Unit 2: Respiration

Respiration Involves Four Processes

1. Pulmonary Ventilation (Breathing): Movement of air into & out of the lungs

2. External Respiration: Exchange of O₂ & CO₂ between lungs & blood

3. Transport: Of O₂ & CO₂ in blood

4. Internal Respiration: Exchange of O₂ & CO₂ between systemic blood vessels & tissues 

• Respiratory System (1-3)

• Circulatory System (4)

Major Respiratory Organs in Relation to Surrounding Structures

The Pharynx, Larynx, & Upper Trachea

Lower Respiratory System

• Consists of: Larynx, Trachea, Bronchi, & Lungs

• Broken into two zones

  • Respiratory Zone

  • Conducting Zone

Lower Respiratory System: Respiratory Zone

• Definition: Site of gas exchange

  • Consists of microscopic structures such as respiratory, bronchioles, alveolar ducts, & alveoli

Lower Respiratory System: Conducting Zone

• Definition: Conduits that transport gas to & from gas exchange sites

  • Includes all other respiratory structures

  • Cleanses, warms, & humidifies air

The Larynx (anterior view)

The Larynx (Sagittal Section)

Tissue Composition of the Tracheal Wall

Inspirations begins as…

• the diaphragm contracts

Levels of Tissue Fluid

• Po₂ 40 mm Hg

• Pco₂ 46 mm Hg

Levels of Oxygenated Blood

• Po₂ 95 mm Hg

• Pco₂ 40 mm Hg

Levels of Alveolar Air

• Po₂ 104 mm Hg

• Pco₂ 40 mm Hg

Increase O₂ Delivery to Tissues

• Bohr Effect 

• Decreased blood pH

• Increased hematocrit

Decreased O₂ Delivery to Tissues

• Left shift in the O_2- Hb dissociation curve

• Iron-deficiency anemia

• 75% saturation of Hb leaving the alveolus

• Decreased in temperature

• Decreased alveolar Po₂

• CO binding to heme

• Increased tissue Po₂

The ___ is an unpaired cartilage that covers the laryngeal opening during swallowing.

• Epiglottis

The __ is a bone that allows for skeletal muscle attachment.

• Hyoid

The __ is the largest cartilage in the larynx

• Thyroid cartilage

The __ is the only cartilage of the respiratory tract that is a complete ring

• Cricoid cartilage

The __ are 16-20 C shaped cartilage rings

• Tracheal Cartilages

What determines the direction of gas movement?

• The partial pressure differences

Partial Pressure of Gases in the Lungs Correct Statement 

• Po₂ in the lungs > Po₂ in the blood

• P_co2 in the lungs > P_co2 in the blood

Which ring-shaped cartilage forms the inferior part of the voice box?

• The cricoid cartilage