Chapter 36

Question 1

External respiration

Answer 1

pulmonary ventilation = air moving in and out of the lungs (aka breathing)
pulmonary gas exchange = exchange of O2 andCO2 between the air in the lungs and the blood

Question 2

Internal respiration

Answer 2

exchange of gases between the blood and the cells of the body/systemic tissue

Question 3

Cellular respiration

Answer 3

use of oxygen by cells in the process of metabolism (occurs in mitochondria

Question 4

Mechanics of breathing

Answer 4

The process that moves air into and out of the lungs; 2 phases
Inspiration: movement of air into lungs
Expiration: movement of air out of lungs
Changes in size and shape of thorax (caused by respiratory muscles e.g. diaphragm) cause changes in air pressure within the thoracic cavity and the lungs
Air pressure differences cause air to move into and out of the lungs

When pressure within the alveoli of the lungs is lower than atmospheric pressure  inspiration
When pressure in the alveoli of the lungs is higher than atmospheric pressure  expiration

Changes in size and shape of thorax (caused by contraction & relaxation of respiratory muscles e.g. diaphragm) cause changes in air pressure within the thoracic cavity and the lungs
Air pressure differences cause air to move into and out of the lungs

Question 5

Respiration muscles

Answer 5

Diaphragm

Internal and external intercostals

Question 6

Inspiration

Answer 6

Active process/air moves into lungs
Chest cavity enlarges, lungs expand, air rushes in
Inspiratory muscles:
Diaphragm: 
contracts & flattens
↑ ‘height’ of chest cavity

External intercostals
contraction ‘lifts’ ribs
↑ ‘depth’ & ‘width’ of chest cavity

The increased size of chest cavity reduces pressure within it and the lungs, and air enters the lungs

Question 7

Expiration

Answer 7

Normal/quiet expiration (passive process)
inspiratory muscles relax chest cavity returns to its resting size & shape

Elastic recoil of lung tissues aids in expiration

Normal/quiet expiration (passive process)
inspiratory muscles relax chest cavity returns to its resting size & shape

Elastic recoil of lung tissues aids in expiration

Question 8

Tidal volume

Answer 8

Amount of air exhaled after normal inspiration

Question 9

Expiratory reserve volume

Answer 9

Amount of air that can be forcibly exhaled after a normal expiration (after expiring tidal volume)

Question 10

Inspiratory reserve volume

Answer 10

Amount of air that can be forcibly inhaled after a normal insipartion

Question 11

Residual volume

Answer 11

Air left in lungs after the most forceful expiration

Question 12

Vital capacity =

Answer 12

IRV + TV + ERV

largest amount of air that can be breathed out in one respiration/pulmonary ventilation

Question 13

Pulmonary volumes and capacities measured with

Answer 13

Spirometer

Question 14

Regulation of ventilation

Answer 14

Permits the body to adjust to varying demands for oxygen supply and carbon dioxide removal
Respiratory control centers stimulate muscles of respiratory system with nervous impulses
Located in medulla & pons (See Figure in Textbook)
Most important ones in medulla
Inspiratory center
Expiratory center
Normal rate/resting = 12 to 18/minute

Medulla’s respiratory control centres influenced by:
 Cerebral cortex (voluntary but limited)
Individual can change respiration characteristics voluntarily (singing, swimming, blowing balloon, etc.)

Receptors
Chemoreceptors (involuntary)
Located in carotid and aortic bodies (respond to changes in O2, CO2 and pH blood levels)
Pulmonary stretch receptors
Located throughout the pulmonary airways (including alveoli)
Prevent lungs from overinflating

Question 15

Eupnea

Answer 15

Normal breathing

Question 16

Hyperventilation

Answer 16

Rapid and deep respiration

Question 17

Hypoventilation

Answer 17

Slow and shallow respirations

Question 18

Apnea

Answer 18

Stopped respiration

Question 19

Respiratory arrest

Answer 19

Failure to resume breathing after a period of apnea