Module 4 Flashcards
boyles law
if volume increases, pressure decreases
list the 2 inspiratory muscles
- external intercostal muscles
2. diaphragm
during inspiration which way does the ribs and diaphragm move
ribs and sternum up
diaphragm down = > volume = < pressure
during expiration which way does the ribs and diaphragm move
diaphragm relaxes, moves up = < volume = > pressure
passive expiration
- muscles relax
- elastic recoil
forced expiration
- internal intercostals move down
- contracts accessory muscles
= < volume
list the 3 factors which can affect pulmonary ventilation
- resistance
- compliance
- alveolar surface tension
resistance
opposition to gas flow
- friction
- airway diametre
sympathetic = dilation
- resistance = obstructive pulmonary diseases
compliance
ability of the lungs and thoracic cavity to stretch
- a decrease in compliance = restrictive disorders
alveolar surface tension
surface tension b/w water molecules + alveolar fluid
- surfactant reduces tension and prevents collapse
tidal volume
amount of air inhaled/exhaled during quiet breathing
vital capacity
max amount of air that can be expelled after max inspiratory effort (the exchangeable air in lungs)
cause of obstructive disorders and the effect on vital capacity
- reduced diameter
- increased resistance
- VC takes longer to achieve
examples of obstructive disorder
- asthma (inflammation = bronchoconstriction)
- bronchitis (alveolar destruction + collapse)
cause of restrictive disorders and effect on the vital capacity
- decreased compliance
- reduces VC
examples of restrictive disorder
- fibrosis
- arthritis
- paralysis
infant respiratory distress
- don’t produce enough surfactant
- alveoli can not maintain inflation
treatment; spray airways with surfactant
how is the respiratory system divided structurally
- upper
- lower
function of upper respiratory system
- filter, humidify, warm
- reabsorb heat, water
function of lower respiratory system
- conducts air to gas exchange surfaces
how is the respiratory system divided functionally
- conducting
2. respiratory
areas of the conducting areas of respiratory system and its function
passageways that:
- conduct
- humidify
- cleanse
- warm
- reabsorb outgoing heat and water
function of the respiratory area of the respiratory system
- bronchioles
- alveolar ducts
- alveoli
(where gas exchange occurs)
Alveoli
surface area for gas exchange
type 1 epithelial cells
list the 3 compartments of the respiratory membrane
- alveolar epithelial cells
- basement membrane
- capillary endothelial cells
list the 2 bloody supplies of the lungs
- pulmonary circulation
2. bronchial circulation
list the innervations of the lungs (3)
- visceral sensory fibres
- parasympathetic fibres (constrict bronchioles)
- sympathetic fibres (dilate bronchioles)
list the 3 compartments of the pleura
- thoracic wall
- parietal pleura
- visceral pleura
function of pleural space
- lubrication
- facilitates adhesion of visceral pleura + parietal pleura
upper respiratory system - nasal hair function
filters out particulates
upper respiratory system - mucus function
- traps particulates
- moistens air
- contains lysosomes = kill bacteria
upper respiratory system - mucociliary escalator
moves contaminated mucus to throat
upper respiratory system - subepithelial capillary plexus - function
warms the air
upper respiratory system - nasal conche - function
- creates turbulence
- increases surface area for warming
conducting zone of respiratory system - pharynx function
passageway for air + food
conducting zone of respiratory system - larynx function
- facilitates voice
- open airway
- includes escalator
- sorts air + food channels
- surrounds and protects opening of trachea
conducting zone of respiratory system - trachea - function
- windpipe
- includes escalator
conducting zone of respiratory system - bronchi - function
- no escalator
- no cartilage rings
- abundant elastic fibres
- circular muscle fibres
which structure marks the end of the conducting zone
terminal bronchioles
list the types of bronchi/bronchioles (6)
- primary bronchi
- lobar bronchi
- segmental bronchi
- bronchioles
- terminal bronchioles
- respiratory bronchioles
which 4 factors influence pulmonary gas exchange
- partial pressure
- solubility of gas
- alveolar ventilation + pulmonary BF
- structure of respiratory membrane
list the 2 different types of gas diffusion
- external respiration
2. internal respiration
gas diffusion - external respiration
- located at alveoli
- oxygen travels from alveoli to capillaries
- carbon dioxide travels from capillaries to alveoli
gas diffusion - internal respiration
- located at the tissues
- oxygen from blood to the tissues
- carbon dioxide from tissues to plasma
ventilation perfusion coupling
efficient gas exchange requires matching gas flow (ventilation) with blood flow (perfusion)
- carbon dioxide in capillaries determines bronchiole diameter = gas flow
- oxygen in alveoli determines arteriole diameter + thus blood flow into capillaries
list the 4 factors that determine efficiency through respiratory zone
- Gas partial pressure
- Gas solubility
- Ventilation Perfusion Coupling
- Characteristics of respiratory membrane
list the 3 characteristics of the respiratory membrane which provides for efficiency through respiratory zone
- thin membrane = rapid gas exchange
- large surface area = large gas exchange
- alveolar fluid + surfactant
describe oxygen transport
- 1.5 % dissolved in plasma
- poorly soluble in water
- solution: RBC + haemoglobin
- RBC adapted to facilitate
describe carbon dioxide transport
- 10% dissolves, 20 % bind to Hb, 70% bicarbonate ions in plasma
- exits RBC to plasma
describe oxygen binding to Hb
- binds loosely + reversibly
- insures affinity
influenced by:
> temp
< blood pH
> blood carbon dioxide
what happens when oxygen decreases at tissue level
hypoxia
list the causes of hypoxia
- Anemia ( few RBC)
- Ischemia (blocked circulation)
- Hypoxemia (decreased oxygen in blood)
- Histotoxic hypoxia (cells unable to use oxygen)
what is the optimum pH level of plasma
7.4
how is plasma pH regulated
carbonic acid bicarbonate buffer system
function of carbonic acid - bicarbonate buffer system
binds or releases H+ ions to regulate the pH of the plasma
- occurs in RBC and plasma
acidosis
increased PCO2, decreased pH
alkalosis
decreased PCO2, increased pH
hyperventilation
fast breathing
hypoventilation
slow
influence of CO2 on plasma pH - hypoventilation
- co2 accumulates = increase
- increase H+ = decrease pH
influence of CO2 on plasma pH - hyperventilation
- out more co2 = decrease
- decrease in H+ = increase pH
oxygen toxicity
increased oxygen
what does a decrease in co2 =
increase pH
what does an increase in co2 =
decreased pH
describe the neural control of respiratory
- pons
- medulla oblongata
- integrate incoming sensory info into rhythm
list the 4 factors that influence the rate and depth of breathing
- CO2, H+
- stretch/inflation
- emotions
- choice
what is the most powerful mechanism of regulation
carbon dioxide levels
inflation/stretch receptor
stretch receptors in lungs stimulated by lung inflation, sending signals to respiratory centres
list the chemoreceptors which detects respiratory changes
- central (brainstem, detects changes in co2)
2. peripheral (located in aortic arch + carotid sinuses to detect changes in all)