CASE 4 Flashcards
Respiration
- pulmonary ventilation
- external respiration
- transport of respiratory gases
- internal respiration
pulmonary ventilation
air moves in and out the lungs, gases are constantly changed and refreshed
external respiration
oxygen diffuses from lungs to blood and CO2 is moved from tissue
transport of respiratory gases
oxygen is moved towards tissue. CO2 is moved from tissue
internal respiration
oxygen diffuses from blood to tissue cells, CO2 diffuses from tissue cells to blood
Tracheal wall
- consists of mucosa, submucosa, adventitia, hyaline cartilage
mucosa
- pseudostratified epithelium (most of respiratory system)
- cilia propel debris mucus toward the pharynx
submucosa
- connective tissue layer in the mucosa
- contains seromucous glands that help produce mucus sheets
- 16-20 c shaped rings of cartilage
adventitia
- outermost layer of connective tissue
Right and left main (primary) bronchi
- divided from trachea
- right bronchus is wider, shorter, more vertical than left, inhaled foreign object gets stuck there
lobar (secondary) bronchi
- subdivided from each bronchus
- right has three
- left has two
- each supplying one lung lobe
segmental (tertiary) bronchi
- branched of lobar bronchi
- divide repeatedly into smaller and smaller bronchi, bronchioles
order of division of bronchi
- trachea
- right and left main bronchi
- lobar bronchi
- segmental bronchi
- bronchioles
As conducting tubes become smaller these changes occur
- support structures change
- epithelium type changes
- amount of smooth muscle increases
support structures change
- irregular plates of cartilage replace the cartilage rings
- bronchioles dont have cartilage
epithelium type changes
- mucosal epithelium thins from pseudostratified columnar –> columnar –> cuboidal (terminal bronchioles)
amount of smooth muscle increases
- more smooth muscle and lack of cartilage allows the bronchioles to provide resistance to air passage under certain conditions
respiratory zone begins
terminal bronchioles feed into respiratory bronchioles –> winding alveolar ducts –> terminal clusters of alveoli called alveolar sacs
walls of alveoli
- primarily of single layer of squamous epithelial cells
type 1 alveolar cells
- surrounded by thin basement membrane (gas exchange)
- scattered across type 1 alveolar cells are cuboidal type 2 alveolar cells.
type 2 alveolar cells
- secrete surfactant, coats the gas exposed alveolar surfaces
- secrete antimicrobial proteins which are important for natural immunity
respiratory membrane
capillary and alveolar walls and their fused basement
alveoli have 3 features:
- they are surrounded by elastic fibers of the same type that surrounds the entire bronchial tree
- open alveolar pores connecting adjacent alveoli allow air pressure throughout the lung to be equalized and provide alternate air routes to any alveoli whose bronchi have collapsed due to disease
- alveolar macrophages crawl freely along internal alveolar surface. Immune function
lung root
pleurae (pair of serous membranes) connected to the mediastinum by vascular and bronchial attachments