Structure of the respiratory system, Lung volumes and capacities Flashcards
What are the conducting airways of the respiratory system?
- trachea
- bronchi
- bronchioles
- terminal bronchioles
What are the functions of the conducting system of the lungs?
- Bring air in/out
- Warm air
- Humidify air
- filter air
What do the walls of all conducting airways contain?
SMooth muscle
What impact do sympathetic adrenergic neurons have on the conducting system?
They stimulate relaxation and dilation of the airways via B2 receptors
What do parasympathetic cholinergic neurons do to the conducting system?
activate muscarinic receptors which leads to contraction and constriction of airways
What are the components of the respiratory zone of the lungs?
- Respiratory bronchioles
- Alveolar Ducts
- Alveolar Sacs
- Alveoli
The respiratory bronchioles are transitional structures. In what way are they like the conducting zone? In what way are they like the respiratory zone?
They are like the conducting system because they have cilia and smooth muscle.
They are like the respiratory zone because they occasionally have alveoli branching off their walls and participate in gas exchange.
Describe alveolar ducts. What do they terminate into?
They are completely lined with alveoli, have NO cilia and little smooth muscle.
They terminate into alveolar sacs.
Alveolar Sacs are lined with?
Alveoli
Alveolar walls are rimmed with elastic fibers and lined with epithelial cells. What types of epithelial cells will we find here?
Type I and Type II pneumocytes
What is important about Type II pneumocytes?
- They synthesize surfactant
- have regenerative capacity for type I AND II pneumocytes
Where do we find Dust cells?
What do they do?
Dust cells, AKA alveolar macrophages are found in the alveoli.
They keep alveoli free of dust/debris since alveoli have no cilia to perform this function.
Pulmonary arteries travel with? They divide into?
The bronchi.
Divide into increasingly smaller arteries until the pulmonary capillaries.
What impact does gravity have on blood flow in the lungs?
It prevents even distribution of blood in the lungs, when standing the apex of the lung will recieve less blood than the base. Laying supine, we see the effects of gravity dissapear.
How is regulation of pulmonary blood flow accomplished?
Through alteration of the resistance of the pulmonary arterioles