The Respiratory System

PSE4UMr. MacMillan

The Conductive Zone

Nose, pharynx, trachea, bronchi, bronchioles

The Respiratory Zone Respiratory bronchioles, alveolar ducts, alveoli

sacs.

What Makes Up the Respiratory System?

1. Supply Oxygen to the blood

2. Remove CO2 from the blood

3. Regulate blood pH

Main Functions

Is the exchange of gases at the tissue level

where Oxygen is delivered and Carbon Dioxide is removed

Internal Respiration

The processes that occur within the lung

involving the exchange of Oxygen and Carbon Dioxide

External Respiration

Diaphragm

Contracts and moves downward towards the abdominal cavity when stimulated by the brain

Ventilation The combination of inspiration (breathing in)

and expiration (breathing out) Tidal Volume

Volume of air in each breath Respiratory Frequency

The number of breaths taken per minute

Mechanisms of Breathing

Respiratory Control Centre

Found within brain stem Medulla oblongata and pons

Controlling Ventilation

Static Lung Volume

Determined by actual structure of lung Dynamic Lung Volume

Dependent, not only on volume, but on the movement or flow of air

Three important Static Lung volumes Total lung capacity, vital capacity, residual

volume TLC = VC + RV

Lung Volumes

Diffusion

The movement of gas, liquid or solid from a region of high concentration to low concentration.

Gas Exchange

2% of Oxygen found within plasma of blood

Hemoglobin Specialized protein found in erythrocytes that

binds to Oxygen

Oxygen Transport

Small amount is dissolved in the plasma (5 –

10%)

90 – 95% of CO2 diffuses into erythrocytes, passed to alveoli and is exhaled

Carbon Dioxide Transport

Blood pH is a measure of how acidic and basic

blood is Blood pH is close to 7.4 – neutral is 7

More acidic during exercise – lactic acid (decreased pH)

Ventilation increase pH back to normal

Ventilation and pH