gas exchange

Question 1

___ refers to all process of gas movements and metabolism

Answer 1

respiration

Question 2

refers to the oxidative processes within cells

Answer 2

internal or cellular respiration

Question 3

___ is the exchange of O₂ and CO₂ between the organism and its environment

Answer 3

external respiration

Question 4

The two methods of external respiration are ___ and ___

Answer 4

1. Exchange across membranes by diffusion 2. Bulk transport through a medium

Question 5

The four steps in external respiration are ___, ___, ___, and ___

Answer 5

1. Ventilation 2. Respiratory exchange 3. Circulation 4. Cellular exchange

Question 6

In mammals, the volume of air inhaled and exhaled with each breath is called ___

Answer 6

tidal volume

Question 7

Tidal volume averages about ___ in resting humans

Answer 7

500 mL

Question 8

The maximum tidal volume during forced breathing is called ___

Answer 8

vital capacity

Question 9

Vital capacity is about ___ for college-age females and ___ for males

Answer 9

3.4 L (females), 4.8 L (males)

Question 10

Mammals ventilate their lungs by ___

Answer 10

negative pressure breathing

Question 11

The three main components of the respiratory system are ___, ___, and ___

Answer 11

Airways, Lungs, Respiratory muscles

Question 12

The five main respiratory pigments are ___, ___, ___, ___, and ___

Answer 12

1. Hemoglobin 2. Hemocyanin 3. Hemerythrin 4. Chlorocruorin 5. Erthyrocruorin

Question 13

Hemoglobin binds ___

Answer 13

oxygen

Question 14

Oxyhemoglobin is ___

Answer 14

hemoglobin with oxygen bound

Question 15

Deoxyhemoglobin is ___

Answer 15

hemoglobin without oxygen

Question 16

Carboxyhemoglobin is ___

Answer 16

hemoglobin saturated with carbon monoxide

Question 17

Myoglobin is ___

Answer 17

respiratory pigment that stores oxygen in vertebrate muscles

Question 18

Most O₂ in blood combines with ___ to form ___

Answer 18

hemoglobin in red blood cells, oxyhemoglobin

Question 19

Most CO₂ in the blood is transported as ___

Answer 19

bicarbonate ion

Question 20

Some CO₂ combines with hemoglobin to form ___

Answer 20

carbaminohemoglobin

Question 21

The relationship between %Hb saturation and PO₂ is shown in the ___

Answer 21

oxygen dissociation/saturation curve

Question 22

Sub-unit cooperativity means ___

Answer 22

oxygenation of the first heme groups facilitates oxygenation of subsequent heme groups

Question 23

The Law of Mass Action for Hb and O₂ is ___

Answer 23

HbH₄⁺ + 4O₂ ⇌ Hb(O₂)₄ + 4H⁺

Question 24

Increased PCO₂, acid, temperature, and 2,3-bisphosphoglycerate shift the O₂–Hb curve ___

Answer 24

to the right

Question 25

___ is the influence of acid on the release of O₂; acidosis reduces the affinity of Hb for O₂, shifting the curve to the right

Answer 25

Bohr effect

Question 26

____is the effect of acidosis on lowering blood O₂ content—reduces the capacity of binding, shifting the curve downward

Answer 26

Root effect

Question 27

The equation for cellular respiration is ___

Answer 27

C₆H₁₂O₆ + O₂ → 6CO₂ + 6H₂O + ATP

Question 28

The chloride shift is ___

Answer 28

inward shift of Cl⁻ in exchange for the outflux of HCO₃⁻

Question 29

The ____ is the ability of deoxygenated Hb to pick up CO₂ and CO₂-generated H⁺

Answer 29

Haldane effect

Question 30

Alkalosis is ___

Answer 30

alkaline tide in the blood

Question 31

Acidosis is ___

Answer 31

acid tide in the blood

Question 32

The equation relating pH, bicarbonate, and CO₂ is called the ___

Answer 32

Henderson-Hasselbalch equation

Question 33

If extracellular CO₂ increases, what happens to intracellular pH?

Answer 33

CO₂ diffuses rapidly into the cell, forming bicarbonate and causing a sharp fall in intracellular pH

Question 34

If extracellular NH₄Cl increases, what happens to intracellular pH?

Answer 34

NH₃ diffuses rapidly into the cell, combines with H⁺ to form ammonium ions, which diffuse slowly out, resulting in an increase in intracellular pH

Question 35

The Jacob-Stewart cycle is ___

Answer 35

operates the transfer of acid from plasma to cell interior

Question 36

Buffering of intracellular pH occurs by ___

Answer 36

physical buffers (phosphates, proteins), reaction of HCO₃⁻ with H⁺ to form CO₂ (which diffuses out), passive diffusion or active transport of H⁺, cation/anion exchange mechanisms

Question 37

Ventilation/perfusion ratio (V/Q) =

Answer 37

1 (Alveolar ventilation/Pulmonary blood flow)

Question 38

Intrinsic regulation of respiration involves ___

Answer 38

local controls to adjust ventilation and perfusion to match airflow and blood flow in lung areas

Question 39

Extrinsic regulation of respiration involves ___

Answer 39

neural or hormonal regulation

Question 40

Parasympathetic stimulation causes ___

Answer 40

bronchoconstriction from smooth-muscle contraction, increasing airway resistance

Question 41

Sympathetic stimulation (epinephrine) causes ___

Answer 41

bronchodilation, decreased airway resistance by promoting bronchiolar smooth-muscle relaxation

Question 42

The main respiratory control centers in the brain stem are ___

Answer 42

medullary respiratory center: dorsal respiratory group (DRG) and ventral respiratory group (VRG)

Question 43

The pneumotaxic center___

Answer 43

sends impulses to the DRG to help “switch off” inspiratory neurons

Question 44

The apneustic center ___

Answer 44

prevents the inspiratory neurons from being switched off

Question 45

The magnitude of ventilation is adjusted in response to ___

Answer 45

PO₂, PCO₂, and H⁺

Question 46

Feedback monitoring of blood gases and H⁺ occurs ___

Answer 46

both peripherally and centrally

Question 47

Low arterial PO₂ (<60 mm Hg) tends to ___

Answer 47

directly depress the respiratory center via its central chemoreceptors

Question 48

Increased arterial PCO₂ causes ___

Answer 48

elevation in H⁺ concentration in brain ECF, directly stimulating central chemoreceptors, increasing ventilation

Question 49

When the control center registers a slight drop in pH, it ___

Answer 49

increases the depth and rate of breathing, and the excess CO₂ is eliminated in exhaled air

Question 50

Eupnea is ___

Answer 50

normal, quiet breathing typical of an animal at rest

Question 51

Hyperventilation is ___

Answer 51

increase in the amount of air moved in or out of the lung by changes in rate and/or depth of breathing, such that ventilation no longer matches CO₂ production and blood CO₂ levels change

Question 52

Hypoventilation is ___

Answer 52

decrease in the amount of air moved in or out of the lung by changes in rate and/or depth of breathing, such that ventilation no longer matches CO₂ production and blood CO₂ levels change

Question 53

Hyperpnea is ___

Answer 53

increased lung ventilation due to increased breathing in response to increased CO₂ production (e.g., during exercise)

Question 54

Apnea is ___

Answer 54

absence of breathing

Question 55

Dyspnea is ___

Answer 55

labored breathing associated with the unpleasant sensation of breathlessness

Question 56

Polypnea is ___

Answer 56

increase in breathing rate without an increase in the depth of breathing