Chapter 37

How many molecules of O2 can a single hemoglobin molecule carry when fully saturated?

4

What is meant by tidal ventilation?

Air moves into the lungs during inhalation and air moves out of the lungs during exhalation.

Which of these choices increase(s) the amount of oxygen that a fish can extract from the surrounding seawater?

All of these choices are correct. -gills with a large surface area -very thin lamellae -ventilation of the gills with the aid of an operculum -countercurrent exchange

Which of the statements is true regarding CO2 in the mammalian bloodstream?

CO2 is mainly transported through the mammalian bloodstream in the form of bicarbonate ions or carbonic acid.

Which of the statements about open and closed circulatory systems is correct?

Closed circulatory systems can more effectively control the flow of blood to specific body regions than open circulatory systems.

A researcher has introduced molecules of human myoglobin and hemoglobin into a solution containing oxygen. Which of the statements is true of human hemoglobin and myoglobin?

Compared to human hemoglobin, human myoglobin will likely bind to oxygen molecules more quickly when introduced into the oxygen-containing solution.

All of the statements are true except:

Decreasing levels of oxygen in the blood are detected by chemoreceptors in the kidney. True Statements: -Chemoreceptors involved in the homeostatic control of breathing are located in the brainstem and the carotid and aortic bodies. -Breathing is controlled by both voluntary and involuntary mechanisms. -As an organism's activity level increases, the level of CO2 in the blood will increase and stimulate faster or stronger breathing. -Stronger or more frequent contraction of respiratory muscles helps to remove excess CO2 from the blood.

Which of the statements is accurate?

Diving reptiles can alter the pattern of blood circulation to bypass their lungs when submerged.

In mammals, bulk flow only refers to the movement of oxygen (either into or out of the lungs and within the bloodstream). Bulk flow never refers to the movement of carbon dioxide.

False

A scientist is evaluating the hemoglobin in mountain goats compared to the hemoglobin in normal barnyard goats. How will the hemoglobin in these two goat species compare?

Given that mountain goats tend to live at higher altitudes, these goats will have hemoglobin with a greater oxygen-binding affinity compared to the hemoglobin of barnyard goats.

Which of the changes occurs during exhalation?

The diaphragm relaxes and pushes up.

Which of the statements is accurate?

The fish heart consists of a double-pump system, once through the atrium and once through the ventricle.

A researcher is studying a strain of mice that only incorporates 50% of the necessary iron into their hemoglobin molecules. Which of the statements is likely true regarding these mutant mice?

The hemoglobin in these mutant mice will be able to bind half the number of oxygen molecules compared to the hemoglobin of normal or wild-type mice.

Which of the statements about insect respiration is true?

The insect respiratory system is composed of a series of branching tubes called tracheae.

Which of the statements is accurate?

The same amount of oxygen enters the blood through diffusion as is transported by circulation.

Which of the statements about bird respiration is true?

The unidirectional flow of air through a bird's lungs maintains a larger concentration gradient for diffusion than can be obtained through tidal breathing.

If the partial pressure of oxygen outside of a cell is 100 mmHg and the partial pressure of oxygen inside of a cell is 25 mmHg, which of the statements is correct?

There will be a net diffusion of oxygen from outside the cell to inside the cell.

A man has just learned that he has a blockage in one of his arteries. Which of the statements is true regarding this blockage?

This blockage will likely increase the resistance to flow in his circulatory system, and as a result, will decrease the rate of blood flow.

As you read this sentence, you have breathed in and out. What you have just experienced is referred to as "gas exchange," where you have taken oxygen into your lungs and expelled carbon dioxide into the environment.

True

Diffusion is an effective way to exchange gases over short distances but not over large distances.

True

Osmosis requires:

a semipermeable membrane separating areas of different solute concentrations.

A school-aged child is dissecting a grasshopper as part of her biology class. As she breaks the exoskeleton, the grasshopper's circulatory fluid leaks out. This fluid would be referred to as:

hemolymph

Which of these changes would increase the rate of oxygen diffusion from the air into the body cells of a flatworm?

increasing the surface area of the body

Which of the choices describes the correct path of air through the human respiratory system?

larynx, trachea, bronchi, bronchioles, alveoli

What percentage of oxygen in the air is typically extracted by the mammalian lung when an animal is resting?

less than 25%

Which of the choices is an example of bulk flow during gas exchange in vertebrates?

movement of water past a respiratory surface

Insects possess _____ circulatory systems, circulatory systems in which hemolymph completely "bathes" the organs and is not typically contained in distinct arteries or veins.

open

What is the function of surfactant in the mammalian respiratory system?

reduction of surface tension in the fluid covering alveoli

During heavy exercise, blood pH will decrease. This will result in a shift to the _________ of the hemoglobin dissociation curve shown.

right

In which of the heart chambers would deoxygenated blood be found?

right atrium and right ventricle

Which of these organisms would be able to extract the greatest percentage of oxygen from their respiratory medium?

salmon

When stimulated by _____, arterioles supplying the digestive system ______, which decreases blood flow to digestive organs.

sympathetic nerves; constrict

A shift to the right in the hemoglobin dissociation curve means that:

the affinity of hemoglobin for O2 has decreased.

Why do cells in the airways of the lungs produce mucus?

to trap pathogens and guard against infection