Gas Exchange

Question 1

• energy from food is released by oxidative processes, usually with molecular oxygen as the terminal electron acceptor
• oxygen is taken into the body across a respiratory surface

Answer 1

respiration

Question 2

oxidative processes that occur within cells

Answer 2

cellular respiration

Question 3

exchange of gasses between blood and tissues

Answer 3

internal respiration

Question 4

exchange of oxygen and carbon dioxide between the organism and its environment

Answer 4

external respiration

Question 5

To allow diffusion of gases across an aqueous phase, respiratory surfaces must be __ and always kept __

Answer 5

thin
wet

Question 6

lungs

Answer 6

aerial respiration

Question 7

gills

Answer 7

aquatic respiration

Question 8

• frequently supplements gill or lung breathing in larger animals such as amphibians and fishes
• gas exchange occur across skin or outer integument

Answer 8

cutaneous respiration

Question 9

respire through a system of tubes called tracheae that connect to the air via spiracles that can be actively opened or closed

Answer 9

tracheal respiration

Question 10

valvelike openings

Answer 10

spiracles

Question 11

branching system of tubes

Answer 11

tracheae

Question 12

smallest end channels of tracheae are fluid-filled

Answer 12

tracheoles

Question 13

gills of an animal, most typically an amphibian, that are exposed to the environment, rather than set inside the pharynx and covered by gill slits

Answer 13

external gills

Question 14

animal with external gills example

Answer 14

axolotl

Question 15

the structure formed from the outgrowth of pharynx inside the body, consisting of gill slits, which is used to increase the rate of diffusion of gases and help in counter-current mechanism

Answer 15

internal gills

Question 16

help in crawling, swimming, and respiration

Answer 16

parapodia

Question 17

thin filamentous structures, richly supplied with blood vessels arranged so that blood flow is opposite to the flow of water

Answer 17

fish gills

Question 18

arrangement that provides greatest possible extraction of oxygen from the water

Answer 18

countercurrent flow

Question 19

branchial pump

Answer 19

• mouth
• opercular cavities

Question 20

gill ventilation often assisted by the fish’s forward movement through the water with its mouth open

Answer 20

ram ventilation

Question 21

have lungs that can be ventilated by muscle movements to produce a rhythmic exchange of air

Answer 21

terrestrial vertebrates

Question 22

vary from simple, smooth-walled, baglike lungs of some salamanders to the subdivided lungs of frogs and toads

Answer 22

amphibian lungs

Question 23

total surface available for gas exchange is much in lungs which are subdivided into numerous interconnecting air sacs

Answer 23

nonavian reptiles

Question 24

contains millions of small sacs (alveoli) each intimately associated with a rich vascular network

Answer 24

mammalian lungs

Question 25

disadvantage of lungs

Answer 25

1. gas exchange is between blood and air only in alveoli and alveolar ducts 2. dead space - volume of air in lungs that does not participate in gas exchange 3. air must enter and exit through the same channel

Question 26

one-cell-thick air capillaries

Answer 26

parabronchi

Question 27

Parabronchi in birds receive nearly fresh air during both ___ and ___

Answer 27

inspiration expiration

Question 28

(amphibians) action to force air into their lung

Answer 28

positive pressure

Question 29

(amphibians) air is pulled into the lungs by expansion of the thoracic cavity

Answer 29

negative pressure

Question 30

upper respiratory tract

Answer 30

- nasal cavity - pharynx

Question 31

lower respiratory tract

Answer 31

- larynx - trachea - bronchi - lungs

Question 32

nostrils

Answer 32

external nares

Question 33

Three (3) important changes the air undergoes in its passage to the air sacs

Answer 33

1. filtered free from most dust and other foreign substances 2. warmed to body temperature 3. saturated with moisture

Question 34

covers the lungs and interlobar fissures

Answer 34

visceral pleura

Question 35

lines the inner surface of the walls of the chest

Answer 35

parietal pleura

Question 36

"space" between the pleura

Answer 36

pleural cavity

Question 37

lungs maintains a __ __ or the __ __ __ that keeps the lungs expanded to fill the pleural cavity, and therefore no real pleural space exits

Answer 37

partial vacuum or negative intrapleural pressure

Question 38

chest cavity is floored by the ___

Answer 38

diaphragm

Question 39

- to fall below atmospheric pressure - air rushes in through passageways to equalize pressure

Answer 39

intrapulmonary pressure

Question 40

less active process than inspiration

Answer 40

normal expiration

Question 41

occurs during exercise

Answer 41

forced expiration

Question 42

neurons in ___ of the brain regulate normal, quiet breathing

Answer 42

medulla

Question 43

- located close to the heart and the neck region - monitor peripheral changes in blood levels of carbon dioxide and hydrogen ions and send stimulatory signals to the medulla respiratory centers if these levels rise

Answer 43

peripheral chemoreceptors

Question 44

becomes saturated with water vapor as it travels through the air-filled passageways toward the alveoli

Answer 44

inspired air

Question 45

___ ___ of oxygen drops and that of carbon dioxide rises

Answer 45

partial pressure

Question 46

air from the alveoli mixes with air in the dead space to produce still a different mixture

Answer 46

expiration

Question 47

red, iron-containing protein present in all vertebrates and many invertebrates

Answer 47

hemoglobin

Question 48

each molecule of hemoglobin is __ __ and __ __

Answer 48

5% heme 95% globin

Question 49

iron-containing compound giving the red color to blood

Answer 49

heme

Question 50

colorless protein

Answer 50

globin

Question 51

each gram of hemoglobin can carry a maximum of approx. ___ __ of oxygen

Answer 51

1.3 mL

Question 52

How does hemoglobin bind with oxygen

Answer 52

when oxygen concentration is high

Question 53

hemoglobin with bound oxygen

Answer 53

oxyhemoglobin

Question 54

- a result of the effect carbon dioxide has on hemoglobins affinity for oxygen - The rate of O2 unloading is increased in metabolically active tissues due to increased acidity

Answer 54

Bohr effect

Question 55

A lower pH also shifts the hemoglobin saturation curve to the right and causes ___ of oxygen to active tissue

Answer 55

release

Question 56

- blue, copper-containing protein - crustaceans and most molluscs

Answer 56

hemocyanin

Question 57

- green-colored, iron-containing pigment - four families of polychaete tubeworms

Answer 57

chlorocruorin

Question 58

- red pigment found in some polychaete worms - although it contains iron, this metal is not present in a heme group - oxygen-carrying capacity is poor compared to hemoglobin

Answer 58

hemerythrin

Question 59

hydrogen ions combine with hemoglobin

Answer 59

deoxyhemoglobins

Question 60

a chemical complex formed by carbon dioxide and hemoglobin after the release of oxygen by the hemoglobin to a tissue cell

Answer 60

Carbaminohemoglobin