BIOL 273 - Unit 5.3

Question 1

Lung compliance

high vs low lung compliance

Answer 1

the ability for the lung to stretch
- low lung compliance , the harder it is to expand the lungs (breath shallow and rapid)

• high lung compliance indicates that the lungs stretch easily - easy to breathe

Question 2

Lung elastance

what happens when there’s low elastance?

Answer 2

degree and/or speed of return to resting volume after lung is stretched
- low lung elastance; lung does not return to resting volume passively
- expiration becomes active process

Question 3

Airway resistance is primarily determined by what

Answer 3

determined by airway diameter

Question 4

What can increase resistance in the airway

Answer 4

mucus accumulation (normally work needed to overcome airway resistance is low)

Question 5

What can bronchiole diameter be affected by

Answer 5

nervous system
hormones
paracrines

Question 6

What causes bronchodialation

Answer 6

CO2

Question 7

What released in response to tissue damage / allergic reactions

Answer 7

Histamine - causes lumen of airway (bronchoconstriction)

Question 8

Neural control of bronchioles

Answer 8

• primarily by parasympathetic neurons that cause bronchocontriction
  (to protect lower respiratory tract from inhaled irritants)
• no significant sympathetic innervation

Question 9

Hormonal control of bronchioles

Answer 9

• primarily via circulating epinephrine
• through B2 receptors in smooth muscle of bronchioles
  (relax muscles to dialate bronchioles)

Question 10

Why is pulmonary function assessed and what is used

Answer 10

to determine the amount of air a person moves during quiet breathing and maximal breathing effort

use a spirometer

Question 11

(Lung volume) Tidal volume

Answer 11

amount of air moved in a single normal inspiration or expiration

Question 12

(Lung volume) Inspiratory reserve volume

Answer 12

maximum amount of air that can be inspired above tidal volume

Question 13

(Lung volume) Expiratory reserve volume

Answer 13

amount of air that can be exhaled after a normal expiration

Question 14

(Lung volume) Residual volume

Answer 14

amount of air left in the lungs after maximal expiration

Question 15

(Lung volume) Vital capacity

Answer 15

maximum amount of air that can be voluntarily moved into or out of the respiratory system

VC = IRV + ERV + TV

Question 16

(Lung volume) total lung capacity

Answer 16

vital capacity + residual volume

Question 17

Describe minute volume and how to calculate it

Answer 17

estimates the effectiveness of breathing by measuring the total pulmonary ventilation

MV (mL/min) = Vt (mL/breath) X respiratory rate (breaths/min)

Question 18

Anatomic dead space located in the airways and what equation is it involved in

and equation

Answer 18

no gas exchange
(air in trachea, bronchi and bronchioles does not participate in gas exchange)

Alveolar volume = Vt - dead space

Question 19

what is the effectiveness of ventilation determined by

Answer 19

the rate and depth of breathing
(depth is most important because of dead space)

Question 20

Alveolar ventilation

and equation

Answer 20

the amount of air that reaches the alveoli each minute

Alveolar ventilation = ventilation rate X alveolar volume

Question 21

What do alterations in blood flow in the lungs depend on

Answer 21

by the control exerted by O2 levels in the interstitial fluid around the arteriole surrounding the alveoli

Question 22

What happens to the arteriole when there is a decrease/increase in tissue PO2

Answer 22

Increase: vasodilation in the arteriole
Decrease: vasoconstriction (reduce blood flow)

Question 23

Why does the body attempt to match air flow and blood flow

Answer 23

to maximize gas exchange in the capillary beds that surround the alveoli

divert blood away from under-ventilated areas - ensures blood travels to lungs to ensure oxygen can be picked up