intro to respiratory physiology Flashcards
describe pulmonary circulation
delivers carbon dioxide to the lungs and picks up oxygen
blood travels from the heart, to the lungs then back to the heart
describe systemic circulation
delivers oxygenated arterial blood out to the peripheries
tissues use this oxygen and produce carbon dioxide which is returned back to the heart by the veins
what is the function of the pulmonary vein
carries oxygenated blood back to the heart from the lungs
define gas exchange
oxygen is added to the blood from the air and carbon dioxide is removed from the blood into the air
why is gas exchange important
to produce energy via aerobic respiration
what is the respiratory system responsible for?
acquiring oxygen and removing carbon dioxide.
This can’t be done w/o the CVS which transports the oxygen to and removes carbon dioxide from tissues
external respiration requires the integration of these two tissues
where does gas exchange occur
in the lungs and at the systemic capillaries
describe the relationship between net volumes exchanged at a steady state
the net volume of oxygen exchanged in the lungs per unit of time is equal to the net volume exchanged in the tissues (the same applies for carbon dioxide)
average volume of oxygen exchanged per minute
250 ml oxygen consumed
200ml carbon dioxide produced
average breathing rate
12-18breaths/min at rest
40-45 at max exercise in adults
what are the 9 regions of the airways and lungs
nose pharynx epiglottis larynx trachea bronchus bronchioles alveoli diaphragm
describe the nose
air enters here
cilia and mucus trap air particles
the air is warmed and moistened due to the large SA of the nose
describe the pharynx
throat
shared with the digestive system
describe the epiglottis
small flap of tissue that folds over the trachea
prevents food from entering the airway when we swallow
describe the larynx
voice box
contains the vocal chords
describe the trachea
made up of stiff, incomplete rings of cartilage for support
describe the bronchus
trachea bifurcates into L and R 1y bronchi
these split again into the 2y bronchi: 2 on L and 3 on R going to the different lobes of the lung
these split again into 3y bronchi
where are aspirated foreign bodies most commonly lodged and why
R bronchi
it is slightly wider and has a more vertical trajectory
describe the bronchioles
3y bronchi divide into bronchioles
most of the bronchioles have walls too thick for gas exchange
the bronchioles eventually end as alveoli
describe the alveoli
tiny sacs covered in a dense series of capillaries
walls are thin enough for gas exchange
surface is covered with elastic fibres allowing them to stretch and recoil
describe the diaphragm
skeletal muscle
separates the abdominal from the thoracic cavity
what is meant by a ‘patent’ airway
an open airway
the patency of an airway is maintained by the C-shaped rings of cartilage
where does least resistance occur and why
further down the lungs where the diameter is smallest due to increased SA
airway diameter can be altered by the activity of bronchial smooth muscle - contract decreases diameter and increases resistance
what are the two type of pneumocytes
Type I and Type II
what is the role of type I pneumocytes
make up the majority of alveolar surface
very thin and allow gas exchange
what is the role of type II pneumocytes
secrete surfactant which makes breathing easier
what is the respiratory system divided into?
upper and lower
upper - larynx and above
lower - trachea and below
what are the 4 functions of the respiratory system
gas exchange
acid base balance
protection from infection
communication via speech
