respiratory system Flashcards
14: what are the conducting systems compromised of
upper respiratory tract and Lower
14: what does the upper respiratory tract include
nasal cavity
pharynx
larynx
14: what does the lower respiratory tract include
trachea
bronchi
bronchioles
14: what is the respiratory zone compromised of
alveoli and capillary supply
gas exchange surface
14: upper respiratory tract (nasal cavity)
- entry into respiratory system
- inhaled air humidified and debris filtered
14: upper respiratory tract (pharynx)
- inspired air humidify and filtered
- protects against air and food
14: upper respiratory tract (larynx)
- food and liquid cannot enter respiratory tract
- sound production
14: what happens as the the conducting airways divide
the cross sectional area increases exponentially
14: + of conducting airways dividing and increasing cross sectional area
larger surface area for gas exchange at alveoli
14: organs lined by ciliated respiratory epithelial cell Layer
larynx
trachea
primary bronchi
14: epithelial cells of conducting system - goblet cells
form continuous mucus layer over surface of respiratory tract
14: epithelial cells of conducting system - ciliated cells
produce saline, sweep mucus upwards to pharynx
14: epithelial cells of conducting system - mucociliary escalator
removes noxious particles from lungs
14: what is saline secretion essential for
functional mucociliary escalator
14: CFTR
cystic fibrosis transmembrane regulator channel
14: NKCC
na+ , -K+-2,CL- symporter
14: cystic fibrosis
- defect in CFTR channel = decreased mucus
- sticky mucus layer cannot be cleared
- bacteria colonise = lung infections
14: how does the function of the lower conducting system relate to its function (larynx, trachea, primary bronchi)
- c shaped cartilage rings which keep trachea open and allow diameter change during pulmonary ventilation
- posterior surface of trachea covered in connective tissue and smooth muscle = oesophagus can expand during swallowing
14: how does the function of the lower conducting system relate to its function (bronchiole)
non-ciliated epithelium
smooth muscle layer
no cartilage
14: respiratory zone structure - what do alveolar ducts end in
alveolar sacs surrounded by elastic fibres and a network of capillaries
14: respiratory zone structure - vasculature
- extensive capillary network providing large sa for GE
- pulmonary artery supplies deoxygenated blood
- pulmonary vein carries oxygenated blood
14: alveolar structure
type 1 alveolar cell - 90%, thin
type 2 alveolar cell - smaller, thicker, surfactant production
macrophages - protect alveolar surfaces
14: diaphragm - inhalation vs expiration
active contraction of diaphragm vs passive
14: what muscles raise the rib cage upwards and outwards
external intercostal muscles
scalenes
14: expiration during quiet breathing ?
passive
14: thoracic volume during inspiration vs expiration
increase during inspiration and decreased during expiration
14: Boyles law
- relationship between pressure + volume
- volume container increases = pressure gas exerts on the container decreases
14: pulmonary ventilation - gradient
causes air to move into/out of lungs
14: pressure gradients influencing ventilation - atmospheric pressure
- pull of gravity creates atmospheric pressure
- increases below sea level
14: pressure gradients influencing ventilation - intra pulmonary pressure
- air pressure within alveoli
- rise and fall with inspiration + expiration
- eventually equalises m
14: pleural sac
- each lung found in pleural sac which is formed by 2 membranes of elastic connective tissue and capillaries
14: parietal pleura
outer layer serous membrane
14: pleural fluid
thin fluid in cavity which act as lubricant to allow lung to move within thorax
14: elasticity
ability of tissue to return to og state when stretched