Chapter 36

Question 1

What is respiration?

Answer 1

• gas exchange

- 3 steps

Question 2

What are the three different steps of respiration?

Answer 2

• pulmonary ventilation
• external respiration
• internal respiration

Question 3

What is pulmonary ventilation?

Answer 3

-bringing air in from the outside to the alveoli

Question 4

What is external respiration?

Answer 4

-exchange of gas in alveoli and blood in pulmonary capillary

Question 5

What is internal respiration?

Answer 5

-exchange of gases in blood between systemic capillaries and tissue cells

Question 6

What is inspiration?

Answer 6

-moving air into the lungs

Question 7

What is expiration?

Answer 7

-moving air out of the lungs

Question 8

What is the primary principle of ventilation?

Answer 8

-air will travel from high to low pressure

Question 9

Explain the pressure gradient during inspiration.

Answer 9

-pressure outside is greater than the pressure inside

Question 10

Explain the pressure gradient during expiration.

Answer 10

-pressure outside is less than the pressure inside

Question 11

How is pressure manipulated?

Answer 11

-changing the size of the thoracic cavity by moving the diaphragm

Question 12

What structure controls the pressure change?

Answer 12

-diaphragm

Question 13

What is Boyle’s Law?

Answer 13

-the volume of a gas has an inverse relationship with pressure

Question 14

What is the position of the diaphragm during inhalation?

Answer 14

-low in the thoracic cavity

Question 15

Is the diaphragm contracted or relaxed during inhalation? Does it increase or decrease pressure?

Answer 15

• contracted

- decrease pressure

Question 16

Is the diaphragm contracted or relaxed during expiration? Does it increase or decrease pressure?

Answer 16

• relaxed

- increase pressure

Question 17

What is the position of the diaphragm during exhalation?

Answer 17

-high near the 5th intercostal

Question 18

What is occurring normal inspiration?

Answer 18

-the diaphragm only descends 1/2 inch

Question 19

What muscles are involved with strenuous inspiration and what do they do?

Answer 19

• external intercostals: raises the ribs and increases the volume
• sternocleidomastoid: raises the sternum and increases the volume
• scalene muscles: raises 1-2 ribs and increases the volume
• pectoralis minor: raises 3-5 ribs and increases the volume

Question 20

What is occurring during normal expiration?

Answer 20

-when diaphragm is relaxing back to its normal state

Question 21

Why is expiration a passive process?

Answer 21

-because it is only relaxing

Question 22

What muscles are involved during forceful expiration and what do they do?

Answer 22

• internal intercostals
• abdominal muscles
• pull the ribs back down

Question 23

What is significant about the shape of ribs?

Answer 23

-the are curved and down so when the muscles pull them up, it creases an extra pocket of space which creates an increase in volume and decrease in pressure

Question 24

What other factors contribute to ventilation?

Answer 24

• surface tension of alveolar fluid
• compliance of the lungs
• airway resistance

Question 25

What is surface tension?

Answer 25

• when the walls of the alveoli are attracted to each other because of alveolar fluid
• surfactant combats this
• a little surface tension allows for expiration

Question 26

What is surfactant?

Answer 26

-the fluid secreted by type II cells to keep alveoli from sticking together

Question 27

What is compliance and what influences it?

Answer 27

• effort needed to stretch the lungs
• high compliance: chest wall expands easily
• low compliance: resists expansion
• elasticity and surface tension

Question 28

What is airway resistance and what controls it?

Answer 28

• narrowing or obstruction of airways will increase resistance
• controlled by sympathetic nervous system on smooth muscle surrounding bronchioles

Question 29

How does airway resistance relate to asthma?

Answer 29

• when the bronchiole airways constrict

- use an inhaler to stimulate the sympathetic nervous system (norepinephrine)

Question 30

What is tidal volume and how do you calculate it?

Answer 30

-normal inhalation and exhalation

-

Question 31

What is expiratory reserve volume and how do you calculate it?

Answer 31

-how much more air you can exhale

Question 32

What is inspiratory reserve volume and how do you calculate it?

Answer 32

-how much more you can inhale in the lungs

Question 33

What is residual/reserve volume and how do you calculate it?

Answer 33

• the amount of air that always stays in the lungs

- cannot exhale

Question 34

What is vital capacity and how do you calculate it?

Answer 34

-largest amount of air an individual can move in and out of lungs

Question 35

What is inspiratory capacity and how do you calculate it?

Answer 35

-the maximal amount of air an individual can inspire after normal expiration

Question 36

What is functional residual capacity and how do you calculate it?

Answer 36

-the amount of air left in the lungs at the end of normal expiration

Question 37

What is minute ventilation and how do you calculate it?

Answer 37

• volume of air being ventilated per minute

- breaths per min x 500 mL

Question 38

What is alveolar perfusion?

Answer 38

-blood flow to the alveoli

Question 39

What is the purpose of ventilation?

Answer 39

• to maintain blood gases

- oxygen and carbon dioxide

Question 40

What are the three respiratory control centers? Where are they found? What does each respiratory control center manage?

Answer 40

• medullary rhythmicity area: in the medulla, controls respiratory rhythm
• apneustic center: in the pons, controls length and depth of inspiration
• pontine respiratory group: in the pneumotaxic center of the pons; helps inhibit inspiration from filling lungs too full; also helps control other two areas

Question 41

What is the role of the cerebrum in ventilation?

Answer 41

• voluntary breathing

- when you think of it