High School Biology : Understanding Respiratory Functions

Study concepts, example questions & explanations for High School Biology

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Example Questions

Example Question #13 : Respiratory System

What is the primary function of the respiratory system?

Possible Answers:

Fight foreign bacteria and invading viruses

Maintain balance of body fluids

Bring oxygen to the tissues of the body

Provide a site for gas exchange

Aid the body in lactic acid and alcohol fermentation

Correct answer:

Provide a site for gas exchange

Explanation:

The respiratory system is composed of the mouth, trachea, bronchi, bronchioles, and alveoli in the lungs. The primary function of the system is to bring air to the alveoli, where it can interact with blood in nearby capillaries. Oxygen diffuses into the blood from the alveoli, while carbon dioxide is transferred out of the blood, in a process known as gas exchange.

While the respiratory system is responsible for re-oxygenating blood, it is the circulatory system that actually delivers the oxygen to the tissues of the body. The immune system battles foreign pathogens, and the excretory system maintains fluid balance.

Example Question #14 : Respiratory System

Inside the lungs, there are structures called alveoli. These alveoli are designed to __________.

Possible Answers:

increase the flow of blood through the lungs

decrease the surface area available for gas exchange

decrease the flow of blood through the lungs

increase the surface area available for gas exchange

filter particulate matter before it enters the bloodstream

Correct answer:

increase the surface area available for gas exchange

Explanation:

The alveoli are small vessels which increase the surface area available for gas exchange into and out of blood. Oxygen diffuses into the blood while carbon dioxide diffuses out of the blood. These vessels have no control over how much blood is present in the lungs. Also, while these vessels do keep certain things out of the bloodstream, their purpose is not to filter particles. The main filter for our lungs is the mucus coating over the tissues and in our mouth and nose.

Example Question #15 : Respiratory System

What is the primary purpose of the respiratory system?

Possible Answers:

Maintain stable internal water balance

Destroy foreign pathogens

Provide a site for gas exchange

Deliver oxygen to tissues

Correct answer:

Provide a site for gas exchange

Explanation:

The respiratory system is responsible for the exchange of oxygen and carbon dioxide gases between the body and its external environment. The respiratory organs—the lungs—contain alveoli, where gas exchange occurs in concordance with expiration and inspiration, or breathing.

The other choices refer to other organ systems—namely the circulatory, immune, and excretory systems—which should not be confused with the respiratory system.

Example Question #16 : Respiratory System

The function of which respiratory system element is to produce sound?

Possible Answers:

Bronchi

Pharynx

Trachea

Alveoli

Larynx

Correct answer:

Larynx

Explanation:

The larynx, or voice box, contains the vocal cords, which are the source of sound production. The pharynx, or throat, has a dual role in respiration and digestion. The pharynx receives air from the nasal cavity and food and drink from the oral cavity. The trachea, or windpipe, is a rigid tube that transports air from the larynx to the bronchi. The bronchi in turn transport air into the lungs. The alveoli are thin-walled sacs where the exchange of gasses between the lungs and the blood occurs.

Example Question #1 : Understanding Respiratory Functions

Which muscle contracts to promote inhalation and relaxes to promote exhalation?

Possible Answers:

Diaphragm

Deltoid

Masseter

Vastus lateralis

Internal oblique

Correct answer:

Diaphragm

Explanation:

The diaphragm separates the thoracic cavity from the abdominal cavity. When it contracts, it flattens downward and permits the lungs to expand, promoting inhalation. When it relaxes, it rises and compresses the lungs, promoting exhalation. The internal oblique muscle fibers are directed upward from the iliac crest (hip bone) to the lower ribs. The masseter muscle is involved in chewing. The deltoid is a large triangular muscle that covers the shoulder joint. The vastus lateralis extends the leg and is located in the anterior thigh.

Example Question #18 : Respiratory System

What occurs when the diaphragm spasms and the glottis suddenly closes?

Possible Answers:

Snoring

Coughing

Hyperventilation

Hiccups

Sneezing

Correct answer:

Hiccups

Explanation:

Hiccups are reflex spasms of the diaphragm, causing an involuntary inhalation followed by a sudden closure of the glottis that produces an audible sound, the "hic." Snoring is the sound produced while breathing through the mouth during sleep. Sneezing is caused by irritants in the nasal cavity. The glottis stays open while the tongue and soft palate block the flow of air from getting out. Then they suddenly release to let air burst through the nose. Coughing is triggered by irritants in the respiratory tract. High pressure forms in the lower respiratory tract when the glottis closes and muscles contract. The glottis then suddenly opens to release an explosive blast of air. Anxiety may trigger an increase in respiration, hyperventilation, which results in lowered carbon dioxide levels.

Example Question #2 : Understanding Respiratory Functions

The respiratory system does all of the following EXCEPT __________.

Possible Answers:

remove CO2 from the blood

regulate body temperature

secrete hormones into the bloodstream

transport oxygen to the blood

regulate blood acidity

Correct answer:

secrete hormones into the bloodstream

Explanation:

The respitory system transports oxygen to the blood, removes CO2 from the blood, regulates blood acidity, and helps to regulate body temperature. It is the endocrine system that secretes hormones into the blood.

Example Question #20 : Respiratory System

Which of the following is the primary function of the respiratory system?

Possible Answers:

Production of gametes for sexual reproduction

Movement of blood and nutrients throughout the body

Gas exchange between alveoli and capillaries

Movement and coordination

Correct answer:

Gas exchange between alveoli and capillaries

Explanation:

The respiratory system is responsible for moving air into and out of the lungs, where gas exchange occurs between the alveoli and the pulmonary capillaries. The lungs exchange oxygen and carbon dioxide via alveoli and networks of small blood vessels known as capillaries. Production of gametes is a function of the reproductive system. Movement of blood and nutrients throughout the body is the primary function of the circulatory system. Movement and coordination is controlled by the nervous system and requires the structures of the muscular and skeletal systems.

Example Question #3 : Understanding Respiratory Functions

What is tidal volume?

Possible Answers:

The volume of air still in the lungs after forceful exhalation 

The largest possible volume of air an animal can move in and out of its lungs 

The largest volume of air that can enter the lungs after forceful inhalation 

The volume of air that flows in and out of the lungs during relaxed breathing

The total volume of the lungs

Correct answer:

The volume of air that flows in and out of the lungs during relaxed breathing

Explanation:

Tidal volume is nominally and conceptually similar to an ocean tide. Under calm conditions, a tide is not particularly extreme at either its low or high points. During normal, relaxed respiration, an animal breathes in and out moderate volumes of air, creating its tidal volume. 

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