Deck 25: Circulation

Question 1

_______ is delivered to muscle via the circulation to support exercise.

A) Oxygen
B) ATP
C) CO₂
D) Blood

Answer 1

A

Question 2

Which concept(s) regarding circulation was(were) not part of the 18^th century knowledge base?
I) Tissue blood flow
II) Round trip flow in major vessels
III) Blood transport O₂ to tissues
IV) Existence of capillaries
V) Hormones are transported in blood

A) I, II, and III
B) III and V
C) V
D) III

Answer 2

B

Question 3

The most urgent function performed by circulation is

A) the transport of ATP.
B) the transport of hormones.
C) the transport of oxygen.
D) thermoregulatory control.

Answer 3

C

Question 4

Which is the correct sequence of blood movement through the human heart?

A) Vena cavae → left atrium → left ventricle → pulmonary artery → pulmonary vein → right atrium → right ventricle → aorta
B) Vena cavae → right atrium → right ventricle → pulmonary artery → pulmonary vein → left atrium → left ventricle → aorta
C) Vena cavae → right atrium → right ventricle → pulmonary vein → pulmonary artery → left atrium → left ventricle → aorta
D) Aorta → left atrium → left ventricle → pulmonary artery → pulmonary vein → right atrium → right ventricle → vena cavae

Question 5

Refer to the figure shown.
Which area(s) contain oxygenated blood?

A) I, II, and III
B) IV and V
C) IV only
D) III only

Question 6

Refer to the figure shown.
Which area refers to the pulmonary artery?

A) II
B) III
C) IV
D) V

Question 7

Refer to the figure shown.
How many labeled areas refer to arteries?

A) 2
B) 3
C) 4
D) 5

Question 8

Refer to the figure shown.
What is the order of blood flow?

A) I → II → III → IV → V
B) I → V → IV → III → II
C) I → III → IV → V → II
D) IV → V → I → III → II

Question 9

Which statement regarding cardiac output is true?

A) It is independent of stroke volume.
B) It is the product of heart rate and stroke volume.
C) It is the heart rate divided by stroke volume.
D) It is the product of heart rate and blood pressure.

Question 10

Refer to the figure shown.
Which region represents the isovolumetric contraction portion of the heart cycle?

A) I
B) II
C) III
D) IV

Question 11

Refer to the figure shown.
Which region represents the ventricular filling portion of the heart cycle?

A) II
B) III
C) IV
D) V

Question 12

The myocardium of tunas is

A) composed of an outer compact layer with coronary vessels and an inner spongy layer.
B) spongy, with little or no development of coronary vessels.
C) compact, with coronary arteries and veins.
D) a mixed structure, with blood flowing from lumen into coronary veins.

Question 13

Most crustaceans have _______ hearts.

A) myogenic
B) neurogenic
C) hemogenic
D) non innervated

Question 14

The _______ prevents the initial depolarization at the S-A node from spreading across the heart from the atria through the ventricles and ending at the tip of the septum.

A) S-A node
B) connective tissue between the atria and ventricles
C) interventricular septum
D) bundle of Purkinje fibers

Question 15

The pacemaker of a lobster heart is composed of

A) specialized myocardium that functions in a manner similar to the S-A node.
B) specialized myocardium that functions as a central pattern generator.
C) a series of neurons connected to and controlled by the brain.
D) a posterior cardiac neuron that functions as a cellular oscillator and central pattern generator.

Question 16

Which statement describes the Frank-Starling mechanism?

A) An increase in the filling time of the ventricles increases the contraction pressure.
B) Increasing flow from the heart increases arterial pressure.
C) Increasing pressure in the heart increases outflow.
D) Stretching of the cardiac muscle increases the force of its contraction at the cellular level.

Question 17

A neurogenic heart and a myogenic heart both have all the neurons attached to it removed. Which of the following is an accurate representation of the result?

A) The neurogenic heart will continue to beat whereas the myogenic heart will cease to beat.
B) The neurogenic heart will cease to beat whereas the myogenic heart will continue to beat.
C) Both hearts will continue to beat, but at different rates.
D) Both hearts will cease to beat.

Question 18

The P wave of the EKG is produced by the

A) contraction of the atria.
B) contraction of the ventricles.
C) depolarization of the atria.
D) repolarization of the atria.

Question 19

ECG (EKG) electrodes are placed _______ and measures _______.

A) under the skin; voltage differences in the heart muscle
B) under the skin; heart contraction and relaxation
C) on the skin; voltage differences in the heart muscle
D) on the skin; heart contraction and relaxation

Question 20

Which of the following are considered functional properties of the cardiac conduction system?
I) Initiate cardiac contraction
II) Accelerate depolarization across the atria
III) Slows the depolarization across the A-V node
IV) Accelerates depolarization down the bundle branches and Purkinje fibers

A) I and II
B) III and IV
C) II, III, and IV
D) I, II, III, and IV

Question 21

The mean pressure in the systemic aorta in a healthy human is about _______ mm Hg.

A) 120
B) 95
C) 75
D) 50

Question 22

A tall human with normal blood pressure standing upright would be expected to have a pressure of about _______ mm Hg in the leg artery, measured 130 cm shown the heart.

A) 95
B) 120
C) 150
D) 195

Question 23

According to the Poiseuille equation, which of the following does not directly affect flow rate?

A) Temperature of the tube
B) Viscosity of the fluid
C) Radius of the lumen of the tube
D) Pressure at the entry of the tube

Question 24

Halving the radius of a vessel _______ the resistance to flow through the vessel by a factor of _______.

A) decreases; 4
B) decreases; 16
C) increases; 4
D) increases; 16

Question 25

The most important factor modifying flow in blood vessels is the

A) pressure in the vessel.
B) diameter of the vessel.
C) viscosity of fluid in the vessel.
D) length of the vessel.

Question 26

The reason why blood capillaries can be exceedingly thin-walled and yet resist substantial pressures can be explained by

A) Laplace's law.
B) Poiseuille's equation.
C) Hagen's equation.
D) Fick's law.

Question 27

You are measuring the blood pressure (using a standard cuff on the brachial artery) of a patient who insists on holding her arm above her head while you are taking the measurement. How to you deal with the data you collect.

A) As long are you are careful, the data you collect are valid.
B) The measurement in the raised arm will overestimate the actual blood pressure.
C) The measurement in the raised arm will underestimate the actual blood pressure.
D) The pressure measurement will be accurate, but the heart rate measurement will not.

Question 28

The main difference between the pulmonary circuit and the systemic circuit is that the pulmonary circuit

A) has a higher resistance.
B) produces lower pressures.
C) produces lower flows.
D) has a lower cardiac output.

Question 29

Which statement regarding microcirculatory beds is true?

A) Smooth muscles in the walls of arterioles are responsible for vasoconstriction and vasodilation.
B) Anastomoses are the one possible path from an arteriole to a venule.
C) The walls of capillaries consist of vascular endothelium and a smooth muscle layer.
D) Venules and arterioles are the preeminent sites of O₂ and water exchange.

Question 30

Place the patients in order from lowest to highest vascular resistance.
Patient 1) Blood pressure = 120/80 mm Hg; cardiac output 4 L/min
Patient 2) Blood pressure = 140/100 mm Hg; cardiac output 5 L/min
Patient 3) Blood pressure = 100/60 mm Hg; cardiac output 5 L/min

A) Patient 1, Patient 2, Patient 3
B) Patient 3, Patient 2, Patient 1
C) Patient 2, Patient 1, Patient 3
D) Patient 3, Patient 1, Patient 2

Question 31

Refer to the figure shown.
Which vertical section denotes the vascular portion with the highest pressure?

A) I
B) II
C) III
D) IV

Question 32

Refer to the figure shown.
Which vertical section denotes the vascular portion with the lowest mean blood velocity?

A) I
B) II
C) III
D) IV

Question 33

Refer to the figure shown.
Which vertical section denotes the vascular portion with the highest vascular resistance?

A) I
B) II
C) III
D) IV

Question 34

Refer to the figure shown.
In section I, fluid is _______ the capillary due to _______.

A) leaking out of; hydrostatic pressure
B) leaking out of; colloid osmotic pressure
C) moving into; hydrostatic pressure
D) moving into; colloid osmotic pressure

Question 35

Refer to the figure shown.
The figure depicts the _______ hypothesis: the initial loss and then regaining of fluid in the capillaries that results, overall, in a net _______ of fluid.

A) Frank‒Starling; loss
B) Starling‒Landis; loss
C) Frank‒Landis; gain
D) Poiseuille; gain

Question 36

Which of the following best describes the contractile properties of the heart of the elasmobranch fish?

A) There are four chambers, however only the atria and ventricle contract.
B) There are only two chambers, an atria and a ventricle, and they both contract.
C) There are four chambers, and three contract.
D) There are four chambers, and all four contract.

Question 37

Which characteristic is typical of teleost cardiovascular systems?

A) The heart receives oxygenated blood flowing from the gills.
B) Cardiac outputs are lower than those of similar-sized mammals.
C) Blood pressure increases significantly as blood passes through the gills.
D) Arterial pressures are higher than those of similar-sized mammals.

Question 38

Refer to the figure shown.
From where do vessels branch off to supply the head and gut with oxygenated blood?

A) I
B) II
C) III
D) IV

Question 39

Refer to the figure shown.
When an air-breathing organ at the mouth is integrated into the circulation depicted in the figure, a new circulation loop is created connecting

A) I to III.
B) II to III.
C) I to IV.
D) III to IV.

Question 40

In fish that have an air-breathing organ (ABO), the blood

A) leaving the ABO mixes with systemic and venous blood.
B) leaving the ABO mixes with blood leaving the gills.
C) enters the ABO following the exit from the gills.
D) leaving the ABO enters the gills.

Question 41

Which statement describes a characteristic not found in the African lungfish Protopterus?

A) The ventral aorta is extremely long and branched.
B) The atrium and the ventricles are partially divided into left and right halves by septa.
C) The conus arteriosus has longitudinal ridges that divide the lumen into two channels.
D) The four pairs of branchial arteries arise immediately from the conus arteriosus.

Question 42

Fish with _______ are able to swim faster and longer due to _______.

A) compact myocardium; the coronary circulation
B) compact myocardium; greater contractile force and rate
C) spongy myocardium; the coronary circulation
D) spongy myocardium; greater contractile force and rate

Question 43

Refer to the figure shown.
Which plan represents the mammalian circulatory system?

A) II
B) III
C) IV
D) V

Question 44

Refer to the figure shown.
Of the six circulatory plans above, how many partially or completely separate oxygenated and deoxygenated blood in the heart?

A) Two
B) Three
C) Four
D) Five

Question 45

Refer to the figure shown.
Which circulatory plan allows the animals to modulate blood flow to the lungs independently of blood flow to the rest of the body?

A) II and V
B) II, IV, and V
C) I, III, and IV
D) I, IV, and V

Question 46

Which animal does not modulate blood flow to the lungs independently of blood flow to the rest of the body?

A) Lungfish
B) Amphibians
C) Crocodilians
D) Birds

Question 47

Which structure aids crocodilians in diverting blood flow during diving?

A) Foramen ovale
B) Foramen of Panizza
C) Ductus arteriosus
D) Pulmonary artery

Question 48

Which of the following is present in crocodilians but not in amphibians?

A) 2 atria
B) the ability to shunt blood
C) a ventricular septum
D) a pulmonary circulation

Question 49

The _______ circulatory system of squids and octopuses consist of two _______.

A) open; branchial hearts and one systemic heart
B) open; systemic hearts and one branchial heart
C) closed; systemic hearts and one branchial heart
D) closed; branchial hearts and one systemic heart

Question 50

Refer to the figure shown.
This circulatory plan belongs to which group of animals?

A) Decapod crustaceans
B) Invertebrates
C) Fish
D) Cephalopod molluscs

Question 51

Refer to the figure shown.
The most oxygenated blood would be found just exiting the structure(s) at

A) I.
B) II.
C) III.
D) IV.

Question 52

Refer to the figure shown.
According to the diagram, the highest blood pressure would be found just exiting the structure(s) at

A) I.
B) II.
C) III.
D) IV.

Question 53

Which of the following are similar between an octopus heart and mammalian heart?
I) Myogenic heart
II_ Systemic heart
III) Respiratory pump
IV) Pressure from systemic heart around 120 mm Hg

A) I and II
B) I, II, and III
C) I, III, and IV
D) I, II, III, and IV

Question 54

A squid meets the increased demand for O₂ at the tissues during intense exercise by

A) increasing its circulation rate.
B) pulling more O₂ from the blood.
C) both increasing circulation rate and pulling more O₂ from the blood.
D) making use of anaerobic metabolism only.

Question 55

If a squid and a fish both double cardiac output during exercise, circulatory oxygen delivery to the tissues in _______ will _______.

A) both animals; remain the same
B) both animals; double
C) the fish; be higher than in the squid
D) the squid; be higher than in the fish

Question 56

Small spaces among cells of nonvascular organs and tissues are called

A) lacunae.
B) sinuses.
C) ostia.
D) interstitial.

Question 57

Refer to the figure shown.
This circulatory plan belongs to which group of animals?

A) Cephalopod molluscs
B) Invertebrates
C) Fish
D) Decapod crustaceans

Question 58

Refer to the figure shown.
The most oxygenated blood would be found

A) at I.
B) just exiting the structure at II.
C) at III.
D) just exiting the structure at V.

Question 59

Refer to the figure shown.
The wavy boundaries at I and III represent the

A) lack of vessels in the systemic tissues.
B) gills.
C) venous system.
D) branchio-pericardial sinuses.

Question 60

The blood circulation of crustaceans is _______ than that of fish primarily because of _______.

A) faster; lower resistance
B) faster; higher pressure
C) slower; lower pressure
D) slower; higher resistance

Question 61

Which statement regarding the lobster circulatory system is false?

A) Hemolymph returns through holes in the heart called ostia.
B) All vessels connected to the heart are arteries.
C) The primary force that refills the heart is elastic rebound.
D) There is a clear distinction between blood and interstitial fluid.

Question 62

In lobsters and crabs, blood from the _______ collects in the _______ before passing through the gills.

A) heart; pericardial sinus
B) systemic tissues; infrabranchial sinus
C) heart; infrabranchial sinus
D) systemic tissues; pericardial sinus

Question 63

Describe the four systems that have evolved in animals to supply O₂ to the myocardium and name the main animal groups that use each one.

Question 64

Compare and contrast the myogenic and neurogenic heart.

Question 65

Why does the depolarization wave not travel across the mammalian heart from anterior to posterior (atria to ventricles) in a linear wave?

Question 66

Explain, according to the physics of fluid-column effects, why a vascular foot injury needs to be elevated as much and as long as possible.

Question 67

How is vascular resistance related to the Poiseuille equation?

Question 68

Describe and explain the linear velocity profile of red blood cells as they travel from the heart through the systemic tissues and back.

Question 69

Describe how an air-breathing organ is integrated into the circulatory plan of fish and how this physiology relates to the oxygenation of the fish myocardium.

Question 70

Explain how some animals modulate blood flow to their lungs independently of flow to the rest of the body and what the advantages are to this arrangement.

Question 71

Compare and contrast the mammalian and cephalopod circulatory systems.

Question 72

Defend or refute this statement: "Blood flow through open systems is sluggish because of the relatively low-pressure gradients in open circulatory systems."