overview of the respiratory system Flashcards
what is the respiratory tract divided into
- upper respiratory tract
- lower respiratory tract
what does the upper respiratory tract
nose, nasopharynx, pharynx and larynx
what does the lower respiratory tract consist of
tracheae, lungs, Bronchi, alveoli
what are the primary functions of the respiratory tract
a) exchange oxygen and carbon dioxide between blood and atmosphere
b) for olfaction
c) for production of our voice.
what does the nasal supply contain
blood supply and lots of hairs
what is the main function of the hair and blood supply
to warm the air and filter it
what does the blood supply do in the nose
ensures inspired air is full saturated with water vapour
what sinus is involved near the nose
sphenoid sinus
what is the function of a sinus
to lighten the skull and to give the voice some resonance
how does the larynx contribute to voice
controls pitch and volume - strength
what is the larynx supplied with
vagal receptors
what also contributes to volume
the strength of expiration
what are the two pleuras that each lung is surrounded by
outer (parietal) pleura
inner (visceral) pleura
what is the function of the pleural space filled with fluid
to reduce friction
at what level does the trachea end and the bronchi bifurcate
at the sternal angle (angle of louis)
why does inhaled material tend to go to the right lung more than the left
because the right primary bronchus is more directly in line with the bronchus and is steeper
what do the bronchi subdivide into
lobar bronchi (R- upper, middle and lower / L - middle and lower)
segmental bronchi
terminal bronchi
what is the difference in structure between bronchi and bronchioles
bronchi have cartilage and smooth muscle
bronchioles have smooth muscle only
where does the terminal bronchi supply
the acinus
what is the acinus
where branching bronchioles communicate with alveoli
what are the large bronchioles responsible for
for maintaining airflow. smooth msucle can control blood flow by contracting.
what are 95% of the cells in the alveoli
Type 1 pneumocytes - have direct contact with pulmonary capillaries
what do type II pneumocytes do
secrete surfactant
what does olfactory mucosa contain
highly pseudostratified epithelium, it is ciliated and contains olfactory cells.
what is the rest of the nasal cavity lined by
respiratory mucosa - pseudo stratified columnar epithelial cells with cilia and goblet cells.
what is beneath the epithelium
the venous plexus
what are conducting airways lined with
pseudo stratified in nose and trachea
to simple cuboidal in terminal bronchioles.
where are cilia found
as far distally as terminal bronchioles (but number of goblet cells decreases)
what is gas exchange to do with
perfusion
what happens in normal/quite breathing
- diaphragm flattens
- external intercostal muscles contract
- volume of thoracic cavity increases
- air flows in down the pressure gradient into lungs
what muscles in the neck and chest are used in high levels of inspiration
inspiratory muscles
for expiratory what muscles are used
internal intercostal muscles and abdominal muscles
what is inspiration and expiration normally
inspiration = passive expiration = active
what does inspiration or expiration against abnormal resistance use
accessory muscles e.g. sternocleidomastoid / stellate?
what is the anatomical dead space
not all the air reaches the alveoli but remains in the large airways so isnt exchanged
what is hypercapnia
when pCO2 in the body rises (alveolar ventilation is reduced in proportion to co2 excretion)
what is hypocapnia
when pCO2 in body falls (alveolar ventilation becomes excessive)
what is compliance
measure of the ease of lung expansion
distensibility of the lungs
elastic properties of the lungs cause them to retract from the cell wall
what does the upper part of the lungs being less compliant mean
that lower zones of the lungs receive more ventilation than the ones above - distribution of air in the lungs is uneven
total lung capacity =
volume of gas in lung after full inspiration
tidal volume =
amount of air that enters and leaves the lungs during normal breathing
inspiratory capacity =
max volume of air that can be inhaled at the end of normal expiration = sum of tidal volume and inspiratory reserve volume
inspiritory reserve volume
volume of gas within the lungs at the end of expiration.
vital capacity
volume of air expelled by a maximum expiration from a portion of full inspiration
