3.2.1 Intro and Anatomy Flashcards
Functions of the respiratory tract
Maintain proper concs of O2, CO2, H ions in tissues
Non-respiratory functions of lungs
- Immune function and defense against infection
Non-respiratory functions of lungs
- Immune function and defense against infection (musculaocillary escalator, LNs, IgA secretion, alveolar macrophages and neutrophils)
- CV/ Volume regulation
(RAAS, hormones, clotting)
Descibe transitition from trachea to alveolar sacs
Trachea
Bronchi
Bronchioles
(terminal bronchioles)
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
What is anatomic dead space?
Region of airway where there is gas but no gas exchange (ventilated but not perfused)
Describe histology of bronchus
Lined by mucous membrane
Cilliate columnar epithelium
Goblet cells (secretory)
Irregular bronchi cartilage
Bronchial glands between cartilage and smooth muscle
LNs, lymphocytes and plasma cells in CT layer
Peribronchial sheath
Describe histology of bronchioles
Cuboidal epithelium
No mucous-secreting cells
Clara cells
Few cilliated cells
No cartilage
Spiral bronchial muscle
No vascular sheath
Describe histology of alveolar duct
Surrounded by alveoli
Openings guarded by rings of SM
Contraction = gas redistribution
Calibre much greater than resp. bronchiole
Describe histology of alveolar sac
Rotunda-like area at end of alveolar duct
Alveoli around walls
What is an alveolus and what is its function?
A small cavity, pit or hollow
Facilitate gas exchange, increase SA
What are Pores of Kohn?
interconnect neighbouring alveolus
What is Ficks Law?
Rate of gas transfer through a sheet of tissue is
- proportional to tissue area and difference in partial pressure between sides
- inversely proportional to tissue thickness
What is Ficks Law equation?
Vgas = A/T x D x (P1-P2)
