Chapter 16 Flashcards
Internal respiration
Oxidative phosphorylation
External respiration
Pulmonary ventilation
* Exchange between lungs and blood
* Transportation in blood
* Exchange between blood and body tissues
Air passages of the head and neck
- Nasal cavities
- Oral cavity
- Pharynx
Label figure 16.2
What figures are apart of the conducting zone?
Larynx
* Glottis
* Epiglottis
* Trachea
* Bronchi
Bronchioles
Secondary bronchi
- Three on right side to three lobes of right lung
- Two on left side to two lobes of left lung
Tertiary bronchi
20-23 orders of branching
Bronchioles
less than 1mm in diameter
Terminal Bronchioles
Functions of the conducting zone
- Air passageway: 150 mL in volume (dead space)
- Increases air temperature to body temperature
- Humidifies air
Epithelium of the conducting zone
- Goblet cells (secrete mucus)
- Ciliated cells (move particles toward mouth)
- Mucus escalator
Function of the respiratory zone
- Exchange of gases between air and blood
- Mechanism of action: diffusion
Structures of the respiratory zone
- Respiratory bronchioles
- Alveolar ducts
- Alveoli
- Alveolar sacs
Epithelium of the respiratory zone
- Epithelial cell layer of alveoli
- Endothelial cell layer of capillaries
Alveoli
Site of gas exchange
Rich blood supply: capillaries form sheet over alveoli
Alveolar pores
type 1 and type 2
Type I alveolar cells
make up wall of alveoli
* Single layer of epithelial cells
Type II alveolar cells
secrete surfactant
Respiratory membrane
- Barrier for diffusion
- Type I cells + basement membrane
- Capillary endothelial cells + basement membrane
Chest wall
airtight, protects lungs
What composes the chest wall
- Rib cage
- Sternum
- Thoracic vertebrae
- Muscles: internal and external intercostals, diaphragm
Pleura
membrane lining of lungs and chest wall
What surrounds each lung?
pleura
Intrapleural space is filled with?
intrapleural fluid (15ml)
Label figure 16.7
Air moves in and out of lungs by
bulk flow
Air moves from
high to low pressure
Inspiration
pressure in lungs less than atmospheric
pressure
Expiration
pressure in lungs greater than atmospheric
pressure
Atmospheric pressure
- 760 mm Hg at sea level
- Decreases as altitude increases
- Increases under water
Intra-alveolar pressure
- Pressure of air in alveoli
- Given relative to atmospheric pressure
- Varies with phase of respiration
During inspiration what is intra-alveolar pressure?
negative (less than atmospheric)
During expiration what is intra-alveolar pressure?
positive (more than atmospheric)
Difference between Palv and Patm drives?
ventilation
Intrapleural pressure
Pressure inside pleural sac
* Always negative under normal conditions
* Always less than Palv
Intrapleural pressure varies with?
respiration
at rest, -4 mm Hg
Why is intraplearal pressure negative?
Negative due to elasticity in lungs and chest wall
* Lungs recoil inward as chest wall recoils outward
* Opposing forces pull on intrapleural space
* Surface tension of intrapleural fluid prevents wall and lungs from
pulling apart
Transpulmonary pressure
= Palv – Pip
* Distending pressure across the lung wall