Biology 2 Chapter 42 part 2

Atmospheric pressure at the summit of Mount Everest is about one third the pressure at sea level, which is 760 mm Hg. If oxygen makes up 21% of the atmosphere by volume, the partial pressure of oxygen (PO2) on Mount Everest is approximately ________. 255 mm Hg 157 mm Hg 53 mm Hg 760 mm Hg

53 mm Hg

Which lung structure is a tiny sac that functions as an interface between air and blood? Diaphragm. Epithelium. Capillary. Alveolus.

Alveolus.

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

An increase ... a drop

How is most carbon dioxide transported from tissues to the lungs? As carbon dioxide gas. As bicarbonate ions (HCO3−). As protons (H+). As carbonic acid.

As bicarbonate ions (HCO3−).

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

Because capillary beds have a total cross-sectional area much greater than the total cross-sectional area of the arterioles.

Select the correct statement about capillary beds. Capillary beds join arteries and veins. Capillary beds have a total cross-sectional area much smaller than the total cross-sectional area of major arteries. Capillary beds are the site of nutrient and oxygen delivery to tissues.

Capillary beds are the site of nutrient and oxygen delivery to tissues.

True or false? The driving force for the unloading of oxygen from hemoglobin into tissues is the difference in PCO2 levels between the blood and body tissues.

False

True or false? The pressure inside the human chest cavity is always positive, so the lungs stay relatively inflated even upon exhalation.

False

How are gases transported in insect bodies? In open circulatory systems In tracheal systems In closed circulatory systems

In tracheal systems

Which statement about the gas exchange system in fish is correct? It relies on the parallel flow of blood and water in the gills. It enables oxygen to diffuse from the water into the blood over the entire length of the gill capillaries. It enables oxygen to move from where its partial pressure is lower to where its partial pressure is higher. It relies on a higher partial pressure of oxygen in water than in air.

It enables oxygen to diffuse from the water into the blood over the entire length of the gill capillaries.

Which of the following statements about the oxygen-hemoglobin interaction is true? The oxygen-hemoglobin dissociation curve is exponential, which means that hemoglobin can respond quickly to small changes in oxygen demand. The binding of one oxygen molecule to hemoglobin stimulates the binding of other oxygen molecules. The binding of one oxygen molecule to hemoglobin stimulates the unloading of the oxygen molecules that are already bound. Each hemoglobin molecule can bind one oxygen molecule.

The binding of one oxygen molecule to hemoglobin stimulates the binding of other oxygen molecules.

Which statement about oxygen in fish gills is correct? The partial pressure of oxygen in blood increases as it flows through gill capillaries. The partial pressure of oxygen is greater in the blood than in the adjacent water. The partial pressure of oxygen in the blood is lowest where the partial pressure of oxygen in the water is highest. Oxygen diffuses from the bloodstream into the water along the entire length of the capillaries.

The partial pressure of oxygen in blood increases as it flows through gill capillaries.

True or false? The lungs of humans form from the embryonic foregut.

True

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

acidic

In mammals, gas exchange between the atmosphere and the pulmonary blood occurs in the bronchioles. larynx. alveoli. trachea. bronchi.

alveoli.

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

as bicarbonate ions (HCO3 -)

An oil-water mixture works as an insecticidal spray against mosquitoes and other insects because it _____. interferes with gas exchange across the capillaries clogs their bronchi blocks the openings into the tracheal system prevents gases from leaving the atmosphere

blocks the openings into the tracheal system

The smallest airway through which inspired air passes before gas exchange occurs in the mammalian lungs is the _____. pharynx larynx trachea bronchiole bronchus

bronchiole

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

combined with hemoglobin

Which of the following organisms has no specialized respiratory structures? earthworms salmon crabs ants alligators

earthworms

Which barrier(s) must O2O2 and CO2CO2 cross to pass between air and blood inside lungs? extracellular fluid capillary wall diaphragm epithelial cells

extracellular fluid capillary wall epithelial cells

Pulse is a direct measure of heart rate. stroke volume. blood pressure. cardiac output. breathing rate.

heart rate.

Compared with the interstitial fluid that bathes active muscle cells, blood reaching these cells in arteries has a higher P(O2) greater bicarbonate concentration. higher P(CO2) lower pH. lower osmotic pressure.

higher P(O2)

A COVID-19 patient is put on a ventilator. What is the goal of this? reduce blood oxygen stabilize blood oxygen eliminate blood oxygen increase blood oxygen

increase blood oxygen

The amount of oxygen bound to hemoglobin _____. increases as the pH of tissues decreases increases with increasing acidity at the tissue level increases in the presence of high concentrations of oxygen is called the Bohr shift decreases in the presence of high concentrations of oxygen

increases in the presence of high concentrations of oxygen

Voice sounds are produced by the _____. trachea diaphragm bronchioles larynx lungs

larynx

Blood returning to the mammalian heart in a pulmonary vein drains first into the right ventricle. vena cava. left atrium. left ventricle. right atrium.

left atrium.

A large proportion of seriously ill COVID-19 patients are presenting with which of the following strange combination of symptoms? low oxygen levels and damaged lungs high oxygen levels and healthy lungs low oxygen levels and healthy lungs high oxygen levels and damaged lungs

low oxygen levels and healthy lungs

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

nasal cavity

Cellular respiration takes place in specialized organelles called chloroplasts. uses O2 and CO2 as raw materials. produces CO2 and ATP. synthesizes sugars from CO2 and H2O.

produces CO2 and ATP.

When you hold your breath, which of the following blood gas changes first leads to the urge to breathe? rising CO2 falling O2 rising O2 rising CO2 and falling O2 falling CO2

rising CO2

One feature that amphibians and humans have in common is a complete separation of circuits for circulation. a low blood pressure in the systemic circuit. the type of gas exchange tissues. the number of heart chambers. the number of circuits for circulation.

the number of circuits for circulation.

If a molecule of CO2 released into the blood in your left toe is exhaled from your nose, it must pass through all of the following except the right ventricle. the right atrium. an alveolus. the trachea. the pulmonary vein.

the pulmonary vein.