Exam 4 (#21) - Respiration

What are the 4 processes of respiration?

1. Pulmonary ventilation

2. External respiration

3. Transport of respiratory gases

4. Internal respiration

Explain the 4 processes of respiration:

Pulmonary ventilation - air in and out of lungs

External respiration - breathing out

Transport of respiratory gases - CO2 and O2 through the blood

Internal respiration - breathing in

What is pulmonary ventilation?

Air in and out of lungs (bulk air flow)

What is transport of respiratory gases?

CO2 and O2 through the blood

What makes up the upper respiratory system?

• Nose - Filters, humidifies

• Pharynx - Connects nose/mouth to larynx

What makes up the lower respiratory system?

• Larynx - Contains epiglottis and vocal cords

• Trachea - Contain cilia → Move in one direction

• Bronchi/bronchioles

• Lungs

• Diaphragm

How many lungs are there? How many lobes does each lung have?

Two lungs: left lung and right lung

• Left: 2 lobes

• Right: 3 lobes

What is the anatomy of the bronchioles?

• First order bronchioles

• Second order bronchioles

• Third order bronchioles (10 on each side)

• Terminal bronchioles (21-23rd order)

(The first-third is the conducting zone)

Can bronchioles change diameter? Why or why not?

Yes. This is so they can regulate airflow to different parts of the lungs

What do you expect to find in bronchioles?

Smooth muscles

What is the pathway of air into the lungs?

Conducting zone (bulk air flow, contain smooth muscle, dilate or constrict):

Trachea → first order bronchioles → second order bronchioles → third order bronchioles

Respiratory zone (external respiration):

Terminal bronchioles (contain alveoli) → alveoli

Explain the conducting zone and the respiratory zone:

Conducting zone:

• Bulk air flow

• Contain smooth muscle

• Dilate or constrict

Respiratory zone:

• External respiration

Explain the anatomy of the lungs:

• Tip/top: Apex

• Bottom: Base

Can see the indent of ribs (reflects the function)

What surrounds the lungs?

(CT) Pleurae

Explain pleurae surrounding the lungs:

Parietal pleura lines the lungs + visceral pleura is the layer under the parietal pleura.

The space in between ^ is called the pleural cavity (which contains serous fluid)

Do the lungs share the same pleura? Why or why not?

No. They each have one so if the pleura is compromised on only one lung it will not spread to the other lung

How does air enter the lungs?

Pressure gradients - air will move from a high-pressure area to a low-pressure area

Why is air flow - bulk flow?

Because air moves as a single connected unit, not random molecules moving randomly based on individual gradients

What is happening during air flow?

1. Inspiration and expiration due to muscle movements (diaphragm mainly)

2. Creates pressure differentials

3. Air moves → lung volume changes

Flow = ∆P / Resistance

What is the formula for air flow?

Flow = ∆P / Resistance

What are the different pressures involved in air entering the lungs?

1. Atmospheric pressure - pressure of air outside of your body)

2. Intrapulmonary pressure - pressure of air inside your lungs (this changes with muscle contraction + relaxation)

3. Respiratory pressure - can be 1) exhale: air going out of lungs. 2) inhale: air going into lungs

Respiratory pressure = intrapulmonary pressure - atmospheric pressure

What is the formula for respiratory pressure>

intrapulmonary pressure - atmospheric pressure = respiratory pressure