The Respiratory System III

Question 1

Because oxygen very soluble in plasma, _____% of it must be bound to _____
in order to be carried.

Answer 1

is not; 98; hemoglobin

Question 2

Each molecule of hemoglobin can carry _____ molecules of oxygen.

Answer 2

four

Question 3

Hemoglobin that is fully saturated with oxygen is called _____; when no oxygen is bound,
it is called _____.

Answer 3

oxyhemoglobin;

deoxyhemoglobin

Question 4

As the temperature in the blood increases, the binding of oxygen to hemoglobin _____,
and thus the delivery of oxygen to tissue _____

Answer 4

decreases; increases

Question 5

As the partial pressure of carbon dioxide in the blood increases, the binding of oxygen to
hemoglobin _____, and thus the delivery of oxygen to tissue _____.

Answer 5

decreases; increases

Question 6

As blood pH decreases, _____ bind to hemoglobin. This causes the binding of oxygen to
hemoglobin to _____, and thus the delivery of oxygen to tissue to _____. (This is called
the _____.)

Answer 6

hydrogen ions; decrease;

increase; Bohr effect

Question 7

Red blood cells produce _____ to control the binding of oxygen to hemoglobin.

Answer 7

2,3-bisphosphoglycerate (2,3-

BPG)

Question 8

Levels of _____ in erythrocytes are increased at high altitudes to enhance oxygen delivery
to tissues.

Answer 8

2,3-bisphosphoglycerate (2,3-

BPG)

Question 9

As levels of 2,3-bisphosphoglycerate in erythrocytes increase, the binding of oxygen to
hemoglobin _____, and thus the delivery of oxygen to tissue _____.

Answer 9

decreases; increases

Question 10

With each oxygen molecule that hemoglobin binds, its shape changes to allow it to _____.
This allows it to bind oxygen quickly in the lungs, and to release it quickly in oxygen-poor
tissues.

Answer 10

bind the next one with higher

affinity

Question 11

Most tissues don’t need nearly as much oxygen as hemoglobin can carry; however, in
_____, including the _____, the partial pressure of oxygen is very low and most of
hemoglobin’s oxygen is released.

Answer 11

active muscle tissue; heart

Question 12

The partial pressure of carbon dioxide in the alveoli is _____ than in the blood.

Answer 12

slightly lower

Question 13

The partial pressure of carbon dioxide in the tissues is always _____ than in the blood.

Answer 13

higher

Question 14

70% of the carbon dioxide in the blood is transported as _____; conversion of carbon
dioxide to this chemical dramatically increases the rate at which carbon dioxide can be
removed from tissue and transported to the lungs.

Answer 14

bicarbonate ions

Question 15

20% of the carbon dioxide in the blood is transported by _____; 10% or so is found _____.

Answer 15

hemoglobin; in the blood

plasma

Question 16

____ refers to an elevation in carbon dioxide levels in the blood.

Answer 16

Hypercapnia

Question 17

As the oxygen saturation of hemoglobin _____, its ability to carry carbon dioxide _____.
This is known as the _____.

Answer 17

decreases; increases; Haldane

effect

Question 18

The reaction that forms carbonic acid is: _____.

Answer 18

CO2

+ H2O –> H2CO3

Question 19

. Carbonic acid dissociates to form _____ and _____. This reaction is _____.

Answer 19

hydrogen ions OR H+
; 
bicarbonate OR HCO3
-
; 
reversible

Question 20

Much of the bicarbonate in the body is produced by _____.

Answer 20

erythrocytes

Question 21

Formation of carbonic acid in an aqueous solution is spontaneous but slow. In
erythrocytes, where it must occur quickly, it is _____.

Answer 21

catalyzed by an enzyme

Question 22

The carbonic acid/bicarbonate interconversion is \_\_\_\_\_, and this allows bicarbonate to act 
as a(n) \_\_\_\_\_ in the bloodstream. Indeed, it is the most important one!

Answer 22

reversible; buffer

Question 23

As negative bicarbonate ions leave erythrocytes, negative _____ ions enter to maintain
the electrical neutrality of the cell. This is called the _____.

Answer 23

chloride; chloride shift

Question 24

Normal, quiet breathing, at a typical ventilation rate, is called _____.

Answer 24

eupnea

Question 25

Difficult or labored respiration is called _____.

Answer 25

dyspnea

Question 26

Absence of breathing is called _____.

Answer 26

apnea

Question 27

Deep, vigorous respiration, common during exercise, is called _____.

Answer 27

hyperpnea

Question 28

The _____ center, located in the medulla, contains two groups of neurons which control respiration: the _____ and the _____ groups.

Answer 28

medullary respiratory; dorsal | respiratory; ventral respiratory

Question 29

The dorsal respiratory group, located in the _____, generates _____ which stimulate contraction of the _____.

Answer 29

medulla; rhythmic nerve | impulses; diaphragm

Question 30

Although unproven, current thinking holds that nerve impulses from the _____ group not only instigate inspiration but also lead to its time-delayed inhibition.

Answer 30

dorsal respiratory

Question 31

The ventral respiratory group, located in the _____, is required during forceful breathing to recruit the _____.

Answer 31

medulla; intercostal and | abdominal muscles

Question 32

The pontine respiratory group, located in the _____, is thought to _____ and prevent _____ by inhibiting the medullary respiration centers.

Answer 32

pons; modify the breathing rhythm; overinflation of the lungs

Question 33

When the chemoreceptors in the _____, _____ and _____ sense an increase in levels of carbon dioxide in the blood, they signal the respiratory control center to _____ the breathing rate.

Answer 33

medulla oblongata; carotid | arteries; aorta; increase

Question 34

When the chemoreceptors in the _____, _____ and _____ sense a decrease in the pH of the blood, they signal the respiratory control center to _____ the breathing rate.

Answer 34

medulla oblongata; carotid | arteries; aorta; increase

Question 35

When the chemoreceptors in the _____, _____ and _____ sense an increase in levels of hydrogen ions in the blood, they signal the respiratory control center to _____ the breathing rate.

Answer 35

medulla oblongata; carotid | arteries; aorta; increase

Question 36

Of the three major chemoreceptor clusters, detection of _____ by the _____ exerts the most control on breathing rate.

Answer 36

carbon dioxide; medulla | oblongata

Question 37

When the chemoreceptors in the _____ and _____ sense a decrease in levels of oxygen in the blood, they signal the respiratory control center to _____ the breathing rate.

Answer 37

carotid arteries; aorta; increase

Question 38

When stretch receptors in the walls of the bronchi and bronchioles are _____, inspiration is discontinued in a reflex called the _____ or _____.

Answer 38

fully stretched; Hering-Breuer | reflex; inflation reflex

Question 39

Pulmonary irritant reflexes respond to irritation of the respiratory tract by causing _____, followed by increased _____ and _____ through the irritated passageway. Examples include coughing and sneezing.

Answer 39

reflex constriction of the glottis; pulmonary pressure; explosive release

Question 40

The cerebral cortex can exert voluntary control over respiration by bypassing the medullary centers and _____.

Answer 40

directly stimulating the | respiratory muscles

Question 41

Sympathetic centers in the _____ modify the ventilation rate and depth in response to strong emotions, abrupt temperature changes, and pain.

Answer 41

hypothalamus

Question 42

Anaerobic exercises causes a dramatic increase in ventilation rate due to the production of _____, which lowers _____. Indeed, respiration is so rapid that carbon dioxide levels may be _____, and oxygen levels _____, than their resting levels.

Answer 42

lactic acid; blood pH; lower; | higher

Question 43

Aerobic exercise alters breathing rate within seconds, in part due to direct communication between _____ and the _____.

Answer 43

motor pathways; medullary | respiratory center

Question 44

Aerobic exercise alters breathing rate within seconds, in part due to signals sent from _____ to the _____, informing it of the body's exertion.

Answer 44

proprioceptors in the body; | medullary respiratory center

Question 45

After the initial rapid increase in ventilation rate, aerobic exercise causes a slow, sustained increase. 'How' remains unknown, but it is NOT due to changes in average _____, nor to changes in _____ or _____ concentrations, which remain constant.

Answer 45

blood pH; oxygen; carbon | dioxide

Question 46

Adaptations to high altitudes include an increase in _____, elevated _____, and increased production of erythropoietin (and thus of _____).

Answer 46

ventilation rate; 2,3-BPG; RBCs

Question 47

''COPD'' refers to a group of diseases that result in chronic and progressive dyspnea, often accompanied by coughing, frequent pulmonary infections, and respiratory failure. The acronym means, '_____.'

Answer 47

chronic obstructive pulmonary | diseases

Question 48

Obstructive emphysema is a COPD which is characterized by _____ and _____.

Answer 48

permanently enlarged alveoli; | deterioration of alveolar walls

Question 49

Chronic bronchitis is a COPD which results in _____, as well as inflammation and fibrosis of the _____.

Answer 49

excessive mucus production; | lower respiratory mucosa

Question 50

Although asthma is a chronic disease, it is not classified as a “COPD” because the symptoms are not chronic. Asthma is characterized by acute attacks of coughing, dyspnea, wheezing, and chest tightness, brought on by _____.

Answer 50

acute inflammation of the | airways

Question 51

_____ is an infectious disease caused by the bacterium Mycobacterium tuberculosis and spread by coughing and inhalation.

Answer 51

Tuberculosis (TB)

Question 52

Until the 1930s, one third of the deaths in the 20-45 year old age group were due to _____. Antibiotics changed that, but the use of these drugs in ways which allowed one or more bacteria to survive has led to the evolution of _____.

Answer 52

tuberculosis (TB); antibiotic | resistant strains

Question 53

As of the year 2000, one third of all cancer deaths are due to _____: only one in ten affected individuals is a non-smoker, highlighting the contribution of smoking to the development of the disease.

Answer 53

lung cancer

Question 54

One of _____ types of lung cancer, squamous cell carcinoma arises in the _____, and tends to form masses that hollow out and bleed.

Answer 54

three; epithelium of the bronchi

Question 55

One of _____ types of lung cancer, adenocarcinoma originates in _____ as nodules that develop from _____ and _____.

Answer 55

three; peripheral lung areas; | bronchial glands; alveolar cells

Question 56

One of _____ types of lung cancer, small cell carcinoma contains _____ cells that form clusters within the _____ and rapidly metastasize.

Answer 56

three; lymphocyte-like; | mediastinum

Question 57

As we age, the thoracic wall becomes _____, the lungs lose _____, and the amount of oxygen we can use during aerobic respiration decreases. These changes are accelerated markedly in _____ individuals.

Answer 57

more rigid; elasticity; inactive

Question 58

The protection provided by mucus declines with age due to alterations in _____, and a decline in the _____ of epithelial cells in the respiratory tract.

Answer 58

mucous glands; ciliary action