lecture 19+20: resp. 1 and 2 Flashcards
essential things for efficient gas exchange
- diffusion distance between air and blood must be small (in humans, 0.5. micrometers)
- large surface area (~75-100m^2 in humans)
- air clean of pollen/particulates/bacteria/etc.
- air need to be warm (37)
- air needs to be wet
external respiration
oxygen is absorbed from atmosphere into blood in pulmonary capillaries, co2 is excreted
internal respiration
tissue respiration, exchange of gasses between blood in systemic capillaries to and from tissue fluid and the cells
cellular respiration
indivdual cells gaining energy be the breaking down of molecules lke glucose. consumes oxygen and generates co2, occurs in mitochondria
pulmonary ventilation
bulk movement of air into and out of lungs. the pump consists of rib cage + muscles, and the diaphragm
nasal cavities and functions
- nares: entry with hairs
- 3 conchae: boney shelves lined with resp. epithelium
- create turbulent flow to slow air down so it can be moistened and filtered
- rich blood vessels to transport warm blood to heat air
- glands to secrete watery stuff
mucociliary escalator
responsible for movement of mucus up and out of the respiratory tract; mucus traps particles and cilia propel mucus up and out of the lungs
resp. epithelium
pseudostratified ciliated columnar + goblet + basal cells
regions of the pharynx
- nasopharynx
- orophraynx
- laryngopharynx
in order of inspirations, list the conducting part of resp. system
- nasal cavities,
- pharynx,
- larynx,
- trachea,
- bronchi, (lobar, segmental, smaller)
- bronchioles (+terminal)
respitory part of resp. system
- respitory bronchioles
- alveolar ducts
- alveolar sacs
- alveli
movement of oxygen
- air
- nasal cavities
- pharynx
- larynx
- trachea
- bronchi
- bronchioles
- resp. bronchioles
- alveolar ducts
- alveolar sacs
- alveoli
- diffusion into blood
- blood to left side of heart
- blood to body
- oxygen to cells
clinical significance of the 16-19 generation of air way branching
at and beyond 16-19, infection/damage/trauma risk is becomes moderate to high
main features of the trachea
- c shaped cartilage rings to keep airway open
- trachealis muscle connects free ends of cartiale on the posterior wall
- lined with resp. epitheliuim
club cells
- located in bronchiole
- secrete watery club cell secretion that is anti microbial and helps to humidify
asthma treatment
-beta agonist to relax smooth muscle in bronchioles
- steroids to control inflammation
cells of the alveolar wall
- type 1 pneumocyte: squamous cells that are the alveoli wall, site of diffusion
- type 2 pneumocyte: secretes surfactant to reduce surface tension between air and liquid layer. helps prevetn alveolar collapsing and walls sticking together
- alveolar macrophage: wandering around to injust foreign matter
- capilliaries: the other side of the diffusion barriar.
constitution of diffusion barrier
- type 1 pneumocyte
- basement membrane of capilary and type 1 are fused
- capillary endothelium
lung segment
- supplied by tertiary bronchi.
- 8 on left side, 10 on right
clinical significance of lung segment
each has their own blood and air supply. so they can function somewhat independently of each other. if one collapses, the others may not necessarily and one can be removed while the others can work as normal
plurae
- double layer membrane lining the lung
- visceral attaches to lungs
- parietal attaches to ribs
- pleural space is lined with a vary thin fluid. this creates surface tension to brings lungs with ribs
muscles responsible for lung ventilation
- external intercostal moves ribs out so air goes in
- internal intercostal moves ribs down so air goes out
- diaphragm which flattens to increase volume and air goes in
how do movements of the rib cage and diaphragm cause ventilation?
increase in volume, decrease in pressure, so air rushes into lungs which are pulled out with the ribs and diaphragm
upper respitory system (descending)
- nose
- pharynx
- larynx
lower respiratory system (descending)
- trachea
- bronchi
- lungs
