Respiratory System

Question 1

Functions of respiratory system:

Answer 1

Conducts air into & out of lungs
Exchanges gases between air & blood
Humidifies air
Warms air
Filters air

Question 2

Alveoli:

Answer 2

Saclike structures surrounded by capillaries
site of exchange of oxygen and CO2
300 million in lung
Provides surface area where diffusion takes place

Question 3

What are the two cell membranes that aid diffusion?

Answer 3

membrane of alveolar cells

membrane of cells of capillary wall

Question 4

Visceral (pulmonary) pleura

Answer 4

outer surface of lungs

Question 5

Parietal pleura

Answer 5

inner surface of thoracic cavity & diaphragm

Question 6

Pleural fluid

Answer 6

lubricating fluid between 2 membranes

Question 7

Intrapleural pressure

Answer 7

pressure in pleural cavity between 2 membranes; less than atmospheric pressure

Question 8

Increase in volume of intrathoracic cavity

Answer 8

Increases lung volume
Decreases intrapulmonic pressure
Causes air to rush into lungs (inspiration)

Question 9

Decrease in volume of intrathoracic cavity

Answer 9

Decreases lung volume
Increases intrapulmonic pressure
Causes air to rush out of lungs (expiration)

Question 10

What do inspiratory muscles do?

Answer 10

increase intrathoracic cavity volume

Question 11

Muscles that elevate ribs

Answer 11

external intercostals, scalenes, sternocleidomastoid, pectoralis minor

Question 12

Diaphragm

Answer 12

Flattens as it contracts
Puts in motion pressure changes that cause inspiration
Contraction moves abdominal contents forward & downward

Question 13

Expiration:

Answer 13

No muscular effort needed at rest

Passive recoil of diaphragm & other muscles decreases intrathoracic cavity volume

Question 14

What muscles work during forced expiration to pull ribs downward?

Answer 14

Internal intercostals
Rectus abdominis
Internal oblique muscles of abdominal wall

Question 15

Airflow equation

Answer 15

Airflow = P1 − P2/Resistance

Question 16

What is P1-P2?

Answer 16

pressure difference between 2 areas

Question 17

What can increase airflow?

Answer 17

Amplifying pressure difference between 2 areas

Decreasing resistance to airflow

Question 18

What is biggest factor affecting airflow at rest?

Answer 18

Diameter of airway

Question 19

What decreases resistance to airflow in exercise?

Answer 19

bronchodilation

Question 20

Tidal volume

Answer 20

amount of air moved per breath

Question 21

Pulmonary ventilation

Answer 21

anatomical dead space + alveolar ventilation

Question 22

Volume of air moved per minute

Answer 22

VE = VT × f

Question 23

Residual volume:

Answer 23

air left in lungs after max. exhalation

Question 24

What are factors promoting diffusion?

Answer 24

Large surface area of alveoli
Thinness of respiratory membrane
Pressure differences of oxygen & carbon dioxide between air in alveoli & blood
Partial pressure

Question 25

Partial pressure

Answer 25

portion of pressure due to a particular gas in a mixture of gases

Question 26

PO2 at sea level

Answer 26

159.1 mm Hg

Question 27

PO2 in alveoli

Answer 27

105 mm Hg

Question 28

PO2 in arterial blood entering lungs

Answer 28

40 mm Hg

Question 29

PO2 in blood leaving lungs

Answer 29

100 mm Hg

Question 30

PO2 in tissues

Answer 30

40 mm Hg

Question 31

What provides the driving force for diffusion of oxygen?

Answer 31

differences between PO2 in alveoli & blood (65 mm Hg) and between blood & tissue (60 mm Hg)

Question 32

PCO2 in atmospheric air

Answer 32

0.2 mm Hg

Question 33

PCO2 in alveoli

Answer 33

40 mm Hg

Question 34

PCO2 in arterial blood entering lungs

Answer 34

46 mm Hg

Question 35

PCO2 in blood leaving lungs

Answer 35

40 mm Hg

Question 36

PCO2 in tissues

Answer 36

46 mm Hg

Question 37

Oxyhemoglobin

Answer 37

oxygen bound to hemoglobin

Question 38

Deoxyhemoglobin

Answer 38

hemoglobin not bound to oxygen

Question 39

How does an increase in temperature affect oxyhemoglobin disassociation?

Answer 39

Decreases affinity of hemoglobin for oxygen

Question 40

How to pH effect oxyhemoglobin disassociation?

Answer 40

increase in acidity: decreases affinity | decrease in acidity: increase in affinity

Question 41

How is carbon dioxide transported in body?

Answer 41

7% to 10% is dissolved in plasma 20% is bound to hemoglobin 70% is transported as bicarbonate

Question 42

Oxygen capacity for females

Answer 42

14*1.34=18.8 volume %

Question 43

Oxygen capacity for males

Answer 43

16*1.34=21.4Volume %

Question 44

Repiratory control center

Answer 44

Portion of medulla oblongata & pons | Serves as pacemaker, generating a rhythmical breathing pattern

Question 45

te & depth of breathing can be modified by

Answer 45

Higher brain centers Chemoreceptors in medulla Other peripheral inputs

Question 46

Central Chemoreceptors

Answer 46

Located in medulla, separate from respiratory control center | Respond to changes within CSF, esp. in H+ concentration or

Question 47

Peripheral Chemoreceptors

Answer 47

Located in carotid arteries & aortic arch | Respond to changes in blood PCO2 & H+ concentration

Question 48

Other Neural Input

Answer 48

Stretch receptors in lungs & respiratory muscles | Proprioceptors & chemoreceptors in skeletal muscle & joints

Question 49

Ventilatory equivalent of oxygen

Answer 49

ratio of pulmonary ventilation (VE) to oxygen (VO2): VE/VO2

Question 50

Ventilatory equivalent of carbon dioxide

Answer 50

ratio of pulmonary ventilation (VE) to carbon dioxide (VCO2): VE/VCO2

Question 51

Light-intensity:

Answer 51

less than VT

Question 52

Moderate-intensity

Answer 52

between VT and RCP

Question 53

High-intensity

Answer 53

>RCP