The Respiratory System Flashcards
Respiration
Involves both respiratory and circulatory systems
4 processes that supply the body with O2 and dispose of CO2
Pulmonary ventilation (breathing)
External respiration
Transport
Internal respiration
Pulmonary ventilation (breathing)
movement of air into and out of the lungs
External respiration
O2 and CO2 exchange between the lungs and the blood
Transport
O2 and CO2 in the blood
Internal respiration
O2 and CO2 exchange between systemic blood vessels and tissues
Major organs?
Nose, nasal cavity, and paranasal sinuses
Pharynx
Larynx
Trachea
Bronchi and their branches
Lungs and alveoli
Respiratory zone:
site of gas exchange
Microscopic structures
respiratory bronchioles, alveolar ducts, and alveoli
Conducting zone
conduits to gas exchange sites
includes all other respiratory structures
Respiratory muscles
diaphragm and other muscles that promote ventilation
MALT
Mucosa-associated lymphatic tissue
Protects the digestive and respiratory systems from foreign matter
MALT (digestive tract)
Peyer’s patches, tonsils, and the appendix
MALT (respiratory tract)
Lymphoid nodules in the walls of the bronchi
From bronchi through bronchioles, structural
changes occur
- Cartilage rings give way to plates; cartilage is absent from bronchioles
- Epithelium changes from pseudostratified columnar to cuboidal; cilia and goblet cells become sparse
- Relative amount of smooth muscle increases
Clusters of alveoli
Respiratory bronchioles, alveolar ducts, alveolar sacs
Respiratory Membrane
Alveolar and capillary walls and their fused basement membranes
Alveolar walls
Single layer of squamous epithelium surrounded by fine elastic fibers
Hold alveolar macrophages that keep alveolar surfaces sterile
Scattered cuboidal cells secrete
surfactant and antimicrobial proteins
Intrapulmonary pressure
Pressure inside lung decreases as lung volume increases during inspiration; pressure increases during expiration
Intrapleural pressure
Pleural cavity pressure becomes more negative as chest wall expands during inspiration.
Returns to initial value as chest wall recoils
Volume of breath
During each breath, the pressure gradients move
0.5 liter of air into and out of the lungs.
Pontine respiratory centers
interact with the medullary respiratory centers to smooth the respiratory pattern
Ventral respiratory group (VRG)
contains rhythm generators whose output drives respiration.