Compliance Flashcards
Alveoli
Alveolar walls consist of
type I alveolar (………. pulmonary epithelial) cells, simple squamous cells where gas exchange occurs
type …. alveolar (……..) cells, free surface has microvilli and secrete ………… fluid containing surfactant. Surfactant ………. the surface tension of alveolar fluid, preventing the collapse of alveoli with each ………….. It is a complex mixture of phosp…….. and lipopr………..
alveolar macrophages (dust cells), wandering macrophages remove d..
……..
Gas exchange occurs across the alveolar-…….. membrane
Alveoli
Alveolar walls consist of type I alveolar (squamous pulmonary epithelial) cells, simple squamous cells where gas exchange occurs type II alveolar (septal) cells, free surface has microvilli and secrete alveolar fluid containing surfactant. Surfactant lowers the surface tension of alveolar fluid, preventing the collapse of alveoli with each expiration. It is a complex mixture of phospholipids and lipoproteins alveolar macrophages (dust cells), wandering macrophages remove debris
Gas exchange occurs across the alveolar-capillary membrane
The Alveolus The lungs contain approximately ……….. million alveoli
The Alveolus The lungs contain approximately 300 million alveoli
Alveolar-Capillary Membrane
Alveolar-Capillary Membrane
Respiratory membrane = ½ micron thick
Exchange of gas from alveoli to blood
4 Layers of membrane to cross
- alveolar epithelial wall of type I cells
- alv…….. epit………
- b. m.
- capi………. b……… membrane
- en……….. cells of cap……….
Large surface area = 70 m2
Respiratory membrane = ½ micron thick
Exchange of gas from alveoli to blood
4 Layers of membrane to cross
- alveolar epithelial wall of type I cells
- alveolar epithelial
- basement membrane
- capillary basement membrane
- endothelial cells of capillary
Large surface area = 70 m2
The Respiratory Membrane
Note that there is very little in……….. fluid (space) because blood pressure is very low and there is little ……… flow out of the capillaries
Look-up Bulk Flow with respect to the cardiovascular lectures
This has the effect of reducing the distance for gaseous diff……… in the lungs, thereby increasing the effic…….. of gas exchange (in both directions)
The Respiratory Membrane
Note that there is very little interstitial fluid (space) because blood pressure is very low and there is little bulk flow out of the capillaries
Look-up Bulk Flow with respect to the cardiovascular lectures
This has the effect of reducing the distance for gaseous diffusion in the lungs, thereby increasing the efficiency of gas exchange (in both directions)
Alv…….. Sur………. Ten………Thin layer of fluid in alveoli causes inwardly directed force = surface tension
water molecules strongly attracted to each other
Causes alveoli to remain as small as possible
Detergent-like substance called surfactant produced by Type …. alve……… cells….
lowers alve………. surface ten………
insufficient in premature babies so that alveoli collapse at end of each exha………..
Alveolar Surface TensionThin layer of fluid in alveoli causes inwardly directed force = surface tension
water molecules strongly attracted to each other
Causes alveoli to remain as small as possible
Detergent-like substance called surfactant produced by Type II alveolar cells
lowers alveolar surface tension
insufficient in premature babies so that alveoli collapse at end of each exhalation
Compliance of the Lungs
Ease with which lungs & chest wall expand depends upon elasticity of lungs & surface tension
Some diseases reduce compliance
- tuber………… forms scar tissue
- pulmonary oedema — fl…… in lungs & red……… surfa………..
- para……….
Compliance of the Lungs
Ease with which lungs & chest wall expand depends upon elasticity of lungs & surface tension
Some diseases reduce compliance
- tuberculosis forms scar tissue
- pulmonary oedema — fluid in lungs & reduced surfactant
- paralysis
Role of Surfactant
water in the al……….. fluid creates s………. tension
surface tension is due to the strong attr……….. betw…… water molecules at the surface of a liq……., which draws the water molecules closer together
Surfa…….. is a mixture of phos…….. and lipoproteins which lowers the surface tension of the ……….olar fluid
Role of Surfactant
water in the alveolar fluid creates surface tension
surface tension is due to the strong attraction between water molecules at the surface of a liquid, which draws the water molecules closer togetehr
Surfactant is a mixture of phospholipids and lipoproteins which lowers the surface tension of the alveolar fluid
Lung Compliance & Surfactant
Lung compliance : surface tension
The second factor affecting lung comp……. is surface tens….. with the alv…….
Lung Compliance & Surfactant
Lung Compliance & Surfactant
Lung compliance : surface tension
The second factor affecting lung compliance is surface tension with the alveoli.
Respiratory Distress Syndrome
Without surfactant, alveoli have high su……. tension, and they tend to collapse. Collapsed alveoli resist ex……., so lung compl….. is low. This condition is known as respiratory dist…. syndrome of the newborn
Surfactant low….. surface tension and incre……… lu….. compliance
Respiratory Distress Syndrome
Without surfactant, alveoli have high surface tension, and they tend to collapse. Collapsed alveoli resist expansion, so lung compliance is low. This condition is known as respiratory distress syndrome of the newborn
Surfactant lowers surface tension and increases lung compliance
