Handout packet 4 (Exam 1)

Steps in Gas Transport​

1. Ventilation

2. Lung diffusion

3. circulation

4. capillary exchange

5. metabolism

Conducting zone designed for ________ (no alveoli)​

Gas Flow

Respiratory zone designed for _________ (Alveoli present)​

Gas exchange

Key Adaptations: conducting zone ​

1. Large lumens for low resistance to air flow ​

2. Thick walls to prevent gas exchange​

3. Smooth muscle to regulate resistance ​

4. Branching airways aids gas distribution ​

from conducting zone to respiratory zone

1. Trachea

2. bronchi

3. bronchioles

4. terminal bronchioles

Key adaptations: Respiratory zone​

1. Alveoli (300million/lung)​

2. Dense capillary network ​

3. Provides link between pulmonary and cardiovascular systems ​

The blood gas barrier is also known as the

Respiratory membrane

Red blood cells flow _______ through the capillary network​​

single file

Capillary (~10 um) RBC's (~8 um)

Respiratory muscles (Inspiration)​

1. Diaphragm: primary muscle of inspiration(lengthens thoracic cavity ​

2. External intercostals: Accessory muscles for inspiration (elevates ribcage (widens thoracic cavity))​

Respiratory muscles (expiration)​

1. Inspiration muscles relax​

2. Internal intercostals contract (Compresses ribcage)​

3. Abdominals contract (increases abdominal pressure)​

​

which respiratory muscles are recruited primarily during exercise​

Internal intercostals and abdominals

Pressure changes pulmonary system

1. Gasses flow from high to low pressure ​

2. During inspiration Alveolar pressure < atmospheric pressure ​

3. During expiration alveolar pressure greater than atmospheric pressure ​

• Atmospheric pressure at sea level (760 mmHg) constant ​

• Alveolar pressure (758 in, 763 out)​

• Intrapleural pressure has to be lowest or lungs collapse ​

__________ pressure has to be lowest or lungs collapse

Intrapleural

Volume of air moved in and out of the lungs with a single breath

Tidal volume

Additional volume that can be used as needed

Inspiratory reserve volume and expiratory reserve volume

Ventilatory response to exercise ​

1. Tidal volume increases during exercise (tap into inspiratory/expiratory volume or both (3 ways))​

2. Inspiratory reserve volume and expiratory reserve volume decrease, so tidal volume can increase​

maximal exercise​ in relation to ventilation

1. Breakpoint in Ventilation is the ventilatory threshold ​

2. The exaggerated increase in Ventilation rids the body of CO2​

Ventilatory threshold occurs at ______ VO2 max​

65-75%