Respiratory system

Question 1

What does the respiratory system consist of?

Answer 1

• Lungs
• Bronchi
• Larynx
• Pharynx
• trachea
• Nose

Question 2

Describe what the trachea branches into…

Answer 2

1. Branches into bronchi (primary, secondary, and tertiary)
2. Then into terminal and respiratory bronchioles
3. Then alveolar ducts
4. Lastly to alveoli

Question 3

What happens with branching?

Answer 3

With branching, supportive cartilage is gradually replaced by smooth muscle

Question 4

What function does smooth muscle serve? And what are the effects?

Answer 4

Contraction and relaxation of the smooth muscle constricts or dilates the bronchioles which effects airway resistance

Question 5

What are the results of airway dilation during exercise?

Answer 5

dilation –> think getting bigger —> when you give birth

1. Reduces airway resistance making the flow of air easier

Question 6

What are the results of airways that are overly constricted during an asthma attack?

Answer 6

Makes breathing difficult

Question 7

What are conducting airways?

Answer 7

Conducting airways leads inspired air to the alveoli, but is not involved in gas exchange

Question 8

What is the average volume of anatomic dead space ?

Answer 8

150 ml

Question 9

Why is conducting airways called atomic dead space?

Answer 9

Because they are not involved in the exchange of gases

Question 10

What does VD stand for

Answer 10

anatomic dead space

Question 11

Alveoli:

Answer 11

1. small, thin-walled sacs that have capillary beds in their walls
2. site of gas molecule exchange (O2 and CO2) between air and blood
3. There are millions of alveoli

Question 12

Respiratory membrane:

Answer 12

1. Separates the air molecules in the alveoli from the blood in the capillaries

O2 entering the bloodstream and CO2 leaving

2. Average thickness of 0.6 micrometers, very thin optimized for diffusion, very large surface area (70 square meters…size of a tennis court)

Question 13

What do lungs contain?

Answer 13

1. conducting airways
2. alveoli
3. blood vessels
4. elastic tissue

Question 14

Mechanisms for breathing:

Answer 14

1. Pulmonary ventilation is the movement of air into and out of the lung
   - this results from a pressure difference between the pulmonary air and atmosphere
   - molecules move from an area of high pressure to areas of low pressure

Question 15

Boyles law

Answer 15

The pressure of a gas is inversely propotional to its volume

Question 16

Compliance

Answer 16

The amount of volume change for a given change in alveolar pressure

Question 17

Describe the process of inspiration

Answer 17

1. diaphragm descends and intercostal muscles contract which increases the volume of the thoracic cavity.
2. The decreased pressure in the thoracic cavity causes 1-2 mm Hg drop in intra-alveolar pressure at rest compared to the outside atmospheric pressure
3. air molecules move through the respiratory tubes into the lungs from the atmosphere following the pressure gradient

Question 18

What happens when inspiratory muscles work their hardest?

Answer 18

they can produce a negative pressure up to -30 mm Hg below atmospheric pressure within the alveoli

Question 19

Describe the process of expiration (passive process)

Answer 19

1. Diaphragm and intercostal muscles rest thus decreasing the volume of the thoracic cavity
2. Therefore, the pressure of the thoracic caivity increases above atmospheric pressure
3. air molecules move out of lung following pressure gradient

Question 20

Expiration (active process during exercise)

Answer 20

1. Secondary muscles such as abdominal muscles and intercostal muscles become involved in exercise
2. Forced expiration can produce intra-alveolar pressure as great as +50 mm Hg above atmospheric pressure

Question 21

What happens during exercise

Answer 21

Nose breathing tends to turn into mouth breathing which results in less resistance to airflow

Question 22

Vital capacity (VC)

Answer 22

the greatest volume of gas that can be expelled by voluntary effort after maximal inspiration

Question 23

Inspiratory capacity (IC)

Answer 23

the maximal volume of gas that can be inspired from the resting end-expiratory position

(approx 75% of vital capacity at rest)

Question 24

Expiratory reserve volume (ERV)

Answer 24

the maximal volume that can be exhaled from the resting end-expiratory position

(approx 25% of vital capacity at rest)

Question 25

What gives the sum of vital capacity

Answer 25

inspiratory capacity + expiratory reserve volume

Question 26

Functional residual capacity (FRC)

Answer 26

the volume of gas remaining in the lungs at the end of a quiet expiration

Question 27

What is the sum of the functional residual capacity

Answer 27

expiratory reserve volume + residual volume

Question 28

Residual volume

Answer 28

the volume of gas remaining in the lungs after forced expiration

Question 29

Total lung capacity

Answer 29

the volume of gas in the lungs at the time of maximal inspiration inspiratory capacity + expiratory reserve volume + residual volume

Question 30

Tidal volume (Vt)

Answer 30

the volume of gas inspired or expired with each breath at rest or during any stated activity

Question 31

What is the breathing frequency? (Fr)

Answer 31

12-16 breaths per minute - during maximal aerobic exercise breathing frequency can increase up to 60 breaths per minute and tidal volume can increase up to 50% of vital capacity

Question 32

Minute ventilation (Ve)

Answer 32

the volume of gas that's either inspired or expired (but not both) per minute Tidal volume x number of breaths

Question 33

Forced vital capacity (FVC)

Answer 33

when the subject is instructed the expire as fast and hard as possible for 4 seconds

Question 34

Forced expiration volume in one second (FEV1)

Answer 34

the volume of air expired during the first 1 second of a forced vital capacity manoeuvre

Question 35

Alveolar ventilation

Answer 35

- the volume of air that reaches the alveoli per minute - this is the only air that participates in gas exchange with the blood Va: Fr x (Tidal volume - anatomical dead space)

Question 36

Most volume capacities _________ when a person lies down and _________ when standing. EXPLAIN WHY!!!

Answer 36

decrease, increase 1. abdominal contents push up against diaphragm 2. There is an increase in the intrapulmonay blood volume in the horizontal position which decreases the space available for pulmonary air

Question 37

Pulmonary function test norms are based on....

Answer 37

sex, age, and height

Question 38

Problems with pulmonary function norms

Answer 38

1. don't consider the size of the subject, particularly chest size 2. better to use sitting height than standing height

Question 39

Ventilation during incremental exercise

Answer 39

Minute ventilation increases linearly with increased exercise intensity and oxygen uptake until about 50-60% VO2 max in untrained subjects and about 75-80% of VO2 max in endurance athletes

Question 40

Ventilation threshold

Answer 40

the point which minute ventilation increases dispraportionally with oxygen consumption during graded exercise

Question 41

Name the two chronic respiratory dysfunctions

Answer 41

1. obstructive disorders 2. restrictive disorders

Question 42

Obstructive disorders

Answer 42

blockage or narrowing of the airway causing increased airway resistance (asthma, bronchitis, emphysema) - bronchiolar obstruction can result from inflammation and edema, smooth muscle constriction, and bronchiolar secretion - more difficult to move air in and out which decreases FEV1 - FEV1/VC decreases much less than 80% and decreased MBC

Question 43

Restrictive disorder

Answer 43

- damage to the lung tissue - loss of elasticity and compliance limiting the expansion of the lung - all lung volumes are reduced (VC, RV, FRC, TLC because lung tissue is stiff and can't be expanded - FEV1 and MBC decrease - FEV1/VC ratio is 90% or greater

Question 44

maximum breating capacity

Answer 44

maximum volume of air that can be breathed during maximum effort

Question 45

Diffusing capacity can be affected by

Answer 45

- thickness of the respiratory membrane - the number of red blood cells or hemoglobin - the SA of the respiratory membrane available for diffusion (diffusion capacity is decreased for emphysema)