Respiratory System

Question 1

3major functions of respiratory?

Answer 1

Pulmonary ventilation
Gas exchange/transport
Regulation of respiration

Question 2

Inspiration

Answer 2

Contraction of inspiratory muscles+diaphragm
Increase of chest cavity, lungs expanding
Decrease in pressure causes air to be sucked in
Active

Question 3

Expiration

Answer 3

Relaxation of inspiratory muscles+diaphragm
Contraction of expiration muscles, depression of chest cavity
Positive pressure presses air out
Passive

Question 4

Eupnea

Answer 4

Normal breathing

Question 5

Hyperpnea

Answer 5

Greater range of motion

Question 6

Polypnea

Answer 6

Increased frequency du to thermal regulation

Question 7

Tachypnea

Answer 7

Increased frequency due to other reasons

Question 8

Apnea

Answer 8

Respiratory arrest

Question 9

Lung compliance

Answer 9

Distensibility=volume/pressure

Depends on elasticity and surface tension of alveoli

Question 10

Tidal volume

Answer 10

Vet

Air in and out during normal breath

Question 11

Inspiratory reserve volume

Answer 11

IRV
Amount of air able to force in after tidal volume
Forced inspiration

Question 12

Expiratory reserve volume

Answer 12

ERV
Amount of air able to force out after tidal volume
Forced expiration

Question 13

Residual volume

Answer 13

RV

Amount of air left in lungs after maximal expiration

Question 14

Inspiratory capacity

Answer 14

IC
Amount of air that can be inspired after normal inspiration
IC=Vt+IRV

Question 15

Functional residue capacity

Answer 15

FRC
Amounts of air left after normal respiration
FRC=ERV+RV

Question 16

Vital capacity

Answer 16

VC
Amount of air in lungs after maximal inhalation
VC=Vt+IRV+ERV

Question 17

Total lung capacity

Answer 17

TLC
amount of air in lungs after maximal inspiration
TLC=Vt+IRV+ERV+RV

Question 18

Pulmonary ventilation

Answer 18

Amount of air into lungs per min

Vol/min=Vt*respiratory frequency

Question 19

Alveolar ventilation

Answer 19

Amount of air reaching alveoli/min

Alveolar volume/min=(VT-dead space volume)*respiratory frequency

Question 20

Gas exchange betw lungs and blood

Answer 20

Passive diffusion due to pressure gradients

Depend on pressure differentials, solubility of gas into fluid, temperature

Question 21

Mechanisms of O2 transport

Answer 21

Dissolved in plasma

Together with hemoglobin

Question 22

Oxyhemoglobin

Answer 22

Hb with O2

Question 23

Deoxyhemoglobin

Answer 23

Hb without O2

Question 24

Transport of CO2 in blood

Answer 24

Dissolved in plasma 10%
Carbamino hemoglobin 20%
Bicarbonate ions 70%

Question 25

Voluntary respiratory regulation

Answer 25

Cerebral cortex

Question 26

Involuntary respiratory regulation

Answer 26

Respiratory center in brain stem - medulla oblongada - pons

Question 27

Rhythmicity center

Answer 27

In medulla oblongada Dorsal respiratory group- inspiratory Ventral respiratory group- expiratory

Question 28

Accessory respiratory regions

Answer 28

In pons Apneustic center-promotes inspiration Pneumotaxic center-inhibits respiration Modifies activities of rhytmicity center

Question 29

Dorsal respiratory group

Answer 29

In medulla oblongada Sets basic respiratory rate Stimulates contraction of inspiratory muscles

Question 30

Ventral respiratory center

Answer 30

In medulla oblongada Inactive in normal quiet respiration When increased inhalation=signals to dorsal Stimulation of inspiratory and expiratory muscles

Question 31

Pneumotaxic center

Answer 31

In pons Inhibits inspiration Continous inhibitory impulses to dorsal group to avoid excessive filling Inhibits inspiration=increased rate of inspiration

Question 32

Apneustic center

Answer 32

In pons Promotes inspiration Excitatory impulses to dorsal group=prolonged inspiration, delaying signals from pneumotaxic center

Question 33

Factors affecting respiratory center

Answer 33

+higher centers of brain (speech, emotions, voluntary breath...) +chemoreceptors in aortic+carotid body +proprioreceptors in muscles/joints +receptors for touch, temp, pain -higher centers in brain -Hering-Breuer reflex=stretch receptors in lung

Question 34

Peripheral chemoreceptors

Answer 34

Aortic bodies- in aortic arch, sensitive to PO2 changes | Carotid bodies- bifurcation of carotid A, sensitive to changes of PO2

Question 35

Central chemoreceptors

Answer 35

In medulla oblongada | Sensitive to changes in OO2 and pH

Question 36

Chemoreceptors role

Answer 36

Modifies ventilation to maintain CO2, O2, pH levels | PO2 most important due to effects of blood pH

Question 37

Hypocapnia

Answer 37

Low CO2 in blood | Caused by hyperventilation

Question 38

Hypercapnea

Answer 38

High CO2 in blood | Caused by hypoventilation