Chapter 42 Study Guide Flashcards
Which type of circulatory system is most likely present in organisms with a circulating body fluid that is distinct from the fluid that directly surrounds the body’s cells?
A:an open circulatory system
B:a closed circulatory system
C:a gastrovascular cavity
D:branched tracheae
a closed circulatory system
Circulatory systems help to overcome which of the following physiological challenges?
A:temperature differences between the lungs and the active tissue
B:the slow rate at which diffusion occurs over large distances
C:the problem of communication systems involving only the nervous system
D:The need to cushion animals from trauma
the slow rate at which diffusion occurs over large distances
Which of the following results in the greatest blood pressure in the mammalian aorta?
A:systole of the left atrium
B:diastole of the right ventricle
C:systole of the left ventricle
D:diastole of the right atrium
systole of the left ventricle
Damage to the SA node in humans is most likely to result in a ______
A:blockage of conductance between the bundle branches and the Purkinje fibers
B:Negative effect on peripheral resistance
C:disruption on the rate and timing of cardiac muscle contractions
D: direct effect on blood pressure monitors in the aorta
disruption on the rate and timing of cardiac muscle contractions
which of the following mechanisms are used to regulate blood pressure in the closed circulatory system of vertebrates?
A:changing the strength of heart contraction and constricting and relaxing smooth muscle in the walls of arterioles
B:changing the strength of heart contraction and opening and closing precapillary sphincters
C: constricting and relaxing smooth muscle in the walls of arterioles and opening or closing precapillary sphincters
D: changing the strength of heart contraction, constricting and relaxing smooth muscle in the walls of arterioles, and opening or closing precapillary sphincters
changing the strength of heart contraction, constricting and relaxing smooth muscle in the walls of arterioles, and opening or closing precapillary sphincters
Suppose an organism had a mutation in the thrombin gene such that the thrombin protein was nonfunctional. Which of the following is the most likely impact that the mutation would have on this organism________
A: the organism would not be able to produce new erythrocytes
B:the organism’s blood would not clot effectively
C:the organisms immune system would be weakened
D: the organism would not be able to exchange gases as well
the organisms blood would not clot effectively
Countercurrent exchange in the fish gill helps to maximize_________
A: blood pressure
B:diffusion
C:active transport
D:osmosis
diffusion
Which of the following represents the correct flow of air into the lung of a mammal?
A: trachea->bronchioles->bronchi->alveoli
B:larynx->trachea->bronchi->bronchioles->alveoli
C:trachea->tracheoles->bronchi->alveoli
D:alveoli->tracheoles->bronchi->trachea
larynx->trachea->bronchi->bronchioles->alveoli
which of the following best describes how an organism senses a disturbance in gas levels?
A:the brain directly measures and monitors oxygen levels and causes breathing changes accordingly
B:the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing
C:the brain alters the pH of the cerebrospinal fluid to force the animal to retain more or less carbon dioxide
D:stretch receptors in the lungs cause the medulla oblongata to speed up or slow breathing
the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing
Which statement best describes what happens to the carbon dioxide produced by humans?
A:it is converted to bicarbonate ions
B:it is bound to hemoglobin
C: it is transported in the erythrocytes as carbonic acid
D: it is simply dissolved in the plasma
it is converted to bicarbonate ions
When you hold your breath, which of the following blood gas changes first leads to the urge to breathe?
A:rising O2
B:falling O2
C:rising CO2
D:falling Co2
rising CO2
Which of the following would an organism need to adjust blood pressure independently in the blood vessels of the gas-exchange surface and in the blood vessels of the general body circulation?
A:open circulatory system
B:hemocoel
C:two chambered heart
D:four chambered heart
four chambered heart
