mastering bio circulatory and respiratory

From the pulmonary veins, blood flows to the _____. A right atrium B left atrium C aorta D capillaries of the lungs E posterior vena cava

B

In the blood most of the oxygen that will be used in cellular respiration is carried from the lungs to the body tissues _____. A as bicarbonate ions (HCO3 -) B combined with hemoglobin C by the trachea D water (H2O) E dissolved in blood plasma

B

What will be the long-term effect of blocking the lymphatic vessels associated with a capillary bed? A the area of the blockage becoming abnormally small B the accumulation of more fluid in the interstitial areas C fewer proteins leaking out of the blood to enter the interstitial fluid D an increase in the blood pressure in the capillary bed E more fluid entering the venous capillaries

B

Why does the velocity of blood slow greatly as blood flows from arterioles into capillaries? A Because the narrow capillaries offer great resistance to blood flow. B Because capillary beds have a total cross-sectional area much greater than the total cross-sectional area of the arterioles. C Because capillary beds are the site of nutrient and oxygen delivery to tissues.

B; Because the cross-sectional area is much greater in capillary beds than in the arteries or any other part of the circulatory system, there is a dramatic decrease in velocity from the arteries to the capillaries. Blood travels 500 times slower in the capillaries (about 0.1 cm/sec) than in the aorta (about 48 cm/sec). Read about blood flow velocity.

Which event occurs first during diastole? Which event occurs first during diastole? A The atria contract while blood flows into the relaxed ventricles. B The atria and ventricles are relaxed, and blood flows into the atria. C The atria and ventricles contract simultaneously. D Blood flows into the relaxed atria while the ventricles contract.

B; Diastole is the relaxation phase of the cardiac cycle during which the chambers of the heart are relaxed and blood can enter them passively.

What is the function of the left ventricle? A It receives deoxygenated blood from the lungs. B It pumps oxygenated blood around the body via the systemic circulation. C It receives oxygenated blood from the lungs. D It pumps deoxygenated blood to the lungs via the pulmonary circulation.

B; The left ventricle receives oxygenated blood from the lungs and pumps it to the rest of the body.

By picking up hydrogen ions, hemoglobin prevents the blood from becoming too _____. A, acidic B basic C thick D low in oxygen concentration E red

A

From the anterior vena cava, blood flows to the _____. A right atrium B left atrium C aorta D capillaries of the lungs E posterior vena cava

A

capillary

A microscopic blood vessel that penetrates the tissues and consists of a single layer of endothelial cells that allows exchange between the blood and interstitial fluid.

Stroke occurs when _____. A a blood clot enters the cerebral circulation, blocking an artery and causing the death of brain tissue B the pacemaker of the heart becomes defective, producing an irregular heartbeat C a blood clot dislodges from a vein and moves into the lung, where it blocks a pulmonary artery D a blood clot enters and blocks one of the coronary arteries E the walls of an artery in the leg accumulate deposits and lose their flexibility and elasticity

A; Once deprived of oxygen, brain cells begin to die within a few minutes. Because brain cells rarely divide in adulthood, they cannot be quickly replaced.

What is the function of a circulatory system? A It brings a transport liquid into close contact with all cells in the body. B It is the site of blood cell production. C It acts as a reservoir for the storage of blood. D It exchanges oxygen and carbon dioxide with the outside air.

A; This transport liquid exchanges gases, nutrients, and wastes with the cells in the body.

Which event of the cardiac cycle occurs when systolic blood pressure is measured? A The ventricles contract, carrying blood into the aorta, and blood flows into the relaxed atria. B The atria and ventricles contract simultaneously. C The atria contract while blood flows into the relaxed ventricles. D The atria and ventricles are relaxed, and blood flows into the atria.

A;The systolic blood pressure is the peak blood pressure, resulting from contraction of the ventricles.

Circulatory systems compensate for A the problem of communication systems involving only the nervous system. B temperature differences between the lungs and the active tissue. C the need to cushion animals from trauma. D the slow rate at which diffusion occurs over large distances. E the need fetal organisms have for maintaining an optimal body temperature.

D

The primary functions of the _____ are to warm, filter, and humidify air. A lungs B trachea C bronchus D nasal cavity E alveoli

D

Voice sounds are produced by the _____. A trachea B diaphragm C bronchioles D larynx E lungs

D

Which of the following best describes an artery? A Arteries contain valves. B Arteries carry oxygenated blood. C Arteries carry blood away from capillaries. D Arteries carry blood away from the heart. E Arteries have thin walls compared with veins.

D

Why do the circulatory systems of land vertebrates have separate circuits to the lungs and to the rest of the body? A Blood is pumped to the lungs to be oxygenated before being pumped to the rest of the body. B The circuits increase the amount of surface area available for the diffusion of gases and nutrients in the body. C Land vertebrates are bigger and require more tubing to reach all areas of the body. D The large decrease in blood pressure as blood moves through the lungs may prevent efficient circulation through the rest of the body.

D; The changes in blood pressure as blood moves through the lungs of land-dwelling vertebrates make it necessary to have separate circuits to the lungs and the rest of the body.

Which of the following statements about blood circulation in the body is true? A As the right ventricle contracts, it sends oxygenated blood through the aorta to all tissues of the body. B Deoxygenated blood flowing through the pulmonary veins is carried to the right atrium. C During one cardiac cycle, the two ventricles contract first, and then the two atria contract. D Valves prevent the backflow of blood into the atria and ventricles.

D; Valves are flaps of tissue that close when the ventricles contract to prevent the backflow of blood into the atria and also when the ventricles relax to prevent the backflow of blood from exiting vessels to the ventricles.

____ in carbon dioxide in your red blood cells, which causes _____ in pH, causes your breathing to speed up. A An increase ... a rise B A decrease ... a drop C A decrease ... a rise D An increase ... a drop E Actually, it is the rise and fall of oxygen, not carbon dioxide, that controls breathing.

D; Water and carbon dioxide combine, in the presence of the enzyme carbonic anhydrase (found inside red blood cells), to form carbonic acid, which dissociates to hydrogen ion and bicarbonate. The higher concentration of hydrogen ions leads to a drop in pH.

From the capillaries of the abdominal organs and hind limbs, blood flows to the _____. A right atrium B left atrium C aorta D capillaries of the lungs E posterior vena cava

E

Large proteins such as albumin remain in capillaries rather than diffusing out, resulting in the A loss of osmotic pressure in the capillaries. B increased diffusion of CO2. C increased diffusion of Hb. D loss of fluid from capillaries. e development of an osmotic pressure difference across capillary walls.

E

blood pressure

The hydrostatic force that blood exerts against the wall of a vessel.

interstitial fluid

The internal environment of vertebrates, consisting of the fluid filling the spaces between cells.

cellular respiration

The most prevalent and efficient catabolic pathway for the production of ATP, in which oxygen is consumed as a reactant along with the organic fuel.

Oxygen release from hemoglobin:

When four oxygen molecules are bound to hemoglobin's subunits and one subunit releases its oxygen, the other three subunits change shape again. This causes them to release their oxygen more readily.

when the lungs expand

air pressure in the lungs drops, causing air to flow into the lungs

the relaxation phase

allows each chamber to refill before the next contraction

Most gas exchange with blood vessels occurs across the walls of the

alveoli

oxygen diffuses from the

alveolus to the blood

Blood enters the right atrium from the

anterior and posterior venae cavae.

oxygen content of the blood is the greatest at the

aorta, left atrium, and pulmonary vein

the only veins that carry oxygenated blood

are pulmonary veins

blood pressure is highest

at the aorta

blood vessel walls are the thinnest

at the capillaries

carbon dioxide leaves the blood

at the capillaries of the left and right lung

where do the paths of food and air cross?

at the pharynx

what do valves (flaplike) prevent?

blood from flowing backward into the chambers

where does blood move the fastest?

blood moves the fasted at the aorta

diastolic blood pressure

blood pressure measured in the systematic arterial circulation just prior to ventricular contraction and ejection of blood into the aorta.

systolic blood pressure

blood pressure measured in the systemic arterial circulation of ventricular contraction and ejection of blood into the aorta

carbon dioxide diffuses from the

blood to the alveolus

the two places that oxygen leaves the blood are

capillaries of the head, forelimbs, abdominal organs, and hind limbs

Pulmonary veins

carry oxygenated blood from the lungs to the left atrium.

carbon dioxide transportation options:

enters red blood cells, binds to hemoglobin, or is converted to bicarbonate

IN THE LUNGS carbon dioxide diffuses

from the capillaries into the alveoli.

where does blood move the slowest?

in the capillaries (slow)

when you inhale, your diaphragm and rib muscles contract _________ the volume of your lungs; when you exhale your muscles relax and _____ the volume of the lungs

increasing; decrease

oxygenated (red) blood

is left atrium section

deoxygenated (blue) blood

is right atrium section

the bronchiole is

one of the fine tubes that carries inhaled air to the alveoli

vena cava

one of the two large veins (inferior & superior) that return oxygen-depleted blood from the tissues of the body to the right atrium

pulmonary vein

one of the two veins that returns oxygenated blood from the lungs to the left atrium

Cells need _____ to obtain energy through cellular respiration, and to get rid of the waste product_____

oxygen (O2), carbon dioxide (CO2)

the right atrium receives

oxygen-depleted blood through two veins called the inferior and superior venae cavae

the left atrium receives

oxygenated blood through two veins called the pulmonary veins.

the contraction phase

produces the pressure required to move blood into the systemic and pulmonary circulations

capillary has cells, surrounded by endothelial layer

that allows net fluid movement out for small tissues

where is blood pressure the lowest?

the anterior and posterior vena cava

systemic circulation (left atrium) serves

the body

Within an open circulatory system, such as that operating in insects,

the body fluid, called hemolymph, bathes the organs directly as it is pumped between open spaces in the body.

oxygen enters the blood at

the capillaries of the left and right lung

Both arteries and veins are defined by

the direction relative to the heart in which blood is transported.

The semilunar valves of the mammalian heart The semilunar valves of the mammalian heart A prevent backflow of blood in the aorta and pulmonary arteries. B are the route by which blood flows from the atria to the ventricles. C are found only on the right side of the heart. D are at the places where the anterior and posterior venae cavae empty into the heart. E are the attachment site where the pulmonary veins empty into the heart.

A

Which of the following develops the greatest pressure on the blood in the mammalian aorta? A systole of the left ventricle B diastole of the right atrium C systole of the left atrium D diastole of the left atrium E diastole of the right ventricle

A

double circulation

A circulation scheme with separate pulmonary and systemic circuits, which ensures vigorous blood flow to all organs.

Most carbon dioxide is carried from the body tissues to the lungs _____. A as bicarbonate ions (HCO3 -) B combined with hemoglobin C by the trachea D as hydrogen ions (H+) E dissolved in blood plasma

A; Most carbon dioxide released from body tissues combines with water to form carbonic acid, which then breaks up into hydrogen and bicarbonate ions

The _____ has(have) the thinnest walls. A aorta B capillaries C posterior vena cava D pulmonary artery E right ventricle

B;The thin walls of the capillaries facilitate gas exchange

True or false? The circulatory systems of land-dwelling vertebrates are composed of two pumping circuits: the systemic circulation, which is a lower-pressure circuit to the lung, and the pulmonary circulation, which is a higher-pressure circuit to the rest of the body

False; The pulmonary circulation is the lower-pressure circuit to the lung, whereas the systemic circulation is the higher-pressure circuit to the rest of the body.

Oxygen binding to hemoglobin:

When one molecule of oxygen binds to one of hemoglobin's four subunits, the other subunits change shape slightly, increasing their affinity for oxygen.

IN THE LUNGS Oxygen diffuses

from the alveoli to capillaries

aorta

the large artery that carries oxygenated blood from the left ventricle to branch arteries for distribution throughout the body

pulmonary circulation (right atrium) serves

the lungs

diastole

the phase of the cardiac cycle during which the chambers of the heart relax and the ventricles dilate, allowing blood to flow in.

systole

the phase of the cardiac cycle during which the ventricles contract, pumping blood into the aorta and pulmonary artery

osmotic pressure

the pressure produced by the difference in solute concentration across a membrane

Blood enters the left atrium via

the pulmonary veins

what are the only veins that carry oxygenated blood?

the pulmonary veins (oxy)

where is the heart beat initiated?

the right atrium

the left ventricle has the

thickest walls of the four chambers

oxygen is used by a cells mitochindria

to produce ATP during cellular respiration

the alveoli is the location of the respiratory surface

where gases are actually exchanged

In which of the following animals are the blood and the interstitial fluid considered to be the same body fluid? In which of the following animals are the blood and the interstitial fluid considered to be the same body fluid? A grasshoppers B fishes C sparrows D dogs E jellyfish and cnidarians

A

Arteries carry blood _____. A away from capillaries B away from the heart and away from the lungs C to the heart and away from the lungs D to the heart only E away from the heart only

E

Carbon dioxide enters the blood at the _____. A capillaries of the lungs B capillaries of the abdominal organs C capillaries of the hind limbs D capillaries of the head and forelimbs E capillaries of the head, forelimbs, abdominal organs, and hind limbs

E

diffusion

The spontaneous tendency of a substance to move down its concentration gradient from a more concentrated to a less concentrated area.

partial pressure of oxygen (PO2).

This is a measure of the amount of oxygen present in a tissue

oxygen saturation of hemoglobin (O2 saturation).

This is the percentage of oxygen-binding sites on hemoglobin molecules that are actually bound to oxygen.

Blood returns to the heart via the _____. A aorta B pulmonary arteries C pulmonary veins D aorta and pulmonary arteries E aorta and pulmonary vein

C

oxygen diffuses into a red blood cell and binds to hemoglobin

a protein made up of four subunits; one oxygen molecule can bind to each sub unit

cardiac cycle

a sequence of relaxation and contraction consisting of one diastole and one systole from both the atria and ventricles

atrium (atria)

a thin-walled chamber of the heart that receives blood from veins and pumps it to a neighboring chamber (the ventricle)