respiratory system Flashcards
hypoxemia
reduced oxygen being carried in the blood
hypoxia
low oxygen in the tissues
hypercapnia
retention of carbon dioxide
what is the respiratory system split up into?
upper and lower respiratory tract
what is in the upper respiratory tract?
nose, the pharynx, the larynx
what is in the lower respiratory tract?
trachea, lungs and all segments in the bronchial tree
function of the nasal cavity
- humidifies the air before its gets to the lungs
- small hairs (cilia) act as a filter, removing dirt and particles before the air enters the lungs
pharynx function
- pass through air and food
- role in speech
larynx function
essential to human speech
trachea function
main airway to the lungs
lungs function
provides oxygen to the capillaries and exhales carbon dioxide
bronchi function
create the network of intricate passages that supply the lungs with air
diaphragm function
main respiratory muscle that contracts and relaxes to allow air into the lungs
what are conducting zones?
movement of air through respiratory system
what are conducting airways?
move air to areas for gas exchange
cilia function
allows protective layers
goblet cells function
secrete mucus which coats the respiratory epithelia which collects foreign particles
2 adaptations of the airways
- smooth muscle underlies the lumen surfaces
- cartilage support is present until the bronchioles
musociliary escalator
the end of the cilia move the gel layer towards the mouth, the cilia then detach and move backwards through the periciliary layer before reattaching and starting the process again.
adaptations of the trachea
- a flexible and mobile tube
- 16-20 C shaped rings of cartilage ( can expand and flatten)
- strengthens and prevents collapse
what is the lungs divided into?
- three lobes on the left lung
- two lobes on the right lung
pleura
the serous membranes that line the lungs and thoracic cavity
2 types of pleura
visceral and parietal
visceral pleura
covers the lungs - vital for inhalation and exhalation
parietal pleura
covers the internal surface of the thoracic cavity
pleura cavity
space between the viscera and parietal pleura
two functions of the pleura cavity
- lubricates the pleurae: allowing them to slide over each other
- creates surface tension: pulls the visceral and parietal pleura close to each other, which prevents the lungs collapsing when we exhale.
bronchioles functions
- the bronchioles dilate to permit greater airflow
- bronchioles can constrict to prevent the pollution of the lungs
respiratory zone
where gas exchange occurs
adaptations of the respiratory zone
- thin membrane
- alveolus made up of type 1 alveolar cells: flat and thin, allows efficient gas exchange
- type 2 alveolar cells: secretes surfactant, prevents lungs from collapsing
- alveolar macrophages - defence
- lots of elastic fibres
alveoli
the final branching of the respiratory tree and act as the primary gas exchange units of the lung.
external respiration
exchange of gases between the atmosphere and the body via the alveoli and the bloodstream
internal respiration
exchange of gases between the blood and the cells of the body
inspiration
contraction of external intercostal muscles and diaphragm, increases volume of the chest cavity (active process)
expiration
relaxation of external intercostal muscles and diaphragm, decreases volume of chest cavity (passive or active process)
3 main regions of the respiratory centre
- Ventral respiratory group
- Dorsal respiratory group
- Pontine respiratory centres
ventral respiratory group
sets the basic rhythm
dorsal respiratory group
integrates receptor information and modifies VRG
pontine respiratory group
fine tunes breathing rhythm (eg: talking, sleeping)
lung compliance
the change in lung volume at a given pressure
3 factors that make up elastic resistance
surface tension, elastic tissue, thoracic cage
elastic tissue
made up of elastin, contributes to recoil, pulls airways open during inspiration, prevents airway collapse during expiration
surface tension (Alveolar)
forms layer between gas and air, surface tension lowered by surfactant
thoracic cage
pressure within the chest, if movement is restricted- ventilation will be impaired.
cells within the respiratory system
ciliated epithelial cells, goblet cells and basal cells.
ciliated epithelial cells
propel mucus up the airway to be coughed up- cilia helps this.
goblet cells
- secretes mucin and create a protective mucus layer
- protects lining of trachea and bronchi by trapping dust and micro-organisms (prevents infection)
basal cells
provide an attachment site for ciliated and goblet cells to the basal lamina (lining of the respiratory tract)
type 1 alveolar cells
- compromise the major gas exchange surface area
- 95% of the alveolar surface
- help maintain the permeability of the membrane
type 2 alveolar cells
- surfactant production, lubricates surfaces
- 5% of the alveolar surface
- maintenance of lung fluid balance
what should our oxygen saturation levels be?
96-100%
normal resting respiratory rate for an adult?
12-18
reduced gaseous exchange leads to
decreased O2 in the bloodstream
pathological illnesses related
COPD, lung cancer, pneumonia, cystic fibrosis
reduced lung capacity leads to
decreased gaseous exchange, prevents full inspiration and lung expansion
pneumothorax
collection of air outside the lung but within the pleural cavity
pleural effusion
increase in fluid in the pleural space
chronic bronchitis
- inflammation of the bronchi, hyper secretion of muscus by goblet cells.
- air becomes trapped and gaseous exchange is affected
emphysema
permanent abnormal enlargement of the alveoli
toxins cause inflammation of the type 1 and type 2 alveolar cells
inspiratory reserve volume
maximal volume of air that can be inhaled above normal quiet inhalation
tidal volume
volume of air in/out of lungs during quiet breathing
expiratory reserve volume
maximal volume of air that can be exhaled above normal quiet exhalation
residual volme
volume of air remaining in lungs following maximal exhalation
inspiratory capacity
maximal volume that can be inhaled following normal quiet exhalation
functional residual capacity
volume of air in lungs after normal exhalation
vital capacity
total volume that can be exhaled following maximum inhalation
COPD patient signs
shortness of breath, increased respiratory rate and hyperinflated lungs
COPD appearance on images
hyperinflation of lungs, barrel-chest appearance, flattening of the hemi- diaphragms
cystic fibrosis
hereditary disorder, lung congestion, infection of nutrients by the pancreas
pneumonia
inflammation of alveoli caused by infection
radiographic appearance of pneumonia
- increased opacification - areas with white haziness
- often confined within a lobe (one region)
- inflammatory secretions from the alveoli
tuberculosis
can affect any organ in the body, symptoms include: chronic cough, blood in the sputum, weight loss
radiographic appearance of tuberculosis
scar tissue
pneumoconiosis
lung disease caused by breathing in certain kinds of dust particles
silicosis
long term lung disease caused by inhaling large amounts of crystalline silica dust
bronchiectasis
long term condition where the airways of lungs become widened
pancoast tumour
apical region of lungs, near clavicles
four properties of the alveoli that make them adapted to gas exchange
large surface area, thin membranes, more capillaries, produces surfactant
