Respiration PHYISIOLOGY Flashcards
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Functional events in respiration
Ventilation
Pulmonary gas exchange
Gas transport
Utilization of oxygen by cells
What are the secondary functions of the respiratory system?
Regulate body pH(controlling carbon dioxide levels)
Storage(lungs have 12 percent of blood)
Defense (macrophages in alveolar cells, mucocilliary escalator trapping dust and things, and immunoglobulin/antibodies produced by lungs into bronchial mucus
Metabolic activation and inactivation of biological substances
Which substances are inactivated by pulmonary circulation as a metabolic function of the respiratory system
Bradykinin, serotonin, some prostaglandins(E1, E2…), norepinephrine.
Note that only a small fraction of epinephrine is inactivated
Which substances are not significantly affected
Vasopressin
Angiotensin II
Other prostaglandins A1 and A2
Which substances are activated
Angiotestin Converting Enzyme
Which converts Angiotensin I to Angiotensin II. It is a powerful vasoconstrictor
Synthesis if biological substances is a function of the respiratory system. What are examples of some of the substances synthesized
Phospholipid(dipalmitoyl phosphatidyl choline) component of surfactant)
Arachidonic acid metabolites(leukotrine and prostaglandins)
Embryonic stage?
4-7 weeks after fertilization
Lung bud differentiation
Formation of trachea and bronchi
Pulmonary vein and artery
Pseudoglandular stage?
7 to 17 weeks Conducting airways form Terminal bronchioles Immature neural networks form Pre acinar blood vessels Lung has glandular appearance
Canalicular
17 to 26
Lungs develop to respiratory bronchioles
Cartilage, muscles and blood vessels form
Sacfular
27 to 36 weeks
Alveolar saccules form
Extra cellular matrix forms
Neural network formation
Alveolar
36 to 2 years
Expansion of gas exchange area, nerves and capillaries.
Development of alveoli
After this, alveolar cells continue to increase in number and lung growth and expansion occur till about 18 years apparently
Side note
At birth, each terminal bronchioles opens into a single alveoulus instead of a whole fully developed alveolar clustering
Disadvantages of nasal breathing?
Increased resistance to air flow and more likely to be obstructed (by polyps, adenoids of congestion of the nasal mucosa)
Mention the components of the conducting zone and the respiratory zone
Trachea
Bronchi
Bronchioles
Terminal bronchioles
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
Application of the composition of the walls of the airways
The large airways, trachea and bronchi are kept open by cartilage.
The small airways, bronchioles and alveolar ducts rely in transpulmonary pressure to keep them open
Same mechanism keeps alveolar open
Bronchilar diameter is under autonomic control
Why is the left bronchus more obliquely slanted?
Because it has to extend laterally behind the arch of aorta to reach its lung hilum
What are bronchiopulmonary segments
Functional unit of the respiratory system
Largest sub division of a lobe
19 bronchiopulmonary segments. 10 on right, and 9 on left. List for right
Right upper lobe
Apical
Posterior
Anterior
Middle lobe
Lateral
Media
Lower lobe Lateral basal Medial basal Anterior basal Posterior basal Apical
List for left
Upper lobe
Apical
Posterior
Anterior
Middle lobe(lingula)
Superior
Inferior
Lower lobe Lateral basal Posterior basal Anterior basal Apical
Note
LOOK AT SLIDE 32!
Notes about type 1 alveolar cells(pneumocytes)
Thin
Simple squamous epithelial cells
Large surface area. 90 to 95 percent of alveolar surface
Cannot replicate. When undamaged, type 11 cells may proliferate and differentiate into type 1 cells
Presence of occluding junctions which prevent the leakage of tissue fluid into alveolar air space
What are pores of Kohn
They are pores between alveoli which facilitate collateral ventilation in case of bronchial obstructions
Vibrissae hairs?
Filter particulate matter. Found in the nose
PH of blood?
Partial pressure of carbon dioxide
Partial pressure of oxygen
7.35 4o 7.45
35 - 45 mm Hg
80 - 100 mm Hg
