Chapter 49-The Respiratory System

Question 1

Oxygen is needed why?

Answer 1

final electron acceptor during electron transport. Without oxygen, animal cells obtain insufficient energy to survive

Question 2

Gas exchange

Answer 2

• the gases diffuse into the aqueous layer covering the epithelial cells that line the respiratory organs
• diffusion of gasses is passive, driven only by the difference in O2 and CO2 concentrations on the two sides of the membranes and their relative solubilities in the plasma membrane

Question 3

Body surface for gas exchange

Answer 3

only in amphibians and annelids, a few others

Question 4

tracheal tubes

Answer 4

insect’s structure for gas exchange

Question 5

lungs

Answer 5

reptiles, birds, and mammals structure for gas exchange

Question 6

Gills

Answer 6

specialized extensions of tissue that project into water, extract oxygen from water and release carbon dioxide
-increase surface area for diffusion

Question 7

Internal gills

Answer 7

gills of bondy fishes are located between oral cavity and opercular cavities

• two cavities function as pumps that alternately expand.
• move water into mouth, through gills, and out of the fish through the open operculum or gill cover

Question 8

Lamellae

Answer 8

each gill filament is made of these, thin membranous plates that project into water flow

Question 9

countercurrent flow

Answer 9

blood flows opposite to direction of water movement in lamellae

• maximizes ocygenation of blood
• gills are more efficient of all respiratory organs

Question 10

cutaneous respiration

Answer 10

amphibians who exchange gas through body surface

Question 11

1 atm of pressure

Answer 11

is a pressure of 760mm Hg

Question 12

partial pressure

Answer 12

pressure contributed by a gas (i.e. oxygen) to the total atmospheric pressure

Question 13

how does pressure change

Answer 13

changing the number of molecules exerting the force or by changing the surface area

Question 14

positive pressure breathing

Answer 14

force air into their lungs by creating a positive pressure in the buccal cavity (push oxygen into lungs) (frogs)

Question 15

negative pressure breathing

Answer 15

expand rib cages by muscular contractions, creating lower pressure inside the lungs

Question 16

Tubes of respiratory system

Answer 16

larynx, glottis, trachea, right and left bronchi, bronchioles, alveoli

Question 17

partial pressure of oxygen depleted blood returning from systemic circulation

Answer 17

partial pressure of 40mm Hg

Question 18

Partial pressure of oxygen in alveoli

Answer 18

105 mm Hg

Question 19

partial pressure of oxygen in blood leaving lungs

Answer 19

100mm Hg

Question 20

partial pressure of CO2 in alveoli

Answer 20

40 mm Hg

Question 21

partial pressure of CO2 in blood leaving lungs

Answer 21

40 mm Hg

Question 22

partial pressure of CO2 in blood entering lungs

Answer 22

46 mm Hg

Question 23

How do lungs move

Answer 23

attached to thoracic cavity through pleural cavity

• during inhalation, thoracic volume increases through contraction of external intercosal muscles (expands rib cage) and contraction of the diaphragm (expands volume of thorax and lungs
• -this increases surface area and decrease pressure to below atmospheric pressure

Question 24

tidal volume

Answer 24

volume of air moving in and out of lungs in a person at rest

Question 25

vital capacity

Answer 25

macimum amount of air that can be expired after a forceful respiration

Question 26

Hypoventilation

Answer 26

insufficient breathing, blood has abnormally high CO2 partial pressure

Question 27

Hyperventiliation

Answer 27

excessive breathing, blood has an abnormally low CO2 partial pressure

Question 28

what initiates each breath

Answer 28

neurons in a respiratory control center in the medulla oblongata (autonomic nervous system)
-stimulates external intercostal muscles and diaphragm to contract, causing inhalation

Question 29

what causes exhalation

Answer 29

the neurons stop producing impulses, respiratory muscles relax

Question 30

carbonic acid

Answer 30

produced in the event of a rise in blood CO2, lowers blood pH.

Question 31

COPD

Answer 31

chronic obstructive pulmonary disease

-refers to any disorder that obstructs airflow on a long term basis

Question 32

Asthma

Answer 32

COPD

-allergen triggers the release of histamine, causing intense constriction of the bronchi and sometimes suffocation

Question 33

Emphysema

Answer 33

COPD

• alveolar walls break down and the lung exhibits larger but fewer alveoli
• lungs become less elastic
• often caused by smoking

Question 34

Lung cancer

Answer 34

caused mainly by cigarette smoking

-spreads so rapidly its usually in other organs by the time of diagnosis

Question 35

Hmoglobin

Answer 35

consists of 4 polypeptide chains

-each chain is associated with a heme group, which binds with oxygen

Question 36

Bohr shift

Answer 36

pH effect on hemoglobins affinity for 02

• increased CO2 increases H+
• lower pH reduces hemoglobins affinity for O2
• increased temperature has similar effect

Question 37

transportation of CO2

Answer 37

20% of CO2 is bound to hemoglobin

• 8% is dissolved in plasma
• 72% is in red blood cells