nervous system, which is responsible for calming the body down and reducing heart rate and arterial pressure.

Question 16

An antelope sprints quickly away from a predator, relying on anaerobic respiration in the powerful skeletal muscles of its legs.What might you expect to see in its circulatory system while escaping the predator?

Accepted Answer

During a fight-or-flight response, the body redirects blood flow away from non-essential organs such as the gut and towards the skeletal muscles and other vital organs, like the heart and lungs. This is achieved through the contraction of precapillary sphincters, which serve capillaries of non-essential organs, reducing blood flow to those organs, and redirecting it towards the essential organs. In the case of the sprinting antelope, an increase in blood flow to its skeletal muscles would be necessary to support its anaerobic respiration, making it likely that precapillary sphincters in the gut would contract to reduce blood flow to that area.

Question 17

A high _______ will lead to an autoregulatory increase of blood flow to a tissue.

Accepted Answer

A high CO₂ concentration in a tissue leads to vasodilation, which increases blood flow to remove excess CO₂ and supply more oxygen.

Question 18

One advantage of having separate pulmonary and systemic circuits is that the circuits can operate at different pressures.In birds and mammals, the pulmonary circuit can function at _______ pressures than the systemic circuit.

Accepted Answer

The answer of One advantage of having separate pulmonary and...

Question 19

Which situation would most likely cause a decrease in ADH (also called vasopressin) secretion?

Accepted Answer

ADH (antidiuretic hormone) secretion decreases in response to a rise in blood pressure because its primary function is to help regulate the body's water balance and blood pressure. When blood pressure is high, the body doesn't need to conserve water as much, leading to a decrease in ADH secretion.

Question 20

When a piece of thrombus breaks loose and lodges in a smaller vessel, blocking the flow of blood, the condition is called

Accepted Answer

A thrombus that breaks loose and travels to a smaller vessel, where it obstructs blood flow, is called an embolism. Thrombosis refers to the formation of a blood clot in a vessel, while an infarction occurs when blood flow is completely blocked, leading to tissue death. Atherosclerosis and arteriosclerosis are both conditions involving the hardening and narrowing of arteries.

Quiz 49: Circulatory Systems