Human Physiology and Pathology-Respiration
- Created by: jessica
- Created on: 06-02-13 14:20
View mindmap
- Respiration
- Lung structure and function
- Large surface area for gas exchange
- Have a role in acid base balnce
- Water and CO2 combine to form carbonic acid
- Involved in speech and breath control
- Respiratory system
- Nasal passage, oral cavity, pharynx, larynx, trachea and lungs
- Trachea goes into bronchi, goes into bronchioles to alveoli
- Alveolar sacs make up 50-100m2 surface area.
- Alveoli contain type 1 and type 2 epithelial cells
- Alveolar sacs make up 50-100m2 surface area.
- Made of conducting and respiratory zone
- Respiratory zone
- terminal bronchioles to alveoli
- Alveolar ventilation
- Va=(Vt x RR)- (DSV-RR)
- the measure of fresh air volume reaching the alveoli per minute
- Alveolar ventilation
- terminal bronchioles to alveoli
- Conducting zone
- Larynx to terminal bronicholes
- considered dead space as it doesnt involve gas exchange
- Respiratory zone
- Diaphragm contracts for inspiration
- Nasal turbinates circulate, humidify air
- Mucociliary escalator
- cilia beat mucus up and out of the lungs/respiratory tract taking dust and bacteria with it
- Lung ventilation
- Pressures
- Partial pressure of oxygen during inspiration is 149mmHg
- Gases have different partial pressures
- Pressure of the air at sea level is 760mmHg
- SVP=Saturated vapour pressure (when water is present in the gases)
- Intrapleural pressure
- -5cmH2O at end expiration when there is no gas flow
- Transpulmonary pressure
- The force acting on the lungs to expand
- Larger in small alveoli when the adjacent one has the same surface tension
- Pulmonary surfactant released in small avleoli to prevent the collapse of the alveoli
- Flow=Pressure difference/R
- Pressure difference= atmospheric pressure-alveolar pressure
- Muscles of respiration
- Sternocleidomastoid, Scalene muscles, external intercostal muscles and diaphragm used for inspiration
- Internal intercostal muscles, external oblique, internal oblique and rectus abdomens used for active respiration
- Lung compliance
- stretchiness of the lungs
- Compliance= change in lung volume/ transpulmonary pressure
- Large lung compliance better
- Pressures
- Gas transport in the blood and control of respiration
- Henry's Law-gas in solution is proportional to partial pressure of gas and solubility of gases.
- Lungs have two circulations-pulmonary and bronchiole
- Fick's Law
- Vgas=A.P.(P1-P2)/T
- Erythrocytes
- Hb molecule has 4 subunits. Haem groups contains Fe for binding to O2.
- Respiration controlled by pons, medulla,
- Peripheral and central chemoreceptors detect changes in PO2 and PCO2, interacting with the brain to inspire/expire
- Respiratory diseases
- Respiratory failure when PO2 is less than 60mmHg at sea level
- Obstructive diseases
- increased resistance to airflow
- Lung function tests
- Restrictive diseases
- Expansion of lungs restricted
- Lung structure and function
Comments
No comments have yet been made